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Date:   Wed,  4 Oct 2023 18:29:35 -0700
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Subject: Re: [PATCH v3] KVM: x86: Use fast path for Xen timer delivery
From:   Sean Christopherson <seanjc@google.com>
To:     Sean Christopherson <seanjc@google.com>, kvm <kvm@vger.kernel.org>,
        David Woodhouse <dwmw2@infradead.org>
Cc:     Paul Durrant <paul@xen.org>, Paolo Bonzini <pbonzini@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>, linux-kernel@vger.kernel.org
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On Sat, 30 Sep 2023 14:58:35 +0100, David Woodhouse wrote:
> Most of the time there's no need to kick the vCPU and deliver the timer
> event through kvm_xen_inject_timer_irqs(). Use kvm_xen_set_evtchn_fast()
> directly from the timer callback, and only fall back to the slow path
> when it's necessary to do so.
> 
> This gives a significant improvement in timer latency testing (using
> nanosleep() for various periods and then measuring the actual time
> elapsed).
> 
> [...]

Applied to kvm-x86 xen, thanks!

[1/1] KVM: x86: Use fast path for Xen timer delivery
      https://github.com/kvm-x86/linux/commit/77c9b9dea4fb

--
https://github.com/kvm-x86/linux/tree/next