From: Maxim Levitsky <mlevitsk@redhat.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
"Maciej S . Szmigiero" <maciej.szmigiero@oracle.com>
Subject: Re: [PATCH v2 07/11] KVM: x86: Trace re-injected exceptions
Date: Thu, 28 Apr 2022 12:48:39 +0300 [thread overview]
Message-ID: <339842b37b50c922b94f609bc20bad3edc74dd1f.camel@redhat.com> (raw)
In-Reply-To: <20220423021411.784383-8-seanjc@google.com>
On Sat, 2022-04-23 at 02:14 +0000, Sean Christopherson wrote:
> 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>
> ---
> 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 951d0a78ccda..c3ee8dc00d3a 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -9393,6 +9393,11 @@ 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);
> @@ -9450,13 +9455,6 @@ 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);
> @@ -9470,6 +9468,10 @@ 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;
> }
>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Best regards,
Maxim Levitsky
next prev parent reply other threads:[~2022-04-28 9:59 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-23 2:14 [PATCH v2 00/11] KVM: SVM: Fix soft int/ex re-injection Sean Christopherson
2022-04-23 2:14 ` [PATCH v2 01/11] KVM: nSVM: Sync next_rip field from vmcb12 to vmcb02 Sean Christopherson
2022-04-28 9:33 ` Maxim Levitsky
2022-04-23 2:14 ` [PATCH v2 02/11] KVM: SVM: Don't BUG if userspace injects a soft interrupt with GIF=0 Sean Christopherson
2022-04-28 7:35 ` Maxim Levitsky
2022-04-28 13:27 ` Maciej S. Szmigiero
2022-04-28 14:34 ` Maxim Levitsky
2022-04-28 15:04 ` Sean Christopherson
2022-04-28 16:33 ` Maciej S. Szmigiero
2022-04-23 2:14 ` [PATCH v2 03/11] KVM: SVM: Unwind "speculative" RIP advancement if INTn injection "fails" Sean Christopherson
2022-04-23 2:14 ` [PATCH v2 04/11] KVM: SVM: Stuff next_rip on emulated INT3 injection if NRIPS is supported Sean Christopherson
2022-04-23 2:14 ` [PATCH v2 05/11] KVM: SVM: Re-inject INT3/INTO instead of retrying the instruction Sean Christopherson
2022-04-25 22:59 ` Maciej S. Szmigiero
2022-04-28 9:37 ` Maxim Levitsky
2022-04-28 13:36 ` Maciej S. Szmigiero
2022-04-28 14:25 ` Sean Christopherson
2022-04-23 2:14 ` [PATCH v2 06/11] KVM: SVM: Re-inject INTn instead of retrying the insn on "failure" Sean Christopherson
2022-04-23 2:14 ` [PATCH v2 07/11] KVM: x86: Trace re-injected exceptions Sean Christopherson
2022-04-28 9:48 ` Maxim Levitsky [this message]
2022-04-23 2:14 ` [PATCH v2 08/11] KVM: x86: Print error code in exception injection tracepoint iff valid Sean Christopherson
2022-04-28 9:49 ` Maxim Levitsky
2022-04-23 2:14 ` [PATCH v2 09/11] KVM: x86: Differentiate Soft vs. Hard IRQs vs. reinjected in tracepoint Sean Christopherson
2022-04-25 22:59 ` Maciej S. Szmigiero
2022-04-23 2:14 ` [PATCH v2 10/11] KVM: selftests: nSVM: Add svm_nested_soft_inject_test Sean Christopherson
2022-04-25 23:00 ` Maciej S. Szmigiero
2022-04-23 2:14 ` [PATCH v2 11/11] KVM: SVM: Drop support for CPUs without NRIPS (NextRIP Save) support Sean Christopherson
2022-04-24 9:34 ` Maxim Levitsky
2022-04-25 23:00 ` Maciej S. Szmigiero
2022-04-25 23:01 ` [PATCH v2 00/11] KVM: SVM: Fix soft int/ex re-injection Maciej S. Szmigiero
2022-04-27 18:21 ` Maciej S. Szmigiero
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