[PATCH 5.13 074/800] KVM: nVMX: Handle split-lock #AC exceptions that happen in L2
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-07-12 08:15:33
Also in:
lkml
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 <redacted>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: [off-list ref]
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@@ -5806,6 +5806,9 @@ 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
@@ -4829,7 +4829,7 @@ 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;
@@ -4937,7 +4937,7 @@ 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
@@ -387,6 +387,7 @@ void vmx_get_segment(struct kvm_vcpu *vc void vmx_set_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg); u64 construct_eptp(struct kvm_vcpu *vcpu, hpa_t 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);