From: Sean Christopherson seanjc@google.com
commit b33bb78a1fada6445c265c585ee0dd0fc6279102 upstream.
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@intel.com Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20210622172244.3561540-1-seanjc@google.com Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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(-)
--- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -5775,6 +5775,9 @@ static bool nested_vmx_l0_wants_exit(str 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; return false; case EXIT_REASON_EXTERNAL_INTERRUPT: return true; --- a/arch/x86/kvm/vmx/vmcs.h +++ b/arch/x86/kvm/vmx/vmcs.h @@ -117,6 +117,11 @@ static inline bool is_gp_fault(u32 intr_ return is_exception_n(intr_info, GP_VECTOR); }
+static inline bool is_alignment_check(u32 intr_info) +{ + return is_exception_n(intr_info, AC_VECTOR); +} + static inline bool is_machine_check(u32 intr_info) { return is_exception_n(intr_info, MC_VECTOR); --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4796,7 +4796,7 @@ static int handle_machine_check(struct k * - Guest has #AC detection enabled in CR0 * - Guest EFLAGS has AC bit set */ -static inline bool guest_inject_ac(struct kvm_vcpu *vcpu) +bool vmx_guest_inject_ac(struct kvm_vcpu *vcpu) { if (!boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT)) return true; @@ -4905,7 +4905,7 @@ static int handle_exception_nmi(struct k kvm_run->debug.arch.exception = ex_no; break; case AC_VECTOR: - if (guest_inject_ac(vcpu)) { + if (vmx_guest_inject_ac(vcpu)) { kvm_queue_exception_e(vcpu, AC_VECTOR, error_code); return 1; } --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -379,6 +379,7 @@ void vmx_set_segment(struct kvm_vcpu *vc u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa, int root_level);
+bool vmx_guest_inject_ac(struct kvm_vcpu *vcpu); void vmx_update_exception_bitmap(struct kvm_vcpu *vcpu); void vmx_update_msr_bitmap(struct kvm_vcpu *vcpu); bool vmx_nmi_blocked(struct kvm_vcpu *vcpu);