On 6/23/2021 1:22 AM, Sean Christopherson wrote:
Mark #ACs that won't be reinjected to the guest as wanted by L0 so that
KVM handles split-lock #AC from L2 instead of forwarding the exception to
L1. Split-lock #AC isn't yet virtualized, i.e. L1 will treat it like a
regular #AC and do the wrong thing, e.g. reinject it into L2.
Fixes: e6f8b6c12f03 ("KVM: VMX: Extend VMXs #AC interceptor to handle split lock #AC in guest")
Cc: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 3 +++
arch/x86/kvm/vmx/vmcs.h | 5 +++++
arch/x86/kvm/vmx/vmx.c | 4 ++--
arch/x86/kvm/vmx/vmx.h | 1 +
4 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 183fd9d62fc5..fa3f50f0a3fa 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5833,6 +5833,9 @@ static bool nested_vmx_l0_wants_exit(struct kvm_vcpu *vcpu,
else if (is_breakpoint(intr_info) &&
vcpu->guest_debug & KVM_GUESTDBG_USE_SW_BP)
return true;
+ else if (is_alignment_check(intr_info) &&
+ !vmx_guest_inject_ac(vcpu))
+ return true;
Why choose to check in nested_vmx_l0_wants_exit, not in
nested_vmx_l1_wants_exit()?
return false;
case EXIT_REASON_EXTERNAL_INTERRUPT:
return true;
