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authorPaolo Bonzini <pbonzini@redhat.com>2018-01-11 16:55:24 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2018-01-11 16:55:24 +0100
commitbd89525a823ce6edddcedbe9aed79faa1b9cf544 (patch)
tree0fa8919b8016ba59387b83ca38c0d39cf99bbb73 /arch/x86/kvm/vmx.c
parentx86: kvm: propagate register_shrinker return code (diff)
downloadlinux-bd89525a823ce6edddcedbe9aed79faa1b9cf544.tar.xz
linux-bd89525a823ce6edddcedbe9aed79faa1b9cf544.zip
KVM: x86: emulate #UD while in guest mode
This reverts commits ae1f57670703656cc9f293722c3b8b6782f8ab3f and ac9b305caa0df6f5b75d294e4b86c1027648991e. If the hardware doesn't support MOVBE, but L0 sets CPUID.01H:ECX.MOVBE in L1's emulated CPUID information, then L1 is likely to pass that CPUID bit through to L2. L2 will expect MOVBE to work, but if L1 doesn't intercept #UD, then any MOVBE instruction executed in L2 will raise #UD, and the exception will be delivered in L2. Commit ac9b305caa0df6f5b75d294e4b86c1027648991e is a better and more complete version of ae1f57670703 ("KVM: nVMX: Do not emulate #UD while in guest mode"); however, neither considers the above case. Suggested-by: Jim Mattson <jmattson@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to '')
-rw-r--r--arch/x86/kvm/vmx.c5
1 files changed, 1 insertions, 4 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5c14d65f676a..427fd3200dd8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1887,7 +1887,7 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu)
{
u32 eb;
- eb = (1u << PF_VECTOR) | (1u << MC_VECTOR) |
+ eb = (1u << PF_VECTOR) | (1u << UD_VECTOR) | (1u << MC_VECTOR) |
(1u << DB_VECTOR) | (1u << AC_VECTOR);
if ((vcpu->guest_debug &
(KVM_GUESTDBG_ENABLE | KVM_GUESTDBG_USE_SW_BP)) ==
@@ -1905,8 +1905,6 @@ static void update_exception_bitmap(struct kvm_vcpu *vcpu)
*/
if (is_guest_mode(vcpu))
eb |= get_vmcs12(vcpu)->exception_bitmap;
- else
- eb |= 1u << UD_VECTOR;
vmcs_write32(EXCEPTION_BITMAP, eb);
}
@@ -5917,7 +5915,6 @@ static int handle_exception(struct kvm_vcpu *vcpu)
return 1; /* already handled by vmx_vcpu_run() */
if (is_invalid_opcode(intr_info)) {
- WARN_ON_ONCE(is_guest_mode(vcpu));
er = emulate_instruction(vcpu, EMULTYPE_TRAP_UD);
if (er == EMULATE_USER_EXIT)
return 0;