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2023-11-06x86: kvm Require const tsc for RTThomas Gleixner1-0/+8
Non constant TSC is a nightmare on bare metal already, but with virtualization it becomes a complete disaster because the workarounds are horrible latency wise. That's also a preliminary for running RT in a guest on top of a RT host. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2021-10-31Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds3-22/+56
Pull kvm fixes from Paolo Bonzini: - Fixes for s390 interrupt delivery - Fixes for Xen emulator bugs showing up as debug kernel WARNs - Fix another issue with SEV/ES string I/O VMGEXITs * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Take srcu lock in post_kvm_run_save() KVM: SEV-ES: fix another issue with string I/O VMGEXITs KVM: x86/xen: Fix kvm_xen_has_interrupt() sleeping in kvm_vcpu_block() KVM: x86: switch pvclock_gtod_sync_lock to a raw spinlock KVM: s390: preserve deliverable_mask in __airqs_kick_single_vcpu KVM: s390: clear kicked_mask before sleeping again
2021-10-28KVM: x86: Take srcu lock in post_kvm_run_save()David Woodhouse1-0/+8
The Xen interrupt injection for event channels relies on accessing the guest's vcpu_info structure in __kvm_xen_has_interrupt(), through a gfn_to_hva_cache. This requires the srcu lock to be held, which is mostly the case except for this code path: [ 11.822877] WARNING: suspicious RCU usage [ 11.822965] ----------------------------- [ 11.823013] include/linux/kvm_host.h:664 suspicious rcu_dereference_check() usage! [ 11.823131] [ 11.823131] other info that might help us debug this: [ 11.823131] [ 11.823196] [ 11.823196] rcu_scheduler_active = 2, debug_locks = 1 [ 11.823253] 1 lock held by dom:0/90: [ 11.823292] #0: ffff998956ec8118 (&vcpu->mutex){+.+.}, at: kvm_vcpu_ioctl+0x85/0x680 [ 11.823379] [ 11.823379] stack backtrace: [ 11.823428] CPU: 2 PID: 90 Comm: dom:0 Kdump: loaded Not tainted 5.4.34+ #5 [ 11.823496] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 11.823612] Call Trace: [ 11.823645] dump_stack+0x7a/0xa5 [ 11.823681] lockdep_rcu_suspicious+0xc5/0x100 [ 11.823726] __kvm_xen_has_interrupt+0x179/0x190 [ 11.823773] kvm_cpu_has_extint+0x6d/0x90 [ 11.823813] kvm_cpu_accept_dm_intr+0xd/0x40 [ 11.823853] kvm_vcpu_ready_for_interrupt_injection+0x20/0x30 < post_kvm_run_save() inlined here > [ 11.823906] kvm_arch_vcpu_ioctl_run+0x135/0x6a0 [ 11.823947] kvm_vcpu_ioctl+0x263/0x680 Fixes: 40da8ccd724f ("KVM: x86/xen: Add event channel interrupt vector upcall") Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Cc: stable@vger.kernel.org Message-Id: <606aaaf29fca3850a63aa4499826104e77a72346.camel@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-27KVM: SEV-ES: fix another issue with string I/O VMGEXITsPaolo Bonzini1-3/+12
If the guest requests string I/O from the hypervisor via VMGEXIT, SW_EXITINFO2 will contain the REP count. However, sev_es_string_io was incorrectly treating it as the size of the GHCB buffer in bytes. This fixes the "outsw" test in the experimental SEV tests of kvm-unit-tests. Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Reported-by: Marc Orr <marcorr@google.com> Tested-by: Marc Orr <marcorr@google.com> Reviewed-by: Marc Orr <marcorr@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-25KVM: x86/xen: Fix kvm_xen_has_interrupt() sleeping in kvm_vcpu_block()David Woodhouse1-5/+22
In kvm_vcpu_block, the current task is set to TASK_INTERRUPTIBLE before making a final check whether the vCPU should be woken from HLT by any incoming interrupt. This is a problem for the get_user() in __kvm_xen_has_interrupt(), which really shouldn't be sleeping when the task state has already been set. I think it's actually harmless as it would just manifest itself as a spurious wakeup, but it's causing a debug warning: [ 230.963649] do not call blocking ops when !TASK_RUNNING; state=1 set at [<00000000b6bcdbc9>] prepare_to_swait_exclusive+0x30/0x80 Fix the warning by turning it into an *explicit* spurious wakeup. When invoked with !task_is_running(current) (and we might as well add in_atomic() there while we're at it), just return 1 to indicate that an IRQ is pending, which will cause a wakeup and then something will call it again in a context that *can* sleep so it can fault the page back in. Cc: stable@vger.kernel.org Fixes: 40da8ccd724f ("KVM: x86/xen: Add event channel interrupt vector upcall") Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <168bf8c689561da904e48e2ff5ae4713eaef9e2d.camel@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-25KVM: x86: switch pvclock_gtod_sync_lock to a raw spinlockDavid Woodhouse1-14/+14
On the preemption path when updating a Xen guest's runstate times, this lock is taken inside the scheduler rq->lock, which is a raw spinlock. This was shown in a lockdep warning: [ 89.138354] ============================= [ 89.138356] [ BUG: Invalid wait context ] [ 89.138358] 5.15.0-rc5+ #834 Tainted: G S I E [ 89.138360] ----------------------------- [ 89.138361] xen_shinfo_test/2575 is trying to lock: [ 89.138363] ffffa34a0364efd8 (&kvm->arch.pvclock_gtod_sync_lock){....}-{3:3}, at: get_kvmclock_ns+0x1f/0x130 [kvm] [ 89.138442] other info that might help us debug this: [ 89.138444] context-{5:5} [ 89.138445] 4 locks held by xen_shinfo_test/2575: [ 89.138447] #0: ffff972bdc3b8108 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x77/0x6f0 [kvm] [ 89.138483] #1: ffffa34a03662e90 (&kvm->srcu){....}-{0:0}, at: kvm_arch_vcpu_ioctl_run+0xdc/0x8b0 [kvm] [ 89.138526] #2: ffff97331fdbac98 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0xff/0xbd0 [ 89.138534] #3: ffffa34a03662e90 (&kvm->srcu){....}-{0:0}, at: kvm_arch_vcpu_put+0x26/0x170 [kvm] ... [ 89.138695] get_kvmclock_ns+0x1f/0x130 [kvm] [ 89.138734] kvm_xen_update_runstate+0x14/0x90 [kvm] [ 89.138783] kvm_xen_update_runstate_guest+0x15/0xd0 [kvm] [ 89.138830] kvm_arch_vcpu_put+0xe6/0x170 [kvm] [ 89.138870] kvm_sched_out+0x2f/0x40 [kvm] [ 89.138900] __schedule+0x5de/0xbd0 Cc: stable@vger.kernel.org Reported-by: syzbot+b282b65c2c68492df769@syzkaller.appspotmail.com Fixes: 30b5c851af79 ("KVM: x86/xen: Add support for vCPU runstate information") Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <1b02a06421c17993df337493a68ba923f3bd5c0f.camel@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-22Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds4-61/+119
Pull more x86 kvm fixes from Paolo Bonzini: - Cache coherency fix for SEV live migration - Fix for instruction emulation with PKU - fixes for rare delaying of interrupt delivery - fix for SEV-ES buffer overflow * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: SEV-ES: go over the sev_pio_data buffer in multiple passes if needed KVM: SEV-ES: keep INS functions together KVM: x86: remove unnecessary arguments from complete_emulator_pio_in KVM: x86: split the two parts of emulator_pio_in KVM: SEV-ES: clean up kvm_sev_es_ins/outs KVM: x86: leave vcpu->arch.pio.count alone in emulator_pio_in_out KVM: SEV-ES: rename guest_ins_data to sev_pio_data KVM: SEV: Flush cache on non-coherent systems before RECEIVE_UPDATE_DATA KVM: MMU: Reset mmu->pkru_mask to avoid stale data KVM: nVMX: promptly process interrupts delivered while in guest mode KVM: x86: check for interrupts before deciding whether to exit the fast path
2021-10-22KVM: SEV-ES: go over the sev_pio_data buffer in multiple passes if neededPaolo Bonzini1-16/+56
The PIO scratch buffer is larger than a single page, and therefore it is not possible to copy it in a single step to vcpu->arch/pio_data. Bound each call to emulator_pio_in/out to a single page; keep track of how many I/O operations are left in vcpu->arch.sev_pio_count, so that the operation can be restarted in the complete_userspace_io callback. For OUT, this means that the previous kvm_sev_es_outs implementation becomes an iterator of the loop, and we can consume the sev_pio_data buffer before leaving to userspace. For IN, instead, consuming the buffer and decreasing sev_pio_count is always done in the complete_userspace_io callback, because that is when the memcpy is done into sev_pio_data. Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Reported-by: Felix Wilhelm <fwilhelm@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-22KVM: SEV-ES: keep INS functions togetherPaolo Bonzini1-9/+9
Make the diff a little nicer when we actually get to fixing the bug. No functional change intended. Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-22KVM: x86: remove unnecessary arguments from complete_emulator_pio_inPaolo Bonzini1-5/+6
complete_emulator_pio_in can expect that vcpu->arch.pio has been filled in, and therefore does not need the size and count arguments. This makes things nicer when the function is called directly from a complete_userspace_io callback. No functional change intended. Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-22KVM: x86: split the two parts of emulator_pio_inPaolo Bonzini1-17/+28
emulator_pio_in handles both the case where the data is pending in vcpu->arch.pio.count, and the case where I/O has to be done via either an in-kernel device or a userspace exit. For SEV-ES we would like to split these, to identify clearly the moment at which the sev_pio_data is consumed. To this end, create two different functions: __emulator_pio_in fills in vcpu->arch.pio.count, while complete_emulator_pio_in clears it and releases vcpu->arch.pio.data. Because this patch has to be backported, things are left a bit messy. kernel_pio() operates on vcpu->arch.pio, which leads to emulator_pio_in() having with two calls to complete_emulator_pio_in(). It will be fixed in the next release. While at it, remove the unused void* val argument of emulator_pio_in_out. The function currently hardcodes vcpu->arch.pio_data as the source/destination buffer, which sucks but will be fixed after the more severe SEV-ES buffer overflow. No functional change intended. Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-22KVM: SEV-ES: clean up kvm_sev_es_ins/outsPaolo Bonzini1-16/+15
A few very small cleanups to the functions, smushed together because the patch is already very small like this: - inline emulator_pio_in_emulated and emulator_pio_out_emulated, since we already have the vCPU - remove the data argument and pull setting vcpu->arch.sev_pio_data into the caller - remove unnecessary clearing of vcpu->arch.pio.count when emulation is done by the kernel (and therefore vcpu->arch.pio.count is already clear on exit from emulator_pio_in and emulator_pio_out). No functional change intended. Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-22KVM: x86: leave vcpu->arch.pio.count alone in emulator_pio_in_outPaolo Bonzini1-4/+9
Currently emulator_pio_in clears vcpu->arch.pio.count twice if emulator_pio_in_out performs kernel PIO. Move the clear into emulator_pio_out where it is actually necessary. No functional change intended. Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-22KVM: SEV-ES: rename guest_ins_data to sev_pio_dataPaolo Bonzini1-2/+2
We will be using this field for OUTS emulation as well, in case the data that is pushed via OUTS spans more than one page. In that case, there will be a need to save the data pointer across exits to userspace. So, change the name to something that refers to any kind of PIO. Also spell out what it is used for, namely SEV-ES. No functional change intended. Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-21KVM: SEV: Flush cache on non-coherent systems before RECEIVE_UPDATE_DATAMasahiro Kozuka1-0/+7
Flush the destination page before invoking RECEIVE_UPDATE_DATA, as the PSP encrypts the data with the guest's key when writing to guest memory. If the target memory was not previously encrypted, the cache may contain dirty, unecrypted data that will persist on non-coherent systems. Fixes: 15fb7de1a7f5 ("KVM: SVM: Add KVM_SEV_RECEIVE_UPDATE_DATA command") Cc: stable@vger.kernel.org Cc: Peter Gonda <pgonda@google.com> Cc: Marc Orr <marcorr@google.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Masahiro Kozuka <masa.koz@kozuka.jp> [sean: converted bug report to changelog] Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210914210951.2994260-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-21KVM: MMU: Reset mmu->pkru_mask to avoid stale dataChenyi Qiang1-3/+3
When updating mmu->pkru_mask, the value can only be added but it isn't reset in advance. This will make mmu->pkru_mask keep the stale data. Fix this issue. Fixes: 2d344105f57c ("KVM, pkeys: introduce pkru_mask to cache conditions") Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com> Message-Id: <20211021071022.1140-1-chenyi.qiang@intel.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-21KVM: nVMX: promptly process interrupts delivered while in guest modePaolo Bonzini1-11/+6
Since commit c300ab9f08df ("KVM: x86: Replace late check_nested_events() hack with more precise fix") there is no longer the certainty that check_nested_events() tries to inject an external interrupt vmexit to L1 on every call to vcpu_enter_guest. Therefore, even in that case we need to set KVM_REQ_EVENT. This ensures that inject_pending_event() is called, and from there kvm_check_nested_events(). Fixes: c300ab9f08df ("KVM: x86: Replace late check_nested_events() hack with more precise fix") Cc: stable@vger.kernel.org Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-21KVM: x86: check for interrupts before deciding whether to exit the fast pathPaolo Bonzini1-5/+5
The kvm_x86_sync_pir_to_irr callback can sometimes set KVM_REQ_EVENT. If that happens exactly at the time that an exit is handled as EXIT_FASTPATH_REENTER_GUEST, vcpu_enter_guest will go incorrectly through the loop that calls kvm_x86_run, instead of processing the request promptly. Fixes: 379a3c8ee444 ("KVM: VMX: Optimize posted-interrupt delivery for timer fastpath") Cc: stable@vger.kernel.org Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-20Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds5-17/+32
Pull kvm fixes from Paolo Bonzini: "Tools: - kvm_stat: do not show halt_wait_ns since it is not a cumulative statistic x86: - clean ups and fixes for bus lock vmexit and lazy allocation of rmaps - two fixes for SEV-ES (one more coming as soon as I get reviews) - fix for static_key underflow ARM: - Properly refcount pages used as a concatenated stage-2 PGD - Fix missing unlock when detecting the use of MTE+VM_SHARED" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: SEV-ES: reduce ghcb_sa_len to 32 bits KVM: VMX: Remove redundant handling of bus lock vmexit KVM: kvm_stat: do not show halt_wait_ns KVM: x86: WARN if APIC HW/SW disable static keys are non-zero on unload Revert "KVM: x86: Open code necessary bits of kvm_lapic_set_base() at vCPU RESET" KVM: SEV-ES: Set guest_state_protected after VMSA update KVM: X86: fix lazy allocation of rmaps KVM: SEV-ES: fix length of string I/O KVM: arm64: Release mmap_lock when using VM_SHARED with MTE KVM: arm64: Report corrupted refcount at EL2 KVM: arm64: Fix host stage-2 PGD refcount KVM: s390: Function documentation fixes
2021-10-18KVM: SEV-ES: reduce ghcb_sa_len to 32 bitsPaolo Bonzini1-1/+1
The size of the GHCB scratch area is limited to 16 KiB (GHCB_SCRATCH_AREA_LIMIT), so there is no need for it to be a u64. This fixes a build error on 32-bit systems: i686-linux-gnu-ld: arch/x86/kvm/svm/sev.o: in function `sev_es_string_io: sev.c:(.text+0x110f): undefined reference to `__udivdi3' Cc: stable@vger.kernel.org Fixes: 019057bd73d1 ("KVM: SEV-ES: fix length of string I/O") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-18KVM: VMX: Remove redundant handling of bus lock vmexitHao Xiang1-6/+9
Hardware may or may not set exit_reason.bus_lock_detected on BUS_LOCK VM-Exits. Dealing with KVM_RUN_X86_BUS_LOCK in handle_bus_lock_vmexit could be redundant when exit_reason.basic is EXIT_REASON_BUS_LOCK. We can remove redundant handling of bus lock vmexit. Unconditionally Set exit_reason.bus_lock_detected in handle_bus_lock_vmexit(), and deal with KVM_RUN_X86_BUS_LOCK only in vmx_handle_exit(). Signed-off-by: Hao Xiang <hao.xiang@linux.alibaba.com> Message-Id: <1634299161-30101-1-git-send-email-hao.xiang@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-18KVM: x86: WARN if APIC HW/SW disable static keys are non-zero on unloadSean Christopherson1-0/+2
WARN if the static keys used to track if any vCPU has disabled its APIC are left elevated at module exit. Unlike the underflow case, nothing in the static key infrastructure will complain if a key is left elevated, and because an elevated key only affects performance, nothing in KVM will fail if either key is improperly incremented. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211013003554.47705-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-18Revert "KVM: x86: Open code necessary bits of kvm_lapic_set_base() at vCPU ↵Sean Christopherson1-7/+11
RESET" Revert a change to open code bits of kvm_lapic_set_base() when emulating APIC RESET to fix an apic_hw_disabled underflow bug due to arch.apic_base and apic_hw_disabled being unsyncrhonized when the APIC is created. If kvm_arch_vcpu_create() fails after creating the APIC, kvm_free_lapic() will see the initialized-to-zero vcpu->arch.apic_base and decrement apic_hw_disabled without KVM ever having incremented apic_hw_disabled. Using kvm_lapic_set_base() in kvm_lapic_reset() is also desirable for a potential future where KVM supports RESET outside of vCPU creation, in which case all the side effects of kvm_lapic_set_base() are needed, e.g. to handle the transition from x2APIC => xAPIC. Alternatively, KVM could temporarily increment apic_hw_disabled (and call kvm_lapic_set_base() at RESET), but that's a waste of cycles and would impact the performance of other vCPUs and VMs. The other subtle side effect is that updating the xAPIC ID needs to be done at RESET regardless of whether the APIC was previously enabled, i.e. kvm_lapic_reset() needs an explicit call to kvm_apic_set_xapic_id() regardless of whether or not kvm_lapic_set_base() also performs the update. That makes stuffing the enable bit at vCPU creation slightly more palatable, as doing so affects only the apic_hw_disabled key. Opportunistically tweak the comment to explicitly call out the connection between vcpu->arch.apic_base and apic_hw_disabled, and add a comment to call out the need to always do kvm_apic_set_xapic_id() at RESET. Underflow scenario: kvm_vm_ioctl() { kvm_vm_ioctl_create_vcpu() { kvm_arch_vcpu_create() { if (something_went_wrong) goto fail_free_lapic; /* vcpu->arch.apic_base is initialized when something_went_wrong is false. */ kvm_vcpu_reset() { kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event) { vcpu->arch.apic_base = APIC_DEFAULT_PHYS_BASE | MSR_IA32_APICBASE_ENABLE; } } return 0; fail_free_lapic: kvm_free_lapic() { /* vcpu->arch.apic_base is not yet initialized when something_went_wrong is true. */ if (!(vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE)) static_branch_slow_dec_deferred(&apic_hw_disabled); // <= underflow bug. } return r; } } } This (mostly) reverts commit 421221234ada41b4a9f0beeb08e30b07388bd4bd. Fixes: 421221234ada ("KVM: x86: Open code necessary bits of kvm_lapic_set_base() at vCPU RESET") Reported-by: syzbot+9fc046ab2b0cf295a063@syzkaller.appspotmail.com Debugged-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211013003554.47705-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-18KVM: X86: fix lazy allocation of rmapsPaolo Bonzini1-1/+2
If allocation of rmaps fails, but some of the pointers have already been written, those pointers can be cleaned up when the memslot is freed, or even reused later for another attempt at allocating the rmaps. Therefore there is no need to WARN, as done for example in memslot_rmap_alloc, but the allocation *must* be skipped lest KVM will overwrite the previous pointer and will indeed leak memory. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-18KVM: SEV-ES: Set guest_state_protected after VMSA updatePeter Gonda1-1/+6
The refactoring in commit bb18a6777465 ("KVM: SEV: Acquire vcpu mutex when updating VMSA") left behind the assignment to svm->vcpu.arch.guest_state_protected; add it back. Signed-off-by: Peter Gonda <pgonda@google.com> [Delta between v2 and v3 of Peter's patch, which had already been committed; the commit message is my own. - Paolo] Fixes: bb18a6777465 ("KVM: SEV: Acquire vcpu mutex when updating VMSA") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-15KVM: SEV-ES: fix length of string I/OPaolo Bonzini1-1/+1
The size of the data in the scratch buffer is not divided by the size of each port I/O operation, so vcpu->arch.pio.count ends up being larger than it should be by a factor of size. Cc: stable@vger.kernel.org Fixes: 7ed9abfe8e9f ("KVM: SVM: Support string IO operations for an SEV-ES guest") Acked-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-03kvm: fix objtool relocation warningLinus Torvalds1-1/+0
The recent change to make objtool aware of more symbol relocation types (commit 24ff65257375: "objtool: Teach get_alt_entry() about more relocation types") also added another check, and resulted in this objtool warning when building kvm on x86: arch/x86/kvm/emulate.o: warning: objtool: __ex_table+0x4: don't know how to handle reloc symbol type: kvm_fastop_exception The reason seems to be that kvm_fastop_exception() is marked as a global symbol, which causes the relocation to ke kept around for objtool. And at the same time, the kvm_fastop_exception definition (which is done as an inline asm statement) doesn't actually set the type of the global, which then makes objtool unhappy. The minimal fix is to just not mark kvm_fastop_exception as being a global symbol. It's only used in that one compilation unit anyway, so it was always pointless. That's how all the other local exception table labels are done. I'm not entirely happy about the kinds of games that the kvm code plays with doing its own exception handling, and the fact that it confused objtool is most definitely a symptom of the code being a bit too subtle and ad-hoc. But at least this trivial one-liner makes objtool no longer upset about what is going on. Fixes: 24ff65257375 ("objtool: Teach get_alt_entry() about more relocation types") Link: https://lore.kernel.org/lkml/CAHk-=wiZwq-0LknKhXN4M+T8jbxn_2i9mcKpO+OaBSSq_Eh7tg@mail.gmail.com/ Cc: Borislav Petkov <bp@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-30KVM: x86: Swap order of CPUID entry "index" vs. "significant flag" checksSean Christopherson1-2/+2
Check whether a CPUID entry's index is significant before checking for a matching index to hack-a-fix an undefined behavior bug due to consuming uninitialized data. RESET/INIT emulation uses kvm_cpuid() to retrieve CPUID.0x1, which does _not_ have a significant index, and fails to initialize the dummy variable that doubles as EBX/ECX/EDX output _and_ ECX, a.k.a. index, input. Practically speaking, it's _extremely_ unlikely any compiler will yield code that causes problems, as the compiler would need to inline the kvm_cpuid() call to detect the uninitialized data, and intentionally hose the kernel, e.g. insert ud2, instead of simply ignoring the result of the index comparison. Although the sketchy "dummy" pattern was introduced in SVM by commit 66f7b72e1171 ("KVM: x86: Make register state after reset conform to specification"), it wasn't actually broken until commit 7ff6c0350315 ("KVM: x86: Remove stateful CPUID handling") arbitrarily swapped the order of operations such that "index" was checked before the significant flag. Avoid consuming uninitialized data by reverting to checking the flag before the index purely so that the fix can be easily backported; the offending RESET/INIT code has been refactored, moved, and consolidated from vendor code to common x86 since the bug was introduced. A future patch will directly address the bad RESET/INIT behavior. The undefined behavior was detected by syzbot + KernelMemorySanitizer. BUG: KMSAN: uninit-value in cpuid_entry2_find arch/x86/kvm/cpuid.c:68 BUG: KMSAN: uninit-value in kvm_find_cpuid_entry arch/x86/kvm/cpuid.c:1103 BUG: KMSAN: uninit-value in kvm_cpuid+0x456/0x28f0 arch/x86/kvm/cpuid.c:1183 cpuid_entry2_find arch/x86/kvm/cpuid.c:68 [inline] kvm_find_cpuid_entry arch/x86/kvm/cpuid.c:1103 [inline] kvm_cpuid+0x456/0x28f0 arch/x86/kvm/cpuid.c:1183 kvm_vcpu_reset+0x13fb/0x1c20 arch/x86/kvm/x86.c:10885 kvm_apic_accept_events+0x58f/0x8c0 arch/x86/kvm/lapic.c:2923 vcpu_enter_guest+0xfd2/0x6d80 arch/x86/kvm/x86.c:9534 vcpu_run+0x7f5/0x18d0 arch/x86/kvm/x86.c:9788 kvm_arch_vcpu_ioctl_run+0x245b/0x2d10 arch/x86/kvm/x86.c:10020 Local variable ----dummy@kvm_vcpu_reset created at: kvm_vcpu_reset+0x1fb/0x1c20 arch/x86/kvm/x86.c:10812 kvm_apic_accept_events+0x58f/0x8c0 arch/x86/kvm/lapic.c:2923 Reported-by: syzbot+f3985126b746b3d59c9d@syzkaller.appspotmail.com Reported-by: Alexander Potapenko <glider@google.com> Fixes: 2a24be79b6b7 ("KVM: VMX: Set EDX at INIT with CPUID.0x1, Family-Model-Stepping") Fixes: 7ff6c0350315 ("KVM: x86: Remove stateful CPUID handling") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Message-Id: <20210929222426.1855730-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-27KVM: VMX: Fix a TSX_CTRL_CPUID_CLEAR field mask issueZhenzhong Duan1-1/+1
When updating the host's mask for its MSR_IA32_TSX_CTRL user return entry, clear the mask in the found uret MSR instead of vmx->guest_uret_msrs[i]. Modifying guest_uret_msrs directly is completely broken as 'i' does not point at the MSR_IA32_TSX_CTRL entry. In fact, it's guaranteed to be an out-of-bounds accesses as is always set to kvm_nr_uret_msrs in a prior loop. By sheer dumb luck, the fallout is limited to "only" failing to preserve the host's TSX_CTRL_CPUID_CLEAR. The out-of-bounds access is benign as it's guaranteed to clear a bit in a guest MSR value, which are always zero at vCPU creation on both x86-64 and i386. Cc: stable@vger.kernel.org Fixes: 8ea8b8d6f869 ("KVM: VMX: Use common x86's uret MSR list as the one true list") Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210926015545.281083-1-zhenzhong.duan@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-23KVM: X86: Synchronize the shadow pagetable before link itLai Jiangshan2-9/+31
If gpte is changed from non-present to present, the guest doesn't need to flush tlb per SDM. So the host must synchronze sp before link it. Otherwise the guest might use a wrong mapping. For example: the guest first changes a level-1 pagetable, and then links its parent to a new place where the original gpte is non-present. Finally the guest can access the remapped area without flushing the tlb. The guest's behavior should be allowed per SDM, but the host kvm mmu makes it wrong. Fixes: 4731d4c7a077 ("KVM: MMU: out of sync shadow core") Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210918005636.3675-3-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-23KVM: X86: Fix missed remote tlb flush in rmap_write_protect()Lai Jiangshan1-21/+2
When kvm->tlbs_dirty > 0, some rmaps might have been deleted without flushing tlb remotely after kvm_sync_page(). If @gfn was writable before and it's rmaps was deleted in kvm_sync_page(), and if the tlb entry is still in a remote running VCPU, the @gfn is not safely protected. To fix the problem, kvm_sync_page() does the remote flush when needed to avoid the problem. Fixes: a4ee1ca4a36e ("KVM: MMU: delay flush all tlbs on sync_page path") Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210918005636.3675-2-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-23KVM: x86: nSVM: don't copy virt_ext from vmcb12Maxim Levitsky1-1/+0
These field correspond to features that we don't expose yet to L2 While currently there are no CVE worthy features in this field, if AMD adds more features to this field, that could allow guest escapes similar to CVE-2021-3653 and CVE-2021-3656. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210914154825.104886-6-mlevitsk@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-23KVM: x86: nSVM: test eax for 4K alignment for GP errata workaroundMaxim Levitsky1-0/+4
GP SVM errata workaround made the #GP handler always emulate the SVM instructions. However these instructions #GP in case the operand is not 4K aligned, but the workaround code didn't check this and we ended up emulating these instructions anyway. This is only an emulation accuracy check bug as there is no harm for KVM to read/write unaligned vmcb images. Fixes: 82a11e9c6fa2 ("KVM: SVM: Add emulation support for #GP triggered by SVM instructions") Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210914154825.104886-4-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-23KVM: x86: nSVM: restore int_vector in svm_clear_vintrMaxim Levitsky1-0/+2
In svm_clear_vintr we try to restore the virtual interrupt injection that might be pending, but we fail to restore the interrupt vector. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210914154825.104886-2-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22kvm: x86: Add AMD PMU MSRs to msrs_to_save_all[]Fares Mehanna1-0/+7
Intel PMU MSRs is in msrs_to_save_all[], so add AMD PMU MSRs to have a consistent behavior between Intel and AMD when using KVM_GET_MSRS, KVM_SET_MSRS or KVM_GET_MSR_INDEX_LIST. We have to add legacy and new MSRs to handle guests running without X86_FEATURE_PERFCTR_CORE. Signed-off-by: Fares Mehanna <faresx@amazon.de> Message-Id: <20210915133951.22389-1-faresx@amazon.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: nVMX: re-evaluate emulation_required on nested VM exitMaxim Levitsky3-4/+7
If L1 had invalid state on VM entry (can happen on SMM transactions when we enter from real mode, straight to nested guest), then after we load 'host' state from VMCS12, the state has to become valid again, but since we load the segment registers with __vmx_set_segment we weren't always updating emulation_required. Update emulation_required explicitly at end of load_vmcs12_host_state. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210913140954.165665-8-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: nVMX: don't fail nested VM entry on invalid guest state if ↵Maxim Levitsky2-2/+10
!from_vmentry It is possible that when non root mode is entered via special entry (!from_vmentry), that is from SMM or from loading the nested state, the L2 state could be invalid in regard to non unrestricted guest mode, but later it can become valid. (for example when RSM emulation restores segment registers from SMRAM) Thus delay the check to VM entry, where we will check this and fail. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210913140954.165665-7-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: VMX: synthesize invalid VM exit when emulating invalid guest stateMaxim Levitsky1-3/+14
Since no actual VM entry happened, the VM exit information is stale. To avoid this, synthesize an invalid VM guest state VM exit. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210913140954.165665-6-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: nSVM: refactor svm_leave_smm and smm_enter_smmMaxim Levitsky1-66/+69
Use return statements instead of nested if, and fix error path to free all the maps that were allocated. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210913140954.165665-2-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: SVM: call KVM_REQ_GET_NESTED_STATE_PAGES on exit from SMM modeMaxim Levitsky3-5/+9
Currently the KVM_REQ_GET_NESTED_STATE_PAGES on SVM only reloads PDPTRs, and MSR bitmap, with former not really needed for SMM as SMM exit code reloads them again from SMRAM'S CR3, and later happens to work since MSR bitmap isn't modified while in SMM. Still it is better to be consistient with VMX. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210913140954.165665-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: reset pdptrs_from_userspace when exiting smmMaxim Levitsky1-0/+7
When exiting SMM, pdpts are loaded again from the guest memory. This fixes a theoretical bug, when exit from SMM triggers entry to the nested guest which re-uses some of the migration code which uses this flag as a workaround for a legacy userspace. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210913140954.165665-4-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: nSVM: restore the L1 host state prior to resuming nested guest on ↵Maxim Levitsky1-5/+7
SMM exit Otherwise guest entry code might see incorrect L1 state (e.g paging state). Fixes: 37be407b2ce8 ("KVM: nSVM: Fix L1 state corruption upon return from SMM") Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20210913140954.165665-3-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: nVMX: Filter out all unsupported controls when eVMCS was activatedVitaly Kuznetsov2-7/+14
Windows Server 2022 with Hyper-V role enabled failed to boot on KVM when enlightened VMCS is advertised. Debugging revealed there are two exposed secondary controls it is not happy with: SECONDARY_EXEC_ENABLE_VMFUNC and SECONDARY_EXEC_SHADOW_VMCS. These controls are known to be unsupported, as there are no corresponding fields in eVMCSv1 (see the comment above EVMCS1_UNSUPPORTED_2NDEXEC definition). Previously, commit 31de3d2500e4 ("x86/kvm/hyper-v: move VMX controls sanitization out of nested_enable_evmcs()") introduced the required filtering mechanism for VMX MSRs but for some reason put only known to be problematic (and not full EVMCS1_UNSUPPORTED_* lists) controls there. Note, Windows Server 2022 seems to have gained some sanity check for VMX MSRs: it doesn't even try to launch a guest when there's something it doesn't like, nested_evmcs_check_controls() mechanism can't catch the problem. Let's be bold this time and instead of playing whack-a-mole just filter out all unsupported controls from VMX MSRs. Fixes: 31de3d2500e4 ("x86/kvm/hyper-v: move VMX controls sanitization out of nested_enable_evmcs()") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210907163530.110066-1-vkuznets@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect()Vitaly Kuznetsov1-5/+5
KASAN reports the following issue: BUG: KASAN: stack-out-of-bounds in kvm_make_vcpus_request_mask+0x174/0x440 [kvm] Read of size 8 at addr ffffc9001364f638 by task qemu-kvm/4798 CPU: 0 PID: 4798 Comm: qemu-kvm Tainted: G X --------- --- Hardware name: AMD Corporation DAYTONA_X/DAYTONA_X, BIOS RYM0081C 07/13/2020 Call Trace: dump_stack+0xa5/0xe6 print_address_description.constprop.0+0x18/0x130 ? kvm_make_vcpus_request_mask+0x174/0x440 [kvm] __kasan_report.cold+0x7f/0x114 ? kvm_make_vcpus_request_mask+0x174/0x440 [kvm] kasan_report+0x38/0x50 kasan_check_range+0xf5/0x1d0 kvm_make_vcpus_request_mask+0x174/0x440 [kvm] kvm_make_scan_ioapic_request_mask+0x84/0xc0 [kvm] ? kvm_arch_exit+0x110/0x110 [kvm] ? sched_clock+0x5/0x10 ioapic_write_indirect+0x59f/0x9e0 [kvm] ? static_obj+0xc0/0xc0 ? __lock_acquired+0x1d2/0x8c0 ? kvm_ioapic_eoi_inject_work+0x120/0x120 [kvm] The problem appears to be that 'vcpu_bitmap' is allocated as a single long on stack and it should really be KVM_MAX_VCPUS long. We also seem to clear the lower 16 bits of it with bitmap_zero() for no particular reason (my guess would be that 'bitmap' and 'vcpu_bitmap' variables in kvm_bitmap_or_dest_vcpus() caused the confusion: while the later is indeed 16-bit long, the later should accommodate all possible vCPUs). Fixes: 7ee30bc132c6 ("KVM: x86: deliver KVM IOAPIC scan request to target vCPUs") Fixes: 9a2ae9f6b6bb ("KVM: x86: Zero the IOAPIC scan request dest vCPUs bitmap") Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210827092516.1027264-7-vkuznets@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: SEV: Allow some commands for mirror VMPeter Gonda1-2/+17
A mirrored SEV-ES VM will need to call KVM_SEV_LAUNCH_UPDATE_VMSA to setup its vCPUs and have them measured, and their VMSAs encrypted. Without this change, it is impossible to have mirror VMs as part of SEV-ES VMs. Also allow the guest status check and debugging commands since they do not change any guest state. Signed-off-by: Peter Gonda <pgonda@google.com> Cc: Marc Orr <marcorr@google.com> Cc: Nathan Tempelman <natet@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Steve Rutherford <srutherford@google.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Fixes: 54526d1fd593 ("KVM: x86: Support KVM VMs sharing SEV context", 2021-04-21) Message-Id: <20210921150345.2221634-3-pgonda@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: SEV: Update svm_vm_copy_asid_from for SEV-ESPeter Gonda1-4/+12
For mirroring SEV-ES the mirror VM will need more then just the ASID. The FD and the handle are required to all the mirror to call psp commands. The mirror VM will need to call KVM_SEV_LAUNCH_UPDATE_VMSA to setup its vCPUs' VMSAs for SEV-ES. Signed-off-by: Peter Gonda <pgonda@google.com> Cc: Marc Orr <marcorr@google.com> Cc: Nathan Tempelman <natet@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Steve Rutherford <srutherford@google.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Fixes: 54526d1fd593 ("KVM: x86: Support KVM VMs sharing SEV context", 2021-04-21) Message-Id: <20210921150345.2221634-2-pgonda@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: nVMX: Fix nested bus lock VM exitChenyi Qiang1-0/+6
Nested bus lock VM exits are not supported yet. If L2 triggers bus lock VM exit, it will be directed to L1 VMM, which would cause unexpected behavior. Therefore, handle L2's bus lock VM exits in L0 directly. Fixes: fe6b6bc802b4 ("KVM: VMX: Enable bus lock VM exit") Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> Message-Id: <20210914095041.29764-1-chenyi.qiang@intel.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: Identify vCPU0 by its vcpu_idx instead of its vCPUs array entrySean Christopherson1-1/+1
Use vcpu_idx to identify vCPU0 when updating HyperV's TSC page, which is shared by all vCPUs and "owned" by vCPU0 (because vCPU0 is the only vCPU that's guaranteed to exist). Using kvm_get_vcpu() to find vCPU works, but it's a rather odd and suboptimal method to check the index of a given vCPU. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210910183220.2397812-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22KVM: x86: Query vcpu->vcpu_idx directly and drop its accessorSean Christopherson2-5/+4
Read vcpu->vcpu_idx directly instead of bouncing through the one-line wrapper, kvm_vcpu_get_idx(), and drop the wrapper. The wrapper is a remnant of the original implementation and serves no purpose; remove it before it gains more users. Back when kvm_vcpu_get_idx() was added by commit 497d72d80a78 ("KVM: Add kvm_vcpu_get_idx to get vcpu index in kvm->vcpus"), the implementation was more than just a simple wrapper as vcpu->vcpu_idx did not exist and retrieving the index meant walking over the vCPU array to find the given vCPU. When vcpu_idx was introduced by commit 8750e72a79dd ("KVM: remember position in kvm->vcpus array"), the helper was left behind, likely to avoid extra thrash (but even then there were only two users, the original arm usage having been removed at some point in the past). No functional change intended. Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20210910183220.2397812-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22kvm: fix wrong exception emulation in check_rdtscHou Wenlong1-1/+1
According to Intel's SDM Vol2 and AMD's APM Vol3, when CR4.TSD is set, use rdtsc/rdtscp instruction above privilege level 0 should trigger a #GP. Fixes: d7eb82030699e ("KVM: SVM: Add intercept checks for remaining group7 instructions") Signed-off-by: Hou Wenlong <houwenlong93@linux.alibaba.com> Message-Id: <1297c0dd3f1bb47a6d089f850b629c7aa0247040.1629257115.git.houwenlong93@linux.alibaba.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
generated by cgit v1.2.3 (git 2.39.0) at 2025-09-03 14:19:02 +0300