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| author |   Sean Christopherson <seanjc@google.com> | 2022-08-30 23:16:06 +0000 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2022-09-26 12:03:10 -0400 |
| commit | 2b384165f4d15540f94998b751f50058642ad110 (patch) | |
| tree | bea78bacbd9cef4e10f97feb5e75aef8441ee82d /arch/x86/kvm/vmx/nested.c | |
| parent | KVM: x86: Evaluate ability to inject SMI/NMI/IRQ after potential VM-Exit (diff) | |
| download | linux-dev-2b384165f4d15540f94998b751f50058642ad110.tar.xz linux-dev-2b384165f4d15540f94998b751f50058642ad110.zip | |
KVM: nVMX: Add a helper to identify low-priority #DB traps
Add a helper to identify "low"-priority #DB traps, i.e. trap-like #DBs
that aren't TSS T flag #DBs, and tweak the related code to operate on any
queued exception. A future commit will separate exceptions that are
intercepted by L1, i.e. cause nested VM-Exit, from those that do NOT
trigger nested VM-Exit. I.e. there will be multiple exception structs
and multiple invocations of the helpers.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20220830231614.3580124-20-seanjc@google.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx/nested.c')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 68533ae52d90..e773f3d8e188 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3912,14 +3912,24 @@ static void nested_vmx_inject_exception_vmexit(struct kvm_vcpu *vcpu, * from the emulator (because such #DBs are fault-like and thus don't trigger * actions that fire on instruction retire). */ -static inline unsigned long vmx_get_pending_dbg_trap(struct kvm_vcpu *vcpu) +static unsigned long vmx_get_pending_dbg_trap(struct kvm_queued_exception *ex) { - if (!vcpu->arch.exception.pending || - vcpu->arch.exception.vector != DB_VECTOR) + if (!ex->pending || ex->vector != DB_VECTOR) return 0; /* General Detect #DBs are always fault-like. */ - return vcpu->arch.exception.payload & ~DR6_BD; + return ex->payload & ~DR6_BD; +} + +/* + * Returns true if there's a pending #DB exception that is lower priority than + * a pending Monitor Trap Flag VM-Exit. TSS T-flag #DBs are not emulated by + * KVM, but could theoretically be injected by userspace. Note, this code is + * imperfect, see above. + */ +static bool vmx_is_low_priority_db_trap(struct kvm_queued_exception *ex) +{ + return vmx_get_pending_dbg_trap(ex) & ~DR6_BT; } /* @@ -3931,8 +3941,9 @@ static inline unsigned long vmx_get_pending_dbg_trap(struct kvm_vcpu *vcpu) */ static void nested_vmx_update_pending_dbg(struct kvm_vcpu *vcpu) { - unsigned long pending_dbg = vmx_get_pending_dbg_trap(vcpu); + unsigned long pending_dbg; + pending_dbg = vmx_get_pending_dbg_trap(&vcpu->arch.exception); if (pending_dbg) vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS, pending_dbg); } @@ -4002,7 +4013,7 @@ static int vmx_check_nested_events(struct kvm_vcpu *vcpu) * prioritize SMI over MTF and trap-like #DBs. */ if (vcpu->arch.exception.pending && - !(vmx_get_pending_dbg_trap(vcpu) & ~DR6_BT)) { + !vmx_is_low_priority_db_trap(&vcpu->arch.exception)) { if (block_nested_exceptions) return -EBUSY; if (!nested_vmx_check_exception(vcpu, &exit_qual)) |