lkml.org 
[lkml]   [2019]   [Sep]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH AUTOSEL 4.19 135/167] KVM: VMX: check CPUID before allowing read/write of IA32_XSS
    Date
    From: Wanpeng Li <wanpengli@tencent.com>

    [ Upstream commit 4d763b168e9c5c366b05812c7bba7662e5ea3669 ]

    Raise #GP when guest read/write IA32_XSS, but the CPUID bits
    say that it shouldn't exist.

    Fixes: 203000993de5 (kvm: vmx: add MSR logic for XSAVES)
    Reported-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
    Reported-by: Tao Xu <tao3.xu@intel.com>
    Cc: Paolo Bonzini <pbonzini@redhat.com>
    Cc: Radim Krčmář <rkrcmar@redhat.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    arch/x86/kvm/vmx.c | 10 ++++++++--
    1 file changed, 8 insertions(+), 2 deletions(-)

    diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
    index 82253d31842a2..2938b4bcc9684 100644
    --- a/arch/x86/kvm/vmx.c
    +++ b/arch/x86/kvm/vmx.c
    @@ -4135,7 +4135,10 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
    return vmx_get_vmx_msr(&vmx->nested.msrs, msr_info->index,
    &msr_info->data);
    case MSR_IA32_XSS:
    - if (!vmx_xsaves_supported())
    + if (!vmx_xsaves_supported() ||
    + (!msr_info->host_initiated &&
    + !(guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) &&
    + guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))))
    return 1;
    msr_info->data = vcpu->arch.ia32_xss;
    break;
    @@ -4302,7 +4305,10 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
    return 1;
    return vmx_set_vmx_msr(vcpu, msr_index, data);
    case MSR_IA32_XSS:
    - if (!vmx_xsaves_supported())
    + if (!vmx_xsaves_supported() ||
    + (!msr_info->host_initiated &&
    + !(guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) &&
    + guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))))
    return 1;
    /*
    * The only supported bit as of Skylake is bit 8, but
    --
    2.20.1
    \
     
     \ /
      Last update: 2019-09-03 18:30    [W:4.376 / U:1.236 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site