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authorOliver Upton <oupton@google.com>2020-02-29 11:30:14 -0800
committerPaolo Bonzini <pbonzini@redhat.com>2020-03-01 19:26:31 +0100
commit86f7e90ce840aa1db407d3ea6e9b3a52b2ce923c (patch)
tree7679ea76c6ff795ed0d53bc755aa43d77b4ce7a5
parente951445f4d3b5d0df69c0c5d18ab1e9058c20e52 (diff)
downloadlinux-sh-86f7e90ce840aa1db407d3ea6e9b3a52b2ce923c.tar.gz
KVM: VMX: check descriptor table exits on instruction emulation
KVM emulates UMIP on hardware that doesn't support it by setting the 'descriptor table exiting' VM-execution control and performing instruction emulation. When running nested, this emulation is broken as KVM refuses to emulate L2 instructions by default. Correct this regression by allowing the emulation of descriptor table instructions if L1 hasn't requested 'descriptor table exiting'. Fixes: 07721feee46b ("KVM: nVMX: Don't emulate instructions in guest mode") Reported-by: Jan Kiszka <jan.kiszka@web.de> Cc: stable@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Jim Mattson <jmattson@google.com> Signed-off-by: Oliver Upton <oupton@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/vmx/vmx.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index ce70a71037ed..40b1e6138cd5 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7177,6 +7177,7 @@ static int vmx_check_intercept_io(struct kvm_vcpu *vcpu,
else
intercept = nested_vmx_check_io_bitmaps(vcpu, port, size);
+ /* FIXME: produce nested vmexit and return X86EMUL_INTERCEPTED. */
return intercept ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE;
}
@@ -7206,6 +7207,20 @@ static int vmx_check_intercept(struct kvm_vcpu *vcpu,
case x86_intercept_outs:
return vmx_check_intercept_io(vcpu, info);
+ case x86_intercept_lgdt:
+ case x86_intercept_lidt:
+ case x86_intercept_lldt:
+ case x86_intercept_ltr:
+ case x86_intercept_sgdt:
+ case x86_intercept_sidt:
+ case x86_intercept_sldt:
+ case x86_intercept_str:
+ if (!nested_cpu_has2(vmcs12, SECONDARY_EXEC_DESC))
+ return X86EMUL_CONTINUE;
+
+ /* FIXME: produce nested vmexit and return X86EMUL_INTERCEPTED. */
+ break;
+
/* TODO: check more intercepts... */
default:
break;