From a61d7c5432ac5a953bbcec17af031661c2bd201d Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Mon, 2 May 2022 00:07:31 +0200 Subject: [PATCH] KVM: x86: Trace re-injected exceptions 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 Reviewed-by: Maxim Levitsky Signed-off-by: Maciej S. Szmigiero Message-Id: <25470690a38b4d2b32b6204875dd35676c65c9f2.1651440202.git.maciej.szmigiero@oracle.com> Signed-off-by: Paolo Bonzini --- 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 de4762517569..d07428e660e3 100644 --- a/arch/x86/kvm/trace.h +++ b/arch/x86/kvm/trace.h @@ -358,25 +358,29 @@ 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 921b1139c303..c9f3ad89bf4c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9408,6 +9408,11 @@ int kvm_check_nested_events(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; static_call(kvm_x86_queue_exception)(vcpu); @@ -9465,13 +9470,6 @@ static int 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); @@ -9485,6 +9483,10 @@ static int 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; } -- GitLab