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| author | Jim Mattson <jmattson@google.com> | 2019-11-22 15:43:55 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-11-23 11:34:46 +0100 |
| commit | 85c9aae9ac8b228f2134b56d4fc743afc446947a (patch) | |
| tree | 5e0cece28dead2c9c85e77da2c24db92d1e60870 /arch/x86/kvm/vmx/vmx.c | |
| parent | ad5996d9a0e8019c3ae5151e687939369acfe044 (diff) | |
| download | lwn-85c9aae9ac8b228f2134b56d4fc743afc446947a.tar.gz lwn-85c9aae9ac8b228f2134b56d4fc743afc446947a.zip | |
kvm: nVMX: Relax guest IA32_FEATURE_CONTROL constraints
Commit 37e4c997dadf ("KVM: VMX: validate individual bits of guest
MSR_IA32_FEATURE_CONTROL") broke the KVM_SET_MSRS ABI by instituting
new constraints on the data values that kvm would accept for the guest
MSR, IA32_FEATURE_CONTROL. Perhaps these constraints should have been
opt-in via a new KVM capability, but they were applied
indiscriminately, breaking at least one existing hypervisor.
Relax the constraints to allow either or both of
FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX and
FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX to be set when nVMX is
enabled. This change is sufficient to fix the aforementioned breakage.
Fixes: 37e4c997dadf ("KVM: VMX: validate individual bits of guest MSR_IA32_FEATURE_CONTROL")
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index d39475e2d44e..d175429c91b0 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7115,10 +7115,12 @@ static void vmx_cpuid_update(struct kvm_vcpu *vcpu) if (nested_vmx_allowed(vcpu)) to_vmx(vcpu)->msr_ia32_feature_control_valid_bits |= + FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX | FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX; else to_vmx(vcpu)->msr_ia32_feature_control_valid_bits &= - ~FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX; + ~(FEATURE_CONTROL_VMXON_ENABLED_INSIDE_SMX | + FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX); if (nested_vmx_allowed(vcpu)) { nested_vmx_cr_fixed1_bits_update(vcpu); |