From: Sean Christopherson Date: Tue, 22 Jun 2021 17:22:44 +0000 (-0700) Subject: KVM: nVMX: Handle split-lock #AC exceptions that happen in L2 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=39d0dfab6c3e6ab7052b502fe4ad24a9359a9de6;p=linux-block.git KVM: nVMX: Handle split-lock #AC exceptions that happen in L2 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 Signed-off-by: Sean Christopherson Message-Id: <20210622172244.3561540-1-seanjc@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 32e6f33c2c45..ec8803bdc575 100644 --- 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(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; return false; case EXIT_REASON_EXTERNAL_INTERRUPT: return true; diff --git a/arch/x86/kvm/vmx/vmcs.h b/arch/x86/kvm/vmx/vmcs.h index 1472c6c376f7..571d9ad80a59 100644 --- 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_info) 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); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 45877364e682..de24d3826788 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4755,7 +4755,7 @@ static int handle_machine_check(struct kvm_vcpu *vcpu) * - 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 kvm_vcpu *vcpu) 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; } diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index ae3a89ac0600..73d87d44b657 100644 --- 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 *vcpu, struct kvm_segment *var, int seg); 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);