From: Gavin Shan <gshan@redhat.com>
To: Marc Zyngier <maz@kernel.org>,
Alexandru Elisei <alexandru.elisei@arm.com>
Cc: kvmarm@lists.cs.columbia.edu, shan.gavin@gmail.com
Subject: Re: [PATCH] arm64/kvm: Fix zapping stage2 page table wrongly
Date: Thu, 3 Sep 2020 09:55:09 +1000 [thread overview]
Message-ID: <3dc0bb34-d0cf-1848-d4a7-9b5c6f152297@redhat.com> (raw)
In-Reply-To: <9bcb88aff4fbacfad28d13234681bc2f@kernel.org>
Hi Marc,
On 9/2/20 9:10 PM, Marc Zyngier wrote:
> On 2020-09-02 11:59, Alexandru Elisei wrote:
[...]
>
> From 2a345a826a47f9061bb37045a1d89ea54b51fb80 Mon Sep 17 00:00:00 2001
> From: Marc Zyngier <maz@kernel.org>
> Date: Wed, 2 Sep 2020 11:18:29 +0100
> Subject: [PATCH] KVM: arm64: Do not try to map PUDs when they are folded into
> PMD
>
> For the obscure cases where PMD and PUD are the same size
> (64kB pages with 42bit VA, for example, which results in only
> two levels of page tables), we can't map anything as a PUD,
> because there is... erm... no PUD to speak of. Everything is
> either a PMD or a PTE.
>
> So let's only try and map a PUD when its size is different from
> that of a PMD.
>
> Cc: stable@vger.kernel.org
> Fixes: b8e0ba7c8bea ("KVM: arm64: Add support for creating PUD hugepages at stage 2")
> Reported-by: Gavin Shan <gshan@redhat.com>
> Reported-by: Eric Auger <eric.auger@redhat.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arch/arm64/kvm/mmu.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
It worked for me either:
Reviewed-by: Gavin Shan <gshan@redhat.com>
Tested-by: Gavin Shan <gshan@redhat.com>
> diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
> index ba00bcc0c884..c3a92fa537fd 100644
> --- a/arch/arm64/kvm/mmu.c
> +++ b/arch/arm64/kvm/mmu.c
> @@ -1970,7 +1970,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
> (fault_status == FSC_PERM &&
> stage2_is_exec(mmu, fault_ipa, vma_pagesize));
>
> - if (vma_pagesize == PUD_SIZE) {
> + if (PUD_SIZE != PMD_SIZE && vma_pagesize == PUD_SIZE) {
> pud_t new_pud = kvm_pfn_pud(pfn, mem_type);
>
> new_pud = kvm_pud_mkhuge(new_pud);
Thanks,
Gavin
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prev parent reply other threads:[~2020-09-02 23:55 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-22 2:44 [PATCH] arm64/kvm: Fix zapping stage2 page table wrongly Gavin Shan
2020-08-22 10:01 ` Marc Zyngier
2020-08-22 23:59 ` Gavin Shan
2020-09-01 16:50 ` Marc Zyngier
2020-09-02 10:59 ` Alexandru Elisei
2020-09-02 11:10 ` Marc Zyngier
2020-09-02 11:53 ` Alexandru Elisei
2020-09-02 11:56 ` Alexandru Elisei
2020-09-02 12:04 ` Marc Zyngier
2020-09-02 13:58 ` Alexandru Elisei
2020-09-02 17:38 ` Auger Eric
2020-09-02 23:55 ` Gavin Shan [this message]
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