[GIT PULL] KVM/riscv fixes for 5.19, take #2

Anup Patel anup at brainfault.org
Wed Jul 13 00:17:13 PDT 2022


On Wed, Jul 13, 2022 at 11:30 AM Paolo Bonzini <pbonzini at redhat.com> wrote:
>
> On 7/13/22 07:47, Anup Patel wrote:
> > Hi Paolo,
> >
> > We have two more fixes for 5.19 which were discovered recently:
> > 1) Fix missing PAGE_PFN_MASK
> > 2) Fix SRCU deadlock caused by kvm_riscv_check_vcpu_requests()
>
> Pulled, thanks.
>
> For the latter, my suggestion is to remove KVM_REQ_SLEEP completely and
> key the waiting on kvm_arch_vcpu_runnable using kvm_vcpu_halt or
> kvm_vcpu_block.

We are using KVM_REQ_SLEEP for VCPU hotplug. The secondary
VCPUs will block until woken-up by using an SBI call from other VCPU.
This is different from blocking on WFI where VCPU will wake-up upon
any interrupt.

I agree with your suggestion, we should definitely use kvm_vcpu_block()
here.

>
> Also, I only had a quick look but it seems like vcpu->arch.pause is
> never written?

Yes, the vcpu->arch.pause is redundant. I will remove it.

>
> Paolo
>

Thanks,
Anup



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