On Wed, 20 Nov 2019 at 02:36, Sean Christopherson <sean.j.christopherson@xxxxxxxxx> wrote: [...] > > From 1ea8ff1aa766928c869ef7c1eb437fe4f7b8daf9 Mon Sep 17 00:00:00 2001 > From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> > Date: Tue, 19 Nov 2019 09:50:42 -0800 > Subject: [PATCH] KVM: x86: Add a fast path for sending virtual IPIs in x2APIC > mode > > Add a fast path to handle writes to the ICR when the local APIC is > emulated in the kernel and x2APIC is enabled. The fast path is invoked > at ->handle_exit_irqoff() to emulate only the effect of the ICR write > itself, i.e. the sending of IPIs. Sending IPIs early in the VM-Exit > flow reduces the latency of virtual IPIs by avoiding the expensive bits > of transitioning from guest to host, e.g. reacquiring KVM's SRCU lock. > > Suggested-by: Wanpeng Li <wanpengli@xxxxxxxxxxx> > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Hmm, I welcome the idea to improve the original patch, but this is too much for me. :(
