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2020-02-12docs: kvm: Convert api.txt to ReST formatMauro Carvalho Chehab
convert api.txt document to ReST format while trying to keep its format as close as possible with the authors intent, and avoid adding uneeded markups. - Use document title and chapter markups; - Convert tables; - Add markups for literal blocks; - use :field: for field descriptions; - Add blank lines and adjust indentation Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-05Merge tag 'kvm-s390-next-5.6-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Fixes and cleanups for 5.6 - fix register corruption - ENOTSUPP/EOPNOTSUPP mixed - reset cleanups/fixes - selftests
2020-01-31KVM: s390: Add new reset vcpu APIJanosch Frank
The architecture states that we need to reset local IRQs for all CPU resets. Because the old reset interface did not support the normal CPU reset we never did that on a normal reset. Let's implement an interface for the missing normal and clear resets and reset all local IRQs, registers and control structures as stated in the architecture. Userspace might already reset the registers via the vcpu run struct, but as we need the interface for the interrupt clearing part anyway, we implement the resets fully and don't rely on userspace to reset the rest. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Link: https://lore.kernel.org/r/20200131100205.74720-4-frankja@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2020-01-23arm64: KVM: Add UAPI notes for swapped registersAndrew Jones
Two UAPI system register IDs do not derive their values from the ARM system register encodings. This is because their values were accidentally swapped. As the IDs are API, they cannot be changed. Add WARNING notes to point them out. Suggested-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Andrew Jones <drjones@redhat.com> [maz: turned XXX into WARNING] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200120130825.28838-1-drjones@redhat.com
2019-11-29Merge tag 'kvm-ppc-uvmem-5.5-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD KVM: Add support for secure guests under the Protected Execution Framework (PEF) Ultravisor on POWER. This enables secure memory to be represented as device memory, which provides a way for the host to keep track of which pages of a secure guest have been moved into secure memory managed by the ultravisor and are no longer accessible by the host, and manage movement of pages between secure and normal memory.
2019-11-29Documentation: kvm: Fix mention to number of ioctls classesWainer dos Santos Moschetta
In api.txt it is said that KVM ioctls belong to three classes but in reality it is four. Fixed this, but do not count categories anymore to avoid such as outdated information in the future. Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-28KVM: PPC: Book3S HV: Support reset of secure guestBharata B Rao
Add support for reset of secure guest via a new ioctl KVM_PPC_SVM_OFF. This ioctl will be issued by QEMU during reset and includes the the following steps: - Release all device pages of the secure guest. - Ask UV to terminate the guest via UV_SVM_TERMINATE ucall - Unpin the VPA pages so that they can be migrated back to secure side when guest becomes secure again. This is required because pinned pages can't be migrated. - Reinit the partition scoped page tables After these steps, guest is ready to issue UV_ESM call once again to switch to secure mode. Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> [Implementation of uv_svm_terminate() and its call from guest shutdown path] Signed-off-by: Ram Pai <linuxram@us.ibm.com> [Unpinning of VPA pages] Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-11-21Merge tag 'kvmarm-5.5' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm updates for Linux 5.5: - Allow non-ISV data aborts to be reported to userspace - Allow injection of data aborts from userspace - Expose stolen time to guests - GICv4 performance improvements - vgic ITS emulation fixes - Simplify FWB handling - Enable halt pool counters - Make the emulated timer PREEMPT_RT compliant Conflicts: include/uapi/linux/kvm.h
2019-10-21KVM: arm/arm64: Allow user injection of external data abortsChristoffer Dall
In some scenarios, such as buggy guest or incorrect configuration of the VMM and firmware description data, userspace will detect a memory access to a portion of the IPA, which is not mapped to any MMIO region. For this purpose, the appropriate action is to inject an external abort to the guest. The kernel already has functionality to inject an external abort, but we need to wire up a signal from user space that lets user space tell the kernel to do this. It turns out, we already have the set event functionality which we can perfectly reuse for this. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21KVM: arm/arm64: Allow reporting non-ISV data aborts to userspaceChristoffer Dall
For a long time, if a guest accessed memory outside of a memslot using any of the load/store instructions in the architecture which doesn't supply decoding information in the ESR_EL2 (the ISV bit is not set), the kernel would print the following message and terminate the VM as a result of returning -ENOSYS to userspace: load/store instruction decoding not implemented The reason behind this message is that KVM assumes that all accesses outside a memslot is an MMIO access which should be handled by userspace, and we originally expected to eventually implement some sort of decoding of load/store instructions where the ISV bit was not set. However, it turns out that many of the instructions which don't provide decoding information on abort are not safe to use for MMIO accesses, and the remaining few that would potentially make sense to use on MMIO accesses, such as those with register writeback, are not used in practice. It also turns out that fetching an instruction from guest memory can be a pretty horrible affair, involving stopping all CPUs on SMP systems, handling multiple corner cases of address translation in software, and more. It doesn't appear likely that we'll ever implement this in the kernel. What is much more common is that a user has misconfigured his/her guest and is actually not accessing an MMIO region, but just hitting some random hole in the IPA space. In this scenario, the error message above is almost misleading and has led to a great deal of confusion over the years. It is, nevertheless, ABI to userspace, and we therefore need to introduce a new capability that userspace explicitly enables to change behavior. This patch introduces KVM_CAP_ARM_NISV_TO_USER (NISV meaning Non-ISV) which does exactly that, and introduces a new exit reason to report the event to userspace. User space can then emulate an exception to the guest, restart the guest, suspend the guest, or take any other appropriate action as per the policy of the running system. Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Alexander Graf <graf@amazon.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-10-21KVM: PPC: Report single stepping capabilityFabiano Rosas
When calling the KVM_SET_GUEST_DEBUG ioctl, userspace might request the next instruction to be single stepped via the KVM_GUESTDBG_SINGLESTEP control bit of the kvm_guest_debug structure. This patch adds the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability in order to inform userspace about the state of single stepping support. We currently don't have support for guest single stepping implemented in Book3S HV so the capability is only present for Book3S PR and BookE. Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2019-09-24KVM/Hyper-V: Add new KVM capability KVM_CAP_HYPERV_DIRECT_TLBFLUSHTianyu Lan
Hyper-V direct tlb flush function should be enabled for guest that only uses Hyper-V hypercall. User space hypervisor(e.g, Qemu) can disable KVM identification in CPUID and just exposes Hyper-V identification to make sure the precondition. Add new KVM capability KVM_CAP_ HYPERV_DIRECT_TLBFLUSH for user space to enable Hyper-V direct tlb function and this function is default to be disabled in KVM. Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-11Merge tag 'kvm-s390-next-5.4-1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD * More selftests * Improved KVM_S390_MEM_OP ioctl input checking * Add kvm_valid_regs and kvm_dirty_regs invalid bit checking
2019-09-10doc: kvm: Fix return description of KVM_SET_MSRSXiaoyao Li
Userspace can use ioctl KVM_SET_MSRS to update a set of MSRs of guest. This ioctl set specified MSRs one by one. If it fails to set an MSR, e.g., due to setting reserved bits, the MSR is not supported/emulated by KVM, etc..., it stops processing the MSR list and returns the number of MSRs have been set successfully. Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-09KVM: arm/arm64: vgic: Allow more than 256 vcpus for KVM_IRQ_LINEMarc Zyngier
While parts of the VGIC support a large number of vcpus (we bravely allow up to 512), other parts are more limited. One of these limits is visible in the KVM_IRQ_LINE ioctl, which only allows 256 vcpus to be signalled when using the CPU or PPI types. Unfortunately, we've cornered ourselves badly by allocating all the bits in the irq field. Since the irq_type subfield (8 bit wide) is currently only taking the values 0, 1 and 2 (and we have been careful not to allow anything else), let's reduce this field to only 4 bits, and allocate the remaining 4 bits to a vcpu2_index, which acts as a multiplier: vcpu_id = 256 * vcpu2_index + vcpu_index With that, and a new capability (KVM_CAP_ARM_IRQ_LINE_LAYOUT_2) allowing this to be discovered, it becomes possible to inject PPIs to up to 4096 vcpus. But please just don't. Whilst we're there, add a clarification about the use of KVM_IRQ_LINE on arm, which is not completely conditionned by KVM_CAP_IRQCHIP. Reported-by: Zenghui Yu <yuzenghui@huawei.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-08-29KVM: s390: improve documentation for S390_MEM_OPCornelia Huck
Explicitly specify the valid ranges for size and ar, and reword buf requirements a bit. Signed-off-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Link: https://lkml.kernel.org/r/20190829124746.28665-1-cohuck@redhat.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2019-07-24Documentation: move Documentation/virtual to Documentation/virtChristoph Hellwig
Renaming docs seems to be en vogue at the moment, so fix on of the grossly misnamed directories. We usually never use "virtual" as a shortcut for virtualization in the kernel, but always virt, as seen in the virt/ top-level directory. Fix up the documentation to match that. Fixes: ed16648eb5b8 ("Move kvm, uml, and lguest subdirectories under a common "virtual" directory, I.E:") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>