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2023-05-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-5/+70
Pull kvm updates from Paolo Bonzini: "s390: - More phys_to_virt conversions - Improvement of AP management for VSIE (nested virtualization) ARM64: - Numerous fixes for the pathological lock inversion issue that plagued KVM/arm64 since... forever. - New framework allowing SMCCC-compliant hypercalls to be forwarded to userspace, hopefully paving the way for some more features being moved to VMMs rather than be implemented in the kernel. - Large rework of the timer code to allow a VM-wide offset to be applied to both virtual and physical counters as well as a per-timer, per-vcpu offset that complements the global one. This last part allows the NV timer code to be implemented on top. - A small set of fixes to make sure that we don't change anything affecting the EL1&0 translation regime just after having having taken an exception to EL2 until we have executed a DSB. This ensures that speculative walks started in EL1&0 have completed. - The usual selftest fixes and improvements. x86: - Optimize CR0.WP toggling by avoiding an MMU reload when TDP is enabled, and by giving the guest control of CR0.WP when EPT is enabled on VMX (VMX-only because SVM doesn't support per-bit controls) - Add CR0/CR4 helpers to query single bits, and clean up related code where KVM was interpreting kvm_read_cr4_bits()'s "unsigned long" return as a bool - Move AMD_PSFD to cpufeatures.h and purge KVM's definition - Avoid unnecessary writes+flushes when the guest is only adding new PTEs - Overhaul .sync_page() and .invlpg() to utilize .sync_page()'s optimizations when emulating invalidations - Clean up the range-based flushing APIs - Revamp the TDP MMU's reaping of Accessed/Dirty bits to clear a single A/D bit using a LOCK AND instead of XCHG, and skip all of the "handle changed SPTE" overhead associated with writing the entire entry - Track the number of "tail" entries in a pte_list_desc to avoid having to walk (potentially) all descriptors during insertion and deletion, which gets quite expensive if the guest is spamming fork() - Disallow virtualizing legacy LBRs if architectural LBRs are available, the two are mutually exclusive in hardware - Disallow writes to immutable feature MSRs (notably PERF_CAPABILITIES) after KVM_RUN, similar to CPUID features - Overhaul the vmx_pmu_caps selftest to better validate PERF_CAPABILITIES - Apply PMU filters to emulated events and add test coverage to the pmu_event_filter selftest - AMD SVM: - Add support for virtual NMIs - Fixes for edge cases related to virtual interrupts - Intel AMX: - Don't advertise XTILE_CFG in KVM_GET_SUPPORTED_CPUID if XTILE_DATA is not being reported due to userspace not opting in via prctl() - Fix a bug in emulation of ENCLS in compatibility mode - Allow emulation of NOP and PAUSE for L2 - AMX selftests improvements - Misc cleanups MIPS: - Constify MIPS's internal callbacks (a leftover from the hardware enabling rework that landed in 6.3) Generic: - Drop unnecessary casts from "void *" throughout kvm_main.c - Tweak the layout of "struct kvm_mmu_memory_cache" to shrink the struct size by 8 bytes on 64-bit kernels by utilizing a padding hole Documentation: - Fix goof introduced by the conversion to rST" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (211 commits) KVM: s390: pci: fix virtual-physical confusion on module unload/load KVM: s390: vsie: clarifications on setting the APCB KVM: s390: interrupt: fix virtual-physical confusion for next alert GISA KVM: arm64: Have kvm_psci_vcpu_on() use WRITE_ONCE() to update mp_state KVM: arm64: Acquire mp_state_lock in kvm_arch_vcpu_ioctl_vcpu_init() KVM: selftests: Test the PMU event "Instructions retired" KVM: selftests: Copy full counter values from guest in PMU event filter test KVM: selftests: Use error codes to signal errors in PMU event filter test KVM: selftests: Print detailed info in PMU event filter asserts KVM: selftests: Add helpers for PMC asserts in PMU event filter test KVM: selftests: Add a common helper for the PMU event filter guest code KVM: selftests: Fix spelling mistake "perrmited" -> "permitted" KVM: arm64: vhe: Drop extra isb() on guest exit KVM: arm64: vhe: Synchronise with page table walker on MMU update KVM: arm64: pkvm: Document the side effects of kvm_flush_dcache_to_poc() KVM: arm64: nvhe: Synchronise with page table walker on TLBI KVM: arm64: Handle 32bit CNTPCTSS traps KVM: arm64: nvhe: Synchronise with page table walker on vcpu run KVM: arm64: vgic: Don't acquire its_lock before config_lock KVM: selftests: Add test to verify KVM's supported XCR0 ...
2023-04-26Merge tag 'kvm-x86-generic-6.4' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini1-0/+1
Common KVM changes for 6.4: - Drop unnecessary casts from "void *" throughout kvm_main.c - Tweak the layout of "struct kvm_mmu_memory_cache" to shrink the struct size by 8 bytes on 64-bit kernels by utilizing a padding hole - Fix a documentation format goof that was introduced when the KVM docs were converted to ReST - Constify MIPS's internal callbacks (a leftover from the hardware enabling rework that landed in 6.3)
2023-04-26Merge tag 'kvmarm-6.4' of ↵Paolo Bonzini1-4/+67
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.4 - Numerous fixes for the pathological lock inversion issue that plagued KVM/arm64 since... forever. - New framework allowing SMCCC-compliant hypercalls to be forwarded to userspace, hopefully paving the way for some more features being moved to VMMs rather than be implemented in the kernel. - Large rework of the timer code to allow a VM-wide offset to be applied to both virtual and physical counters as well as a per-timer, per-vcpu offset that complements the global one. This last part allows the NV timer code to be implemented on top. - A small set of fixes to make sure that we don't change anything affecting the EL1&0 translation regime just after having having taken an exception to EL2 until we have executed a DSB. This ensures that speculative walks started in EL1&0 have completed. - The usual selftest fixes and improvements.
2023-04-24Merge tag 'docs-6.4' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation updates from Jonathan Corbet: "Commit volume in documentation is relatively low this time, but there is still a fair amount going on, including: - Reorganize the architecture-specific documentation under Documentation/arch This makes the structure match the source directory and helps to clean up the mess that is the top-level Documentation directory a bit. This work creates the new directory and moves x86 and most of the less-active architectures there. The current plan is to move the rest of the architectures in 6.5, with the patches going through the appropriate subsystem trees. - Some more Spanish translations and maintenance of the Italian translation - A new "Kernel contribution maturity model" document from Ted - A new tutorial on quickly building a trimmed kernel from Thorsten Plus the usual set of updates and fixes" * tag 'docs-6.4' of git://git.lwn.net/linux: (47 commits) media: Adjust column width for pdfdocs media: Fix building pdfdocs docs: clk: add documentation to log which clocks have been disabled docs: trace: Fix typo in ftrace.rst Documentation/process: always CC responsible lists docs: kmemleak: adjust to config renaming ELF: document some de-facto PT_* ABI quirks Documentation: arm: remove stih415/stih416 related entries docs: turn off "smart quotes" in the HTML build Documentation: firmware: Clarify firmware path usage docs/mm: Physical Memory: Fix grammar Documentation: Add document for false sharing dma-api-howto: typo fix docs: move m68k architecture documentation under Documentation/arch/ docs: move parisc documentation under Documentation/arch/ docs: move ia64 architecture docs under Documentation/arch/ docs: Move arc architecture docs under Documentation/arch/ docs: move nios2 documentation under Documentation/arch/ docs: move openrisc documentation under Documentation/arch/ docs: move superh documentation under Documentation/arch/ ...
2023-04-21Merge branch kvm-arm64/smccc-filtering into kvmarm-master/nextMarc Zyngier1-4/+29
* kvm-arm64/smccc-filtering: : . : SMCCC call filtering and forwarding to userspace, courtesy of : Oliver Upton. From the cover letter: : : "The Arm SMCCC is rather prescriptive in regards to the allocation of : SMCCC function ID ranges. Many of the hypercall ranges have an : associated specification from Arm (FF-A, PSCI, SDEI, etc.) with some : room for vendor-specific implementations. : : The ever-expanding SMCCC surface leaves a lot of work within KVM for : providing new features. Furthermore, KVM implements its own : vendor-specific ABI, with little room for other implementations (like : Hyper-V, for example). Rather than cramming it all into the kernel we : should provide a way for userspace to handle hypercalls." : . KVM: selftests: Fix spelling mistake "KVM_HYPERCAL_EXIT_SMC" -> "KVM_HYPERCALL_EXIT_SMC" KVM: arm64: Test that SMC64 arch calls are reserved KVM: arm64: Prevent userspace from handling SMC64 arch range KVM: arm64: Expose SMC/HVC width to userspace KVM: selftests: Add test for SMCCC filter KVM: selftests: Add a helper for SMCCC calls with SMC instruction KVM: arm64: Let errors from SMCCC emulation to reach userspace KVM: arm64: Return NOT_SUPPORTED to guest for unknown PSCI version KVM: arm64: Introduce support for userspace SMCCC filtering KVM: arm64: Add support for KVM_EXIT_HYPERCALL KVM: arm64: Use a maple tree to represent the SMCCC filter KVM: arm64: Refactor hvc filtering to support different actions KVM: arm64: Start handling SMCs from EL1 KVM: arm64: Rename SMC/HVC call handler to reflect reality KVM: arm64: Add vm fd device attribute accessors KVM: arm64: Add a helper to check if a VM has ran once KVM: x86: Redefine 'longmode' as a flag for KVM_EXIT_HYPERCALL Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-04-05KVM: arm64: Expose SMC/HVC width to userspaceMarc Zyngier1-0/+8
When returning to userspace to handle a SMCCC call, we consistently set PC to point to the instruction immediately after the HVC/SMC. However, should userspace need to know the exact address of the trapping instruction, it needs to know about the *size* of that instruction. For AArch64, this is pretty easy. For AArch32, this is a bit more funky, as Thumb has 16bit encodings for both HVC and SMC. Expose this to userspace with a new flag that directly derives from ESR_EL2.IL. Also update the documentation to reflect the PC state at the point of exit. Finally, this fixes a small buglet where the hypercall.{args,ret} fields would not be cleared on exit, and could contain some random junk. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/86pm8iv8tj.wl-maz@kernel.org
2023-04-05KVM: arm64: Introduce support for userspace SMCCC filteringOliver Upton1-0/+4
As the SMCCC (and related specifications) march towards an 'everything and the kitchen sink' interface for interacting with a system it becomes less likely that KVM will support every related feature. We could do better by letting userspace have a crack at it instead. Allow userspace to define an 'SMCCC filter' that applies to both HVCs and SMCs initiated by the guest. Supporting both conduits with this interface is important for a couple of reasons. Guest SMC usage is table stakes for a nested guest, as HVCs are always taken to the virtual EL2. Additionally, guests may want to interact with a service on the secure side which can now be proxied by userspace. Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230404154050.2270077-10-oliver.upton@linux.dev
2023-04-05KVM: arm64: Add support for KVM_EXIT_HYPERCALLOliver Upton1-2/+16
In anticipation of user hypercall filters, add the necessary plumbing to get SMCCC calls out to userspace. Even though the exit structure has space for KVM to pass register arguments, let's just avoid it altogether and let userspace poke at the registers via KVM_GET_ONE_REG. This deliberately stretches the definition of a 'hypercall' to cover SMCs from EL1 in addition to the HVCs we know and love. KVM doesn't support EL1 calls into secure services, but now we can paint that as a userspace problem and be done with it. Finally, we need a flag to let userspace know what conduit instruction was used (i.e. SMC vs. HVC). Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230404154050.2270077-9-oliver.upton@linux.dev
2023-04-05KVM: x86: Redefine 'longmode' as a flag for KVM_EXIT_HYPERCALLOliver Upton1-2/+1
The 'longmode' field is a bit annoying as it blows an entire __u32 to represent a boolean value. Since other architectures are looking to add support for KVM_EXIT_HYPERCALL, now is probably a good time to clean it up. Redefine the field (and the remaining padding) as a set of flags. Preserve the existing ABI by using bit 0 to indicate if the guest was in long mode and requiring that the remaining 31 bits must be zero. Cc: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230404154050.2270077-2-oliver.upton@linux.dev
2023-04-04docs: kvm: x86: Fix broken field listTakahiro Itazuri1-2/+2
Add a missing ":" to fix a broken field list. Signed-off-by: Takahiro Itazuri <itazur@amazon.com> Fixes: ba7bb663f554 ("KVM: x86: Provide per VM capability for disabling PMU virtualization") Message-Id: <20230331093116.99820-1-itazur@amazon.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-03-30docs: move x86 documentation into Documentation/arch/Jonathan Corbet1-1/+1
Move the x86 documentation under Documentation/arch/ as a way of cleaning up the top-level directory and making the structure of our docs more closely match the structure of the source directories it describes. All in-kernel references to the old paths have been updated. Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20230315211523.108836-1-corbet@lwn.net/ Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-03-30KVM: arm64: Document KVM_ARM_SET_CNT_OFFSETS and coMarc Zyngier1-0/+38
Add some basic documentation on the effects of KVM_ARM_SET_CNT_OFFSETS. Reviewed-by: Colton Lewis <coltonlewis@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230330174800.2677007-16-maz@kernel.org
2023-03-24KVM: Add the missed title formatShaoqin Huang1-0/+1
The 7.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 now is not a title, make it as a title to keep the format consistent. Signed-off-by: Shaoqin Huang <shahuang@redhat.com> Fixes: 106ee47dc633 ("docs: kvm: Convert api.txt to ReST format") Reviewed-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20230220034910.11024-1-shahuang@redhat.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-03-16KVM: arm64: Limit length in kvm_vm_ioctl_mte_copy_tags() to INT_MAXThomas Huth1-1/+2
In case of success, this function returns the amount of handled bytes. However, this does not work for large values: The function is called from kvm_arch_vm_ioctl() (which still returns a long), which in turn is called from kvm_vm_ioctl() in virt/kvm/kvm_main.c. And that function stores the return value in an "int r" variable. So the upper 32-bits of the "long" return value are lost there. KVM ioctl functions should only return "int" values, so let's limit the amount of bytes that can be requested here to INT_MAX to avoid the problem with the truncated return value. We can then also change the return type of the function to "int" to make it clearer that it is not possible to return a "long" here. Fixes: f0376edb1ddc ("KVM: arm64: Add ioctl to fetch/store tags in a guest") Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Steven Price <steven.price@arm.com> Message-Id: <20230208140105.655814-5-thuth@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-02-15Merge tag 'kvm-s390-next-6.3-1' of ↵Paolo Bonzini1-9/+37
https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD * Two more V!=R patches * The last part of the cmpxchg patches * A few fixes
2023-02-15Merge tag 'kvm-riscv-6.3-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini1-3/+7
KVM/riscv changes for 6.3 - Fix wrong usage of PGDIR_SIZE to check page sizes - Fix privilege mode setting in kvm_riscv_vcpu_trap_redirect() - Redirect illegal instruction traps to guest - SBI PMU support for guest
2023-02-07Documentation: KVM: s390: Describe KVM_S390_MEMOP_F_CMPXCHGJanis Schoetterl-Glausch1-3/+25
Describe the semantics of the new KVM_S390_MEMOP_F_CMPXCHG flag for absolute vm write memops which allows user space to perform (storage key checked) cmpxchg operations on guest memory. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20230206164602.138068-14-scgl@linux.ibm.com Message-Id: <20230206164602.138068-14-scgl@linux.ibm.com> [frankja@de.ibm.com: Removed a line from an earlier version] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2023-02-07KVM: s390: disable migration mode when dirty tracking is disabledNico Boehr1-6/+12
Migration mode is a VM attribute which enables tracking of changes in storage attributes (PGSTE). It assumes dirty tracking is enabled on all memslots to keep a dirty bitmap of pages with changed storage attributes. When enabling migration mode, we currently check that dirty tracking is enabled for all memslots. However, userspace can disable dirty tracking without disabling migration mode. Since migration mode is pointless with dirty tracking disabled, disable migration mode whenever userspace disables dirty tracking on any slot. Also update the documentation to clarify that dirty tracking must be enabled when enabling migration mode, which is already enforced by the code in kvm_s390_vm_start_migration(). Also highlight in the documentation for KVM_S390_GET_CMMA_BITS that it can now fail with -EINVAL when dirty tracking is disabled while migration mode is on. Move all the error codes to a table so this stays readable. To disable migration mode, slots_lock should be held, which is taken in kvm_set_memory_region() and thus held in kvm_arch_prepare_memory_region(). Restructure the prepare code a bit so all the sanity checking is done before disabling migration mode. This ensures migration mode isn't disabled when some sanity check fails. Cc: stable@vger.kernel.org Fixes: 190df4a212a7 ("KVM: s390: CMMA tracking, ESSA emulation, migration mode") Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20230127140532.230651-2-nrb@linux.ibm.com Message-Id: <20230127140532.230651-2-nrb@linux.ibm.com> [frankja@linux.ibm.com: fixed commit message typo, moved api.rst error table upwards] Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2023-02-04Merge tag 'kvmarm-fixes-6.2-3' of ↵Paolo Bonzini1-3/+7
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.2, take #3 - Yet another fix for non-CPU accesses to the memory backing the VGICv3 subsystem - A set of fixes for the setlftest checking for the S1PTW behaviour after the fix that went in ealier in the cycle
2023-01-29KVM: arm64: Allow no running vcpu on saving vgic3 pending tableGavin Shan1-1/+3
We don't have a running VCPU context to save vgic3 pending table due to KVM_DEV_ARM_VGIC_{GRP_CTRL, SAVE_PENDING_TABLES} command on KVM device "kvm-arm-vgic-v3". The unknown case is caught by kvm-unit-tests. # ./kvm-unit-tests/tests/its-pending-migration WARNING: CPU: 120 PID: 7973 at arch/arm64/kvm/../../../virt/kvm/kvm_main.c:3325 \ mark_page_dirty_in_slot+0x60/0xe0 : mark_page_dirty_in_slot+0x60/0xe0 __kvm_write_guest_page+0xcc/0x100 kvm_write_guest+0x7c/0xb0 vgic_v3_save_pending_tables+0x148/0x2a0 vgic_set_common_attr+0x158/0x240 vgic_v3_set_attr+0x4c/0x5c kvm_device_ioctl+0x100/0x160 __arm64_sys_ioctl+0xa8/0xf0 invoke_syscall.constprop.0+0x7c/0xd0 el0_svc_common.constprop.0+0x144/0x160 do_el0_svc+0x34/0x60 el0_svc+0x3c/0x1a0 el0t_64_sync_handler+0xb4/0x130 el0t_64_sync+0x178/0x17c Use vgic_write_guest_lock() to save vgic3 pending table. Reported-by: Zenghui Yu <yuzenghui@huawei.com> Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230126235451.469087-5-gshan@redhat.com
2023-01-29KVM: arm64: Allow no running vcpu on restoring vgic3 LPI pending statusGavin Shan1-3/+5
We don't have a running VCPU context to restore vgic3 LPI pending status due to command KVM_DEV_ARM_{VGIC_GRP_CTRL, ITS_RESTORE_TABLES} on KVM device "kvm-arm-vgic-its". Use vgic_write_guest_lock() to restore vgic3 LPI pending status. Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20230126235451.469087-4-gshan@redhat.com
2023-01-24KVM: x86/pmu: Introduce masked events to the pmu event filterAaron Lewis1-7/+71
When building a list of filter events, it can sometimes be a challenge to fit all the events needed to adequately restrict the guest into the limited space available in the pmu event filter. This stems from the fact that the pmu event filter requires each event (i.e. event select + unit mask) be listed, when the intention might be to restrict the event select all together, regardless of it's unit mask. Instead of increasing the number of filter events in the pmu event filter, add a new encoding that is able to do a more generalized match on the unit mask. Introduce masked events as another encoding the pmu event filter understands. Masked events has the fields: mask, match, and exclude. When filtering based on these events, the mask is applied to the guest's unit mask to see if it matches the match value (i.e. umask & mask == match). The exclude bit can then be used to exclude events from that match. E.g. for a given event select, if it's easier to say which unit mask values shouldn't be filtered, a masked event can be set up to match all possible unit mask values, then another masked event can be set up to match the unit mask values that shouldn't be filtered. Userspace can query to see if this feature exists by looking for the capability, KVM_CAP_PMU_EVENT_MASKED_EVENTS. This feature is enabled by setting the flags field in the pmu event filter to KVM_PMU_EVENT_FLAG_MASKED_EVENTS. Events can be encoded by using KVM_PMU_ENCODE_MASKED_ENTRY(). It is an error to have a bit set outside the valid bits for a masked event, and calls to KVM_SET_PMU_EVENT_FILTER will return -EINVAL in such cases, including the high bits of the event select (35:32) if called on Intel. With these updates the filter matching code has been updated to match on a common event. Masked events were flexible enough to handle both event types, so they were used as the common event. This changes how guest events get filtered because regardless of the type of event used in the uAPI, they will be converted to masked events. Because of this there could be a slight performance hit because instead of matching the filter event with a lookup on event select + unit mask, it does a lookup on event select then walks the unit masks to find the match. This shouldn't be a big problem because I would expect the set of common event selects to be small, and if they aren't the set can likely be reduced by using masked events to generalize the unit mask. Using one type of event when filtering guest events allows for a common code path to be used. Signed-off-by: Aaron Lewis <aaronlewis@google.com> Link: https://lore.kernel.org/r/20221220161236.555143-5-aaronlewis@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-01-11Merge tag 'kvmarm-fixes-6.2-1' of ↵Paolo Bonzini1-0/+8
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/arm64 fixes for 6.2, take #1 - Fix the PMCR_EL0 reset value after the PMU rework - Correctly handle S2 fault triggered by a S1 page table walk by not always classifying it as a write, as this breaks on R/O memslots - Document why we cannot exit with KVM_EXIT_MMIO when taking a write fault from a S1 PTW on a R/O memslot - Put the Apple M2 on the naughty step for not being able to correctly implement the vgic SEIS feature, just liek the M1 before it - Reviewer updates: Alex is stepping down, replaced by Zenghui
2023-01-09KVM: x86: Do not return host topology information from KVM_GET_SUPPORTED_CPUIDPaolo Bonzini1-0/+14
Passing the host topology to the guest is almost certainly wrong and will confuse the scheduler. In addition, several fields of these CPUID leaves vary on each processor; it is simply impossible to return the right values from KVM_GET_SUPPORTED_CPUID in such a way that they can be passed to KVM_SET_CPUID2. The values that will most likely prevent confusion are all zeroes. Userspace will have to override it anyway if it wishes to present a specific topology to the guest. Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-05Merge branch kvm-arm64/s1ptw-write-fault into kvmarm-master/fixesMarc Zyngier1-0/+8
* kvm-arm64/s1ptw-write-fault: : . : Fix S1PTW fault handling that was until then always taken : as a write. From the cover letter: : : `Recent developments on the EFI front have resulted in guests that : simply won't boot if the page tables are in a read-only memslot and : that you're a bit unlucky in the way S2 gets paged in... The core : issue is related to the fact that we treat a S1PTW as a write, which : is close enough to what needs to be done. Until to get to RO memslots. : : The first patch fixes this and is definitely a stable candidate. It : splits the faulting of page tables in two steps (RO translation fault, : followed by a writable permission fault -- should it even happen). : The second one documents the slightly odd behaviour of PTW writes to : RO memslot, which do not result in a KVM_MMIO exit. The last patch is : totally optional, only tangentially related, and randomly repainting : stuff (maybe that's contagious, who knows)." : : . KVM: arm64: Convert FSC_* over to ESR_ELx_FSC_* KVM: arm64: Document the behaviour of S1PTW faults on RO memslots KVM: arm64: Fix S1PTW handling on RO memslots Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-01-03KVM: arm64: Document the behaviour of S1PTW faults on RO memslotsMarc Zyngier1-0/+8
Although the KVM API says that a write to a RO memslot must result in a KVM_EXIT_MMIO describing the write, the arm64 architecture doesn't provide the *data* written by a Stage-1 page table walk (we only get the address). Since there isn't much userspace can do with so little information anyway, document the fact that such an access results in a guest exception, not an exit. This is consistent with the guest being terminally broken anyway. Reviewed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-12-28Merge branch 'kvm-late-6.1-fixes' into HEADPaolo Bonzini1-20/+26
x86: * several fixes to nested VMX execution controls * fixes and clarification to the documentation for Xen emulation * do not unnecessarily release a pmu event with zero period * MMU fixes * fix Coverity warning in kvm_hv_flush_tlb() selftests: * fixes for the ucall mechanism in selftests * other fixes mostly related to compilation with clang
2022-12-27KVM: x86/xen: Documentation updates and clarificationsDavid Woodhouse1-15/+26
Most notably, the KVM_XEN_EVTCHN_RESET feature had escaped documentation entirely. Along with how to turn most stuff off on SHUTDOWN_soft_reset. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20221226120320.1125390-6-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-27KVM: Delete extra block of "};" in the KVM API documentationSean Christopherson1-5/+0
Delete an extra block of code/documentation that snuck in when KVM's documentation was converted to ReST format. Fixes: 106ee47dc633 ("docs: kvm: Convert api.txt to ReST format") Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221207003637.2041211-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-15Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-109/+165
Pull kvm updates from Paolo Bonzini: "ARM64: - Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. - Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on (see merge commit 382b5b87a97d: "Fix a number of issues with MTE, such as races on the tags being initialised vs the PG_mte_tagged flag as well as the lack of support for VM_SHARED when KVM is involved. Patches from Catalin Marinas and Peter Collingbourne"). - Merge the pKVM shadow vcpu state tracking that allows the hypervisor to have its own view of a vcpu, keeping that state private. - Add support for the PMUv3p5 architecture revision, bringing support for 64bit counters on systems that support it, and fix the no-quite-compliant CHAIN-ed counter support for the machines that actually exist out there. - Fix a handful of minor issues around 52bit VA/PA support (64kB pages only) as a prefix of the oncoming support for 4kB and 16kB pages. - Pick a small set of documentation and spelling fixes, because no good merge window would be complete without those. s390: - Second batch of the lazy destroy patches - First batch of KVM changes for kernel virtual != physical address support - Removal of a unused function x86: - Allow compiling out SMM support - Cleanup and documentation of SMM state save area format - Preserve interrupt shadow in SMM state save area - Respond to generic signals during slow page faults - Fixes and optimizations for the non-executable huge page errata fix. - Reprogram all performance counters on PMU filter change - Cleanups to Hyper-V emulation and tests - Process Hyper-V TLB flushes from a nested guest (i.e. from a L2 guest running on top of a L1 Hyper-V hypervisor) - Advertise several new Intel features - x86 Xen-for-KVM: - Allow the Xen runstate information to cross a page boundary - Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured - Add support for 32-bit guests in SCHEDOP_poll - Notable x86 fixes and cleanups: - One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). - Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. - Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. - Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. - Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. - Advertise (on AMD) that the SMM_CTL MSR is not supported - Remove unnecessary exports Generic: - Support for responding to signals during page faults; introduces new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks Selftests: - Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. - Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. - Introduce actual atomics for clear/set_bit() in selftests - Add support for pinning vCPUs in dirty_log_perf_test. - Rename the so called "perf_util" framework to "memstress". - Add a lightweight psuedo RNG for guest use, and use it to randomize the access pattern and write vs. read percentage in the memstress tests. - Add a common ucall implementation; code dedup and pre-work for running SEV (and beyond) guests in selftests. - Provide a common constructor and arch hook, which will eventually be used by x86 to automatically select the right hypercall (AMD vs. Intel). - A bunch of added/enabled/fixed selftests for ARM64, covering memslots, breakpoints, stage-2 faults and access tracking. - x86-specific selftest changes: - Clean up x86's page table management. - Clean up and enhance the "smaller maxphyaddr" test, and add a related test to cover generic emulation failure. - Clean up the nEPT support checks. - Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values. - Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). Documentation: - Remove deleted ioctls from documentation - Clean up the docs for the x86 MSR filter. - Various fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (361 commits) KVM: x86: Add proper ReST tables for userspace MSR exits/flags KVM: selftests: Allocate ucall pool from MEM_REGION_DATA KVM: arm64: selftests: Align VA space allocator with TTBR0 KVM: arm64: Fix benign bug with incorrect use of VA_BITS KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow KVM: x86: Advertise that the SMM_CTL MSR is not supported KVM: x86: remove unnecessary exports KVM: selftests: Fix spelling mistake "probabalistic" -> "probabilistic" tools: KVM: selftests: Convert clear/set_bit() to actual atomics tools: Drop "atomic_" prefix from atomic test_and_set_bit() tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests perf tools: Use dedicated non-atomic clear/set bit helpers tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers KVM: arm64: selftests: Enable single-step without a "full" ucall() KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself KVM: Remove stale comment about KVM_REQ_UNHALT KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTR KVM: Reference to kvm_userspace_memory_region in doc and comments KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl ...
2022-12-14KVM: x86: Add proper ReST tables for userspace MSR exits/flagsSean Christopherson1-8/+12
Add ReST formatting to the set of userspace MSR exits/flags so that the resulting HTML docs generate a table instead of malformed gunk. This also fixes a warning that was introduced by a recent cleanup of the relevant documentation (yay copy+paste). >> Documentation/virt/kvm/api.rst:7287: WARNING: Block quote ends without a blank line; unexpected unindent. Fixes: 1ae099540e8c ("KVM: x86: Allow deflecting unknown MSR accesses to user space") Fixes: 1f158147181b ("KVM: x86: Clean up KVM_CAP_X86_USER_SPACE_MSR documentation") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221207000959.2035098-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-12Merge remote-tracking branch 'kvm/queue' into HEADPaolo Bonzini1-92/+90
x86 Xen-for-KVM: * Allow the Xen runstate information to cross a page boundary * Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured * add support for 32-bit guests in SCHEDOP_poll x86 fixes: * One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). * Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. * Clean up the MSR filter docs. * Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. * Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. * Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. * Advertise (on AMD) that the SMM_CTL MSR is not supported * Remove unnecessary exports Selftests: * Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. * Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). * Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. * Introduce actual atomics for clear/set_bit() in selftests Documentation: * Remove deleted ioctls from documentation * Various fixes
2022-12-09Merge tag 'kvmarm-6.2' of ↵Paolo Bonzini1-10/+31
https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for 6.2 - Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. - Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on. - Merge the pKVM shadow vcpu state tracking that allows the hypervisor to have its own view of a vcpu, keeping that state private. - Add support for the PMUv3p5 architecture revision, bringing support for 64bit counters on systems that support it, and fix the no-quite-compliant CHAIN-ed counter support for the machines that actually exist out there. - Fix a handful of minor issues around 52bit VA/PA support (64kB pages only) as a prefix of the oncoming support for 4kB and 16kB pages. - Add/Enable/Fix a bunch of selftests covering memslots, breakpoints, stage-2 faults and access tracking. You name it, we got it, we probably broke it. - Pick a small set of documentation and spelling fixes, because no good merge window would be complete without those. As a side effect, this tag also drags: - The 'kvmarm-fixes-6.1-3' tag as a dependency to the dirty-ring series - A shared branch with the arm64 tree that repaints all the system registers to match the ARM ARM's naming, and resulting in interesting conflicts
2022-12-05Merge branch kvm-arm64/mte-map-shared into kvmarm-master/nextMarc Zyngier1-2/+3
* kvm-arm64/mte-map-shared: : . : Update the MTE support to allow the VMM to use shared mappings : to back the memslots exposed to MTE-enabled guests. : : Patches courtesy of Catalin Marinas and Peter Collingbourne. : . : Fix a number of issues with MTE, such as races on the tags : being initialised vs the PG_mte_tagged flag as well as the : lack of support for VM_SHARED when KVM is involved. : : Patches from Catalin Marinas and Peter Collingbourne. : . Documentation: document the ABI changes for KVM_CAP_ARM_MTE KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled arm64: mte: Lock a page for MTE tag initialisation mm: Add PG_arch_3 page flag KVM: arm64: Simplify the sanitise_mte_tags() logic arm64: mte: Fix/clarify the PG_mte_tagged semantics mm: Do not enable PG_arch_2 for all 64-bit architectures Signed-off-by: Marc Zyngier <maz@kernel.org>
2022-12-02KVM: Document the interaction between KVM_CAP_HALT_POLL and halt_poll_nsDavid Matlack1-8/+7
Clarify the existing documentation about how KVM_CAP_HALT_POLL and halt_poll_ns interact to make it clear that VMs using KVM_CAP_HALT_POLL ignore halt_poll_ns. Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20221201195249.3369720-3-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-02Merge tag 'kvm-x86-fixes-6.2-1' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini1-58/+59
Misc KVM x86 fixes and cleanups for 6.2: - One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). - Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. - Clean up the MSR filter docs. - Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. - Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. - Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency.
2022-12-02KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTRJavier Martinez Canillas1-0/+2
The ioctls are missing an architecture property that is present in others. Suggested-by: Sergio Lopez Pascual <slp@redhat.com> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Message-Id: <20221202105011.185147-5-javierm@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-02KVM: Reference to kvm_userspace_memory_region in doc and commentsJavier Martinez Canillas1-1/+1
There are still references to the removed kvm_memory_region data structure but the doc and comments should mention struct kvm_userspace_memory_region instead, since that is what's used by the ioctl that replaced the old one and this data structure support the same set of flags. Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Message-Id: <20221202105011.185147-4-javierm@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-02KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctlJavier Martinez Canillas1-11/+0
The documentation says that the ioctl has been deprecated, but it has been actually removed and the remaining references are just left overs. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Message-Id: <20221202105011.185147-3-javierm@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-02KVM: Delete all references to removed KVM_SET_MEMORY_REGION ioctlJavier Martinez Canillas1-16/+0
The documentation says that the ioctl has been deprecated, but it has been actually removed and the remaining references are just left overs. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Message-Id: <20221202105011.185147-2-javierm@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-12-01KVM: x86: Clean up KVM_CAP_X86_USER_SPACE_MSR documentationSean Christopherson1-16/+24
Clean up the KVM_CAP_X86_USER_SPACE_MSR documentation to eliminate misleading and/or inconsistent verbiage, and to actually document what accesses are intercepted by which flags. - s/will/may since not all #GPs are guaranteed to be intercepted - s/deflect/intercept to align with common KVM terminology - s/user space/userspace to align with the majority of KVM docs - Avoid using "trap" terminology, as KVM exits to userspace _before_ stepping, i.e. doesn't exhibit trap-like behavior - Actually document the flags Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20220831001706.4075399-4-seanjc@google.com
2022-12-01KVM: x86: Reword MSR filtering docs to more precisely define behaviorSean Christopherson1-35/+35
Reword the MSR filtering documentatiion to more precisely define the behavior of filtering using common virtualization terminology. - Explicitly document KVM's behavior when an MSR is denied - s/handled/allowed as there is no guarantee KVM will "handle" the MSR access - Drop the "fall back" terminology, which incorrectly suggests that there is existing KVM behavior to fall back to - Fix an off-by-one error in the range (the end is exclusive) - Call out the interaction between MSR filtering and KVM_CAP_X86_USER_SPACE_MSR's KVM_MSR_EXIT_REASON_FILTER - Delete the redundant paragraph on what '0' and '1' in the bitmap means, it's covered by the sections on KVM_MSR_FILTER_{READ,WRITE} - Delete the clause on x2APIC MSR behavior depending on APIC base, this is covered by stating that KVM follows architectural behavior when emulating/virtualizing MSR accesses Reported-by: Aaron Lewis <aaronlewis@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20220831001706.4075399-3-seanjc@google.com
2022-12-01KVM: x86: Delete documentation for READ|WRITE in KVM_X86_SET_MSR_FILTERSean Christopherson1-7/+0
Delete the paragraph that describes the behavior when both KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE are set for a range. There is nothing special about KVM's handling of this combination, whereas explicitly documenting the combination suggests that there is some magic behavior the user needs to be aware of. Signed-off-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20220831001706.4075399-2-seanjc@google.com
2022-11-30KVM: x86/xen: Allow XEN_RUNSTATE_UPDATE flag behaviour to be configuredDavid Woodhouse1-6/+28
Closer inspection of the Xen code shows that we aren't supposed to be using the XEN_RUNSTATE_UPDATE flag unconditionally. It should be explicitly enabled by guests through the HYPERVISOR_vm_assist hypercall. If we randomly set the top bit of ->state_entry_time for a guest that hasn't asked for it and doesn't expect it, that could make the runtimes fail to add up and confuse the guest. Without the flag it's perfectly safe for a vCPU to read its own vcpu_runstate_info; just not for one vCPU to read *another's*. I briefly pondered adding a word for the whole set of VMASST_TYPE_* flags but the only one we care about for HVM guests is this, so it seemed a bit pointless. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20221127122210.248427-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-11-29Documentation: document the ABI changes for KVM_CAP_ARM_MTEPeter Collingbourne1-2/+3
Document both the restriction on VM_MTE_ALLOWED mappings and the relaxation for shared mappings. Signed-off-by: Peter Collingbourne <pcc@google.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221104011041.290951-9-pcc@google.com
2022-11-23KVM: s390: pv: api documentation for asynchronous destroyClaudio Imbrenda1-4/+37
Add documentation for the new commands added to the KVM_S390_PV_COMMAND ioctl. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20221111170632.77622-3-imbrenda@linux.ibm.com Message-Id: <20221111170632.77622-3-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
2022-11-10KVM: arm64: Enable ring-based dirty memory trackingGavin Shan1-1/+1
Enable ring-based dirty memory tracking on ARM64: - Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL. - Enable CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP. - Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page offset. - Add ARM64 specific kvm_arch_allow_write_without_running_vcpu() to keep the site of saving vgic/its tables out of the no-running-vcpu radar. Signed-off-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110104914.31280-5-gshan@redhat.com
2022-11-10KVM: Support dirty ring in conjunction with bitmapGavin Shan1-7/+27
ARM64 needs to dirty memory outside of a VCPU context when VGIC/ITS is enabled. It's conflicting with that ring-based dirty page tracking always requires a running VCPU context. Introduce a new flavor of dirty ring that requires the use of both VCPU dirty rings and a dirty bitmap. The expectation is that for non-VCPU sources of dirty memory (such as the VGIC/ITS on arm64), KVM writes to the dirty bitmap. Userspace should scan the dirty bitmap before migrating the VM to the target. Use an additional capability to advertise this behavior. The newly added capability (KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP) can't be enabled before KVM_CAP_DIRTY_LOG_RING_ACQ_REL on ARM64. In this way, the newly added capability is treated as an extension of KVM_CAP_DIRTY_LOG_RING_ACQ_REL. Suggested-by: Marc Zyngier <maz@kernel.org> Suggested-by: Peter Xu <peterx@redhat.com> Co-developed-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Gavin Shan <gshan@redhat.com> Acked-by: Peter Xu <peterx@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221110104914.31280-4-gshan@redhat.com
2022-10-03Merge tag 'kvmarm-6.1' of ↵Paolo Bonzini1-2/+15
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 updates for v6.1 - Fixes for single-stepping in the presence of an async exception as well as the preservation of PSTATE.SS - Better handling of AArch32 ID registers on AArch64-only systems - Fixes for the dirty-ring API, allowing it to work on architectures with relaxed memory ordering - Advertise the new kvmarm mailing list - Various minor cleanups and spelling fixes
2022-09-29KVM: Document weakly ordered architecture requirements for dirty ringMarc Zyngier1-2/+15
Now that the kernel can expose to userspace that its dirty ring management relies on explicit ordering, document these new requirements for VMMs to do the right thing. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/r/20220926145120.27974-5-maz@kernel.org