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2021-06-17KVM: nVMX: Drop obsolete (and pointless) pdptrs_changed() checkSean Christopherson1-5/+3
Remove the pdptrs_changed() check when loading L2's CR3. The set of available registers is always reset when switching VMCSes (see commit e5d03de5937e, "KVM: nVMX: Reset register cache (available and dirty masks) on VMCS switch"), thus the "are PDPTRs available" check will always fail. And even if it didn't fail, reading guest memory to check the PDPTRs is just as expensive as reading guest memory to load 'em. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: selftests: Introduce hyperv_features testVitaly Kuznetsov4-0/+817
The initial implementation of the test only tests that access to Hyper-V MSRs and hypercalls is in compliance with guest visible CPUID feature bits. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: selftests: Move evmcs.h to x86_64/Vitaly Kuznetsov1-1/+1
evmcs.h is x86_64 only thing, move it to x86_64/ subdirectory. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: selftests: move Hyper-V MSR definitions to hyperv.hVitaly Kuznetsov2-7/+20
These defines can be shared by multiple tests, move them to a dedicated header. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED bitVitaly Kuznetsov1-0/+8
Hypercalls which use extended processor masks are only available when HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED privilege bit is exposed (and 'RECOMMENDED' is rather a misnomer). Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_X64_CLUSTER_IPI_RECOMMENDED bitVitaly Kuznetsov1-0/+4
Hyper-V partition must possess 'HV_X64_CLUSTER_IPI_RECOMMENDED' privilege ('recommended' is rather a misnomer) to issue HVCALL_SEND_IPI hypercalls. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED bitVitaly Kuznetsov1-0/+6
Hyper-V partition must possess 'HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED' privilege ('recommended' is rather a misnomer) to issue HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST/SPACE hypercalls. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_DEBUGGING privilege bitVitaly Kuznetsov1-0/+9
Hyper-V partition must possess 'HV_DEBUGGING' privilege to issue HVCALL_POST_DEBUG_DATA/HVCALL_RETRIEVE_DEBUG_DATA/ HVCALL_RESET_DEBUG_SESSION hypercalls. Note, when SynDBG is disabled hv_check_hypercall_access() returns 'true' (like for any other unknown hypercall) so the result will be HV_STATUS_INVALID_HYPERCALL_CODE and not HV_STATUS_ACCESS_DENIED. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_SIGNAL_EVENTS privilege bitVitaly Kuznetsov1-0/+2
Hyper-V partition must possess 'HV_SIGNAL_EVENTS' privilege to issue HVCALL_SIGNAL_EVENT hypercalls. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_POST_MESSAGES privilege bitVitaly Kuznetsov1-0/+2
Hyper-V partition must possess 'HV_POST_MESSAGES' privilege to issue HVCALL_POST_MESSAGE hypercalls. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Check access to HVCALL_NOTIFY_LONG_SPIN_WAIT hypercallVitaly Kuznetsov1-0/+11
TLFS6.0b states that partition issuing HVCALL_NOTIFY_LONG_SPIN_WAIT must posess 'UseHypercallForLongSpinWait' privilege but there's no corresponding feature bit. Instead, we have "Recommended number of attempts to retry a spinlock failure before notifying the hypervisor about the failures. 0xFFFFFFFF indicates never notify." Use this to check access to the hypercall. Also, check against zero as the corresponding CPUID must be set (and '0' attempts before re-try is weird anyway). Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Prepare to check access to Hyper-V hypercallsVitaly Kuznetsov1-0/+11
Introduce hv_check_hypercallr_access() to check if the particular hypercall should be available to guest, this will be used with KVM_CAP_HYPERV_ENFORCE_CPUID mode. No functional change intended. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_STIMER_DIRECT_MODE_AVAILABLE privilege bitVitaly Kuznetsov1-0/+6
Synthetic timers can only be configured in 'direct' mode when HV_STIMER_DIRECT_MODE_AVAILABLE bit was exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Inverse the default in hv_check_msr_access()Vitaly Kuznetsov1-1/+1
Access to all MSRs is now properly checked. To avoid 'forgetting' to properly check access to new MSRs in the future change the default to 'false' meaning 'no access'. No functional change intended. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_FEATURE_DEBUG_MSRS_AVAILABLE privilege bitVitaly Kuznetsov1-0/+4
Synthetic debugging MSRs (HV_X64_MSR_SYNDBG_CONTROL, HV_X64_MSR_SYNDBG_STATUS, HV_X64_MSR_SYNDBG_SEND_BUFFER, HV_X64_MSR_SYNDBG_RECV_BUFFER, HV_X64_MSR_SYNDBG_PENDING_BUFFER, HV_X64_MSR_SYNDBG_OPTIONS) are only available to guest when HV_FEATURE_DEBUG_MSRS_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE privilege bitVitaly Kuznetsov1-0/+4
HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4, HV_X64_MSR_CRASH_CTL are only available to guest when HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_ACCESS_REENLIGHTENMENT privilege bitVitaly Kuznetsov1-0/+5
HV_X64_MSR_REENLIGHTENMENT_CONTROL/HV_X64_MSR_TSC_EMULATION_CONTROL/ HV_X64_MSR_TSC_EMULATION_STATUS are only available to guest when HV_ACCESS_REENLIGHTENMENT bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_ACCESS_FREQUENCY_MSRS privilege bitVitaly Kuznetsov1-0/+4
HV_X64_MSR_TSC_FREQUENCY/HV_X64_MSR_APIC_FREQUENCY are only available to guest when HV_ACCESS_FREQUENCY_MSRS bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_MSR_APIC_ACCESS_AVAILABLE privilege bitVitaly Kuznetsov1-0/+7
HV_X64_MSR_EOI, HV_X64_MSR_ICR, HV_X64_MSR_TPR, and HV_X64_MSR_VP_ASSIST_PAGE are only available to guest when HV_MSR_APIC_ACCESS_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_MSR_SYNTIMER_AVAILABLE privilege bitVitaly Kuznetsov1-0/+10
Synthetic timers MSRs (HV_X64_MSR_STIMER[0-3]_CONFIG, HV_X64_MSR_STIMER[0-3]_COUNT) are only available to guest when HV_MSR_SYNTIMER_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_MSR_SYNIC_AVAILABLE privilege bitVitaly Kuznetsov1-0/+8
SynIC MSRs (HV_X64_MSR_SCONTROL, HV_X64_MSR_SVERSION, HV_X64_MSR_SIEFP, HV_X64_MSR_SIMP, HV_X64_MSR_EOM, HV_X64_MSR_SINT0 ... HV_X64_MSR_SINT15) are only available to guest when HV_MSR_SYNIC_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_MSR_REFERENCE_TSC_AVAILABLE privilege bitVitaly Kuznetsov1-0/+3
HV_X64_MSR_REFERENCE_TSC is only available to guest when HV_MSR_REFERENCE_TSC_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_MSR_RESET_AVAILABLE privilege bitVitaly Kuznetsov1-0/+3
HV_X64_MSR_RESET is only available to guest when HV_MSR_RESET_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_MSR_VP_INDEX_AVAILABLE privilege bitVitaly Kuznetsov1-0/+3
HV_X64_MSR_VP_INDEX is only available to guest when HV_MSR_VP_INDEX_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_MSR_TIME_REF_COUNT_AVAILABLE privilege bitVitaly Kuznetsov1-0/+3
HV_X64_MSR_TIME_REF_COUNT is only available to guest when HV_MSR_TIME_REF_COUNT_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_MSR_VP_RUNTIME_AVAILABLE privilege bitVitaly Kuznetsov1-0/+3
HV_X64_MSR_VP_RUNTIME is only available to guest when HV_MSR_VP_RUNTIME_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Honor HV_MSR_HYPERCALL_AVAILABLE privilege bitVitaly Kuznetsov1-0/+12
HV_X64_MSR_GUEST_OS_ID/HV_X64_MSR_HYPERCALL are only available to guest when HV_MSR_HYPERCALL_AVAILABLE bit is exposed. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Prepare to check access to Hyper-V MSRsVitaly Kuznetsov1-0/+18
Introduce hv_check_msr_access() to check if the particular MSR should be accessible by guest, this will be used with KVM_CAP_HYPERV_ENFORCE_CPUID mode. No functional change intended. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Cache guest CPUID leaves determining features availabilityVitaly Kuznetsov2-10/+47
Limiting exposed Hyper-V features requires a fast way to check if the particular feature is exposed in guest visible CPUIDs or not. To aboid looping through all CPUID entries on every hypercall/MSR access cache the required leaves on CPUID update. Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Introduce KVM_CAP_HYPERV_ENFORCE_CPUIDVitaly Kuznetsov6-0/+39
Modeled after KVM_CAP_ENFORCE_PV_FEATURE_CPUID, the new capability allows for limiting Hyper-V features to those exposed to the guest in Hyper-V CPUIDs (0x40000003, 0x40000004, ...). Signed-off-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17asm-generic/hyperv: add HV_STATUS_ACCESS_DENIED definitionVitaly Kuznetsov1-0/+1
From TLFSv6.0b, this status means: "The caller did not possess sufficient access rights to perform the requested operation." Signed-off-by: Vitaly Kuznetsov <[email protected]> Acked-by: Wei Liu <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: SVM: hyper-v: Direct Virtual Flush supportVineeth Pillai4-0/+84
From Hyper-V TLFS: "The hypervisor exposes hypercalls (HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx, HvFlushVirtualAddressList, and HvFlushVirtualAddressListEx) that allow operating systems to more efficiently manage the virtual TLB. The L1 hypervisor can choose to allow its guest to use those hypercalls and delegate the responsibility to handle them to the L0 hypervisor. This requires the use of a partition assist page." Add the Direct Virtual Flush support for SVM. Related VMX changes: commit 6f6a657c9998 ("KVM/Hyper-V/VMX: Add direct tlb flush support") Signed-off-by: Vineeth Pillai <[email protected]> Message-Id: <fc8d24d8eb7017266bb961e39a171b0caf298d7f.1622730232.git.viremana@linux.microsoft.com> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: SVM: hyper-v: Enlightened MSR-Bitmap supportVineeth Pillai3-0/+35
Enlightened MSR-Bitmap as per TLFS: "The L1 hypervisor may collaborate with the L0 hypervisor to make MSR accesses more efficient. It can enable enlightened MSR bitmaps by setting the corresponding field in the enlightened VMCS to 1. When enabled, L0 hypervisor does not monitor the MSR bitmaps for changes. Instead, the L1 hypervisor must invalidate the corresponding clean field after making changes to one of the MSR bitmaps." Enable this for SVM. Related VMX changes: commit ceef7d10dfb6 ("KVM: x86: VMX: hyper-v: Enlightened MSR-Bitmap support") Signed-off-by: Vineeth Pillai <[email protected]> Message-Id: <87df0710f95d28b91cc4ea014fc4d71056eebbee.1622730232.git.viremana@linux.microsoft.com> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: SVM: hyper-v: Remote TLB flush for SVMVineeth Pillai2-0/+75
Enable remote TLB flush for SVM. Signed-off-by: Vineeth Pillai <[email protected]> Message-Id: <1ee364e397e142aed662d2920d198cd03772f1a5.1622730232.git.viremana@linux.microsoft.com> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: SVM: Software reserved fieldsVineeth Pillai3-4/+25
SVM added support for certain reserved fields to be used by software or hypervisor. Add the following reserved fields: - VMCB offset 0x3e0 - 0x3ff - Clean bit 31 - SVM intercept exit code 0xf0000000 Later patches will make use of this for supporting Hyper-V nested virtualization enhancements. Signed-off-by: Vineeth Pillai <[email protected]> Message-Id: <a1f17a43a8e9e751a1a9cc0281649d71bdbf721b.1622730232.git.viremana@linux.microsoft.com> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: hyper-v: Move the remote TLB flush logic out of vmxVineeth Pillai7-112/+150
Currently the remote TLB flush logic is specific to VMX. Move it to a common place so that SVM can use it as well. Signed-off-by: Vineeth Pillai <[email protected]> Message-Id: <4f4e4ca19778437dae502f44363a38e99e3ef5d1.1622730232.git.viremana@linux.microsoft.com> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17hyperv: SVM enlightened TLB flush support flagVineeth Pillai1-0/+9
Bit 22 of HYPERV_CPUID_FEATURES.EDX is specific to SVM and specifies support for enlightened TLB flush. With this enlightenment enabled, ASID invalidations flushes only gva->hpa entries. To flush TLB entries derived from NPT, hypercalls should be used (HvFlushGuestPhysicalAddressSpace or HvFlushGuestPhysicalAddressList) Signed-off-by: Vineeth Pillai <[email protected]> Reviewed-by: Michael Kelley <[email protected]> Message-Id: <a060f872d0df1955e52e30b877b3300485edb27c.1622730232.git.viremana@linux.microsoft.com> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17hyperv: Detect Nested virtualization support for SVMVineeth Pillai1-3/+7
Previously, to detect nested virtualization enlightenment support, we were using HV_X64_ENLIGHTENED_VMCS_RECOMMENDED feature bit of HYPERV_CPUID_ENLIGHTMENT_INFO.EAX CPUID as docuemented in TLFS: "Bit 14: Recommend a nested hypervisor using the enlightened VMCS interface. Also indicates that additional nested enlightenments may be available (see leaf 0x4000000A)". Enlightened VMCS, however, is an Intel only feature so the above detection method doesn't work for AMD. So, use the HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS.EAX CPUID information ("The maximum input value for hypervisor CPUID information.") and this works for both AMD and Intel. Signed-off-by: Vineeth Pillai <[email protected]> Reviewed-by: Michael Kelley <[email protected]> Message-Id: <43b25ff21cd2d9a51582033c9bdd895afefac056.1622730232.git.viremana@linux.microsoft.com> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: nVMX: nSVM: Add a new VCPU statistic to show if VCPU is in guest modeKrish Sadhukhan4-0/+16
Add the following per-VCPU statistic to KVM debugfs to show if a given VCPU is in guest mode: guest_mode Also add this as a per-VM statistic to KVM debugfs to show the total number of VCPUs that are in guest mode in a given VM. Signed-off-by: Krish Sadhukhan <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: nVMX: nSVM: 'nested_run' should count guest-entry attempts that make it ↵Krish Sadhukhan4-5/+18
to guest code Currently, the 'nested_run' statistic counts all guest-entry attempts, including those that fail during vmentry checks on Intel and during consistency checks on AMD. Convert this statistic to count only those guest-entries that make it past these state checks and make it to guest code. This will tell us the number of guest-entries that actually executed or tried to execute guest code. Signed-off-by: Krish Sadhukhan <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Drop "pre_" from enter/leave_smm() helpersSean Christopherson7-24/+23
Now that .post_leave_smm() is gone, drop "pre_" from the remaining helpers. The helpers aren't invoked purely before SMI/RSM processing, e.g. both helpers are invoked after state is snapshotted (from regs or SMRAM), and the RSM helper is invoked after some amount of register state has been stuffed. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Drop .post_leave_smm(), i.e. the manual post-RSM MMU resetSean Christopherson3-9/+8
Drop the .post_leave_smm() emulator callback, which at this point is just a wrapper to kvm_mmu_reset_context(). The manual context reset is unnecessary, because unlike enter_smm() which calls vendor MSR/CR helpers directly, em_rsm() bounces through the KVM helpers, e.g. kvm_set_cr4(), which are responsible for processing side effects. em_rsm() is already subtly relying on this behavior as it doesn't manually do kvm_update_cpuid_runtime(), e.g. to recognize CR4.OSXSAVE changes. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Rename SMM tracepoint to make it reflect realitySean Christopherson2-2/+2
Rename the SMM tracepoint, which handles both entering and exiting SMM, from kvm_enter_smm to kvm_smm_transition. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Move "entering SMM" tracepoint into kvm_smm_changed()Sean Christopherson1-4/+2
Invoke the "entering SMM" tracepoint from kvm_smm_changed() instead of enter_smm(), effectively moving it from before reading vCPU state to after reading state (but still before writing it to SMRAM!). The primary motivation is to consolidate code, but calling the tracepoint from kvm_smm_changed() also makes its invocation consistent with respect to SMI and RSM, and with respect to KVM_SET_VCPU_EVENTS (which previously only invoked the tracepoint when forcing the vCPU out of SMM). Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Move (most) SMM hflags modifications into kvm_smm_changed()Sean Christopherson1-13/+11
Move the core of SMM hflags modifications into kvm_smm_changed() and use kvm_smm_changed() in enter_smm(). Clear HF_SMM_INSIDE_NMI_MASK for leaving SMM but do not set it for entering SMM. If the vCPU is executing outside of SMM, the flag should unequivocally be cleared, e.g. this technically fixes a benign bug where the flag could be left set after KVM_SET_VCPU_EVENTS, but the reverse is not true as NMI blocking depends on pre-SMM state or userspace input. Note, this adds an extra kvm_mmu_reset_context() to enter_smm(). The extra/early reset isn't strictly necessary, and in a way can never be necessary since the vCPU/MMU context is in a half-baked state until the final context reset at the end of the function. But, enter_smm() is not a hot path, and exploding on an invalid root_hpa is probably better than having a stale SMM flag in the MMU role; it's at least no worse. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Invoke kvm_smm_changed() immediately after clearing SMM flagSean Christopherson1-2/+2
Move RSM emulation's call to kvm_smm_changed() from .post_leave_smm() to .exiting_smm(), leaving behind the MMU context reset. The primary motivation is to allow for future cleanup, but this also fixes a bug of sorts by queueing KVM_REQ_EVENT even if RSM causes shutdown, e.g. to let an INIT wake the vCPU from shutdown. Of course, KVM doesn't properly emulate a shutdown state, e.g. KVM doesn't block SMIs after shutdown, and immediately exits to userspace, so the event request is a moot point in practice. Moving kvm_smm_changed() also moves the RSM tracepoint. This isn't strictly necessary, but will allow consolidating the SMI and RSM tracepoints in a future commit (by also moving the SMI tracepoint). Invoking the tracepoint before loading SMRAM state also means the SMBASE that reported in the tracepoint will point that the state that will be used for RSM, as opposed to the SMBASE _after_ RSM completes, which is arguably a good thing if the tracepoint is being used to debug a RSM/SMM issue. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Replace .set_hflags() with dedicated .exiting_smm() helperSean Christopherson3-6/+5
Replace the .set_hflags() emulator hook with a dedicated .exiting_smm(), moving the SMM and SMM_INSIDE_NMI flag handling out of the emulator in the process. This is a step towards consolidating much of the logic in kvm_smm_changed(), including the SMM hflags updates. No functional change intended. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Emulate triple fault shutdown if RSM emulation failsSean Christopherson3-5/+14
Use the recently introduced KVM_REQ_TRIPLE_FAULT to properly emulate shutdown if RSM from SMM fails. Note, entering shutdown after clearing the SMM flag and restoring NMI blocking is architecturally correct with respect to AMD's APM, which KVM also uses for SMRAM layout and RSM NMI blocking behavior. The APM says: An RSM causes a processor shutdown if an invalid-state condition is found in the SMRAM state-save area. Only an external reset, external processor-initialization, or non-maskable external interrupt (NMI) can cause the processor to leave the shutdown state. Of note is processor-initialization (INIT) as a valid shutdown wake event, as INIT is blocked by SMM, implying that entering shutdown also forces the CPU out of SMM. For recent Intel CPUs, restoring NMI blocking is technically wrong, but so is restoring NMI blocking in the first place, and Intel's RSM "architecture" is such a mess that just about anything is allowed and can be justified as micro-architectural behavior. Per the SDM: On Pentium 4 and later processors, shutdown will inhibit INTR and A20M but will not change any of the other inhibits. On these processors, NMIs will be inhibited if no action is taken in the SMI handler to uninhibit them (see Section 34.8). where Section 34.8 says: When the processor enters SMM while executing an NMI handler, the processor saves the SMRAM state save map but does not save the attribute to keep NMI interrupts disabled. Potentially, an NMI could be latched (while in SMM or upon exit) and serviced upon exit of SMM even though the previous NMI handler has still not completed. I.e. RSM unconditionally unblocks NMI, but shutdown on RSM does not, which is in direct contradiction of KVM's behavior. But, as mentioned above, KVM follows AMD architecture and restores NMI blocking on RSM, so that micro-architectural detail is already lost. And for Pentium era CPUs, SMI# can break shutdown, meaning that at least some Intel CPUs fully leave SMM when entering shutdown: In the shutdown state, Intel processors stop executing instructions until a RESET#, INIT# or NMI# is asserted. While Pentium family processors recognize the SMI# signal in shutdown state, P6 family and Intel486 processors do not. In other words, the fact that Intel CPUs have implemented the two extremes gives KVM carte blanche when it comes to honoring Intel's architecture for handling shutdown during RSM. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> [Return X86EMUL_CONTINUE after triple fault. - Paolo] Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Drop vendor specific functions for APICv/AVIC enablementVitaly Kuznetsov4-6/+3
Now that APICv/AVIC enablement is kept in common 'enable_apicv' variable, there's no need to call kvm_apicv_init() from vendor specific code. No functional change intended. Reviewed-by: Sean Christopherson <[email protected]> Reviewed-by: Maxim Levitsky <[email protected]> Signed-off-by: Vitaly Kuznetsov <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
2021-06-17KVM: x86: Use common 'enable_apicv' variable for both APICv and AVICVitaly Kuznetsov7-22/+23
Unify VMX and SVM code by moving APICv/AVIC enablement tracking to common 'enable_apicv' variable. Note: unlike APICv, AVIC is disabled by default. No functional change intended. Suggested-by: Sean Christopherson <[email protected]> Signed-off-by: Vitaly Kuznetsov <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>