From: Sean Christopherson seanjc@google.com
[ Upstream commit a61d7c5432ac5a953bbcec17af031661c2bd201d ]
Trace exceptions that are re-injected, not just those that KVM is injecting for the first time. Debugging re-injection bugs is painful enough as is, not having visibility into what KVM is doing only makes things worse.
Delay propagating pending=>injected in the non-reinjection path so that the tracing can properly identify reinjected exceptions.
Signed-off-by: Sean Christopherson seanjc@google.com Reviewed-by: Maxim Levitsky mlevitsk@redhat.com Signed-off-by: Maciej S. Szmigiero maciej.szmigiero@oracle.com Message-Id: 25470690a38b4d2b32b6204875dd35676c65c9f2.1651440202.git.maciej.szmigiero@oracle.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Stable-dep-of: 5623f751bd9c ("KVM: x86: Treat #DBs from the emulator as fault-like (code and DR7.GD=1)") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kvm/trace.h | 12 ++++++++---- arch/x86/kvm/x86.c | 16 +++++++++------- 2 files changed, 17 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h index a2835d784f4b..3d4988ea8b57 100644 --- a/arch/x86/kvm/trace.h +++ b/arch/x86/kvm/trace.h @@ -304,25 +304,29 @@ TRACE_EVENT(kvm_inj_virq, * Tracepoint for kvm interrupt injection: */ TRACE_EVENT(kvm_inj_exception, - TP_PROTO(unsigned exception, bool has_error, unsigned error_code), - TP_ARGS(exception, has_error, error_code), + TP_PROTO(unsigned exception, bool has_error, unsigned error_code, + bool reinjected), + TP_ARGS(exception, has_error, error_code, reinjected),
TP_STRUCT__entry( __field( u8, exception ) __field( u8, has_error ) __field( u32, error_code ) + __field( bool, reinjected ) ),
TP_fast_assign( __entry->exception = exception; __entry->has_error = has_error; __entry->error_code = error_code; + __entry->reinjected = reinjected; ),
- TP_printk("%s (0x%x)", + TP_printk("%s (0x%x)%s", __print_symbolic(__entry->exception, kvm_trace_sym_exc), /* FIXME: don't print error_code if not present */ - __entry->has_error ? __entry->error_code : 0) + __entry->has_error ? __entry->error_code : 0, + __entry->reinjected ? " [reinjected]" : "") );
/* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f3473418dcd5..17bb3d0e2d13 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8347,6 +8347,11 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu)
static void kvm_inject_exception(struct kvm_vcpu *vcpu) { + trace_kvm_inj_exception(vcpu->arch.exception.nr, + vcpu->arch.exception.has_error_code, + vcpu->arch.exception.error_code, + vcpu->arch.exception.injected); + if (vcpu->arch.exception.error_code && !is_protmode(vcpu)) vcpu->arch.exception.error_code = false; kvm_x86_ops.queue_exception(vcpu); @@ -8404,13 +8409,6 @@ static void inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit
/* try to inject new event if pending */ if (vcpu->arch.exception.pending) { - trace_kvm_inj_exception(vcpu->arch.exception.nr, - vcpu->arch.exception.has_error_code, - vcpu->arch.exception.error_code); - - vcpu->arch.exception.pending = false; - vcpu->arch.exception.injected = true; - if (exception_type(vcpu->arch.exception.nr) == EXCPT_FAULT) __kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) | X86_EFLAGS_RF); @@ -8424,6 +8422,10 @@ static void inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit }
kvm_inject_exception(vcpu); + + vcpu->arch.exception.pending = false; + vcpu->arch.exception.injected = true; + can_inject = false; }