Re: [PATCH AUTOSEL 5.0 29/98] KVM: arm/arm64: Enforce PTE mappings at stage2 when needed

[Sasha Levin]

On Tue, Apr 23, 2019 at 10:27:26AM +0100, Suzuki K Poulose wrote:
> Hi Sasha,
>
> On 04/22/2019 08:40 PM, Sasha Levin wrote:
> > From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> >
> > [ Upstream commit a80868f398554842b14d07060012c06efb57c456 ]
> >
> > commit 6794ad5443a2118 ("KVM: arm/arm64: Fix unintended stage 2 PMD mappings")
> > made the checks to skip huge mappings, stricter. However it introduced
> > a bug where we still use huge mappings, ignoring the flag to
> > use PTE mappings, by not reseting the vma_pagesize to PAGE_SIZE.
> >
> > Also, the checks do not cover the PUD huge pages, that was
> > under review during the same period. This patch fixes both
> > the issues.
> >
> > Fixes : 6794ad5443a2118 ("KVM: arm/arm64: Fix unintended stage 2 PMD mappings")
> > Reported-by: Zenghui Yu <yuzenghui@xxxxxxxxxx>
> > Cc: Zenghui Yu <yuzenghui@xxxxxxxxxx>
> > Cc: Christoffer Dall <christoffer.dall@xxxxxxx>
> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> > Signed-off-by: Sasha Levin (Microsoft) <sashal@xxxxxxxxxx>
>
> Please be aware that we need a follow up fix for this patch to fix the
> problem for THP backed memory.
>
> http://lists.infradead.org/pipermail/linux-arm-kernel/2019-April/645324.html
>
>
> It should appear upstream soon.

Since it's not upstream yet, I'll drop this patch for now and queue it
for a later release.

--
Thanks,
Sasha