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2022-04-02kvm: x86: SVM: remove unused definesMaxim Levitsky
Remove some unused #defines from svm.c Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220322172449.235575-7-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-02KVM: x86: SVM: move tsc ratio definitions to svm.hMaxim Levitsky
Another piece of SVM spec which should be in the header file Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220322172449.235575-6-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-02KVM: x86: Add wrappers for setting/clearing APICv inhibitsSean Christopherson
Add set/clear wrappers for toggling APICv inhibits to make the call sites more readable, and opportunistically rename the inner helpers to align with the new wrappers and to make them more readable as well. Invert the flag from "activate" to "set"; activate is painfully ambiguous as it's not obvious if the inhibit is being activated, or if APICv is being activated, in which case the inhibit is being deactivated. For the functions that take @set, swap the order of the inhibit reason and @set so that the call sites are visually similar to those that bounce through the wrapper. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220311043517.17027-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-21KVM: x86: do not use KVM_X86_OP_OPTIONAL_RET0 for get_mt_maskMaxim Levitsky
KVM_X86_OP_OPTIONAL_RET0 can only be used with 32-bit return values on 32-bit systems, because unsigned long is only 32-bits wide there and 64-bit values are returned in edx:eax. Reported-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-04Merge branch 'kvm-bugfixes' into HEADPaolo Bonzini
Merge bugfixes from 5.17 before merging more tricky work.
2022-03-01KVM: SVM: Disable preemption across AVIC load/put during APICv refreshSean Christopherson
Disable preemption when loading/putting the AVIC during an APICv refresh. If the vCPU task is preempted and migrated ot a different pCPU, the unprotected avic_vcpu_load() could set the wrong pCPU in the physical ID cache/table. Pull the necessary code out of avic_vcpu_{,un}blocking() and into a new helper to reduce the probability of introducing this exact bug a third time. Fixes: df7e4827c549 ("KVM: SVM: call avic_vcpu_load/avic_vcpu_put when enabling/disabling AVIC") Cc: stable@vger.kernel.org Reported-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-24KVM: x86: nSVM: disallow userspace setting of MSR_AMD64_TSC_RATIO to non ↵Maxim Levitsky
default value when tsc scaling disabled If nested tsc scaling is disabled, MSR_AMD64_TSC_RATIO should never have non default value. Due to way nested tsc scaling support was implmented in qemu, it would set this msr to 0 when nested tsc scaling was disabled. Ignore that value for now, as it causes no harm. Fixes: 5228eb96a487 ("KVM: x86: nSVM: implement nested TSC scaling") Cc: stable@vger.kernel.org Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220223115649.319134-1-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18KVM: x86: allow defining return-0 static callsPaolo Bonzini
A few vendor callbacks are only used by VMX, but they return an integer or bool value. Introduce KVM_X86_OP_OPTIONAL_RET0 for them: if a func is NULL in struct kvm_x86_ops, it will be changed to __static_call_return0 when updating static calls. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18KVM: x86: make several APIC virtualization callbacks optionalPaolo Bonzini
All their invocations are conditional on vcpu->arch.apicv_active, meaning that they need not be implemented by vendor code: even though at the moment both vendors implement APIC virtualization, all of them can be optional. In fact SVM does not need many of them, and their implementation can be deleted now. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-18KVM: x86: return 1 unconditionally for availability of KVM_CAP_VAPICPaolo Bonzini
The two ioctls used to implement userspace-accelerated TPR, KVM_TPR_ACCESS_REPORTING and KVM_SET_VAPIC_ADDR, are available even if hardware-accelerated TPR can be used. So there is no reason not to report KVM_CAP_VAPIC. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-14KVM: SVM: Rename AVIC helpers to use "avic" prefix instead of "svm"Sean Christopherson
Use "avic" instead of "svm" for SVM's all of APICv hooks and make a few additional funciton name tweaks so that the AVIC functions conform to their associated kvm_x86_ops hooks. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-19-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-14Merge remote-tracking branch 'kvm/master' into HEADPaolo Bonzini
Merge bugfix patches from Linux 5.17-rc.
2022-02-11KVM: SVM: fix race between interrupt delivery and AVIC inhibitionMaxim Levitsky
If svm_deliver_avic_intr is called just after the target vcpu's AVIC got inhibited, it might read a stale value of vcpu->arch.apicv_active which can lead to the target vCPU not noticing the interrupt. To fix this use load-acquire/store-release so that, if the target vCPU is IN_GUEST_MODE, we're guaranteed to see a previous disabling of the AVIC. If AVIC has been disabled in the meanwhile, proceed with the KVM_REQ_EVENT-based delivery. Incomplete IPI vmexit has the same races as svm_deliver_avic_intr, and in fact it can be handled in exactly the same way; the only difference lies in who has set IRR, whether svm_deliver_interrupt or the processor. Therefore, svm_complete_interrupt_delivery can be used to fix incomplete IPI vmexits as well. Co-developed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-11KVM: SVM: set IRR in svm_deliver_interruptPaolo Bonzini
SVM has to set IRR for both the AVIC and the software-LAPIC case, so pull it up to the common function that handles both configurations. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: nSVM: Track whether changes in L0 require MSR bitmap for L2 to be rebuiltVitaly Kuznetsov
Similar to nVMX commit ed2a4800ae9d ("KVM: nVMX: Track whether changes in L0 require MSR bitmap for L2 to be rebuilt"), introduce a flag to keep track of whether MSR bitmap for L2 needs to be rebuilt due to changes in MSR bitmap for L1 or switching to a different L2. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20220202095100.129834-2-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: SVM: Rename hook implementations to conform to kvm_x86_ops' namesSean Christopherson
Massage SVM's implementation names that still diverge from kvm_x86_ops to allow for wiring up all SVM-defined functions via kvm-x86-ops.h. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-22-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: SVM: Rename SEV implemenations to conform to kvm_x86_ops hooksSean Christopherson
Rename svm_vm_copy_asid_from() and svm_vm_migrate_from() to conform to the names used by kvm_x86_ops, and opportunistically use "sev" instead of "svm" to more precisely identify the role of the hooks. svm_vm_copy_asid_from() in particular was poorly named as the function does much more than simply copy the ASID. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-21-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: x86: Use more verbose names for mem encrypt kvm_x86_ops hooksSean Christopherson
Use slightly more verbose names for the so called "memory encrypt", a.k.a. "mem enc", kvm_x86_ops hooks to bridge the gap between the current super short kvm_x86_ops names and SVM's more verbose, but non-conforming names. This is a step toward using kvm-x86-ops.h with KVM_X86_CVM_OP() to fill svm_x86_ops. Opportunistically rename mem_enc_op() to mem_enc_ioctl() to better reflect its true nature, as it really is a full fledged ioctl() of its own. Ideally, the hook would be named confidential_vm_ioctl() or so, as the ioctl() is a gateway to more than just memory encryption, and because its underlying purpose to support Confidential VMs, which can be provided without memory encryption, e.g. if the TCB of the guest includes the host kernel but not host userspace, or by isolation in hardware without encrypting memory. But, diverging from KVM_MEMORY_ENCRYPT_OP even further is undeseriable, and short of creating alises for all related ioctl()s, which introduces a different flavor of divergence, KVM is stuck with the nomenclature. Defer renaming SVM's functions to a future commit as there are additional changes needed to make SVM fully conforming and to match reality (looking at you, svm_vm_copy_asid_from()). No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-20-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: SVM: Remove unused MAX_INST_SIZE #defineSean Christopherson
Remove SVM's MAX_INST_SIZE, which has long since been obsoleted by the common MAX_INSN_SIZE. Note, the latter's "insn" is also the generally preferred abbreviation of instruction. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-18-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: SVM: Rename svm_flush_tlb() to svm_flush_tlb_current()Sean Christopherson
Rename svm_flush_tlb() to svm_flush_tlb_current() so that at least one of the flushing operations in svm_x86_ops can be filled via kvm-x86-ops.h, and to document the scope of the flush (specifically that it doesn't flush "all"). Opportunistically make svm_tlb_flush_current(), was svm_flush_tlb(), static. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-17-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: x86: Move get_cs_db_l_bits() helper to SVMSean Christopherson
Move kvm_get_cs_db_l_bits() to SVM and rename it appropriately so that its svm_x86_ops entry can be filled via kvm-x86-ops, and to eliminate a superfluous export from KVM x86. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-16-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: x86: Rename kvm_x86_ops pointers to align w/ preferred vendor namesSean Christopherson
Rename a variety of kvm_x86_op function pointers so that preferred name for vendor implementations follows the pattern <vendor>_<function>, e.g. rename .run() to .vcpu_run() to match {svm,vmx}_vcpu_run(). This will allow vendor implementations to be wired up via the KVM_X86_OP macro. In many cases, VMX and SVM "disagree" on the preferred name, though in reality it's VMX and x86 that disagree as SVM blindly prepended _svm to the kvm_x86_ops name. Justification for using the VMX nomenclature: - set_{irq,nmi} => inject_{irq,nmi} because the helper is injecting an event that has already been "set" in e.g. the vIRR. SVM's relevant VMCB field is even named event_inj, and KVM's stat is irq_injections. - prepare_guest_switch => prepare_switch_to_guest because the former is ambiguous, e.g. it could mean switching between multiple guests, switching from the guest to host, etc... - update_pi_irte => pi_update_irte to allow for matching match the rest of VMX's posted interrupt naming scheme, which is vmx_pi_<blah>(). - start_assignment => pi_start_assignment to again follow VMX's posted interrupt naming scheme, and to provide context for what bit of code might care about an otherwise undescribed "assignment". The "tlb_flush" => "flush_tlb" creates an inconsistency with respect to Hyper-V's "tlb_remote_flush" hooks, but Hyper-V really is the one that's wrong. x86, VMX, and SVM all use flush_tlb, and even common KVM is on a variant of the bandwagon with "kvm_flush_remote_tlbs", e.g. a more appropriate name for the Hyper-V hooks would be flush_remote_tlbs. Leave that change for another time as the Hyper-V hooks always start as NULL, i.e. the name doesn't matter for using kvm-x86-ops.h, and changing all names requires an astounding amount of churn. VMX and SVM function names are intentionally left as is to minimize the diff. Both VMX and SVM will need to rename even more functions in order to fully utilize KVM_X86_OPS, i.e. an additional patch for each is inevitable. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-5-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: SVM: improve split between svm_prepare_guest_switch and ↵Paolo Bonzini
sev_es_prepare_guest_switch KVM performs the VMSAVE to the host save area for both regular and SEV-ES guests, so hoist it up to svm_prepare_guest_switch. And because sev_es_prepare_guest_switch does not really need to know the details of struct svm_cpu_data *, just pass it the pointer to the host save area inside the HSAVE page. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10KVM: x86/svm: Remove unused "vcpu" of svm_check_exit_valid()Jinrong Liang
The "struct kvm_vcpu *vcpu" parameter of svm_check_exit_valid() is not used, so remove it. No functional change intended. Signed-off-by: Jinrong Liang <cloudliang@tencent.com> Message-Id: <20220125095909.38122-7-cloudliang@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-08KVM: x86: nSVM: deal with L1 hypervisor that intercepts interrupts but lets ↵Maxim Levitsky
L2 control them Fix a corner case in which the L1 hypervisor intercepts interrupts (INTERCEPT_INTR) and either doesn't set virtual interrupt masking (V_INTR_MASKING) or enters a nested guest with EFLAGS.IF disabled prior to the entry. In this case, despite the fact that L1 intercepts the interrupts, KVM still needs to set up an interrupt window to wait before injecting the INTR vmexit. Currently the KVM instead enters an endless loop of 'req_immediate_exit'. Exactly the same issue also happens for SMIs and NMI. Fix this as well. Note that on VMX, this case is impossible as there is only 'vmexit on external interrupts' execution control which either set, in which case both host and guest's EFLAGS.IF are ignored, or not set, in which case no VMexits are delivered. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220207155447.840194-8-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-08KVM: x86: nSVM: expose clean bit support to the guestMaxim Levitsky
KVM already honours few clean bits thus it makes sense to let the nested guest know about it. Note that KVM also doesn't check if the hardware supports clean bits, and therefore nested KVM was already setting clean bits and L0 KVM was already honouring them. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220207155447.840194-6-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-08KVM: x86: nSVM/nVMX: set nested_run_pending on VM entry which is a result of RSMMaxim Levitsky
While RSM induced VM entries are not full VM entries, they still need to be followed by actual VM entry to complete it, unlike setting the nested state. This patch fixes boot of hyperv and SMM enabled windows VM running nested on KVM, which fail due to this issue combined with lack of dirty bit setting. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Cc: stable@vger.kernel.org Message-Id: <20220207155447.840194-5-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-08KVM: x86: nSVM: mark vmcb01 as dirty when restoring SMM saved stateMaxim Levitsky
While usually, restoring the smm state makes the KVM enter the nested guest thus a different vmcb (vmcb02 vs vmcb01), KVM should still mark it as dirty, since hardware can in theory cache multiple vmcbs. Failure to do so, combined with lack of setting the nested_run_pending (which is fixed in the next patch), might make KVM re-enter vmcb01, which was just exited from, with completely different set of guest state registers (SMM vs non SMM) and without proper dirty bits set, which results in the CPU reusing stale IDTR pointer which leads to a guest shutdown on any interrupt. On the real hardware this usually doesn't happen, but when running nested, L0's KVM does check and honour few dirty bits, causing this issue to happen. This patch fixes boot of hyperv and SMM enabled windows VM running nested on KVM. Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Cc: stable@vger.kernel.org Message-Id: <20220207155447.840194-4-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-08KVM: x86: SVM: don't passthrough SMAP/SMEP/PKE bits in !NPT && !gCR0.PG caseMaxim Levitsky
When the guest doesn't enable paging, and NPT/EPT is disabled, we use guest't paging CR3's as KVM's shadow paging pointer and we are technically in direct mode as if we were to use NPT/EPT. In direct mode we create SPTEs with user mode permissions because usually in the direct mode the NPT/EPT doesn't need to restrict access based on guest CPL (there are MBE/GMET extenstions for that but KVM doesn't use them). In this special "use guest paging as direct" mode however, and if CR4.SMAP/CR4.SMEP are enabled, that will make the CPU fault on each access and KVM will enter endless loop of page faults. Since page protection doesn't have any meaning in !PG case, just don't passthrough these bits. The fix is the same as was done for VMX in commit: commit 656ec4a4928a ("KVM: VMX: fix SMEP and SMAP without EPT") This fixes the boot of windows 10 without NPT for good. (Without this patch, BSP boots, but APs were stuck in endless loop of page faults, causing the VM boot with 1 CPU) Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Cc: stable@vger.kernel.org Message-Id: <20220207155447.840194-2-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-05Merge tag 'kvmarm-fixes-5.17-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 5.17, take #2 - A couple of fixes when handling an exception while a SError has been delivered - Workaround for Cortex-A510's single-step[ erratum
2022-02-01kvm/x86: rework guest entry logicMark Rutland
For consistency and clarity, migrate x86 over to the generic helpers for guest timing and lockdep/RCU/tracing management, and remove the x86-specific helpers. Prior to this patch, the guest timing was entered in kvm_guest_enter_irqoff() (called by svm_vcpu_enter_exit() and svm_vcpu_enter_exit()), and was exited by the call to vtime_account_guest_exit() within vcpu_enter_guest(). To minimize duplication and to more clearly balance entry and exit, both entry and exit of guest timing are placed in vcpu_enter_guest(), using the new guest_timing_{enter,exit}_irqoff() helpers. When context tracking is used a small amount of additional time will be accounted towards guests; tick-based accounting is unnaffected as IRQs are disabled at this point and not enabled until after the return from the guest. This also corrects (benign) mis-balanced context tracking accounting introduced in commits: ae95f566b3d22ade ("KVM: X86: TSCDEADLINE MSR emulation fastpath") 26efe2fd92e50822 ("KVM: VMX: Handle preemption timer fastpath") Where KVM can enter a guest multiple times, calling vtime_guest_enter() without a corresponding call to vtime_account_guest_exit(), and with vtime_account_system() called when vtime_account_guest() should be used. As account_system_time() checks PF_VCPU and calls account_guest_time(), this doesn't result in any functional problem, but is unnecessarily confusing. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jim Mattson <jmattson@google.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Sean Christopherson <seanjc@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Wanpeng Li <wanpengli@tencent.com> Message-Id: <20220201132926.3301912-4-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01KVM: x86: Move delivery of non-APICv interrupt into vendor codeSean Christopherson
Handle non-APICv interrupt delivery in vendor code, even though it means VMX and SVM will temporarily have duplicate code. SVM's AVIC has a race condition that requires KVM to fall back to legacy interrupt injection _after_ the interrupt has been logged in the vIRR, i.e. to fix the race, SVM will need to open code the full flow anyways[*]. Refactor the code so that the SVM bug without introducing other issues, e.g. SVM would return "success" and thus invoke trace_kvm_apicv_accept_irq() even when delivery through the AVIC failed, and to opportunistically prepare for using KVM_X86_OP to fill each vendor's kvm_x86_ops struct, which will rely on the vendor function matching the kvm_x86_op pointer name. No functional change intended. [*] https://lore.kernel.org/all/20211213104634.199141-4-mlevitsk@redhat.com Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220128005208.4008533-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-28Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "Two larger x86 series: - Redo incorrect fix for SEV/SMAP erratum - Windows 11 Hyper-V workaround Other x86 changes: - Various x86 cleanups - Re-enable access_tracking_perf_test - Fix for #GP handling on SVM - Fix for CPUID leaf 0Dh in KVM_GET_SUPPORTED_CPUID - Fix for ICEBP in interrupt shadow - Avoid false-positive RCU splat - Enable Enlightened MSR-Bitmap support for real ARM: - Correctly update the shadow register on exception injection when running in nVHE mode - Correctly use the mm_ops indirection when performing cache invalidation from the page-table walker - Restrict the vgic-v3 workaround for SEIS to the two known broken implementations Generic code changes: - Dead code cleanup" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (43 commits) KVM: eventfd: Fix false positive RCU usage warning KVM: nVMX: Allow VMREAD when Enlightened VMCS is in use KVM: nVMX: Implement evmcs_field_offset() suitable for handle_vmread() KVM: nVMX: Rename vmcs_to_field_offset{,_table} KVM: nVMX: eVMCS: Filter out VM_EXIT_SAVE_VMX_PREEMPTION_TIMER KVM: nVMX: Also filter MSR_IA32_VMX_TRUE_PINBASED_CTLS when eVMCS selftests: kvm: check dynamic bits against KVM_X86_XCOMP_GUEST_SUPP KVM: x86: add system attribute to retrieve full set of supported xsave states KVM: x86: Add a helper to retrieve userspace address from kvm_device_attr selftests: kvm: move vm_xsave_req_perm call to amx_test KVM: x86: Sync the states size with the XCR0/IA32_XSS at, any time KVM: x86: Update vCPU's runtime CPUID on write to MSR_IA32_XSS KVM: x86: Keep MSR_IA32_XSS unchanged for INIT KVM: x86: Free kvm_cpuid_entry2 array on post-KVM_RUN KVM_SET_CPUID{,2} KVM: nVMX: WARN on any attempt to allocate shadow VMCS for vmcs02 KVM: selftests: Don't skip L2's VMCALL in SMM test for SVM guest KVM: x86: Check .flags in kvm_cpuid_check_equal() too KVM: x86: Forcibly leave nested virt when SMM state is toggled KVM: SVM: drop unnecessary code in svm_hv_vmcb_dirty_nested_enlightenments() KVM: SVM: hyper-v: Enable Enlightened MSR-Bitmap support for real ...
2022-01-26KVM: x86: Forcibly leave nested virt when SMM state is toggledSean Christopherson
Forcibly leave nested virtualization operation if userspace toggles SMM state via KVM_SET_VCPU_EVENTS or KVM_SYNC_X86_EVENTS. If userspace forces the vCPU out of SMM while it's post-VMXON and then injects an SMI, vmx_enter_smm() will overwrite vmx->nested.smm.vmxon and end up with both vmxon=false and smm.vmxon=false, but all other nVMX state allocated. Don't attempt to gracefully handle the transition as (a) most transitions are nonsencial, e.g. forcing SMM while L2 is running, (b) there isn't sufficient information to handle all transitions, e.g. SVM wants access to the SMRAM save state, and (c) KVM_SET_VCPU_EVENTS must precede KVM_SET_NESTED_STATE during state restore as the latter disallows putting the vCPU into L2 if SMM is active, and disallows tagging the vCPU as being post-VMXON in SMM if SMM is not active. Abuse of KVM_SET_VCPU_EVENTS manifests as a WARN and memory leak in nVMX due to failure to free vmcs01's shadow VMCS, but the bug goes far beyond just a memory leak, e.g. toggling SMM on while L2 is active puts the vCPU in an architecturally impossible state. WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline] WARNING: CPU: 0 PID: 3606 at free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656 Modules linked in: CPU: 1 PID: 3606 Comm: syz-executor725 Not tainted 5.17.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:free_loaded_vmcs arch/x86/kvm/vmx/vmx.c:2665 [inline] RIP: 0010:free_loaded_vmcs+0x158/0x1a0 arch/x86/kvm/vmx/vmx.c:2656 Code: <0f> 0b eb b3 e8 8f 4d 9f 00 e9 f7 fe ff ff 48 89 df e8 92 4d 9f 00 Call Trace: <TASK> kvm_arch_vcpu_destroy+0x72/0x2f0 arch/x86/kvm/x86.c:11123 kvm_vcpu_destroy arch/x86/kvm/../../../virt/kvm/kvm_main.c:441 [inline] kvm_destroy_vcpus+0x11f/0x290 arch/x86/kvm/../../../virt/kvm/kvm_main.c:460 kvm_free_vcpus arch/x86/kvm/x86.c:11564 [inline] kvm_arch_destroy_vm+0x2e8/0x470 arch/x86/kvm/x86.c:11676 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1217 [inline] kvm_put_kvm+0x4fa/0xb00 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1250 kvm_vm_release+0x3f/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1273 __fput+0x286/0x9f0 fs/file_table.c:311 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xb29/0x2a30 kernel/exit.c:806 do_group_exit+0xd2/0x2f0 kernel/exit.c:935 get_signal+0x4b0/0x28c0 kernel/signal.c:2862 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae </TASK> Cc: stable@vger.kernel.org Reported-by: syzbot+8112db3ab20e70d50c31@syzkaller.appspotmail.com Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220125220358.2091737-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: SVM: Don't kill SEV guest if SMAP erratum triggers in usermodeSean Christopherson
Inject a #GP instead of synthesizing triple fault to try to avoid killing the guest if emulation of an SEV guest fails due to encountering the SMAP erratum. The injected #GP may still be fatal to the guest, e.g. if the userspace process is providing critical functionality, but KVM should make every attempt to keep the guest alive. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: SVM: Don't apply SEV+SMAP workaround on code fetch or PT accessSean Christopherson
Resume the guest instead of synthesizing a triple fault shutdown if the instruction bytes buffer is empty due to the #NPF being on the code fetch itself or on a page table access. The SMAP errata applies if and only if the code fetch was successful and ucode's subsequent data read from the code page encountered a SMAP violation. In practice, the guest is likely hosed either way, but crashing the guest on a code fetch to emulated MMIO is technically wrong according to the behavior described in the APM. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: SVM: Inject #UD on attempted emulation for SEV guest w/o insn bufferSean Christopherson
Inject #UD if KVM attempts emulation for an SEV guests without an insn buffer and instruction decoding is required. The previous behavior of allowing emulation if there is no insn buffer is undesirable as doing so means KVM is reading guest private memory and thus decoding cyphertext, i.e. is emulating garbage. The check was previously necessary as the emulation type was not provided, i.e. SVM needed to allow emulation to handle completion of emulation after exiting to userspace to handle I/O. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-8-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: SVM: WARN if KVM attempts emulation on #UD or #GP for SEV guestsSean Christopherson
WARN if KVM attempts to emulate in response to #UD or #GP for SEV guests, i.e. if KVM intercepts #UD or #GP, as emulation on any fault except #NPF is impossible since KVM cannot read guest private memory to get the code stream, and the CPU's DecodeAssists feature only provides the instruction bytes on #NPF. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-7-seanjc@google.com> [Warn on EMULTYPE_TRAP_UD_FORCED according to Liam Merwick's review. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: x86: Pass emulation type to can_emulate_instruction()Sean Christopherson
Pass the emulation type to kvm_x86_ops.can_emulate_insutrction() so that a future commit can harden KVM's SEV support to WARN on emulation scenarios that should never happen. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-6-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: SVM: Don't intercept #GP for SEV guestsSean Christopherson
Never intercept #GP for SEV guests as reading SEV guest private memory will return cyphertext, i.e. emulating on #GP can't work as intended. Cc: stable@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-4-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26Revert "KVM: SVM: avoid infinite loop on NPF from bad address"Sean Christopherson
Revert a completely broken check on an "invalid" RIP in SVM's workaround for the DecodeAssists SMAP errata. kvm_vcpu_gfn_to_memslot() obviously expects a gfn, i.e. operates in the guest physical address space, whereas RIP is a virtual (not even linear) address. The "fix" worked for the problematic KVM selftest because the test identity mapped RIP. Fully revert the hack instead of trying to translate RIP to a GPA, as the non-SEV case is now handled earlier, and KVM cannot access guest page tables to translate RIP. This reverts commit e72436bc3a5206f95bb384e741154166ddb3202e. Fixes: e72436bc3a52 ("KVM: SVM: avoid infinite loop on NPF from bad address") Reported-by: Liam Merwick <liam.merwick@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: SVM: Never reject emulation due to SMAP errata for !SEV guestsSean Christopherson
Always signal that emulation is possible for !SEV guests regardless of whether or not the CPU provided a valid instruction byte stream. KVM can read all guest state (memory and registers) for !SEV guests, i.e. can fetch the code stream from memory even if the CPU failed to do so because of the SMAP errata. Fixes: 05d5a4863525 ("KVM: SVM: Workaround errata#1096 (insn_len maybe zero on SMAP violation)") Cc: stable@vger.kernel.org Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-26KVM: x86: nSVM: skip eax alignment check for non-SVM instructionsDenis Valeev
The bug occurs on #GP triggered by VMware backdoor when eax value is unaligned. eax alignment check should not be applied to non-SVM instructions because it leads to incorrect omission of the instructions emulation. Apply the alignment check only to SVM instructions to fix. Fixes: d1cba6c92237 ("KVM: x86: nSVM: test eax for 4K alignment for GP errata workaround") Signed-off-by: Denis Valeev <lemniscattaden@gmail.com> Message-Id: <Yexlhaoe1Fscm59u@q> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-22Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
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 Christopherson
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 Christopherson
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: Use kvm_vcpu_is_blocking() in AVIC load to handle preemptionSean Christopherson
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: VMX: Reject KVM_RUN if emulation is required with pending exceptionSean Christopherson
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 Xu
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 Torvalds
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() ...