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path: root/drivers/hv/hv_common.c
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2024-04-26dma-mapping: Simplify arch_setup_dma_ops()Robin Murphy
The dma_base, size and iommu arguments are only used by ARM, and can now easily be deduced from the device itself, so there's no need to pass them through the callchain as well. Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Michael Kelley <mhklinux@outlook.com> # For Hyper-V Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Hanjun Guo <guohanjun@huawei.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/5291c2326eab405b1aa7693aa964e8d3cb7193de.1713523152.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2024-03-18x86/hyperv: Use Hyper-V entropy to seed guest random number generatorMichael Kelley
A Hyper-V host provides its guest VMs with entropy in a custom ACPI table named "OEM0". The entropy bits are updated each time Hyper-V boots the VM, and are suitable for seeding the Linux guest random number generator (rng). See a brief description of OEM0 in [1]. Generation 2 VMs on Hyper-V use UEFI to boot. Existing EFI code in Linux seeds the rng with entropy bits from the EFI_RNG_PROTOCOL. Via this path, the rng is seeded very early during boot with good entropy. The ACPI OEM0 table provided in such VMs is an additional source of entropy. Generation 1 VMs on Hyper-V boot from BIOS. For these VMs, Linux doesn't currently get any entropy from the Hyper-V host. While this is not fundamentally broken because Linux can generate its own entropy, using the Hyper-V host provided entropy would get the rng off to a better start and would do so earlier in the boot process. Improve the rng seeding for Generation 1 VMs by having Hyper-V specific code in Linux take advantage of the OEM0 table to seed the rng. For Generation 2 VMs, use the OEM0 table to provide additional entropy beyond the EFI_RNG_PROTOCOL. Because the OEM0 table is custom to Hyper-V, parse it directly in the Hyper-V code in the Linux kernel and use add_bootloader_randomness() to add it to the rng. Once the entropy bits are read from OEM0, zero them out in the table so they don't appear in /sys/firmware/acpi/tables/OEM0 in the running VM. The zero'ing is done out of an abundance of caution to avoid potential security risks to the rng. Also set the OEM0 data length to zero so a kexec or other subsequent use of the table won't try to use the zero'ed bits. [1] https://download.microsoft.com/download/1/c/9/1c9813b8-089c-4fef-b2ad-ad80e79403ba/Whitepaper%20-%20The%20Windows%2010%20random%20number%20generation%20infrastructure.pdf Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20240318155408.216851-1-mhklinux@outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20240318155408.216851-1-mhklinux@outlook.com>
2024-03-12mshyperv: Introduce hv_get_hypervisor_version functionNuno Das Neves
Introduce x86_64 and arm64 functions to get the hypervisor version information and store it in a structure for simpler parsing. Use the new function to get and parse the version at boot time. While at it, move the printing code to hv_common_init() so it is not duplicated. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Acked-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1709852618-29110-1-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1709852618-29110-1-git-send-email-nunodasneves@linux.microsoft.com>
2024-03-04hyperv-tlfs: Change prefix of generic HV_REGISTER_* MSRs to HV_MSR_*Nuno Das Neves
The HV_REGISTER_ are used as arguments to hv_set/get_register(), which delegate to arch-specific mechanisms for getting/setting synthetic Hyper-V MSRs. On arm64, HV_REGISTER_ defines are synthetic VP registers accessed via the get/set vp registers hypercalls. The naming matches the TLFS document, although these register names are not specific to arm64. However, on x86 the prefix HV_REGISTER_ indicates Hyper-V MSRs accessed via rdmsrl()/wrmsrl(). This is not consistent with the TLFS doc, where HV_REGISTER_ is *only* used for used for VP register names used by the get/set register hypercalls. To fix this inconsistency and prevent future confusion, change the arch-generic aliases used by callers of hv_set/get_register() to have the prefix HV_MSR_ instead of HV_REGISTER_. Use the prefix HV_X64_MSR_ for the x86-only Hyper-V MSRs. On x86, the generic HV_MSR_'s point to the corresponding HV_X64_MSR_. Move the arm64 HV_REGISTER_* defines to the asm-generic hyperv-tlfs.h, since these are not specific to arm64. On arm64, the generic HV_MSR_'s point to the corresponding HV_REGISTER_. While at it, rename hv_get/set_registers() and related functions to hv_get/set_msr(), hv_get/set_nested_msr(), etc. These are only used for Hyper-V MSRs and this naming makes that clear. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1708440933-27125-1-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1708440933-27125-1-git-send-email-nunodasneves@linux.microsoft.com>
2023-12-12iommu: Remove struct iommu_ops *iommu from arch_setup_dma_ops()Jason Gunthorpe
This is not being used to pass ops, it is just a way to tell if an iommu driver was probed. These days this can be detected directly via device_iommu_mapped(). Call device_iommu_mapped() in the two places that need to check it and remove the iommu parameter everywhere. Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Moritz Fischer <mdf@kernel.org> Acked-by: Christoph Hellwig <hch@lst.de> Acked-by: Rob Herring <robh@kernel.org> Tested-by: Hector Martin <marcan@marcan.st> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/1-v2-16e4def25ebb+820-iommu_fwspec_p1_jgg@nvidia.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-10-11Drivers: hv: Remove now superfluous sentinel element from ctl_table arrayJoel Granados
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel from hv_ctl_table Signed-off-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-09-04Merge tag 'hyperv-next-signed-20230902' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Support for SEV-SNP guests on Hyper-V (Tianyu Lan) - Support for TDX guests on Hyper-V (Dexuan Cui) - Use SBRM API in Hyper-V balloon driver (Mitchell Levy) - Avoid dereferencing ACPI root object handle in VMBus driver (Maciej Szmigiero) - A few misecllaneous fixes (Jiapeng Chong, Nathan Chancellor, Saurabh Sengar) * tag 'hyperv-next-signed-20230902' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits) x86/hyperv: Remove duplicate include x86/hyperv: Move the code in ivm.c around to avoid unnecessary ifdef's x86/hyperv: Remove hv_isolation_type_en_snp x86/hyperv: Use TDX GHCI to access some MSRs in a TDX VM with the paravisor Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the paravisor x86/hyperv: Introduce a global variable hyperv_paravisor_present Drivers: hv: vmbus: Support >64 VPs for a fully enlightened TDX/SNP VM x86/hyperv: Fix serial console interrupts for fully enlightened TDX guests Drivers: hv: vmbus: Support fully enlightened TDX guests x86/hyperv: Support hypercalls for fully enlightened TDX guests x86/hyperv: Add hv_isolation_type_tdx() to detect TDX guests x86/hyperv: Fix undefined reference to isolation_type_en_snp without CONFIG_HYPERV x86/hyperv: Add missing 'inline' to hv_snp_boot_ap() stub hv: hyperv.h: Replace one-element array with flexible-array member Drivers: hv: vmbus: Don't dereference ACPI root object handle x86/hyperv: Add hyperv-specific handling for VMMCALL under SEV-ES x86/hyperv: Add smp support for SEV-SNP guest clocksource: hyper-v: Mark hyperv tsc page unencrypted in sev-snp enlightened guest x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp enlightened guest drivers: hv: Mark percpu hvcall input arg page unencrypted in SEV-SNP enlightened guest ...
2023-08-25x86/hyperv: Remove hv_isolation_type_en_snpDexuan Cui
In ms_hyperv_init_platform(), do not distinguish between a SNP VM with the paravisor and a SNP VM without the paravisor. Replace hv_isolation_type_en_snp() with !ms_hyperv.paravisor_present && hv_isolation_type_snp(). The hv_isolation_type_en_snp() in drivers/hv/hv.c and drivers/hv/hv_common.c can be changed to hv_isolation_type_snp() since we know !ms_hyperv.paravisor_present is true there. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-10-decui@microsoft.com
2023-08-25x86/hyperv: Introduce a global variable hyperv_paravisor_presentDexuan Cui
The new variable hyperv_paravisor_present is set only when the VM is a SNP/TDX VM with the paravisor running: see ms_hyperv_init_platform(). We introduce hyperv_paravisor_present because we can not use ms_hyperv.paravisor_present in arch/x86/include/asm/mshyperv.h: struct ms_hyperv_info is defined in include/asm-generic/mshyperv.h, which is included at the end of arch/x86/include/asm/mshyperv.h, but at the beginning of arch/x86/include/asm/mshyperv.h, we would already need to use struct ms_hyperv_info in hv_do_hypercall(). We use hyperv_paravisor_present only in include/asm-generic/mshyperv.h, and use ms_hyperv.paravisor_present elsewhere. In the future, we'll introduce a hypercall function structure for different VM types, and at boot time, the right function pointers would be written into the structure so that runtime testing of TDX vs. SNP vs. normal will be avoided and hyperv_paravisor_present will no longer be needed. Call hv_vtom_init() when it's a VBS VM or when ms_hyperv.paravisor_present is true, i.e. the VM is a SNP VM or TDX VM with the paravisor. Enhance hv_vtom_init() for a TDX VM with the paravisor. In hv_common_cpu_init(), don't decrypt the hyperv_pcpu_input_arg for a TDX VM with the paravisor, just like we don't decrypt the page for a SNP VM with the paravisor. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-7-decui@microsoft.com
2023-08-25Drivers: hv: vmbus: Support >64 VPs for a fully enlightened TDX/SNP VMDexuan Cui
Don't set *this_cpu_ptr(hyperv_pcpu_input_arg) before the function set_memory_decrypted() returns, otherwise we run into this ticky issue: For a fully enlightened TDX/SNP VM, in hv_common_cpu_init(), *this_cpu_ptr(hyperv_pcpu_input_arg) is an encrypted page before the set_memory_decrypted() returns. When such a VM has more than 64 VPs, if the hyperv_pcpu_input_arg is not NULL, hv_common_cpu_init() -> set_memory_decrypted() -> ... -> cpa_flush() -> on_each_cpu() -> ... -> hv_send_ipi_mask() -> ... -> __send_ipi_mask_ex() tries to call hv_do_rep_hypercall() with the hyperv_pcpu_input_arg as the hypercall input page, which must be a decrypted page in such a VM, but the page is still encrypted at this point, and a fatal fault is triggered. Fix the issue by setting *this_cpu_ptr(hyperv_pcpu_input_arg) after set_memory_decrypted(): if the hyperv_pcpu_input_arg is NULL, __send_ipi_mask_ex() returns HV_STATUS_INVALID_PARAMETER immediately, and hv_send_ipi_mask() falls back to orig_apic.send_IPI_mask(), which can use x2apic_send_IPI_all(), which may be slightly slower than the hypercall but still works correctly in such a VM. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-6-decui@microsoft.com
2023-08-25x86/hyperv: Support hypercalls for fully enlightened TDX guestsDexuan Cui
A fully enlightened TDX guest on Hyper-V (i.e. without the paravisor) only uses the GHCI call rather than hv_hypercall_pg. Do not initialize hypercall_pg for such a guest. In hv_common_cpu_init(), the hyperv_pcpu_input_arg page needs to be decrypted in such a guest. Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-3-decui@microsoft.com
2023-08-25x86/hyperv: Add hv_isolation_type_tdx() to detect TDX guestsDexuan Cui
No logic change to SNP/VBS guests. hv_isolation_type_tdx() will be used to instruct a TDX guest on Hyper-V to do some TDX-specific operations, e.g. for a fully enlightened TDX guest (i.e. without the paravisor), hv_do_hypercall() should use __tdx_hypercall() and such a guest on Hyper-V should handle the Hyper-V Event/Message/Monitor pages specially. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-2-decui@microsoft.com
2023-08-22drivers: hv: Mark percpu hvcall input arg page unencrypted in SEV-SNP ↵Tianyu Lan
enlightened guest Hypervisor needs to access input arg, VMBus synic event and message pages. Mark these pages unencrypted in the SEV-SNP guest and free them only if they have been marked encrypted successfully. Reviewed-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230818102919.1318039-5-ltykernel@gmail.com
2023-08-22x86/hyperv: Add sev-snp enlightened guest static keyTianyu Lan
Introduce static key isolation_type_en_snp for enlightened sev-snp guest check. Reviewed-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230818102919.1318039-2-ltykernel@gmail.com
2023-06-28Drivers: hv: Change hv_free_hyperv_page() to take void * argumentKameron Carr
Currently hv_free_hyperv_page() takes an unsigned long argument, which is inconsistent with the void * return value from the corresponding hv_alloc_hyperv_page() function and variants. This creates unnecessary extra casting. Change the hv_free_hyperv_page() argument type to void *. Also remove redundant casts from invocations of hv_alloc_hyperv_page() and variants. Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Link: https://lore.kernel.org/r/1687558189-19734-1-git-send-email-kameroncarr@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-06-17x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offlineMichael Kelley
These commits a494aef23dfc ("PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg") 2c6ba4216844 ("PCI: hv: Enable PCI pass-thru devices in Confidential VMs") update the Hyper-V virtual PCI driver to use the hyperv_pcpu_input_arg because that memory will be correctly marked as decrypted or encrypted for all VM types (CoCo or normal). But problems ensue when CPUs in the VM go online or offline after virtual PCI devices have been configured. When a CPU is brought online, the hyperv_pcpu_input_arg for that CPU is initialized by hv_cpu_init() running under state CPUHP_AP_ONLINE_DYN. But this state occurs after state CPUHP_AP_IRQ_AFFINITY_ONLINE, which may call the virtual PCI driver and fault trying to use the as yet uninitialized hyperv_pcpu_input_arg. A similar problem occurs in a CoCo VM if the MMIO read and write hypercalls are used from state CPUHP_AP_IRQ_AFFINITY_ONLINE. When a CPU is taken offline, IRQs may be reassigned in state CPUHP_TEARDOWN_CPU. Again, the virtual PCI driver may fault trying to use the hyperv_pcpu_input_arg that has already been freed by a higher state. Fix the onlining problem by adding state CPUHP_AP_HYPERV_ONLINE immediately after CPUHP_AP_ONLINE_IDLE (similar to CPUHP_AP_KVM_ONLINE) and before CPUHP_AP_IRQ_AFFINITY_ONLINE. Use this new state for Hyper-V initialization so that hyperv_pcpu_input_arg is allocated early enough. Fix the offlining problem by not freeing hyperv_pcpu_input_arg when a CPU goes offline. Retain the allocated memory, and reuse it if the CPU comes back online later. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Dexuan Cui <decui@microsoft.com> Link: https://lore.kernel.org/r/1684862062-51576-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-04-20Drivers: hv: move panic report code from vmbus to hv early init codeLong Li
The panic reporting code was added in commit 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic") It was added to the vmbus driver. The panic reporting has no dependence on vmbus, and can be enabled at an earlier boot time when Hyper-V is initialized. This patch moves the panic reporting code out of vmbus. There is no functionality changes. During moving, also refactored some cleanup functions into hv_kmsg_dump_unregister(). Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1682030946-6372-1-git-send-email-longli@linuxonhyperv.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-04-17hv_netvsc: Remove second mapping of send and recv buffersMichael Kelley
With changes to how Hyper-V guest VMs flip memory between private (encrypted) and shared (decrypted), creating a second kernel virtual mapping for shared memory is no longer necessary. Everything needed for the transition to shared is handled by set_memory_decrypted(). As such, remove the code to create and manage the second mapping for the pre-allocated send and recv buffers. This mapping is the last user of hv_map_memory()/hv_unmap_memory(), so delete these functions as well. Finally, hv_map_memory() is the last user of vmap_pfn() in Hyper-V guest code, so remove the Kconfig selection of VMAP_PFN. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/1679838727-87310-11-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-01-12x86/hyperv: Add support for detecting nested hypervisorJinank Jain
Detect if Linux is running as a nested hypervisor in the root partition for Microsoft Hypervisor, using flags provided by MSHV. Expose a new variable hv_nested that is used later for decisions specific to the nested use case. Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/8e3e7112806e81d2292a66a56fe547162754ecea.1672639707.git.jinankjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2022-04-07Merge tag 'hyperv-fixes-signed-20220407' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - Correctly propagate coherence information for VMbus devices (Michael Kelley) - Disable balloon and memory hot-add on ARM64 temporarily (Boqun Feng) - Use barrier to prevent reording when reading ring buffer (Michael Kelley) - Use virt_store_mb in favour of smp_store_mb (Andrea Parri) - Fix VMbus device object initialization (Andrea Parri) - Deactivate sysctl_record_panic_msg on isolated guest (Andrea Parri) - Fix a crash when unloading VMbus module (Guilherme G. Piccoli) * tag 'hyperv-fixes-signed-20220407' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Replace smp_store_mb() with virt_store_mb() Drivers: hv: balloon: Disable balloon and hot-add accordingly Drivers: hv: balloon: Support status report for larger page sizes Drivers: hv: vmbus: Prevent load re-ordering when reading ring buffer PCI: hv: Propagate coherence from VMbus device to PCI device Drivers: hv: vmbus: Propagate VMbus coherence to each VMbus device Drivers: hv: vmbus: Fix potential crash on module unload Drivers: hv: vmbus: Fix initialization of device object in vmbus_device_register() Drivers: hv: vmbus: Deactivate sysctl_record_panic_msg by default in isolated guests
2022-03-29Drivers: hv: vmbus: Propagate VMbus coherence to each VMbus deviceMichael Kelley
VMbus synthetic devices are not represented in the ACPI DSDT -- only the top level VMbus device is represented. As a result, on ARM64 coherence information in the _CCA method is not specified for synthetic devices, so they default to not hardware coherent. Drivers for some of these synthetic devices have been recently updated to use the standard DMA APIs, and they are incurring extra overhead of unneeded software coherence management. Fix this by propagating coherence information from the VMbus node in ACPI to the individual synthetic devices. There's no effect on x86/x64 where devices are always hardware coherent. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/1648138492-2191-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2022-02-18drivers: hv: log when enabling crash_kexec_post_notifiersStephen Brennan
Recently I went down a rabbit hole looking at a race condition in panic() on a Hyper-V guest. I assumed, since it was missing from the command line, that crash_kexec_post_notifiers was disabled. Only after a rather long reproduction and analysis process did I learn that Hyper-V actually enables this setting unconditionally. Users and debuggers alike would like to know when these things happen. I think it would be good to print a message to the kernel log when this happens, so that a grep for "crash_kexec_post_notifiers" shows relevant results. Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20220215013735.358327-1-stephen.s.brennan@oracle.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-12-28Drivers: hv: Fix definition of hypercall input & output arg variablesMichael Kelley
The percpu variables hyperv_pcpu_input_arg and hyperv_pcpu_output_arg have been incorrectly defined since their inception. The __percpu qualifier should be associated with the void * (i.e., a pointer), not with the target of the pointer. This distinction makes no difference to gcc and the generated code, but sparse correctly complains. Fix the definitions in the interest of general correctness in addition to making sparse happy. No functional change. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1640662315-22260-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-12-20net: netvsc: Add Isolation VM support for netvsc driverTianyu Lan
In Isolation VM, all shared memory with host needs to mark visible to host via hvcall. vmbus_establish_gpadl() has already done it for netvsc rx/tx ring buffer. The page buffer used by vmbus_sendpacket_ pagebuffer() stills need to be handled. Use DMA API to map/umap these memory during sending/receiving packet and Hyper-V swiotlb bounce buffer dma address will be returned. The swiotlb bounce buffer has been masked to be visible to host during boot up. rx/tx ring buffer is allocated via vzalloc() and they need to be mapped into unencrypted address space(above vTOM) before sharing with host and accessing. Add hv_map/unmap_memory() to map/umap rx /tx ring buffer. Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20211213071407.314309-6-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-10-28x86/hyperv: Add ghcb hvcall support for SNP VMTianyu Lan
hyperv provides ghcb hvcall to handle VMBus HVCALL_SIGNAL_EVENT and HVCALL_POST_MESSAGE msg in SNP Isolation VM. Add such support. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-8-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-10-28x86/hyperv: Add Write/Read MSR registers via ghcb pageTianyu Lan
Hyperv provides GHCB protocol to write Synthetic Interrupt Controller MSR registers in Isolation VM with AMD SEV SNP and these registers are emulated by hypervisor directly. Hyperv requires to write SINTx MSR registers twice. First writes MSR via GHCB page to communicate with hypervisor and then writes wrmsr instruction to talk with paravisor which runs in VMPL0. Guest OS ID MSR also needs to be set via GHCB page. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-7-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-07-19drivers: hv: Decouple Hyper-V clock/timer code from VMbus driversMichael Kelley
Hyper-V clock/timer code in hyperv_timer.c is mostly independent from other VMbus drivers, but building for ARM64 without hyperv_timer.c shows some remaining entanglements. A default implementation of hv_read_reference_counter can just read a Hyper-V synthetic register and be independent of hyperv_timer.c, so move this code out and into hv_common.c. Then it can be used by the timesync driver even if hyperv_timer.c isn't built on a particular architecture. If hyperv_timer.c *is* built, it can override with a faster implementation. Also provide stubs for stimer functions called by the VMbus driver when hyperv_timer.c isn't built. No functional changes. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1626220906-22629-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-07-15Drivers: hv: Move Hyper-V misc functionality to arch-neutral codeMichael Kelley
The check for whether hibernation is possible, and the enabling of Hyper-V panic notification during kexec, are both architecture neutral. Move the code from under arch/x86 and into drivers/hv/hv_common.c where it can also be used for ARM64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1626287687-2045-4-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-07-15Drivers: hv: Add arch independent default functions for some Hyper-V handlersMichael Kelley
Architecture independent Hyper-V code calls various arch-specific handlers when needed. To aid in supporting multiple architectures, provide weak defaults that can be overridden by arch-specific implementations where appropriate. But when arch-specific overrides aren't needed or haven't been implemented yet for a particular architecture, these stubs reduce the amount of clutter under arch/. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1626287687-2045-3-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-07-15Drivers: hv: Make portions of Hyper-V init code be arch neutralMichael Kelley
The code to allocate and initialize the hv_vp_index array is architecture neutral. Similarly, the code to allocate and populate the hypercall input and output arg pages is architecture neutral. Move both sets of code out from arch/x86 and into utility functions in drivers/hv/hv_common.c that can be shared by Hyper-V initialization on ARM64. No functional changes. However, the allocation of the hypercall input and output arg pages is done differently so that the size is always the Hyper-V page size, even if not the same as the guest page size (such as with ARM64's 64K page size). Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1626287687-2045-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-06-29Merge tag 'hyperv-next-signed-20210629' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: "Just a few minor enhancement patches and bug fixes" * tag 'hyperv-next-signed-20210629' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: PCI: hv: Add check for hyperv_initialized in init_hv_pci_drv() Drivers: hv: Move Hyper-V extended capability check to arch neutral code drivers: hv: Fix missing error code in vmbus_connect() x86/hyperv: fix logical processor creation hv_utils: Fix passing zero to 'PTR_ERR' warning scsi: storvsc: Use blk_mq_unique_tag() to generate requestIDs Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer hv_balloon: Remove redundant assignment to region_start
2021-06-05Drivers: hv: Move Hyper-V extended capability check to arch neutral codeMichael Kelley
The extended capability query code is currently under arch/x86, but it is architecture neutral, and is used by arch neutral code in the Hyper-V balloon driver. Hence the balloon driver fails to build on other architectures. Fix by moving the ext cap code out from arch/x86. Because it is also called from built-in architecture specific code, it can't be in a module, so the Makefile treats as built-in even when CONFIG_HYPERV is "m". Also drivers/Makefile is tweaked because this is the first occurrence of a Hyper-V file that is built-in even when CONFIG_HYPERV is "m". While here, update the hypercall status check to use the new helper function instead of open coding. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Link: https://lore.kernel.org/r/1622669804-2016-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>