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2022-01-22Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds4-301/+331
Pull more kvm updates from Paolo Bonzini: "Generic: - selftest compilation fix for non-x86 - KVM: avoid warning on s390 in mark_page_dirty x86: - fix page write-protection bug and improve comments - use binary search to lookup the PMU event filter, add test - enable_pmu module parameter support for Intel CPUs - switch blocked_vcpu_on_cpu_lock to raw spinlock - cleanups of blocked vCPU logic - partially allow KVM_SET_CPUID{,2} after KVM_RUN (5.16 regression) - various small fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (46 commits) docs: kvm: fix WARNINGs from api.rst selftests: kvm/x86: Fix the warning in lib/x86_64/processor.c selftests: kvm/x86: Fix the warning in pmu_event_filter_test.c kvm: selftests: Do not indent with spaces kvm: selftests: sync uapi/linux/kvm.h with Linux header selftests: kvm: add amx_test to .gitignore KVM: SVM: Nullify vcpu_(un)blocking() hooks if AVIC is disabled KVM: SVM: Move svm_hardware_setup() and its helpers below svm_x86_ops KVM: SVM: Drop AVIC's intermediate avic_set_running() helper KVM: VMX: Don't do full kick when handling posted interrupt wakeup KVM: VMX: Fold fallback path into triggering posted IRQ helper KVM: VMX: Pass desired vector instead of bool for triggering posted IRQ KVM: VMX: Don't do full kick when triggering posted interrupt "fails" KVM: SVM: Skip AVIC and IRTE updates when loading blocking vCPU KVM: SVM: Use kvm_vcpu_is_blocking() in AVIC load to handle preemption KVM: SVM: Remove unnecessary APICv/AVIC update in vCPU unblocking path KVM: SVM: Don't bother checking for "running" AVIC when kicking for IPIs KVM: SVM: Signal AVIC doorbell iff vCPU is in guest mode KVM: x86: Remove defunct pre_block/post_block kvm_x86_ops hooks KVM: x86: Unexport LAPIC's switch_to_{hv,sw}_timer() helpers ...
2022-01-19KVM: SVM: Nullify vcpu_(un)blocking() hooks if AVIC is disabledSean Christopherson3-6/+9
Nullify svm_x86_ops.vcpu_(un)blocking if AVIC/APICv is disabled as the hooks are necessary only to clear the vCPU's IsRunning entry in the Physical APIC and to update IRTE entries if the VM has a pass-through device attached. Opportunistically rename the helpers to clarify their AVIC relationship. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211208015236.1616697-24-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Move svm_hardware_setup() and its helpers below svm_x86_opsSean Christopherson1-233/+234
Move svm_hardware_setup() below svm_x86_ops so that KVM can modify ops during setup, e.g. the vcpu_(un)blocking hooks can be nullified if AVIC is disabled or unsupported. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211208015236.1616697-23-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Drop AVIC's intermediate avic_set_running() helperSean Christopherson1-20/+36
Drop avic_set_running() in favor of calling avic_vcpu_{load,put}() directly, and modify the block+put path to use preempt_disable/enable() instead of get/put_cpu(), as it doesn't actually care about the current pCPU associated with the vCPU. Opportunistically add lockdep assertions as being preempted in avic_vcpu_put() would lead to consuming stale data, even though doing so _in the current code base_ would not be fatal. Add a much needed comment explaining why svm_vcpu_blocking() needs to unload the AVIC and update the IRTE _before_ the vCPU starts blocking. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211208015236.1616697-22-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Skip AVIC and IRTE updates when loading blocking vCPUSean Christopherson1-14/+18
Don't bother updating the Physical APIC table or IRTE when loading a vCPU that is blocking, i.e. won't be marked IsRun{ning}=1, as the pCPU is queried if and only if IsRunning is '1'. If the vCPU was migrated, the new pCPU will be picked up when avic_vcpu_load() is called by svm_vcpu_unblocking(). Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211208015236.1616697-15-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Use kvm_vcpu_is_blocking() in AVIC load to handle preemptionSean Christopherson3-12/+9
Use kvm_vcpu_is_blocking() to determine whether or not the vCPU should be marked running during avic_vcpu_load(). Drop avic_is_running, which really should have been named "vcpu_is_not_blocking", as it tracked if the vCPU was blocking, not if it was actually running, e.g. it was set during svm_create_vcpu() when the vCPU was obviously not running. This is technically a teeny tiny functional change, as the vCPU will be marked IsRunning=1 on being reloaded if the vCPU is preempted between svm_vcpu_blocking() and prepare_to_rcuwait(). But that's a benign change as the vCPU will be marked IsRunning=0 when KVM voluntarily schedules out the vCPU. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211208015236.1616697-14-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Remove unnecessary APICv/AVIC update in vCPU unblocking pathSean Christopherson1-2/+0
Remove handling of KVM_REQ_APICV_UPDATE from svm_vcpu_unblocking(), it's no longer needed as it was made obsolete by commit df7e4827c549 ("KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC"). Prior to that commit, the manual check was necessary to ensure the AVIC stuff was updated by avic_set_running() when a request to enable APICv became pending while the vCPU was blocking, as the request handling itself would not do the update. But, as evidenced by the commit, that logic was flawed and subject to various races. Now that svm_refresh_apicv_exec_ctrl() does avic_vcpu_load/put() in response to an APICv status change, drop the manual check in the unblocking path. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211208015236.1616697-13-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Don't bother checking for "running" AVIC when kicking for IPIsSean Christopherson2-17/+9
Drop the avic_vcpu_is_running() check when waking vCPUs in response to a VM-Exit due to incomplete IPI delivery. The check isn't wrong per se, but it's not 100% accurate in the sense that it doesn't guarantee that the vCPU was one of the vCPUs that didn't receive the IPI. The check isn't required for correctness as blocking == !running in this context. From a performance perspective, waking a live task is not expensive as the only moderately costly operation is a locked operation to temporarily disable preemption. And if that is indeed a performance issue, kvm_vcpu_is_blocking() would be a better check than poking into the AVIC. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20211208015236.1616697-12-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: SVM: Signal AVIC doorbell iff vCPU is in guest modeSean Christopherson1-2/+20
Signal the AVIC doorbell iff the vCPU is running in the guest. If the vCPU is not IN_GUEST_MODE, it's guaranteed to pick up any pending IRQs on the next VMRUN, which unconditionally processes the vIRR. Add comments to document the logic. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211208015236.1616697-11-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19Merge branch 'kvm-pi-raw-spinlock' into HEADPaolo Bonzini1-1/+1
Bring in fix for VT-d posted interrupts before further changing the code in 5.17. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-19KVM: VMX: Reject KVM_RUN if emulation is required with pending exceptionSean Christopherson1-0/+6
Reject KVM_RUN if emulation is required (because VMX is running without unrestricted guest) and an exception is pending, as KVM doesn't support emulating exceptions except when emulating real mode via vm86. The vCPU is hosed either way, but letting KVM_RUN proceed triggers a WARN due to the impossible condition. Alternatively, the WARN could be removed, but then userspace and/or KVM bugs would result in the vCPU silently running in a bad state, which isn't very friendly to users. Originally, the bug was hit by syzkaller with a nested guest as that doesn't require kvm_intel.unrestricted_guest=0. That particular flavor is likely fixed by commit cd0e615c49e5 ("KVM: nVMX: Synthesize TRIPLE_FAULT for L2 if emulation is required"), but it's trivial to trigger the WARN with a non-nested guest, and userspace can likely force bad state via ioctls() for a nested guest as well. Checking for the impossible condition needs to be deferred until KVM_RUN because KVM can't force specific ordering between ioctls. E.g. clearing exception.pending in KVM_SET_SREGS doesn't prevent userspace from setting it in KVM_SET_VCPU_EVENTS, and disallowing KVM_SET_VCPU_EVENTS with emulation_required would prevent userspace from queuing an exception and then stuffing sregs. Note, if KVM were to try and detect/prevent the condition prior to KVM_RUN, handle_invalid_guest_state() and/or handle_emulation_failure() would need to be modified to clear the pending exception prior to exiting to userspace. ------------[ cut here ]------------ WARNING: CPU: 6 PID: 137812 at arch/x86/kvm/vmx/vmx.c:1623 vmx_queue_exception+0x14f/0x160 [kvm_intel] CPU: 6 PID: 137812 Comm: vmx_invalid_nes Not tainted 5.15.2-7cc36c3e14ae-pop #279 Hardware name: ASUS Q87M-E/Q87M-E, BIOS 1102 03/03/2014 RIP: 0010:vmx_queue_exception+0x14f/0x160 [kvm_intel] Code: <0f> 0b e9 fd fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 RSP: 0018:ffffa45c83577d38 EFLAGS: 00010202 RAX: 0000000000000003 RBX: 0000000080000006 RCX: 0000000000000006 RDX: 0000000000000000 RSI: 0000000000010002 RDI: ffff9916af734000 RBP: ffff9916af734000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000006 R13: 0000000000000000 R14: ffff9916af734038 R15: 0000000000000000 FS: 00007f1e1a47c740(0000) GS:ffff99188fb80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1e1a6a8008 CR3: 000000026f83b005 CR4: 00000000001726e0 Call Trace: kvm_arch_vcpu_ioctl_run+0x13a2/0x1f20 [kvm] kvm_vcpu_ioctl+0x279/0x690 [kvm] __x64_sys_ioctl+0x83/0xb0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported-by: syzbot+82112403ace4cbd780d8@syzkaller.appspotmail.com Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211228232437.1875318-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-17KVM: x86: Making the module parameter of vPMU more commonLike Xu3-8/+3
The new module parameter to control PMU virtualization should apply to Intel as well as AMD, for situations where userspace is not trusted. If the module parameter allows PMU virtualization, there could be a new KVM_CAP or guest CPUID bits whereby userspace can enable/disable PMU virtualization on a per-VM basis. If the module parameter does not allow PMU virtualization, there should be no userspace override, since we have no precedent for authorizing that kind of override. If it's false, other counter-based profiling features (such as LBR including the associated CPUID bits if any) will not be exposed. Change its name from "pmu" to "enable_pmu" as we have temporary variables with the same name in our code like "struct kvm_pmu *pmu". Fixes: b1d66dad65dc ("KVM: x86/svm: Add module param to control PMU virtualization") Suggested-by : Jim Mattson <jmattson@google.com> Signed-off-by: Like Xu <likexu@tencent.com> Message-Id: <20220111073823.21885-1-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-16Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds6-139/+308
Pull kvm updates from Paolo Bonzini: "RISCV: - Use common KVM implementation of MMU memory caches - SBI v0.2 support for Guest - Initial KVM selftests support - Fix to avoid spurious virtual interrupts after clearing hideleg CSR - Update email address for Anup and Atish ARM: - Simplification of the 'vcpu first run' by integrating it into KVM's 'pid change' flow - Refactoring of the FP and SVE state tracking, also leading to a simpler state and less shared data between EL1 and EL2 in the nVHE case - Tidy up the header file usage for the nvhe hyp object - New HYP unsharing mechanism, finally allowing pages to be unmapped from the Stage-1 EL2 page-tables - Various pKVM cleanups around refcounting and sharing - A couple of vgic fixes for bugs that would trigger once the vcpu xarray rework is merged, but not sooner - Add minimal support for ARMv8.7's PMU extension - Rework kvm_pgtable initialisation ahead of the NV work - New selftest for IRQ injection - Teach selftests about the lack of default IPA space and page sizes - Expand sysreg selftest to deal with Pointer Authentication - The usual bunch of cleanups and doc update s390: - fix sigp sense/start/stop/inconsistency - cleanups x86: - Clean up some function prototypes more - improved gfn_to_pfn_cache with proper invalidation, used by Xen emulation - add KVM_IRQ_ROUTING_XEN_EVTCHN and event channel delivery - completely remove potential TOC/TOU races in nested SVM consistency checks - update some PMCs on emulated instructions - Intel AMX support (joint work between Thomas and Intel) - large MMU cleanups - module parameter to disable PMU virtualization - cleanup register cache - first part of halt handling cleanups - Hyper-V enlightened MSR bitmap support for nested hypervisors Generic: - clean up Makefiles - introduce CONFIG_HAVE_KVM_DIRTY_RING - optimize memslot lookup using a tree - optimize vCPU array usage by converting to xarray" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (268 commits) x86/fpu: Fix inline prefix warnings selftest: kvm: Add amx selftest selftest: kvm: Move struct kvm_x86_state to header selftest: kvm: Reorder vcpu_load_state steps for AMX kvm: x86: Disable interception for IA32_XFD on demand x86/fpu: Provide fpu_sync_guest_vmexit_xfd_state() kvm: selftests: Add support for KVM_CAP_XSAVE2 kvm: x86: Add support for getting/setting expanded xstate buffer x86/fpu: Add uabi_size to guest_fpu kvm: x86: Add CPUID support for Intel AMX kvm: x86: Add XCR0 support for Intel AMX kvm: x86: Disable RDMSR interception of IA32_XFD_ERR kvm: x86: Emulate IA32_XFD_ERR for guest kvm: x86: Intercept #NM for saving IA32_XFD_ERR x86/fpu: Prepare xfd_err in struct fpu_guest kvm: x86: Add emulation for IA32_XFD x86/fpu: Provide fpu_update_guest_xfd() for IA32_XFD emulation kvm: x86: Enable dynamic xfeatures at KVM_SET_CPUID2 x86/fpu: Provide fpu_enable_guest_xfd_features() for KVM x86/fpu: Add guest support to xfd_enable_feature() ...
2022-01-13Merge tag 'x86_core_for_v5.17_rc1' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Borislav Petkov: - Get rid of all the .fixup sections because this generates misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and LIVEPATCH as the backtrace misses the function which is being fixed up. - Add Straight Line Speculation mitigation support which uses a new compiler switch -mharden-sls= which sticks an INT3 after a RET or an indirect branch in order to block speculation after them. Reportedly, CPUs do speculate behind such insns. - The usual set of cleanups and improvements * tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) x86/entry_32: Fix segment exceptions objtool: Remove .fixup handling x86: Remove .fixup section x86/word-at-a-time: Remove .fixup usage x86/usercopy: Remove .fixup usage x86/usercopy_32: Simplify __copy_user_intel_nocache() x86/sgx: Remove .fixup usage x86/checksum_32: Remove .fixup usage x86/vmx: Remove .fixup usage x86/kvm: Remove .fixup usage x86/segment: Remove .fixup usage x86/fpu: Remove .fixup usage x86/xen: Remove .fixup usage x86/uaccess: Remove .fixup usage x86/futex: Remove .fixup usage x86/msr: Remove .fixup usage x86/extable: Extend extable functionality x86/entry_32: Remove .fixup usage x86/entry_64: Remove .fixup usage x86/copy_mc_64: Remove .fixup usage ...
2022-01-13Merge tag 'perf_core_for_v5.17_rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Borislav Petkov: "Cleanup of the perf/kvm interaction." * tag 'perf_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Drop guest callback (un)register stubs KVM: arm64: Drop perf.c and fold its tiny bits of code into arm.c KVM: arm64: Hide kvm_arm_pmu_available behind CONFIG_HW_PERF_EVENTS=y KVM: arm64: Convert to the generic perf callbacks KVM: x86: Move Intel Processor Trace interrupt handler to vmx.c KVM: Move x86's perf guest info callbacks to generic KVM KVM: x86: More precisely identify NMI from guest when handling PMI KVM: x86: Drop current_vcpu for kvm_running_vcpu + kvm_arch_vcpu variable perf/core: Use static_call to optimize perf_guest_info_callbacks perf: Force architectures to opt-in to guest callbacks perf: Add wrappers for invoking guest callbacks perf/core: Rework guest callbacks to prepare for static_call support perf: Drop dead and useless guest "support" from arm, csky, nds32 and riscv perf: Stop pretending that perf can handle multiple guest callbacks KVM: x86: Register Processor Trace interrupt hook iff PT enabled in guest KVM: x86: Register perf callbacks after calling vendor's hardware_setup() perf: Protect perf_guest_cbs with RCU
2022-01-07KVM: SEV: Mark nested locking of kvm->lockWanpeng Li1-1/+1
Both source and dest vms' kvm->locks are held in sev_lock_two_vms. Mark one with a different subtype to avoid false positives from lockdep. Fixes: c9d61dcb0bc26 (KVM: SEV: accept signals in sev_lock_two_vms) Reported-by: Yiru Xu <xyru1999@gmail.com> Tested-by: Jinrong Liang <cloudliang@tencent.com> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Message-Id: <1641364863-26331-1-git-send-email-wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-07KVM: SVM: include CR3 in initial VMSA state for SEV-ES guestsMichael Roth1-0/+19
Normally guests will set up CR3 themselves, but some guests, such as kselftests, and potentially CONFIG_PVH guests, rely on being booted with paging enabled and CR3 initialized to a pre-allocated page table. Currently CR3 updates via KVM_SET_SREGS* are not loaded into the guest VMCB until just prior to entering the guest. For SEV-ES/SEV-SNP, this is too late, since it will have switched over to using the VMSA page prior to that point, with the VMSA CR3 copied from the VMCB initial CR3 value: 0. Address this by sync'ing the CR3 value into the VMCB save area immediately when KVM_SET_SREGS* is issued so it will find it's way into the initial VMSA. Suggested-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Michael Roth <michael.roth@amd.com> Message-Id: <20211216171358.61140-10-michael.roth@amd.com> [Remove vmx_post_set_cr3; add a remark about kvm_set_cr3 not calling the new hook. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-07KVM: x86/pmu: Reuse pmc_perf_hw_id() and drop find_fixed_event()Like Xu1-7/+4
Since we set the same semantic event value for the fixed counter in pmc->eventsel, returning the perf_hw_id for the fixed counter via find_fixed_event() can be painlessly replaced by pmc_perf_hw_id() with the help of pmc_is_fixed() check. Signed-off-by: Like Xu <likexu@tencent.com> Message-Id: <20211130074221.93635-4-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-07KVM: x86/pmu: Refactoring find_arch_event() to pmc_perf_hw_id()Like Xu1-4/+4
The find_arch_event() returns a "unsigned int" value, which is used by the pmc_reprogram_counter() to program a PERF_TYPE_HARDWARE type perf_event. The returned value is actually the kernel defined generic perf_hw_id, let's rename it to pmc_perf_hw_id() with simpler incoming parameters for better self-explanation. Signed-off-by: Like Xu <likexu@tencent.com> Message-Id: <20211130074221.93635-3-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-21Merge remote-tracking branch 'kvm/master' into HEADPaolo Bonzini1-9/+12
Pick commit fdba608f15e2 ("KVM: VMX: Wake vCPU when delivering posted IRQ even if vCPU == this vCPU"). In addition to fixing a bug, it also aligns the non-nested and nested usage of triggering posted interrupts, allowing for additional cleanups. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-20KVM: x86: Always set kvm_run->if_flagMarc Orr1-9/+12
The kvm_run struct's if_flag is a part of the userspace/kernel API. The SEV-ES patches failed to set this flag because it's no longer needed by QEMU (according to the comment in the source code). However, other hypervisors may make use of this flag. Therefore, set the flag for guests with encrypted registers (i.e., with guest_state_protected set). Fixes: f1c6366e3043 ("KVM: SVM: Add required changes to support intercepts under SEV-ES") Signed-off-by: Marc Orr <marcorr@google.com> Message-Id: <20211209155257.128747-1-marcorr@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
2021-12-08x86: Prepare asm files for straight-line-speculationPeter Zijlstra1-2/+2
Replace all ret/retq instructions with RET in preparation of making RET a macro. Since AS is case insensitive it's a big no-op without RET defined. find arch/x86/ -name \*.S | while read file do sed -i 's/\<ret[q]*\>/RET/' $file done Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/20211204134907.905503893@infradead.org
2021-12-08KVM: X86: Remove mmu parameter from load_pdptrs()Lai Jiangshan2-3/+3
It uses vcpu->arch.walk_mmu always; nested EPT does not have PDPTRs, and nested NPT treats them like all other non-leaf page table levels instead of caching them. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Message-Id: <20211124122055.64424-11-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: SVM: Allocate sd->save_area with __GFP_ZEROLai Jiangshan1-3/+1
And remove clear_page() on it. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Message-Id: <20211118110814.2568-10-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: SVM: Rename get_max_npt_level() to get_npt_level()Lai Jiangshan1-4/+4
It returns the only proper NPT level, so the "max" in the name is not appropriate. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Message-Id: <20211118110814.2568-9-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: vmx, svm: clean up mass updates to regs_avail/regs_dirty bitsPaolo Bonzini2-1/+12
Document the meaning of the three combinations of regs_avail and regs_dirty. Update regs_dirty just after writeback instead of doing it later after vmexit. After vmexit, instead, we clear the regs_avail bits corresponding to lazily-loaded registers. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: SVM: Remove references to VCPU_EXREG_CR3Lai Jiangshan2-3/+0
VCPU_EXREG_CR3 is never cleared from vcpu->arch.regs_avail or vcpu->arch.regs_dirty in SVM; therefore, marking CR3 as available is merely a NOP, and testing it will likewise always succeed. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Message-Id: <20211108124407.12187-9-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: SVM: Remove outdated comment in svm_load_mmu_pgd()Lai Jiangshan1-1/+0
The comment had been added in the commit 689f3bf21628 ("KVM: x86: unify callbacks to load paging root") and its related code was removed later, and it has nothing to do with the next line of code. So the comment should be removed too. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Message-Id: <20211108124407.12187-8-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: SVM: Track dirtiness of PDPTRs even if NPT is disabledLai Jiangshan1-4/+9
Use the same logic to handle the availability of VCPU_EXREG_PDPTR as VMX, also removing a branch in svm_vcpu_run(). Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Message-Id: <20211108124407.12187-4-jiangshanlai@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: x86/svm: Add module param to control PMU virtualizationLike Xu3-0/+16
For Intel, the guest PMU can be disabled via clearing the PMU CPUID. For AMD, all hw implementations support the base set of four performance counters, with current mainstream hardware indicating the presence of two additional counters via X86_FEATURE_PERFCTR_CORE. In the virtualized world, the AMD guest driver may detect the presence of at least one counter MSR. Most hypervisor vendors would introduce a module param (like lbrv for svm) to disable PMU for all guests. Another control proposal per-VM is to pass PMU disable information via MSR_IA32_PERF_CAPABILITIES or one bit in CPUID Fn4000_00[FF:00]. Both of methods require some guest-side changes, so a module parameter may not be sufficiently granular, but practical enough. Signed-off-by: Like Xu <likexu@tencent.com> Message-Id: <20211117080304.38989-1-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: SVM: Ensure target pCPU is read once when signalling AVIC doorbellSean Christopherson1-3/+11
Ensure vcpu->cpu is read once when signalling the AVIC doorbell. If the compiler rereads the field and the vCPU is migrated between the check and writing the doorbell, KVM would signal the wrong physical CPU. Functionally, signalling the wrong CPU in this case is not an issue as task migration means the vCPU has exited and will pick up any pending interrupts on the next VMRUN. Add the READ_ONCE() purely to clean up the code. Opportunistically add a comment explaining the task migration behavior, and rename cpuid=>cpu to avoid conflating the CPU number with KVM's more common usage of CPUID. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211009021236.4122790-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: introduce struct vmcb_ctrl_area_cachedEmanuele Giuseppe Esposito3-23/+103
This structure will replace vmcb_control_area in svm_nested_state, providing only the fields that are actually used by the nested state. This avoids having and copying around uninitialized fields. The cost of this, however, is that all functions (in this case vmcb_is_intercept) expect the old structure, so they need to be duplicated. In addition, in svm_get_nested_state() user space expects a vmcb_control_area struct, so we need to copy back all fields in a temporary structure before copying it to userspace. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20211103140527.752797-7-eesposit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: split out __nested_vmcb_check_controlsPaolo Bonzini1-4/+12
Remove the struct vmcb_control_area parameter from nested_vmcb_check_controls, for consistency with the functions that operate on the save area. This way, VMRUN uses the version without underscores for both areas, while KVM_SET_NESTED_STATE uses the version with underscores. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: use svm->nested.save to load vmcb12 registers and avoid TOC/TOU racesEmanuele Giuseppe Esposito1-18/+6
Use the already checked svm->nested.save cached fields (EFER, CR0, CR4, ...) instead of vmcb12's in nested_vmcb02_prepare_save(). This prevents from creating TOC/TOU races, since the guest could modify the vmcb12 fields. This also avoids the need of force-setting EFER_SVME in nested_vmcb02_prepare_save. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20211103140527.752797-6-eesposit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: use vmcb_save_area_cached in nested_vmcb_valid_sregs()Emanuele Giuseppe Esposito1-4/+14
Now that struct vmcb_save_area_cached contains the required vmcb fields values (done in nested_load_save_from_vmcb12()), check them to see if they are correct in nested_vmcb_valid_sregs(). While at it, rename nested_vmcb_valid_sregs in nested_vmcb_check_save. __nested_vmcb_check_save takes the additional @save parameter, so it is helpful when we want to check a non-svm save state, like in svm_set_nested_state. The reason for that is that save is the L1 state, not L2, so we check it without moving it to svm->nested.save. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20211103140527.752797-5-eesposit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: rename nested_load_control_from_vmcb12 in ↵Emanuele Giuseppe Esposito3-43/+43
nested_copy_vmcb_control_to_cache Following the same naming convention of the previous patch, rename nested_load_control_from_vmcb12. In addition, inline copy_vmcb_control_area as it is only called by this function. __nested_copy_vmcb_control_to_cache() works with vmcb_control_area parameters and it will be useful in next patches, when we use local variables instead of svm cached state. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20211103140527.752797-4-eesposit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: introduce svm->nested.save to cache save area before checksEmanuele Giuseppe Esposito3-0/+41
This is useful in the next patch, to keep a saved copy of vmcb12 registers and pass it around more easily. Instead of blindly copying everything, we just copy EFER, CR0, CR3, CR4, DR6 and DR7 which are needed by the VMRUN checks. If more fields will need to be checked, it will be quite obvious to see that they must be added in struct vmcb_save_area_cached and in nested_copy_vmcb_save_to_cache(). __nested_copy_vmcb_save_to_cache() takes a vmcb_save_area_cached parameter, which is useful in order to save the state to a local variable. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20211103140527.752797-3-eesposit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: nSVM: move nested_vmcb_check_cr3_cr4 logic in nested_vmcb_valid_sregsEmanuele Giuseppe Esposito1-22/+13
Inline nested_vmcb_check_cr3_cr4 as it is not called by anyone else. Doing so simplifies next patches. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20211103140527.752797-2-eesposit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08KVM: Use 'unsigned long' as kvm_for_each_vcpu()'s indexMarc Zyngier2-5/+6
Everywhere we use kvm_for_each_vpcu(), we use an int as the vcpu index. Unfortunately, we're about to move rework the iterator, which requires this to be upgrade to an unsigned long. Let's bite the bullet and repaint all of it in one go. Signed-off-by: Marc Zyngier <maz@kernel.org> Message-Id: <20211116160403.4074052-7-maz@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-05KVM: SVM: Do not terminate SEV-ES guests on GHCB validation failureTom Lendacky1-46/+60
Currently, an SEV-ES guest is terminated if the validation of the VMGEXIT exit code or exit parameters fails. The VMGEXIT instruction can be issued from userspace, even though userspace (likely) can't update the GHCB. To prevent userspace from being able to kill the guest, return an error through the GHCB when validation fails rather than terminating the guest. For cases where the GHCB can't be updated (e.g. the GHCB can't be mapped, etc.), just return back to the guest. The new error codes are documented in the lasest update to the GHCB specification. Fixes: 291bd20d5d88 ("KVM: SVM: Add initial support for a VMGEXIT VMEXIT") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Message-Id: <b57280b5562893e2616257ac9c2d4525a9aeeb42.1638471124.git.thomas.lendacky@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-05KVM: SEV: Fall back to vmalloc for SEV-ES scratch area if necessarySean Christopherson1-4/+4
Use kvzalloc() to allocate KVM's buffer for SEV-ES's GHCB scratch area so that KVM falls back to __vmalloc() if physically contiguous memory isn't available. The buffer is purely a KVM software construct, i.e. there's no need for it to be physically contiguous. Cc: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211109222350.2266045-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-05KVM: SEV: Return appropriate error codes if SEV-ES scratch setup failsSean Christopherson1-13/+17
Return appropriate error codes if setting up the GHCB scratch area for an SEV-ES guest fails. In particular, returning -EINVAL instead of -ENOMEM when allocating the kernel buffer could be confusing as userspace would likely suspect a guest issue. Fixes: 8f423a80d299 ("KVM: SVM: Support MMIO for an SEV-ES guest") Cc: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211109222350.2266045-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-02KVM: ensure APICv is considered inactive if there is no APICPaolo Bonzini1-0/+1
kvm_vcpu_apicv_active() returns false if a virtual machine has no in-kernel local APIC, however kvm_apicv_activated might still be true if there are no reasons to disable APICv; in fact it is quite likely that there is none because APICv is inhibited by specific configurations of the local APIC and those configurations cannot be programmed. This triggers a WARN: WARN_ON_ONCE(kvm_apicv_activated(vcpu->kvm) != kvm_vcpu_apicv_active(vcpu)); To avoid this, introduce another cause for APICv inhibition, namely the absence of an in-kernel local APIC. This cause is enabled by default, and is dropped by either KVM_CREATE_IRQCHIP or the enabling of KVM_CAP_IRQCHIP_SPLIT. Reported-by: Ignat Korchagin <ignat@cloudflare.com> Fixes: ee49a8932971 ("KVM: x86: Move SVM's APICv sanity check to common x86", 2021-10-22) Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Tested-by: Ignat Korchagin <ignat@cloudflare.com> Message-Id: <20211130123746.293379-1-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-02KVM: x86/pmu: Fix reserved bits for AMD PerfEvtSeln registerLike Xu1-1/+1
If we run the following perf command in an AMD Milan guest: perf stat \ -e cpu/event=0x1d0/ \ -e cpu/event=0x1c7/ \ -e cpu/umask=0x1f,event=0x18e/ \ -e cpu/umask=0x7,event=0x18e/ \ -e cpu/umask=0x18,event=0x18e/ \ ./workload dmesg will report a #GP warning from an unchecked MSR access error on MSR_F15H_PERF_CTLx. This is because according to APM (Revision: 4.03) Figure 13-7, the bits [35:32] of AMD PerfEvtSeln register is a part of the event select encoding, which extends the EVENT_SELECT field from 8 bits to 12 bits. Opportunistically update pmu->reserved_bits for reserved bit 19. Reported-by: Jim Mattson <jmattson@google.com> Fixes: ca724305a2b0 ("KVM: x86/vPMU: Implement AMD vPMU code for KVM") Signed-off-by: Like Xu <likexu@tencent.com> Message-Id: <20211118130320.95997-1-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30KVM: fix avic_set_running for preemptable kernelsPaolo Bonzini1-7/+9
avic_set_running() passes the current CPU to avic_vcpu_load(), albeit via vcpu->cpu rather than smp_processor_id(). If the thread is migrated while avic_set_running runs, the call to avic_vcpu_load() can use a stale value for the processor id. Avoid this by blocking preemption over the entire execution of avic_set_running(). Reported-by: Sean Christopherson <seanjc@google.com> Fixes: 8221c1370056 ("svm: Manage vcpu load/unload when enable AVIC") Cc: stable@vger.kernel.org Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30KVM: SEV: accept signals in sev_lock_two_vmsPaolo Bonzini1-6/+16
Generally, kvm->lock is not taken for a long time, but sev_lock_two_vms is different: it takes vCPU locks inside, so userspace can hold it back just by calling a vCPU ioctl. Play it safe and use mutex_lock_killable. Message-Id: <20211123005036.2954379-13-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30KVM: SEV: do not take kvm->lock when destroyingPaolo Bonzini1-4/+0
Taking the lock is useless since there are no other references, and there are already accesses (e.g. to sev->enc_context_owner) that do not take it. So get rid of it. Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211123005036.2954379-12-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30KVM: SEV: Prohibit migration of a VM that has mirrorsPaolo Bonzini2-1/+22
VMs that mirror an encryption context rely on the owner to keep the ASID allocated. Performing a KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM would cause a dangling ASID: 1. copy context from A to B (gets ref to A) 2. move context from A to L (moves ASID from A to L) 3. close L (releases ASID from L, B still references it) The right way to do the handoff instead is to create a fresh mirror VM on the destination first: 1. copy context from A to B (gets ref to A) [later] 2. close B (releases ref to A) 3. move context from A to L (moves ASID from A to L) 4. copy context from L to M So, catch the situation by adding a count of how many VMs are mirroring this one's encryption context. Fixes: 0b020f5af092 ("KVM: SEV: Add support for SEV-ES intra host migration") Message-Id: <20211123005036.2954379-11-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30KVM: SEV: Do COPY_ENC_CONTEXT_FROM with both VMs lockedPaolo Bonzini1-42/+24
Now that we have a facility to lock two VMs with deadlock protection, use it for the creation of mirror VMs as well. One of COPY_ENC_CONTEXT_FROM(dst, src) and COPY_ENC_CONTEXT_FROM(src, dst) would always fail, so the combination is nonsensical and it is okay to return -EBUSY if it is attempted. This sidesteps the question of what happens if a VM is MOVE_ENC_CONTEXT_FROM'd at the same time as it is COPY_ENC_CONTEXT_FROM'd: the locking prevents that from happening. Cc: Peter Gonda <pgonda@google.com> Cc: Sean Christopherson <seanjc@google.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211123005036.2954379-10-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-30KVM: SEV: move mirror status to destination of KVM_CAP_VM_MOVE_ENC_CONTEXT_FROMPaolo Bonzini1-0/+2
Allow intra-host migration of a mirror VM; the destination VM will be a mirror of the same ASID as the source. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Reviewed-by: Sean Christopherson <seanjc@google.com> Message-Id: <20211123005036.2954379-8-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>