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

[Tycho Andersen <tycho@kernel.org>]

Hi Alexander,

On Tue, Jul 28, 2026 at 07:13:56PM +0200, Alexander Lougovski wrote:
> On Mon, Jul 27, 2026 at 01:23:03PM -0600, Tycho Andersen wrote:
> > Can you share the code for the mmap + disk io + DB content generator?
> >
> > We're looking at this and would like to reproduce.
> 
> Hi Tycho,
> 
> Sure, here's everything below.

Thanks for this, I think I've got everything set up the way you've
described on top of 7.2-rc5.

One question,

> query_stream() {
>     local TARGET=$1
>     while true; do
>         case $((RANDOM % 4)) in
>             0) Q="SET NOCOUNT ON; DECLARE @s INT = ABS(CHECKSUM(NEWID())) % 2800000 + 1; UPDATE StressDB.dbo.RandomData SET Col2 = REPLICATE(N'X', 90 + ABS(CHECKSUM(NEWID())) % 10), Col3 = REPLICATE(N'Y', 90 + ABS(CHECKSUM(NEWID())) % 10), Col5 = SYSDATETIME(), Col7 = ABS(CHECKSUM(NEWID())) WHERE ID BETWEEN @s AND @s + 50000" ;;

my LLM complained about the '% 2800000', looks like it's selecting
from 1..2.8M in a 1.6M table, so the updates above 1.6M don't affect
any rows.

I'll leave these grinding for now, I'm trying to scare up more
hardware to run more copies since it's so rare.

Tycho