Commit Graph

1013690 Commits

Author SHA1 Message Date
Vitaly Kuznetsov
4ad81a9111 KVM: x86: hyper-v: Prepare to check access to Hyper-V hypercalls
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-21-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:43 -04:00
Vitaly Kuznetsov
1aa8a4184d KVM: x86: hyper-v: Honor HV_STIMER_DIRECT_MODE_AVAILABLE privilege bit
Synthetic timers can only be configured in 'direct' mode when
HV_STIMER_DIRECT_MODE_AVAILABLE bit was exposed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-20-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:42 -04:00
Vitaly Kuznetsov
d66bfa36f9 KVM: x86: hyper-v: Inverse the default in hv_check_msr_access()
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-19-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:42 -04:00
Vitaly Kuznetsov
17b6d51771 KVM: x86: hyper-v: Honor HV_FEATURE_DEBUG_MSRS_AVAILABLE privilege bit
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-18-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:42 -04:00
Vitaly Kuznetsov
0a19c8992d KVM: x86: hyper-v: Honor HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE privilege bit
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-17-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:42 -04:00
Vitaly Kuznetsov
234d01baec KVM: x86: hyper-v: Honor HV_ACCESS_REENLIGHTENMENT privilege bit
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-16-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:41 -04:00
Vitaly Kuznetsov
9442f3bd90 KVM: x86: hyper-v: Honor HV_ACCESS_FREQUENCY_MSRS privilege bit
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-15-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:41 -04:00
Vitaly Kuznetsov
978b57475c KVM: x86: hyper-v: Honor HV_MSR_APIC_ACCESS_AVAILABLE privilege bit
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-14-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:41 -04:00
Vitaly Kuznetsov
eba60ddae7 KVM: x86: hyper-v: Honor HV_MSR_SYNTIMER_AVAILABLE privilege bit
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-13-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:41 -04:00
Vitaly Kuznetsov
9e2715ca20 KVM: x86: hyper-v: Honor HV_MSR_SYNIC_AVAILABLE privilege bit
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-12-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:40 -04:00
Vitaly Kuznetsov
a1ec661c3f KVM: x86: hyper-v: Honor HV_MSR_REFERENCE_TSC_AVAILABLE privilege bit
HV_X64_MSR_REFERENCE_TSC is only available to guest when
HV_MSR_REFERENCE_TSC_AVAILABLE bit is exposed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-11-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:40 -04:00
Vitaly Kuznetsov
679008e4bb KVM: x86: hyper-v: Honor HV_MSR_RESET_AVAILABLE privilege bit
HV_X64_MSR_RESET is only available to guest when HV_MSR_RESET_AVAILABLE bit
is exposed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-10-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:40 -04:00
Vitaly Kuznetsov
d2ac25d419 KVM: x86: hyper-v: Honor HV_MSR_VP_INDEX_AVAILABLE privilege bit
HV_X64_MSR_VP_INDEX is only available to guest when
HV_MSR_VP_INDEX_AVAILABLE bit is exposed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-9-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:40 -04:00
Vitaly Kuznetsov
c2b32867f2 KVM: x86: hyper-v: Honor HV_MSR_TIME_REF_COUNT_AVAILABLE privilege bit
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-8-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:39 -04:00
Vitaly Kuznetsov
b80a92ff81 KVM: x86: hyper-v: Honor HV_MSR_VP_RUNTIME_AVAILABLE privilege bit
HV_X64_MSR_VP_RUNTIME is only available to guest when
HV_MSR_VP_RUNTIME_AVAILABLE bit is exposed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-7-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:39 -04:00
Vitaly Kuznetsov
1561c2cb87 KVM: x86: hyper-v: Honor HV_MSR_HYPERCALL_AVAILABLE privilege bit
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-6-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:39 -04:00
Vitaly Kuznetsov
b4128000e2 KVM: x86: hyper-v: Prepare to check access to Hyper-V MSRs
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:39 -04:00
Vitaly Kuznetsov
10d7bf1e46 KVM: x86: hyper-v: Cache guest CPUID leaves determining features availability
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:38 -04:00
Vitaly Kuznetsov
644f706719 KVM: x86: hyper-v: Introduce KVM_CAP_HYPERV_ENFORCE_CPUID
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 <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:38 -04:00
Vitaly Kuznetsov
f15cdceab5 asm-generic/hyperv: add HV_STATUS_ACCESS_DENIED definition
From TLFSv6.0b, this status means: "The caller did not possess sufficient
access rights to perform the requested operation."

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:38 -04:00
Vineeth Pillai
1183646a67 KVM: SVM: hyper-v: Direct Virtual Flush support
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 6f6a657c99 ("KVM/Hyper-V/VMX: Add direct tlb flush support")

Signed-off-by: Vineeth Pillai <viremana@linux.microsoft.com>
Message-Id: <fc8d24d8eb7017266bb961e39a171b0caf298d7f.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:38 -04:00
Vineeth Pillai
c4327f15df KVM: SVM: hyper-v: Enlightened MSR-Bitmap support
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 ceef7d10df ("KVM: x86: VMX: hyper-v: Enlightened MSR-Bitmap support")

Signed-off-by: Vineeth Pillai <viremana@linux.microsoft.com>
Message-Id: <87df0710f95d28b91cc4ea014fc4d71056eebbee.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:37 -04:00
Vineeth Pillai
1e0c7d4075 KVM: SVM: hyper-v: Remote TLB flush for SVM
Enable remote TLB flush for SVM.

Signed-off-by: Vineeth Pillai <viremana@linux.microsoft.com>
Message-Id: <1ee364e397e142aed662d2920d198cd03772f1a5.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:37 -04:00
Vineeth Pillai
59d21d67f3 KVM: SVM: Software reserved fields
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 <viremana@linux.microsoft.com>
Message-Id: <a1f17a43a8e9e751a1a9cc0281649d71bdbf721b.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:37 -04:00
Vineeth Pillai
3c86c0d3db KVM: x86: hyper-v: Move the remote TLB flush logic out of vmx
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 <viremana@linux.microsoft.com>
Message-Id: <4f4e4ca19778437dae502f44363a38e99e3ef5d1.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:36 -04:00
Vineeth Pillai
32431fb253 hyperv: SVM enlightened TLB flush support flag
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 <viremana@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Message-Id: <a060f872d0df1955e52e30b877b3300485edb27c.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:36 -04:00
Vineeth Pillai
a6c776a952 hyperv: Detect Nested virtualization support for SVM
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 <viremana@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Message-Id: <43b25ff21cd2d9a51582033c9bdd895afefac056.1622730232.git.viremana@linux.microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:36 -04:00
Krish Sadhukhan
d5a0483f9f KVM: nVMX: nSVM: Add a new VCPU statistic to show if VCPU is in guest mode
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 <Krish.Sadhukhan@oracle.com>
Message-Id: <20210609180340.104248-3-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:36 -04:00
Krish Sadhukhan
b93af02c67 KVM: nVMX: nSVM: 'nested_run' should count guest-entry attempts that make it 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 <Krish.Sadhukhan@oracle.com>
Message-Id: <20210609180340.104248-2-krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:35 -04:00
Sean Christopherson
ecc513e5bb KVM: x86: Drop "pre_" from enter/leave_smm() helpers
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 <seanjc@google.com>
Message-Id: <20210609185619.992058-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:35 -04:00
Sean Christopherson
0128116550 KVM: x86: Drop .post_leave_smm(), i.e. the manual post-RSM MMU reset
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 <seanjc@google.com>
Message-Id: <20210609185619.992058-9-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:35 -04:00
Sean Christopherson
1270e647c8 KVM: x86: Rename SMM tracepoint to make it reflect reality
Rename the SMM tracepoint, which handles both entering and exiting SMM,
from kvm_enter_smm to kvm_smm_transition.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210609185619.992058-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:35 -04:00
Sean Christopherson
0d7ee6f4b5 KVM: x86: Move "entering SMM" tracepoint into kvm_smm_changed()
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 <seanjc@google.com>
Message-Id: <20210609185619.992058-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:34 -04:00
Sean Christopherson
dc87275f47 KVM: x86: Move (most) SMM hflags modifications into kvm_smm_changed()
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 <seanjc@google.com>
Message-Id: <20210609185619.992058-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:34 -04:00
Sean Christopherson
fa75e08bbe KVM: x86: Invoke kvm_smm_changed() immediately after clearing SMM flag
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 <seanjc@google.com>
Message-Id: <20210609185619.992058-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:34 -04:00
Sean Christopherson
edce46548b KVM: x86: Replace .set_hflags() with dedicated .exiting_smm() helper
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 <seanjc@google.com>
Message-Id: <20210609185619.992058-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:34 -04:00
Sean Christopherson
25b17226cd KVM: x86: Emulate triple fault shutdown if RSM emulation fails
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 <seanjc@google.com>
Message-Id: <20210609185619.992058-3-seanjc@google.com>
[Return X86EMUL_CONTINUE after triple fault. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:33 -04:00
Vitaly Kuznetsov
4651fc56ba KVM: x86: Drop vendor specific functions for APICv/AVIC enablement
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 <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210609150911.1471882-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:33 -04:00
Vitaly Kuznetsov
fdf513e37a KVM: x86: Use common 'enable_apicv' variable for both APICv and AVIC
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 <seanjc@google.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210609150911.1471882-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:33 -04:00
Sergey Senozhatsky
7d62874f69 kvm: x86: implement KVM PM-notifier
Implement PM hibernation/suspend prepare notifiers so that KVM
can reliably set PVCLOCK_GUEST_STOPPED on VCPUs and properly
suspend VMs.

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Message-Id: <20210606021045.14159-2-senozhatsky@chromium.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:33 -04:00
Sergey Senozhatsky
2fdef3a2ae kvm: add PM-notifier
Add KVM PM-notifier so that architectures can have arch-specific
VM suspend/resume routines. Such architectures need to select
CONFIG_HAVE_KVM_PM_NOTIFIER and implement kvm_arch_pm_notifier().

Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20210606021045.14159-1-senozhatsky@chromium.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:32 -04:00
Jim Mattson
768d134d8c KVM: selftests: Introduce x2APIC register manipulation functions
Standardize reads and writes of the x2APIC MSRs.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Message-Id: <20210604172611.281819-11-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:32 -04:00
Jim Mattson
4c63c92340 KVM: selftests: Hoist APIC functions out of individual tests
Move the APIC functions into the library to encourage code reuse and
to avoid unintended deviations.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Message-Id: <20210604172611.281819-10-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:32 -04:00
Jim Mattson
150a282d43 KVM: selftests: Move APIC definitions into a separate file
Processor.h is a hodgepodge of definitions. Though the local APIC is
technically built into the CPU these days, move the APIC definitions
into a new header file: apic.h.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Message-Id: <20210604172611.281819-9-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:31 -04:00
Jim Mattson
966eefb896 KVM: nVMX: Disable vmcs02 posted interrupts if vmcs12 PID isn't mappable
Don't allow posted interrupts to modify a stale posted interrupt
descriptor (including the initial value of 0).

Empirical tests on real hardware reveal that a posted interrupt
descriptor referencing an unbacked address has PCI bus error semantics
(reads as all 1's; writes are ignored). However, kvm can't distinguish
unbacked addresses from device-backed (MMIO) addresses, so it should
really ask userspace for an MMIO completion. That's overly
complicated, so just punt with KVM_INTERNAL_ERROR.

Don't return the error until the posted interrupt descriptor is
actually accessed. We don't want to break the existing kvm-unit-tests
that assume they can launch an L2 VM with a posted interrupt
descriptor that references MMIO space in L1.

Fixes: 6beb7bd52e ("kvm: nVMX: Refactor nested_get_vmcs12_pages()")
Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210604172611.281819-8-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:31 -04:00
Jim Mattson
0fe998b295 KVM: nVMX: Fail on MMIO completion for nested posted interrupts
When the kernel has no mapping for the vmcs02 virtual APIC page,
userspace MMIO completion is necessary to process nested posted
interrupts. This is not a configuration that KVM supports. Rather than
silently ignoring the problem, try to exit to userspace with
KVM_INTERNAL_ERROR.

Note that the event that triggers this error is consumed as a
side-effect of a call to kvm_check_nested_events. On some paths
(notably through kvm_vcpu_check_block), the error is dropped. In any
case, this is an incremental improvement over always ignoring the
error.

Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210604172611.281819-7-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:31 -04:00
Jim Mattson
4fe09bcf14 KVM: x86: Add a return code to kvm_apic_accept_events
No functional change intended. At present, the only negative value
returned by kvm_check_nested_events is -EBUSY.

Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210604172611.281819-6-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:31 -04:00
Jim Mattson
a5f6909a71 KVM: x86: Add a return code to inject_pending_event
No functional change intended. At present, 'r' will always be -EBUSY
on a control transfer to the 'out' label.

Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210604172611.281819-5-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:30 -04:00
Jim Mattson
650293c3de KVM: nVMX: Add a return code to vmx_complete_nested_posted_interrupt
No functional change intended.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Message-Id: <20210604172611.281819-4-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:30 -04:00
Jim Mattson
d82ee28195 KVM: x86: Remove guest mode check from kvm_check_nested_events
A survey of the callsites reveals that they all ensure the vCPU is in
guest mode before calling kvm_check_nested_events. Remove this dead
code so that the only negative value this function returns (at the
moment) is -EBUSY.

Signed-off-by: Jim Mattson <jmattson@google.com>
Message-Id: <20210604172611.281819-2-jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:30 -04:00