KVM: x86: don't expose MSR_IA32_UMWAIT_CONTROL unconditionally
This msr is only available when the host supports WAITPKG feature.
This breaks a nested guest, if the L1 hypervisor is set to ignore
unknown msrs, because the only other safety check that the
kernel does is that it attempts to read the msr and
rejects it if it gets an exception.
Cc: stable@vger.kernel.org
Fixes: 6e3ba4abce
("KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL")
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20200523161455.3940-3-mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:

committed by
Paolo Bonzini

parent
0abcc8f65c
commit
f4cfcd2d5a
@@ -5242,6 +5242,10 @@ static void kvm_init_msr_list(void)
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if (!kvm_cpu_cap_has(X86_FEATURE_RDTSCP))
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continue;
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break;
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case MSR_IA32_UMWAIT_CONTROL:
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if (!kvm_cpu_cap_has(X86_FEATURE_WAITPKG))
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continue;
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break;
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case MSR_IA32_RTIT_CTL:
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case MSR_IA32_RTIT_STATUS:
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if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT))
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