| From b33bb78a1fada6445c265c585ee0dd0fc6279102 Mon Sep 17 00:00:00 2001 |
| From: Sean Christopherson <seanjc@google.com> |
| Date: Tue, 22 Jun 2021 10:22:44 -0700 |
| Subject: KVM: nVMX: Handle split-lock #AC exceptions that happen in L2 |
| |
| 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 |
| @@ -5787,6 +5787,9 @@ 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 |
| @@ -4755,7 +4755,7 @@ 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; |
| @@ -4864,7 +4864,7 @@ 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 |
| @@ -352,6 +352,7 @@ 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 update_exception_bitmap(struct kvm_vcpu *vcpu); |
| void vmx_update_msr_bitmap(struct kvm_vcpu *vcpu); |
| bool vmx_nmi_blocked(struct kvm_vcpu *vcpu); |