Re: [PATCH] KVM: SVM: make svm_flush_tlb_gva do a full asid flush if NPT enabled

[Yosry Ahmed]

On Mon, Jul 27, 2026 at 12:23 PM Tycho Andersen <tycho@xxxxxxxxxx> wrote:
>
> Hi all,
>
> On Thu, Jul 23, 2026 at 11:44:19AM +0200, Paolo Bonzini wrote:
> > As to the workload, Alexander threw more or less everything at the same
> > time at the VM:
> >
> > - a full Windows Defender scan every 30 minutes
> >
> > - a disk I/O job
> >
> > - a loop doing repeated mmap of system files (mostly to hope that
> >   it triggers some consistency check in the Windows memory manager)
> >
> > - SQL Express 2022 + StressDB (1.6M rows), with the host doing queries
> >   (75% write/25% read) via sqlcmd
>
> Can you share the code for the mmap + disk io + DB content generator?
>
> We're looking at this and would like to reproduce.

Not sure if this is relevant, but I see that hyperv_tlb_flush is flaky
with npt=0 on Turin at the tip of kvm-x86/next (commit 567329869b9c7).
It's not likely because the problem fixed by this patch happens
specifically with npt=1 and not npt=0 AFAICT, but it is a weird
coincidence :)

Maybe something is wrong in the Hyper-V code that manifests
differently with npt=0/1?