summaryrefslogtreecommitdiff
path: root/arch/s390/kvm
AgeCommit message (Collapse)Author
2024-11-29Merge tag 's390-6.13-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Heiko Carstens: - Add swap entry for hugetlbfs support - Add PTE_MARKER support for hugetlbs mappings; this fixes a regression (possible page fault loop) which was introduced when support for UFFDIO_POISON for hugetlbfs was added - Add ARCH_HAS_PREEMPT_LAZY and PREEMPT_DYNAMIC support - Mark IRQ entries in entry code, so that stack tracers can filter out the non-IRQ parts of stack traces. This fixes stack depot capacity limit warnings, since without filtering the number of unique stack traces is huge - In PCI code fix leak of struct zpci_dev object, and fix potential double remove of hotplug slot - Fix pagefault_disable() / pagefault_enable() unbalance in arch_stack_user_walk_common() - A couple of inline assembly optimizations, more cmpxchg() to try_cmpxchg() conversions, and removal of usages of xchg() and cmpxchg() on one and two byte memory areas - Various other small improvements and cleanups * tag 's390-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (27 commits) Revert "s390/mm: Allow large pages for KASAN shadow mapping" s390/spinlock: Use flag output constraint for arch_cmpxchg_niai8() s390/spinlock: Use R constraint for arch_load_niai4() s390/spinlock: Generate shorter code for arch_spin_unlock() s390/spinlock: Remove condition code clobber from arch_spin_unlock() s390/spinlock: Use symbolic names in inline assemblies s390: Support PREEMPT_DYNAMIC s390/pci: Fix potential double remove of hotplug slot s390/pci: Fix leak of struct zpci_dev when zpci_add_device() fails s390/mm/hugetlbfs: Add missing includes s390/mm: Add PTE_MARKER support for hugetlbfs mappings s390/mm: Introduce region-third and segment table swap entries s390/mm: Introduce region-third and segment table entry present bits s390/mm: Rearrange region-third and segment table entry SW bits KVM: s390: Increase size of union sca_utility to four bytes KVM: s390: Remove one byte cmpxchg() usage KVM: s390: Use try_cmpxchg() instead of cmpxchg() loops s390/ap: Replace xchg() with WRITE_ONCE() s390/mm: Allow large pages for KASAN shadow mapping s390: Add ARCH_HAS_PREEMPT_LAZY support ...
2024-11-27KVM: s390: Remove one byte cmpxchg() usageHeiko Carstens
Within sca_clear_ext_call() cmpxchg() is used to clear one or two bytes (depending on sca format). The cmpxchg() calls are not supposed to fail; if so that would be a bug. Given that cmpxchg() usage on one and two byte areas generates very inefficient code, replace them with block concurrent WRITE_ONCE() calls, and remove the WARN_ON(). Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20241126102515.3178914-3-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-27KVM: s390: Use try_cmpxchg() instead of cmpxchg() loopsHeiko Carstens
Convert all cmpxchg() loops to try_cmpxchg() loops. With gcc 14 and the usage of flag output operands in try_cmpxchg() this allows the compiler to generate slightly better code. Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20241126102515.3178914-2-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-23Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "The biggest change here is eliminating the awful idea that KVM had of essentially guessing which pfns are refcounted pages. The reason to do so was that KVM needs to map both non-refcounted pages (for example BARs of VFIO devices) and VM_PFNMAP/VM_MIXMEDMAP VMAs that contain refcounted pages. However, the result was security issues in the past, and more recently the inability to map VM_IO and VM_PFNMAP memory that _is_ backed by struct page but is not refcounted. In particular this broke virtio-gpu blob resources (which directly map host graphics buffers into the guest as "vram" for the virtio-gpu device) with the amdgpu driver, because amdgpu allocates non-compound higher order pages and the tail pages could not be mapped into KVM. This requires adjusting all uses of struct page in the per-architecture code, to always work on the pfn whenever possible. The large series that did this, from David Stevens and Sean Christopherson, also cleaned up substantially the set of functions that provided arch code with the pfn for a host virtual addresses. The previous maze of twisty little passages, all different, is replaced by five functions (__gfn_to_page, __kvm_faultin_pfn, the non-__ versions of these two, and kvm_prefetch_pages) saving almost 200 lines of code. ARM: - Support for stage-1 permission indirection (FEAT_S1PIE) and permission overlays (FEAT_S1POE), including nested virt + the emulated page table walker - Introduce PSCI SYSTEM_OFF2 support to KVM + client driver. This call was introduced in PSCIv1.3 as a mechanism to request hibernation, similar to the S4 state in ACPI - Explicitly trap + hide FEAT_MPAM (QoS controls) from KVM guests. As part of it, introduce trivial initialization of the host's MPAM context so KVM can use the corresponding traps - PMU support under nested virtualization, honoring the guest hypervisor's trap configuration and event filtering when running a nested guest - Fixes to vgic ITS serialization where stale device/interrupt table entries are not zeroed when the mapping is invalidated by the VM - Avoid emulated MMIO completion if userspace has requested synchronous external abort injection - Various fixes and cleanups affecting pKVM, vCPU initialization, and selftests LoongArch: - Add iocsr and mmio bus simulation in kernel. - Add in-kernel interrupt controller emulation. - Add support for virtualization extensions to the eiointc irqchip. PPC: - Drop lingering and utterly obsolete references to PPC970 KVM, which was removed 10 years ago. - Fix incorrect documentation references to non-existing ioctls RISC-V: - Accelerate KVM RISC-V when running as a guest - Perf support to collect KVM guest statistics from host side s390: - New selftests: more ucontrol selftests and CPU model sanity checks - Support for the gen17 CPU model - List registers supported by KVM_GET/SET_ONE_REG in the documentation x86: - Cleanup KVM's handling of Accessed and Dirty bits to dedup code, improve documentation, harden against unexpected changes. Even if the hardware A/D tracking is disabled, it is possible to use the hardware-defined A/D bits to track if a PFN is Accessed and/or Dirty, and that removes a lot of special cases. - Elide TLB flushes when aging secondary PTEs, as has been done in x86's primary MMU for over 10 years. - Recover huge pages in-place in the TDP MMU when dirty page logging is toggled off, instead of zapping them and waiting until the page is re-accessed to create a huge mapping. This reduces vCPU jitter. - Batch TLB flushes when dirty page logging is toggled off. This reduces the time it takes to disable dirty logging by ~3x. - Remove the shrinker that was (poorly) attempting to reclaim shadow page tables in low-memory situations. - Clean up and optimize KVM's handling of writes to MSR_IA32_APICBASE. - Advertise CPUIDs for new instructions in Clearwater Forest - Quirk KVM's misguided behavior of initialized certain feature MSRs to their maximum supported feature set, which can result in KVM creating invalid vCPU state. E.g. initializing PERF_CAPABILITIES to a non-zero value results in the vCPU having invalid state if userspace hides PDCM from the guest, which in turn can lead to save/restore failures. - Fix KVM's handling of non-canonical checks for vCPUs that support LA57 to better follow the "architecture", in quotes because the actual behavior is poorly documented. E.g. most MSR writes and descriptor table loads ignore CR4.LA57 and operate purely on whether the CPU supports LA57. - Bypass the register cache when querying CPL from kvm_sched_out(), as filling the cache from IRQ context is generally unsafe; harden the cache accessors to try to prevent similar issues from occuring in the future. The issue that triggered this change was already fixed in 6.12, but was still kinda latent. - Advertise AMD_IBPB_RET to userspace, and fix a related bug where KVM over-advertises SPEC_CTRL when trying to support cross-vendor VMs. - Minor cleanups - Switch hugepage recovery thread to use vhost_task. These kthreads can consume significant amounts of CPU time on behalf of a VM or in response to how the VM behaves (for example how it accesses its memory); therefore KVM tried to place the thread in the VM's cgroups and charge the CPU time consumed by that work to the VM's container. However the kthreads did not process SIGSTOP/SIGCONT, and therefore cgroups which had KVM instances inside could not complete freezing. Fix this by replacing the kthread with a PF_USER_WORKER thread, via the vhost_task abstraction. Another 100+ lines removed, with generally better behavior too like having these threads properly parented in the process tree. - Revert a workaround for an old CPU erratum (Nehalem/Westmere) that didn't really work; there was really nothing to work around anyway: the broken patch was meant to fix nested virtualization, but the PERF_GLOBAL_CTRL MSR is virtualized and therefore unaffected by the erratum. - Fix 6.12 regression where CONFIG_KVM will be built as a module even if asked to be builtin, as long as neither KVM_INTEL nor KVM_AMD is 'y'. x86 selftests: - x86 selftests can now use AVX. Documentation: - Use rST internal links - Reorganize the introduction to the API document Generic: - Protect vcpu->pid accesses outside of vcpu->mutex with a rwlock instead of RCU, so that running a vCPU on a different task doesn't encounter long due to having to wait for all CPUs become quiescent. In general both reads and writes are rare, but userspace that supports confidential computing is introducing the use of "helper" vCPUs that may jump from one host processor to another. Those will be very happy to trigger a synchronize_rcu(), and the effect on performance is quite the disaster" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (298 commits) KVM: x86: Break CONFIG_KVM_X86's direct dependency on KVM_INTEL || KVM_AMD KVM: x86: add back X86_LOCAL_APIC dependency Revert "KVM: VMX: Move LOAD_IA32_PERF_GLOBAL_CTRL errata handling out of setup_vmcs_config()" KVM: x86: switch hugepage recovery thread to vhost_task KVM: x86: expose MSR_PLATFORM_INFO as a feature MSR x86: KVM: Advertise CPUIDs for new instructions in Clearwater Forest Documentation: KVM: fix malformed table irqchip/loongson-eiointc: Add virt extension support LoongArch: KVM: Add irqfd support LoongArch: KVM: Add PCHPIC user mode read and write functions LoongArch: KVM: Add PCHPIC read and write functions LoongArch: KVM: Add PCHPIC device support LoongArch: KVM: Add EIOINTC user mode read and write functions LoongArch: KVM: Add EIOINTC read and write functions LoongArch: KVM: Add EIOINTC device support LoongArch: KVM: Add IPI user mode read and write function LoongArch: KVM: Add IPI read and write function LoongArch: KVM: Add IPI device support LoongArch: KVM: Add iocsr and mmio bus simulation in kernel KVM: arm64: Pass on SVE mapping failures ...
2024-11-18Merge tag 's390-6.13-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Add firmware sysfs interface which allows user space to retrieve the dump area size of the machine - Add 'measurement_chars_full' CHPID sysfs attribute to make the complete associated Channel-Measurements Characteristics Block available - Add virtio-mem support - Move gmap aka KVM page fault handling from the main fault handler to KVM code. This is the first step to make s390 KVM page fault handling similar to other architectures. With this first step the main fault handler does not have any special handling anymore, and therefore convert it to support LOCK_MM_AND_FIND_VMA - With gcc 14 s390 support for flag output operand support for inline assemblies was added. This allows for several optimizations: - Provide a cmpxchg inline assembly which makes use of this, and provide all variants of arch_try_cmpxchg() so that the compiler can generate slightly better code - Convert a few cmpxchg() loops to try_cmpxchg() loops - Similar to x86 add a CC_OUT() helper macro (and other macros), and convert all inline assemblies to make use of them, so that depending on compiler version better code can be generated - List installed host-key hashes in sysfs if the machine supports the Query Ultravisor Keys UVC - Add 'Retrieve Secret' ioctl which allows user space in protected execution guests to retrieve previously stored secrets from the Ultravisor - Add pkey-uv module which supports the conversion of Ultravisor retrievable secrets to protected keys - Extend the existing paes cipher to exploit the full AES-XTS hardware acceleration introduced with message-security assist extension 10 - Convert hopefully all sysfs show functions to use sysfs_emit() so that the constant flow of such patches stop - For PCI devices make use of the newly added Topology ID attribute to enable whole card multi-function support despite the change to PCHID per port. Additionally improve the overall robustness and usability of the multifunction support - Various other small improvements, fixes, and cleanups * tag 's390-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (133 commits) s390/cio/ioasm: Convert to use flag output macros s390/cio/qdio: Convert to use flag output macros s390/sclp: Convert to use flag output macros s390/dasd: Convert to use flag output macros s390/boot/physmem: Convert to use flag output macros s390/pci: Convert to use flag output macros s390/kvm: Convert to use flag output macros s390/extmem: Convert to use flag output macros s390/string: Convert to use flag output macros s390/diag: Convert to use flag output macros s390/irq: Convert to use flag output macros s390/smp: Convert to use flag output macros s390/uv: Convert to use flag output macros s390/pai: Convert to use flag output macros s390/mm: Convert to use flag output macros s390/cpu_mf: Convert to use flag output macros s390/cpcmd: Convert to use flag output macros s390/topology: Convert to use flag output macros s390/time: Convert to use flag output macros s390/pageattr: Convert to use flag output macros ...
2024-11-13s390/kvm: Convert to use flag output macrosHeiko Carstens
Use flag output macros in inline asm to allow for better code generation if the compiler has support for the flag output constraint. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12Merge tag 'kvm-s390-next-6.13-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD - second part of the ucontrol selftest - cpumodel sanity check selftest - gen17 cpumodel changes
2024-11-11KVM: s390: add gen17 facilities to CPU modelHendrik Brueckner
Add gen17 facilities and let KVM_CAP_S390_VECTOR_REGISTERS handle the enablement of the vector extension facilities. Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241107152319.77816-4-brueckner@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-ID: <20241107152319.77816-4-brueckner@linux.ibm.com>
2024-11-11KVM: s390: add msa11 to cpu modelHendrik Brueckner
Message-security-assist 11 introduces pckmo subfunctions to encrypt hmac keys. Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241107152319.77816-3-brueckner@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-ID: <20241107152319.77816-3-brueckner@linux.ibm.com>
2024-11-11KVM: s390: add concurrent-function facility to cpu modelHendrik Brueckner
Adding support for concurrent-functions facility which provides additional subfunctions. Signed-off-by: Hendrik Brueckner <brueckner@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241107152319.77816-2-brueckner@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-ID: <20241107152319.77816-2-brueckner@linux.ibm.com>
2024-11-08Merge tag 'kvm-riscv-6.13-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini
KVM/riscv changes for 6.13 - Accelerate KVM RISC-V when running as a guest - Perf support to collect KVM guest statistics from host side
2024-11-07s390/kvm: Mask extra bits from program interrupt codeClaudio Imbrenda
The program interrupt code has some extra bits that are sometimes set by hardware for various reasons; those bits should be ignored when the program interrupt number is needed for interrupt handling. Fixes: 05066cafa925 ("s390/mm/fault: Handle guest-related program interrupts in KVM") Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20241031120316.25462-1-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-31s390/kvm: Initialize uninitialized flags variableClaudio Imbrenda
The flags variable was being used uninitialized. Initialize it to 0 as expected. For some reason neither gcc nor clang reported a warning. Fixes: 05066cafa925 ("s390/mm/fault: Handle guest-related program interrupts in KVM") Reported-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20241030161906.85476-1-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/kvm: Stop using gmap_{en,dis}able()Claudio Imbrenda
Stop using gmap_enable(), gmap_disable(), gmap_get_enabled(). The correct guest ASCE is passed as a parameter of sie64a(), there is no need to save the current gmap in lowcore. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-7-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/mm/fault: Handle guest-related program interrupts in KVMClaudio Imbrenda
Any program interrupt that happens in the host during the execution of a KVM guest will now short circuit the fault handler and return to KVM immediately. Guest fault handling (including pfault) will happen entirely inside KVM. When sie64a() returns zero, current->thread.gmap_int_code will contain the program interrupt number that caused the exit, or zero if the exit was not caused by a host program interrupt. KVM will now take care of handling all guest faults in vcpu_post_run(). Since gmap faults will not be visible by the rest of the kernel, remove GMAP_FAULT, the linux fault handlers for secure execution faults, the exception table entries for the sie instruction, the nop padding after the sie instruction, and all other references to guest faults from the s390 code. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Co-developed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-6-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-29s390/kvm: Remove kvm_arch_fault_in_page()Claudio Imbrenda
kvm_arch_fault_in_page() is a useless wrapper around gmap_fault(); just use gmap_fault() directly instead. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20241022120601.167009-3-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-25KVM: s390: Use kvm_release_page_dirty() to unpin "struct page" memorySean Christopherson
Use kvm_release_page_dirty() when unpinning guest pages, as the pfn was retrieved via pin_guest_page(), i.e. is guaranteed to be backed by struct page memory. This will allow dropping kvm_release_pfn_dirty() and friends. Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20241010182427.1434605-81-seanjc@google.com>
2024-10-25KVM: Drop KVM_ERR_PTR_BAD_PAGE and instead return NULL to indicate an errorSean Christopherson
Remove KVM_ERR_PTR_BAD_PAGE and instead return NULL, as "bad page" is just a leftover bit of weirdness from days of old when KVM stuffed a "bad" page into the guest instead of actually handling missing pages. See commit cea7bb21280e ("KVM: MMU: Make gfn_to_page() always safe"). Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Sean Christopherson <seanjc@google.com> Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20241010182427.1434605-2-seanjc@google.com>
2024-10-25s390: Fix various typosHeiko Carstens
Run codespell on arch/s390 and drivers/s390 and fix all typos. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-10KVM: s390: Change virtual to physical address access in diag 0x258 handlerMichael Mueller
The parameters for the diag 0x258 are real addresses, not virtual, but KVM was using them as virtual addresses. This only happened to work, since the Linux kernel as a guest used to have a 1:1 mapping for physical vs virtual addresses. Fix KVM so that it correctly uses the addresses as real addresses. Cc: stable@vger.kernel.org Fixes: 8ae04b8f500b ("KVM: s390: Guest's memory access functions get access registers") Suggested-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20240917151904.74314-3-nrb@linux.ibm.com Acked-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-10-10KVM: s390: gaccess: Check if guest address is in memslotNico Boehr
Previously, access_guest_page() did not check whether the given guest address is inside of a memslot. This is not a problem, since kvm_write_guest_page/kvm_read_guest_page return -EFAULT in this case. However, -EFAULT is also returned when copy_to/from_user fails. When emulating a guest instruction, the address being outside a memslot usually means that an addressing exception should be injected into the guest. Failure in copy_to/from_user however indicates that something is wrong in userspace and hence should be handled there. To be able to distinguish these two cases, return PGM_ADDRESSING in access_guest_page() when the guest address is outside guest memory. In access_guest_real(), populate vcpu->arch.pgm.code such that kvm_s390_inject_prog_cond() can be used in the caller for injecting into the guest (if applicable). Since this adds a new return value to access_guest_page(), we need to make sure that other callers are not confused by the new positive return value. There are the following users of access_guest_page(): - access_guest_with_key() does the checking itself (in guest_range_to_gpas()), so this case should never happen. Even if, the handling is set up properly. - access_guest_real() just passes the return code to its callers, which are: - read_guest_real() - see below - write_guest_real() - see below There are the following users of read_guest_real(): - ar_translation() in gaccess.c which already returns PGM_* - setup_apcb10(), setup_apcb00(), setup_apcb11() in vsie.c which always return -EFAULT on read_guest_read() nonzero return - no change - shadow_crycb(), handle_stfle() always present this as validity, this could be handled better but doesn't change current behaviour - no change There are the following users of write_guest_real(): - kvm_s390_store_status_unloaded() always returns -EFAULT on write_guest_real() failure. Fixes: 2293897805c2 ("KVM: s390: add architecture compliant guest access functions") Cc: stable@vger.kernel.org Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20240917151904.74314-2-nrb@linux.ibm.com Acked-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-08-19KVM: s390: Fix SORTL and DFLTCC instruction format error in __insn32_queryHariharan Mari
The __insn32_query() function incorrectly uses the RRF instruction format for both the SORTL (RRE format) and DFLTCC (RRF format) instructions. To fix this issue, add separate query functions for SORTL and DFLTCC that use the appropriate instruction formats. Additionally pass the query operand as a pointer to the entire array of 32 elements to slightly optimize performance and readability. Fixes: d668139718a9 ("KVM: s390: provide query function for instructions returning 32 byte") Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Hariharan Mari <hari55@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2024-08-06KVM: s390: fix validity interception issue when gisa is switched offMichael Mueller
We might run into a SIE validity if gisa has been disabled either via using kernel parameter "kvm.use_gisa=0" or by setting the related sysfs attribute to N (echo N >/sys/module/kvm/parameters/use_gisa). The validity is caused by an invalid value in the SIE control block's gisa designation. That happens because we pass the uninitialized gisa origin to virt_to_phys() before writing it to the gisa designation. To fix this we return 0 in kvm_s390_get_gisa_desc() if the origin is 0. kvm_s390_get_gisa_desc() is used to determine which gisa designation to set in the SIE control block. A value of 0 in the gisa designation disables gisa usage. The issue surfaces in the host kernel with the following kernel message as soon a new kvm guest start is attemted. kvm: unhandled validity intercept 0x1011 WARNING: CPU: 0 PID: 781237 at arch/s390/kvm/intercept.c:101 kvm_handle_sie_intercept+0x42e/0x4d0 [kvm] Modules linked in: vhost_net tap tun xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT xt_tcpudp nft_compat x_tables nf_nat_tftp nf_conntrack_tftp vfio_pci_core irqbypass vhost_vsock vmw_vsock_virtio_transport_common vsock vhost vhost_iotlb kvm nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables sunrpc mlx5_ib ib_uverbs ib_core mlx5_core uvdevice s390_trng eadm_sch vfio_ccw zcrypt_cex4 mdev vfio_iommu_type1 vfio sch_fq_codel drm i2c_core loop drm_panel_orientation_quirks configfs nfnetlink lcs ctcm fsm dm_service_time ghash_s390 prng chacha_s390 libchacha aes_s390 des_s390 libdes sha3_512_s390 sha3_256_s390 sha512_s390 sha256_s390 sha1_s390 sha_common dm_mirror dm_region_hash dm_log zfcp scsi_transport_fc scsi_dh_rdac scsi_dh_emc scsi_dh_alua pkey zcrypt dm_multipath rng_core autofs4 [last unloaded: vfio_pci] CPU: 0 PID: 781237 Comm: CPU 0/KVM Not tainted 6.10.0-08682-gcad9f11498ea #6 Hardware name: IBM 3931 A01 701 (LPAR) Krnl PSW : 0704c00180000000 000003d93deb0122 (kvm_handle_sie_intercept+0x432/0x4d0 [kvm]) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 Krnl GPRS: 000003d900000027 000003d900000023 0000000000000028 000002cd00000000 000002d063a00900 00000359c6daf708 00000000000bebb5 0000000000001eff 000002cfd82e9000 000002cfd80bc000 0000000000001011 000003d93deda412 000003ff8962df98 000003d93de77ce0 000003d93deb011e 00000359c6daf960 Krnl Code: 000003d93deb0112: c020fffe7259 larl %r2,000003d93de7e5c4 000003d93deb0118: c0e53fa8beac brasl %r14,000003d9bd3c7e70 #000003d93deb011e: af000000 mc 0,0 >000003d93deb0122: a728ffea lhi %r2,-22 000003d93deb0126: a7f4fe24 brc 15,000003d93deafd6e 000003d93deb012a: 9101f0b0 tm 176(%r15),1 000003d93deb012e: a774fe48 brc 7,000003d93deafdbe 000003d93deb0132: 40a0f0ae sth %r10,174(%r15) Call Trace: [<000003d93deb0122>] kvm_handle_sie_intercept+0x432/0x4d0 [kvm] ([<000003d93deb011e>] kvm_handle_sie_intercept+0x42e/0x4d0 [kvm]) [<000003d93deacc10>] vcpu_post_run+0x1d0/0x3b0 [kvm] [<000003d93deaceda>] __vcpu_run+0xea/0x2d0 [kvm] [<000003d93dead9da>] kvm_arch_vcpu_ioctl_run+0x16a/0x430 [kvm] [<000003d93de93ee0>] kvm_vcpu_ioctl+0x190/0x7c0 [kvm] [<000003d9bd728b4e>] vfs_ioctl+0x2e/0x70 [<000003d9bd72a092>] __s390x_sys_ioctl+0xc2/0xd0 [<000003d9be0e9222>] __do_syscall+0x1f2/0x2e0 [<000003d9be0f9a90>] system_call+0x70/0x98 Last Breaking-Event-Address: [<000003d9bd3c7f58>] __warn_printk+0xe8/0xf0 Cc: stable@vger.kernel.org Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com> Fixes: fe0ef0030463 ("KVM: s390: sort out physical vs virtual pointers usage") Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20240801123109.2782155-1-mimu@linux.ibm.com Message-ID: <20240801123109.2782155-1-mimu@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2024-07-20Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - Initial infrastructure for shadow stage-2 MMUs, as part of nested virtualization enablement - Support for userspace changes to the guest CTR_EL0 value, enabling (in part) migration of VMs between heterogenous hardware - Fixes + improvements to pKVM's FF-A proxy, adding support for v1.1 of the protocol - FPSIMD/SVE support for nested, including merged trap configuration and exception routing - New command-line parameter to control the WFx trap behavior under KVM - Introduce kCFI hardening in the EL2 hypervisor - Fixes + cleanups for handling presence/absence of FEAT_TCRX - Miscellaneous fixes + documentation updates LoongArch: - Add paravirt steal time support - Add support for KVM_DIRTY_LOG_INITIALLY_SET - Add perf kvm-stat support for loongarch RISC-V: - Redirect AMO load/store access fault traps to guest - perf kvm stat support - Use guest files for IMSIC virtualization, when available s390: - Assortment of tiny fixes which are not time critical x86: - Fixes for Xen emulation - Add a global struct to consolidate tracking of host values, e.g. EFER - Add KVM_CAP_X86_APIC_BUS_CYCLES_NS to allow configuring the effective APIC bus frequency, because TDX - Print the name of the APICv/AVIC inhibits in the relevant tracepoint - Clean up KVM's handling of vendor specific emulation to consistently act on "compatible with Intel/AMD", versus checking for a specific vendor - Drop MTRR virtualization, and instead always honor guest PAT on CPUs that support self-snoop - Update to the newfangled Intel CPU FMS infrastructure - Don't advertise IA32_PERF_GLOBAL_OVF_CTRL as an MSR-to-be-saved, as it reads '0' and writes from userspace are ignored - Misc cleanups x86 - MMU: - Small cleanups, renames and refactoring extracted from the upcoming Intel TDX support - Don't allocate kvm_mmu_page.shadowed_translation for shadow pages that can't hold leafs SPTEs - Unconditionally drop mmu_lock when allocating TDP MMU page tables for eager page splitting, to avoid stalling vCPUs when splitting huge pages - Bug the VM instead of simply warning if KVM tries to split a SPTE that is non-present or not-huge. KVM is guaranteed to end up in a broken state because the callers fully expect a valid SPTE, it's all but dangerous to let more MMU changes happen afterwards x86 - AMD: - Make per-CPU save_area allocations NUMA-aware - Force sev_es_host_save_area() to be inlined to avoid calling into an instrumentable function from noinstr code - Base support for running SEV-SNP guests. API-wise, this includes a new KVM_X86_SNP_VM type, encrypting/measure the initial image into guest memory, and finalizing it before launching it. Internally, there are some gmem/mmu hooks needed to prepare gmem-allocated pages before mapping them into guest private memory ranges This includes basic support for attestation guest requests, enough to say that KVM supports the GHCB 2.0 specification There is no support yet for loading into the firmware those signing keys to be used for attestation requests, and therefore no need yet for the host to provide certificate data for those keys. To support fetching certificate data from userspace, a new KVM exit type will be needed to handle fetching the certificate from userspace. An attempt to define a new KVM_EXIT_COCO / KVM_EXIT_COCO_REQ_CERTS exit type to handle this was introduced in v1 of this patchset, but is still being discussed by community, so for now this patchset only implements a stub version of SNP Extended Guest Requests that does not provide certificate data x86 - Intel: - Remove an unnecessary EPT TLB flush when enabling hardware - Fix a series of bugs that cause KVM to fail to detect nested pending posted interrupts as valid wake eents for a vCPU executing HLT in L2 (with HLT-exiting disable by L1) - KVM: x86: Suppress MMIO that is triggered during task switch emulation Explicitly suppress userspace emulated MMIO exits that are triggered when emulating a task switch as KVM doesn't support userspace MMIO during complex (multi-step) emulation Silently ignoring the exit request can result in the WARN_ON_ONCE(vcpu->mmio_needed) firing if KVM exits to userspace for some other reason prior to purging mmio_needed See commit 0dc902267cb3 ("KVM: x86: Suppress pending MMIO write exits if emulator detects exception") for more details on KVM's limitations with respect to emulated MMIO during complex emulator flows Generic: - Rename the AS_UNMOVABLE flag that was introduced for KVM to AS_INACCESSIBLE, because the special casing needed by these pages is not due to just unmovability (and in fact they are only unmovable because the CPU cannot access them) - New ioctl to populate the KVM page tables in advance, which is useful to mitigate KVM page faults during guest boot or after live migration. The code will also be used by TDX, but (probably) not through the ioctl - Enable halt poll shrinking by default, as Intel found it to be a clear win - Setup empty IRQ routing when creating a VM to avoid having to synchronize SRCU when creating a split IRQCHIP on x86 - Rework the sched_in/out() paths to replace kvm_arch_sched_in() with a flag that arch code can use for hooking both sched_in() and sched_out() - Take the vCPU @id as an "unsigned long" instead of "u32" to avoid truncating a bogus value from userspace, e.g. to help userspace detect bugs - Mark a vCPU as preempted if and only if it's scheduled out while in the KVM_RUN loop, e.g. to avoid marking it preempted and thus writing guest memory when retrieving guest state during live migration blackout Selftests: - Remove dead code in the memslot modification stress test - Treat "branch instructions retired" as supported on all AMD Family 17h+ CPUs - Print the guest pseudo-RNG seed only when it changes, to avoid spamming the log for tests that create lots of VMs - Make the PMU counters test less flaky when counting LLC cache misses by doing CLFLUSH{OPT} in every loop iteration" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits) crypto: ccp: Add the SNP_VLEK_LOAD command KVM: x86/pmu: Add kvm_pmu_call() to simplify static calls of kvm_pmu_ops KVM: x86: Introduce kvm_x86_call() to simplify static calls of kvm_x86_ops KVM: x86: Replace static_call_cond() with static_call() KVM: SEV: Provide support for SNP_EXTENDED_GUEST_REQUEST NAE event x86/sev: Move sev_guest.h into common SEV header KVM: SEV: Provide support for SNP_GUEST_REQUEST NAE event KVM: x86: Suppress MMIO that is triggered during task switch emulation KVM: x86/mmu: Clean up make_huge_page_split_spte() definition and intro KVM: x86/mmu: Bug the VM if KVM tries to split a !hugepage SPTE KVM: selftests: x86: Add test for KVM_PRE_FAULT_MEMORY KVM: x86: Implement kvm_arch_vcpu_pre_fault_memory() KVM: x86/mmu: Make kvm_mmu_do_page_fault() return mapped level KVM: x86/mmu: Account pf_{fixed,emulate,spurious} in callers of "do page fault" KVM: x86/mmu: Bump pf_taken stat only in the "real" page fault handler KVM: Add KVM_PRE_FAULT_MEMORY vcpu ioctl to pre-populate guest memory KVM: Document KVM_PRE_FAULT_MEMORY ioctl mm, virt: merge AS_UNMOVABLE and AS_INACCESSIBLE perf kvm: Add kvm-stat for loongarch64 LoongArch: KVM: Add PV steal time support in guest side ...
2024-07-18Merge tag 's390-6.11-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Remove restrictions on PAI NNPA and crypto counters, enabling concurrent per-task and system-wide sampling and counting events - Switch to GENERIC_CPU_DEVICES by setting up the CPU present mask in the architecture code and letting the generic code handle CPU bring-up - Add support for the diag204 busy indication facility to prevent undesirable blocking during hypervisor logical CPU utilization queries. Implement results caching - Improve the handling of Store Data SCLP events by suppressing unnecessary warning, preventing buffer release in I/O during failures, and adding timeout handling for Store Data requests to address potential firmware issues - Provide optimized __arch_hweight*() implementations - Remove the unnecessary CPU KOBJ_CHANGE uevents generated during topology updates, as they are unused and also not present on other architectures - Cleanup atomic_ops, optimize __atomic_set() for small values and __atomic_cmpxchg_bool() for compilers supporting flag output constraint - Couple of cleanups for KVM: - Move and improve KVM struct definitions for DAT tables from gaccess.c to a new header - Pass the asce as parameter to sie64a() - Make the crdte() and cspg() page table handling wrappers return a boolean to indicate success, like the other existing "compare and swap" wrappers - Add documentation for HWCAP flags - Switch to obtaining total RAM pages from memblock instead of totalram_pages() during mm init, to ensure correct calculation of zero page size, when defer_init is enabled - Refactor lowcore access and switch to using the get_lowcore() function instead of the S390_lowcore macro - Cleanups for PG_arch_1 and folio handling in UV and hugetlb code - Add missing MODULE_DESCRIPTION() macros - Fix VM_FAULT_HWPOISON handling in do_exception() * tag 's390-6.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits) s390/mm: Fix VM_FAULT_HWPOISON handling in do_exception() s390/kvm: Move bitfields for dat tables s390/entry: Pass the asce as parameter to sie64a() s390/sthyi: Use cached data when diag is busy s390/sthyi: Move diag operations s390/hypfs_diag: Diag204 busy loop s390/diag: Add busy-indication-facility requirements s390/diag: Diag204 add busy return errno s390/diag: Return errno's from diag204 s390/sclp: Diag204 busy indication facility detection s390/atomic_ops: Make use of flag output constraint s390/atomic_ops: Improve __atomic_set() for small values s390/atomic_ops: Use symbolic names s390/smp: Switch to GENERIC_CPU_DEVICES s390/hwcaps: Add documentation for HWCAP flags s390/pgtable: Make crdte() and cspg() return a value s390/topology: Remove CPU KOBJ_CHANGE uevents s390/sclp: Add timeout to Store Data requests s390/sclp: Prevent release of buffer in I/O s390/sclp: Suppress unnecessary Store Data warning ...
2024-07-16Merge tag 'kvm-x86-generic-6.11' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM generic changes for 6.11 - Enable halt poll shrinking by default, as Intel found it to be a clear win. - Setup empty IRQ routing when creating a VM to avoid having to synchronize SRCU when creating a split IRQCHIP on x86. - Rework the sched_in/out() paths to replace kvm_arch_sched_in() with a flag that arch code can use for hooking both sched_in() and sched_out(). - Take the vCPU @id as an "unsigned long" instead of "u32" to avoid truncating a bogus value from userspace, e.g. to help userspace detect bugs. - Mark a vCPU as preempted if and only if it's scheduled out while in the KVM_RUN loop, e.g. to avoid marking it preempted and thus writing guest memory when retrieving guest state during live migration blackout. - A few minor cleanups
2024-07-12Merge tag 'loongarch-kvm-6.11' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.11 1. Add ParaVirt steal time support. 2. Add some VM migration enhancement. 3. Add perf kvm-stat support for loongarch.
2024-07-10s390/kvm: Move bitfields for dat tablesClaudio Imbrenda
Move and improve the struct definitions for DAT tables from gaccess.c to a new header. Once in a separate header, the structs become available everywhere. One possible usecase is to merge them in the s390 pte_t and p?d_t definitions, which is left as an exercise for the reader. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Link: https://lore.kernel.org/r/20240703155900.103783-3-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-10s390/entry: Pass the asce as parameter to sie64a()Claudio Imbrenda
Pass the guest ASCE explicitly as parameter, instead of having sie64a() take it from lowcore. This removes hidden state from lowcore, and makes things look cleaner. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Link: https://lore.kernel.org/r/20240703155900.103783-2-imbrenda@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-07-04kvm: s390: Reject memory region operations for ucontrol VMsChristoph Schlameuss
This change rejects the KVM_SET_USER_MEMORY_REGION and KVM_SET_USER_MEMORY_REGION2 ioctls when called on a ucontrol VM. This is necessary since ucontrol VMs have kvm->arch.gmap set to 0 and would thus result in a null pointer dereference further in. Memory management needs to be performed in userspace and using the ioctls KVM_S390_UCAS_MAP and KVM_S390_UCAS_UNMAP. Also improve s390 specific documentation for KVM_SET_USER_MEMORY_REGION and KVM_SET_USER_MEMORY_REGION2. Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Fixes: 27e0393f15fc ("KVM: s390: ucontrol: per vcpu address spaces") Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20240624095902.29375-1-schlameuss@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> [frankja@linux.ibm.com: commit message spelling fix, subject prefix fix] Message-ID: <20240624095902.29375-1-schlameuss@linux.ibm.com>
2024-07-04KVM: s390: vsie: retry SIE instruction on host interceptsEric Farman
It's possible that SIE exits for work that the host needs to perform rather than something that is intended for the guest. A Linux guest will ignore this intercept code since there is nothing for it to do, but a more robust solution would rewind the PSW back to the SIE instruction. This will transparently resume the guest once the host completes its work, without the guest needing to process what is effectively a NOP and re-issue SIE itself. Signed-off-by: Eric Farman <farman@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20240301204342.3217540-1-farman@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-ID: <20240301204342.3217540-1-farman@linux.ibm.com>
2024-07-01KVM: s390: fix LPSWEY handlingChristian Borntraeger
in rare cases, e.g. for injecting a machine check we do intercept all load PSW instructions via ICTL_LPSW. With facility 193 a new variant LPSWEY was added. KVM needs to handle that as well. Fixes: a3efa8429266 ("KVM: s390: gen_facilities: allow facilities 165, 193, 194 and 196") Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Message-ID: <20240628163547.2314-1-borntraeger@linux.ibm.com>
2024-06-18KVM: Introduce vcpu->wants_to_runDavid Matlack
Introduce vcpu->wants_to_run to indicate when a vCPU is in its core run loop, i.e. when the vCPU is running the KVM_RUN ioctl and immediate_exit was not set. Replace all references to vcpu->run->immediate_exit with !vcpu->wants_to_run to avoid TOCTOU races with userspace. For example, a malicious userspace could invoked KVM_RUN with immediate_exit=true and then after KVM reads it to set wants_to_run=false, flip it to false. This would result in the vCPU running in KVM_RUN with wants_to_run=false. This wouldn't cause any real bugs today but is a dangerous landmine. Signed-off-by: David Matlack <dmatlack@google.com> Link: https://lore.kernel.org/r/20240503181734.1467938-2-dmatlack@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-06-18s390: Replace S390_lowcore by get_lowcore()Sven Schnelle
Replace all S390_lowcore usages in arch/s390/ by get_lowcore(). Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2024-06-11KVM: s390: Don't re-setup dummy routing when KVM_CREATE_IRQCHIPYi Wang
Now that KVM sets up empty irq routing in kvm_create_vm(), there's no need to setup dummy routing when KVM_CREATE_IRQCHIP. Note, userspace could very theoretically use KVM_CREATE_IRQCHIP after KVM_SET_GSI_ROUTING to reset to empty IRQ routing, but it's extremely unlikely any VMM does that, e.g. the main reason s390 does anything for KVM_CREATE_IRQCHIP is to that s390 doesn't need to be special cased by the VMM. Signed-off-by: Yi Wang <foxywang@tencent.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20240506101751.3145407-4-foxywang@tencent.com [sean: keep use_irqchip check, call out KVM_SET_GSI_ROUTING impact] Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-05-13Merge tag 's390-6.10-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Alexander Gordeev: - Store AP Query Configuration Information in a static buffer - Rework the AP initialization and add missing cleanups to the error path - Swap IRQ and AP bus/device registration to avoid race conditions - Export prot_virt_guest symbol - Introduce AP configuration changes notifier interface to facilitate modularization of the AP bus - Add CONFIG_AP kernel configuration option to allow modularization of the AP bus - Rework CONFIG_ZCRYPT_DEBUG kernel configuration option description and dependency and rename it to CONFIG_AP_DEBUG - Convert sprintf() and snprintf() to sysfs_emit() in CIO code - Adjust indentation of RELOCS command build step - Make crypto performance counters upward compatible - Convert make_page_secure() and gmap_make_secure() to use folio - Rework channel-utilization-block (CUB) handling in preparation of introducing additional CUBs - Use attribute groups to simplify registration, removal and extension of measurement-related channel-path sysfs attributes - Add a per-channel-path binary "ext_measurement" sysfs attribute that provides access to extended channel-path measurement data - Export measurement data for all channel-measurement-groups (CMG), not only for a specific ones. This enables support of new CMG data formats in userspace without the need for kernel changes - Add a per-channel-path sysfs attribute "speed_bps" that provides the operating speed in bits per second or 0 if the operating speed is not available - The CIO tracepoint subchannel-type field "st" is incorrectly set to the value of subchannel-enabled SCHIB "ena" field. Fix that - Do not forcefully limit vmemmap starting address to MAX_PHYSMEM_BITS - Consider the maximum physical address available to a DCSS segment (512GB) when memory layout is set up - Simplify the virtual memory layout setup by reducing the size of identity mapping vs vmemmap overlap - Swap vmalloc and Lowcore/Real Memory Copy areas in virtual memory. This will allow to place the kernel image next to kernel modules - Move everyting KASLR related from <asm/setup.h> to <asm/page.h> - Put virtual memory layout information into a structure to improve code generation - Currently __kaslr_offset is the kernel offset in both physical and virtual memory spaces. Uncouple these offsets to allow uncoupling of the addresses spaces - Currently the identity mapping base address is implicit and is always set to zero. Make it explicit by putting into __identity_base persistent boot variable and use it in proper context - Introduce .amode31 section start and end macros AMODE31_START and AMODE31_END - Introduce OS_INFO entries that do not reference any data in memory, but rather provide only values - Store virtual memory layout in OS_INFO. It is read out by makedumpfile, crash and other tools - Store virtual memory layout in VMCORE_INFO. It is read out by crash and other tools when /proc/kcore device is used - Create additional PT_LOAD ELF program header that covers kernel image only, so that vmcore tools could locate kernel text and data when virtual and physical memory spaces are uncoupled - Uncouple physical and virtual address spaces - Map kernel at fixed location when KASLR mode is disabled. The location is defined by CONFIG_KERNEL_IMAGE_BASE kernel configuration value. - Rework deployment of kernel image for both compressed and uncompressed variants as defined by CONFIG_KERNEL_UNCOMPRESSED kernel configuration value - Move .vmlinux.relocs section in front of the compressed kernel. The interim section rescue step is avoided as result - Correct modules thunk offset calculation when branch target is more than 2GB away - Kernel modules contain their own set of expoline thunks. Now that the kernel modules area is less than 4GB away from kernel expoline thunks, make modules use kernel expolines. Also make EXPOLINE_EXTERN the default if the compiler supports it - userfaultfd can insert shared zeropages into processes running VMs, but that is not allowed for s390. Fallback to allocating a fresh zeroed anonymous folio and insert that instead - Re-enable shared zeropages for non-PV and non-skeys KVM guests - Rename hex2bitmap() to ap_hex2bitmap() and export it for external use - Add ap_config sysfs attribute to provide the means for setting or displaying adapters, domains and control domains assigned to a vfio-ap mediated device in a single operation - Make vfio_ap_mdev_link_queue() ignore duplicate link requests - Add write support to ap_config sysfs attribute to allow atomic update a vfio-ap mediated device state - Document ap_config sysfs attribute - Function os_info_old_init() is expected to be called only from a regular kdump kernel. Enable it to be called from a stand-alone dump kernel - Address gcc -Warray-bounds warning and fix array size in struct os_info - s390 does not support SMBIOS, so drop unneeded CONFIG_DMI checks - Use unwinder instead of __builtin_return_address() with ftrace to prevent returning of undefined values - Sections .hash and .gnu.hash are only created when CONFIG_PIE_BUILD kernel is enabled. Drop these for the case CONFIG_PIE_BUILD is disabled - Compile kernel with -fPIC and link with -no-pie to allow kpatch feature always succeed and drop the whole CONFIG_PIE_BUILD option-enabled code - Add missing virt_to_phys() converter for VSIE facility and crypto control blocks * tag 's390-6.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (54 commits) Revert "s390: Relocate vmlinux ELF data to virtual address space" KVM: s390: vsie: Use virt_to_phys for crypto control block s390: Relocate vmlinux ELF data to virtual address space s390: Compile kernel with -fPIC and link with -no-pie s390: vmlinux.lds.S: Drop .hash and .gnu.hash for !CONFIG_PIE_BUILD s390/ftrace: Use unwinder instead of __builtin_return_address() s390/pci: Drop unneeded reference to CONFIG_DMI s390/os_info: Fix array size in struct os_info s390/os_info: Initialize old os_info in standalone dump kernel docs: Update s390 vfio-ap doc for ap_config sysfs attribute s390/vfio-ap: Add write support to sysfs attr ap_config s390/vfio-ap: Ignore duplicate link requests in vfio_ap_mdev_link_queue s390/vfio-ap: Add sysfs attr, ap_config, to export mdev state s390/ap: Externalize AP bus specific bitmap reading function s390/mm: Re-enable the shared zeropage for !PV and !skeys KVM guests mm/userfaultfd: Do not place zeropages when zeropages are disallowed s390/expoline: Make modules use kernel expolines s390/nospec: Correct modules thunk offset calculation s390/boot: Do not rescue .vmlinux.relocs section s390/boot: Rework deployment of the kernel image ...
2024-05-02Merge branch 'shared-zeropage' into featuresAlexander Gordeev
David Hildenbrand says: =================== This series fixes one issue with uffd + shared zeropages on s390x and fixes that "ordinary" KVM guests can make use of shared zeropages again. userfaultfd could currently end up mapping shared zeropages into processes that forbid shared zeropages. This only apples to s390x, relevant for handling PV guests and guests that use storage kets correctly. Fix it by placing a zeroed folio instead of the shared zeropage during UFFDIO_ZEROPAGE instead. I stumbled over this issue while looking into a customer scenario that is using: (1) Memory ballooning for dynamic resizing. Start a VM with, say, 100 GiB and inflate the balloon during boot to 60 GiB. The VM has ~40 GiB available and additional memory can be "fake hotplugged" to the VM later on demand by deflating the balloon. Actual memory overcommit is not desired, so physical memory would only be moved between VMs. (2) Live migration of VMs between sites to evacuate servers in case of emergency. Without the shared zeropage, during (2), the VM would suddenly consume 100 GiB on the migration source and destination. On the migration source, where we don't excpect memory overcommit, we could easilt end up crashing the VM during migration. Independent of that, memory handed back to the hypervisor using "free page reporting" would end up consuming actual memory after the migration on the destination, not getting freed up until reused+freed again. While there might be ways to optimize parts of this in QEMU, we really should just support the shared zeropage again for ordinary VMs. We only expect legcy guests to make use of storage keys, so let's handle zeropages again when enabling storage keys or when enabling PV. To not break userfaultfd like we did in the past, don't zap the shared zeropages, but instead trigger unsharing faults, just like we do for unsharing KSM pages in break_ksm(). Unsharing faults will simply replace the shared zeropage by a zeroed anonymous folio. We can already trigger the same fault path using GUP, when trying to long-term pin a shared zeropage, but also when unmerging a KSM-placed zeropages, so this is nothing new. Patch #1 tested on 86-64 by forcing mm_forbids_zeropage() to be 1, and running the uffd selftests. Patch #2 tested on s390x: the live migration scenario now works as expected, and kvm-unit-tests that trigger usage of skeys work well, whereby I can see detection and unsharing of shared zeropages. Further (as broken in v2), I tested that the shared zeropage is no longer populated after skeys are used -- that mm_forbids_zeropage() works as expected: ./s390x-run s390x/skey.elf \ -no-shutdown \ -chardev socket,id=monitor,path=/var/tmp/mon,server,nowait \ -mon chardev=monitor,mode=readline Then, in another shell: # cat /proc/`pgrep qemu`/smaps_rollup | grep Rss Rss: 31484 kB # echo "dump-guest-memory tmp" | sudo nc -U /var/tmp/mon ... # cat /proc/`pgrep qemu`/smaps_rollup | grep Rss Rss: 160452 kB -> Reading guest memory does not populate the shared zeropage Doing the same with selftest.elf (no skeys) # cat /proc/`pgrep qemu`/smaps_rollup | grep Rss Rss: 30900 kB # echo "dump-guest-memory tmp" | sudo nc -U /var/tmp/mon ... # cat /proc/`pgrep qemu`/smaps_rollup | grep Rsstmp/mon Rss: 30924 kB -> Reading guest memory does populate the shared zeropage =================== Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-05-02KVM: s390: Check kvm pointer when testing KVM_CAP_S390_HPAGE_1MJean-Philippe Brucker
KVM allows issuing the KVM_CHECK_EXTENSION ioctl either on the /dev/kvm fd or the VM fd. In the first case, kvm_vm_ioctl_check_extension() is called with kvm==NULL. Ensure we don't dereference the pointer in that case. Fixes: 40ebdb8e59df ("KVM: s390: Make huge pages unavailable in ucontrol VMs") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Message-ID: <20240419160723.320910-2-jean-philippe@linaro.org> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
2024-05-01KVM: s390: vsie: Use virt_to_phys for crypto control blockNina Schoetterl-Glausch
The address of the crypto control block in the (shadow) SIE block is absolute/physical. Convert from virtual to physical when shadowing the guest's control block during VSIE. Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Link: https://lore.kernel.org/r/20240429171512.879215-1-nsg@linux.ibm.com Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-18s390/mm: Re-enable the shared zeropage for !PV and !skeys KVM guestsDavid Hildenbrand
commit fa41ba0d08de ("s390/mm: avoid empty zero pages for KVM guests to avoid postcopy hangs") introduced an undesired side effect when combined with memory ballooning and VM migration: memory part of the inflated memory balloon will consume memory. Assuming we have a 100GiB VM and inflated the balloon to 40GiB. Our VM will consume ~60GiB of memory. If we now trigger a VM migration, hypervisors like QEMU will read all VM memory. As s390x does not support the shared zeropage, we'll end up allocating for all previously-inflated memory part of the memory balloon: 50 GiB. So we might easily (unexpectedly) crash the VM on the migration source. Even worse, hypervisors like QEMU optimize for zeropage migration to not consume memory on the migration destination: when migrating a "page full of zeroes", on the migration destination they check whether the target memory is already zero (by reading the destination memory) and avoid writing to the memory to not allocate memory: however, s390x will also allocate memory here, implying that also on the migration destination, we will end up allocating all previously-inflated memory part of the memory balloon. This is especially bad if actual memory overcommit was not desired, when memory ballooning is used for dynamic VM memory resizing, setting aside some memory during boot that can be added later on demand. Alternatives like virtio-mem that would avoid this issue are not yet available on s390x. There could be ways to optimize some cases in user space: before reading memory in an anonymous private mapping on the migration source, check via /proc/self/pagemap if anything is already populated. Similarly check on the migration destination before reading. While that would avoid populating tables full of shared zeropages on all architectures, it's harder to get right and performant, and requires user space changes. Further, with posctopy live migration we must place a page, so there, "avoid touching memory to avoid allocating memory" is not really possible. (Note that a previously we would have falsely inserted shared zeropages into processes using UFFDIO_ZEROPAGE where mm_forbids_zeropage() would have actually forbidden it) PV is currently incompatible with memory ballooning, and in the common case, KVM guests don't make use of storage keys. Instead of zapping zeropages when enabling storage keys / PV, that turned out to be problematic in the past, let's do exactly the same we do with KSM pages: trigger unsharing faults to replace the shared zeropages by proper anonymous folios. What about added latency when enabling storage kes? Having a lot of zeropages in applicable environments (PV, legacy guests, unittests) is unexpected. Further, KSM could today already unshare the zeropages and unmerging KSM pages when enabling storage kets would unshare the KSM-placed zeropages in the same way, resulting in the same latency. [ agordeev: Fixed sparse and checkpatch complaints and error handling ] Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com> Fixes: fa41ba0d08de ("s390/mm: avoid empty zero pages for KVM guests to avoid postcopy hangs") Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20240411161441.910170-3-david@redhat.com Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-04-17KVM: s390: vsie: Use virt_to_phys for facility control blockNina Schoetterl-Glausch
In order for SIE to interpretively execute STFLE, it requires the real or absolute address of a facility-list control block. Before writing the location into the shadow SIE control block, convert it from a virtual address. We currently do not run into this bug because the lower 31 bits are the same for virtual and physical addresses. Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Link: https://lore.kernel.org/r/20240319164420.4053380-3-nsg@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-Id: <20240319164420.4053380-3-nsg@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2024-03-15Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "S390: - Changes to FPU handling came in via the main s390 pull request - Only deliver to the guest the SCLP events that userspace has requested - More virtual vs physical address fixes (only a cleanup since virtual and physical address spaces are currently the same) - Fix selftests undefined behavior x86: - Fix a restriction that the guest can't program a PMU event whose encoding matches an architectural event that isn't included in the guest CPUID. The enumeration of an architectural event only says that if a CPU supports an architectural event, then the event can be programmed *using the architectural encoding*. The enumeration does NOT say anything about the encoding when the CPU doesn't report support the event *in general*. It might support it, and it might support it using the same encoding that made it into the architectural PMU spec - Fix a variety of bugs in KVM's emulation of RDPMC (more details on individual commits) and add a selftest to verify KVM correctly emulates RDMPC, counter availability, and a variety of other PMC-related behaviors that depend on guest CPUID and therefore are easier to validate with selftests than with custom guests (aka kvm-unit-tests) - Zero out PMU state on AMD if the virtual PMU is disabled, it does not cause any bug but it wastes time in various cases where KVM would check if a PMC event needs to be synthesized - Optimize triggering of emulated events, with a nice ~10% performance improvement in VM-Exit microbenchmarks when a vPMU is exposed to the guest - Tighten the check for "PMI in guest" to reduce false positives if an NMI arrives in the host while KVM is handling an IRQ VM-Exit - Fix a bug where KVM would report stale/bogus exit qualification information when exiting to userspace with an internal error exit code - Add a VMX flag in /proc/cpuinfo to report 5-level EPT support - Rework TDP MMU root unload, free, and alloc to run with mmu_lock held for read, e.g. to avoid serializing vCPUs when userspace deletes a memslot - Tear down TDP MMU page tables at 4KiB granularity (used to be 1GiB). KVM doesn't support yielding in the middle of processing a zap, and 1GiB granularity resulted in multi-millisecond lags that are quite impolite for CONFIG_PREEMPT kernels - Allocate write-tracking metadata on-demand to avoid the memory overhead when a kernel is built with i915 virtualization support but the workloads use neither shadow paging nor i915 virtualization - Explicitly initialize a variety of on-stack variables in the emulator that triggered KMSAN false positives - Fix the debugregs ABI for 32-bit KVM - Rework the "force immediate exit" code so that vendor code ultimately decides how and when to force the exit, which allowed some optimization for both Intel and AMD - Fix a long-standing bug where kvm_has_noapic_vcpu could be left elevated if vCPU creation ultimately failed, causing extra unnecessary work - Cleanup the logic for checking if the currently loaded vCPU is in-kernel - Harden against underflowing the active mmu_notifier invalidation count, so that "bad" invalidations (usually due to bugs elsehwere in the kernel) are detected earlier and are less likely to hang the kernel x86 Xen emulation: - Overlay pages can now be cached based on host virtual address, instead of guest physical addresses. This removes the need to reconfigure and invalidate the cache if the guest changes the gpa but the underlying host virtual address remains the same - When possible, use a single host TSC value when computing the deadline for Xen timers in order to improve the accuracy of the timer emulation - Inject pending upcall events when the vCPU software-enables its APIC to fix a bug where an upcall can be lost (and to follow Xen's behavior) - Fall back to the slow path instead of warning if "fast" IRQ delivery of Xen events fails, e.g. if the guest has aliased xAPIC IDs RISC-V: - Support exception and interrupt handling in selftests - New self test for RISC-V architectural timer (Sstc extension) - New extension support (Ztso, Zacas) - Support userspace emulation of random number seed CSRs ARM: - Infrastructure for building KVM's trap configuration based on the architectural features (or lack thereof) advertised in the VM's ID registers - Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to x86's WC) at stage-2, improving the performance of interacting with assigned devices that can tolerate it - Conversion of KVM's representation of LPIs to an xarray, utilized to address serialization some of the serialization on the LPI injection path - Support for _architectural_ VHE-only systems, advertised through the absence of FEAT_E2H0 in the CPU's ID register - Miscellaneous cleanups, fixes, and spelling corrections to KVM and selftests LoongArch: - Set reserved bits as zero in CPUCFG - Start SW timer only when vcpu is blocking - Do not restart SW timer when it is expired - Remove unnecessary CSR register saving during enter guest - Misc cleanups and fixes as usual Generic: - Clean up Kconfig by removing CONFIG_HAVE_KVM, which was basically always true on all architectures except MIPS (where Kconfig determines the available depending on CPU capabilities). It is replaced either by an architecture-dependent symbol for MIPS, and IS_ENABLED(CONFIG_KVM) everywhere else - Factor common "select" statements in common code instead of requiring each architecture to specify it - Remove thoroughly obsolete APIs from the uapi headers - Move architecture-dependent stuff to uapi/asm/kvm.h - Always flush the async page fault workqueue when a work item is being removed, especially during vCPU destruction, to ensure that there are no workers running in KVM code when all references to KVM-the-module are gone, i.e. to prevent a very unlikely use-after-free if kvm.ko is unloaded - Grab a reference to the VM's mm_struct in the async #PF worker itself instead of gifting the worker a reference, so that there's no need to remember to *conditionally* clean up after the worker Selftests: - Reduce boilerplate especially when utilize selftest TAP infrastructure - Add basic smoke tests for SEV and SEV-ES, along with a pile of library support for handling private/encrypted/protected memory - Fix benign bugs where tests neglect to close() guest_memfd files" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits) selftests: kvm: remove meaningless assignments in Makefiles KVM: riscv: selftests: Add Zacas extension to get-reg-list test RISC-V: KVM: Allow Zacas extension for Guest/VM KVM: riscv: selftests: Add Ztso extension to get-reg-list test RISC-V: KVM: Allow Ztso extension for Guest/VM RISC-V: KVM: Forward SEED CSR access to user space KVM: riscv: selftests: Add sstc timer test KVM: riscv: selftests: Change vcpu_has_ext to a common function KVM: riscv: selftests: Add guest helper to get vcpu id KVM: riscv: selftests: Add exception handling support LoongArch: KVM: Remove unnecessary CSR register saving during enter guest LoongArch: KVM: Do not restart SW timer when it is expired LoongArch: KVM: Start SW timer only when vcpu is blocking LoongArch: KVM: Set reserved bits as zero in CPUCFG KVM: selftests: Explicitly close guest_memfd files in some gmem tests KVM: x86/xen: fix recursive deadlock in timer injection KVM: pfncache: simplify locking and make more self-contained KVM: x86/xen: remove WARN_ON_ONCE() with false positives in evtchn delivery KVM: x86/xen: inject vCPU upcall vector when local APIC is enabled KVM: x86/xen: improve accuracy of Xen timers ...
2024-03-14Merge tag 'kvm-s390-next-6.9-1' of ↵Paolo Bonzini
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD - Memop selftest rotate fix - SCLP event bits over indication fix - Missing virt_to_phys for the CRYCB fix
2024-03-12Merge tag 's390-6.9-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Various virtual vs physical address usage fixes - Fix error handling in Processor Activity Instrumentation device driver, and export number of counters with a sysfs file - Allow for multiple events when Processor Activity Instrumentation counters are monitored in system wide sampling - Change multiplier and shift values of the Time-of-Day clock source to improve steering precision - Remove a couple of unneeded GFP_DMA flags from allocations - Disable mmap alignment if randomize_va_space is also disabled, to avoid a too small heap - Various changes to allow s390 to be compiled with LLVM=1, since ld.lld and llvm-objcopy will have proper s390 support witch clang 19 - Add __uninitialized macro to Compiler Attributes. This is helpful with s390's FPU code where some users have up to 520 byte stack frames. Clearing such stack frames (if INIT_STACK_ALL_PATTERN or INIT_STACK_ALL_ZERO is enabled) before they are used contradicts the intention (performance improvement) of such code sections. - Convert switch_to() to an out-of-line function, and use the generic switch_to header file - Replace the usage of s390's debug feature with pr_debug() calls within the zcrypt device driver - Improve hotplug support of the Adjunct Processor device driver - Improve retry handling in the zcrypt device driver - Various changes to the in-kernel FPU code: - Make in-kernel FPU sections preemptible - Convert various larger inline assemblies and assembler files to C, mainly by using singe instruction inline assemblies. This increases readability, but also allows makes it easier to add proper instrumentation hooks - Cleanup of the header files - Provide fast variants of csum_partial() and csum_partial_copy_nocheck() based on vector instructions - Introduce and use a lock to synchronize accesses to zpci device data structures to avoid inconsistent states caused by concurrent accesses - Compile the kernel without -fPIE. This addresses the following problems if the kernel is compiled with -fPIE: - It uses dynamic symbols (.dynsym), for which the linker refuses to allow more than 64k sections. This can break features which use '-ffunction-sections' and '-fdata-sections', including kpatch-build and function granular KASLR - It unnecessarily uses GOT relocations, adding an extra layer of indirection for many memory accesses - Fix shared_cpu_list for CPU private L2 caches, which incorrectly were reported as globally shared * tag 's390-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (117 commits) s390/tools: handle rela R_390_GOTPCDBL/R_390_GOTOFF64 s390/cache: prevent rebuild of shared_cpu_list s390/crypto: remove retry loop with sleep from PAES pkey invocation s390/pkey: improve pkey retry behavior s390/zcrypt: improve zcrypt retry behavior s390/zcrypt: introduce retries on in-kernel send CPRB functions s390/ap: introduce mutex to lock the AP bus scan s390/ap: rework ap_scan_bus() to return true on config change s390/ap: clarify AP scan bus related functions and variables s390/ap: rearm APQNs bindings complete completion s390/configs: increase number of LOCKDEP_BITS s390/vfio-ap: handle hardware checkstop state on queue reset operation s390/pai: change sampling event assignment for PMU device driver s390/boot: fix minor comment style damages s390/boot: do not check for zero-termination relocation entry s390/boot: make type of __vmlinux_relocs_64_start|end consistent s390/boot: sanitize kaslr_adjust_relocs() function prototype s390/boot: simplify GOT handling s390: vmlinux.lds.S: fix .got.plt assertion s390/boot: workaround current 'llvm-objdump -t -j ...' behavior ...
2024-03-11Merge tag 'kvm-x86-xen-6.9' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM Xen and pfncache changes for 6.9: - Rip out the half-baked support for using gfn_to_pfn caches to manage pages that are "mapped" into guests via physical addresses. - Add support for using gfn_to_pfn caches with only a host virtual address, i.e. to bypass the "gfn" stage of the cache. The primary use case is overlay pages, where the guest may change the gfn used to reference the overlay page, but the backing hva+pfn remains the same. - Add an ioctl() to allow mapping Xen's shared_info page using an hva instead of a gpa, so that userspace doesn't need to reconfigure and invalidate the cache/mapping if the guest changes the gpa (but userspace keeps the resolved hva the same). - When possible, use a single host TSC value when computing the deadline for Xen timers in order to improve the accuracy of the timer emulation. - Inject pending upcall events when the vCPU software-enables its APIC to fix a bug where an upcall can be lost (and to follow Xen's behavior). - Fall back to the slow path instead of warning if "fast" IRQ delivery of Xen events fails, e.g. if the guest has aliased xAPIC IDs. - Extend gfn_to_pfn_cache's mutex to cover (de)activation (in addition to refresh), and drop a now-redundant acquisition of xen_lock (that was protecting the shared_info cache) to fix a deadlock due to recursively acquiring xen_lock.
2024-02-22KVM: s390: fix access register usage in ioctlsEric Farman
The routine ar_translation() can be reached by both the instruction intercept path (where the access registers had been loaded with the guest register contents), and the MEM_OP ioctls (which hadn't). Since this routine saves the current registers to vcpu->run, this routine erroneously saves host registers into the guest space. Introduce a boolean in the kvm_vcpu_arch struct to indicate whether the registers contain guest contents. If they do (the instruction intercept path), the save can be performed and the AR translation is done just as it is today. If they don't (the MEM_OP path), the AR can be read from vcpu->run without stashing the current contents. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Eric Farman <farman@linux.ibm.com> Link: https://lore.kernel.org/r/20240220211211.3102609-2-farman@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-22KVM: s390: only deliver the set service event bitsEric Farman
The SCLP driver code masks off the last two bits of the parameter [1] to determine if a read is required, but doesn't care about the contents of those bits. Meanwhile, the KVM code that delivers event interrupts masks off those two bits but sends both to the guest, even if only one was specified by userspace [2]. This works for the driver code, but it means any nuances of those bits gets lost. Use the event pending mask as an actual mask, and only send the bit(s) that were specified in the pending interrupt. [1] Linux: sclp_interrupt_handler() (drivers/s390/char/sclp.c:658) [2] QEMU: service_interrupt() (hw/s390x/sclp.c:360..363) Fixes: 0890ddea1a90 ("KVM: s390: protvirt: Add SCLP interrupt handling") Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20240205214300.1018522-1-farman@linux.ibm.com Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Message-Id: <20240205214300.1018522-1-farman@linux.ibm.com>
2024-02-21KVM: s390: introduce kvm_s390_fpu_(store|load)Janosch Frank
It's a bit nicer than having multiple lines and will help if there's another re-work since we'll only have to change one location. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-02-20KVM: s390: Refactor kvm_is_error_gpa() into kvm_is_gpa_in_memslot()Sean Christopherson
Rename kvm_is_error_gpa() to kvm_is_gpa_in_memslot() and invert the polarity accordingly in order to (a) free up kvm_is_error_gpa() to match with kvm_is_error_{hva,page}(), and (b) to make it more obvious that the helper is doing a memslot lookup, i.e. not simply checking for INVALID_GPA. No functional change intended. Link: https://lore.kernel.org/r/20240215152916.1158-9-paul@xen.org Signed-off-by: Sean Christopherson <seanjc@google.com>
2024-02-16s390/fpu: decrease stack usage for some casesHeiko Carstens
The kernel_fpu structure has a quite large size of 520 bytes. In order to reduce stack footprint introduce several kernel fpu structures with different and also smaller sizes. This way every kernel fpu user must use the correct variant. A compile time check verifies that the correct variant is used. There are several users which use only 16 instead of all 32 vector registers. For those users the new kernel_fpu_16 structure with a size of only 266 bytes can be used. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>