Re: [PATCH v2 3/3] KVM: x86: Add a module param to control and enumerate device posted IRQs

From: Sean Christopherson
Date: Thu Mar 20 2025 - 13:55:11 EST


On Thu, Mar 20, 2025, Jim Mattson wrote:
> On Thu, Mar 20, 2025 at 7:31 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
> >
> > Add a module param to allow disabling device posted interrupts without
> > having to sacrifice all of APICv/AVIC, and to also effectively enumerate
> > to userspace whether or not KVM may be utilizing device posted IRQs.
> > Disabling device posted interrupts is very desirable for testing, and can
> > even be desirable for production environments, e.g. if the host kernel
> > wants to interpose on device interrupts.
>
> Are you referring to CONFIG_X86_POSTED_MSI, or something else that
> doesn't exist yet?

Yeah, that, and/or out-of-tree hackery to do similar coalescing (or ratelimiting).