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Subject: Re: [PATCH] Move VMEnter and VMExit tracepoints closer to the actual
 event
To:     Sean Christopherson <seanjc@google.com>,
        Stefano De Venuto <stefano.devenuto99@gmail.com>
Cc:     linux-kernel@vger.kernel.org, vkuznets@redhat.com,
        wanpengli@tencent.com, jmattson@google.com, x86@kernel.org,
        hpa@zytor.com, kvm@vger.kernel.org, rostedt@goodmis.org,
        y.karadz@gmail.com, Dario Faggioli <dfaggioli@suse.com>
References: <20210519182303.2790-1-stefano.devenuto99@gmail.com>
 <YKaBEn6oUXaVAb0K@google.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <ab44e5b1-4448-d6c8-6cda-5e41866f69f1@redhat.com>
Date:   Thu, 20 May 2021 18:18:38 +0200
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On 20/05/21 17:32, Sean Christopherson wrote:
> On VMX, I think the tracepoint can be moved below the VMWRITEs without much
> contention (though doing so is likely a nop), but moving it below
> kvm_load_guest_xsave_state() requires a bit more discussion.

Indeed; as a rule of thumb, the tracepoint on SVM could match the 
clgi/stgi region, and on VMX it could be placed in a similar location.

Paolo

> I 100% agree that the current behavior can be a bit confusing, but I wonder if
> we'd be better off "solving" that problem through documentation.