From: Marc Zyngier <maz@kernel.org>
To: Will Deacon <will@kernel.org>
Cc: kernel-team@android.com,
Catalin Marinas <catalin.marinas@arm.com>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4 17/21] KVM: arm64: Convert user_mem_abort() to generic page-table API
Date: Thu, 10 Sep 2020 11:58:03 +0100 [thread overview]
Message-ID: <8302f7defdcc90f74519024c3deea2a6@kernel.org> (raw)
In-Reply-To: <20200910105107.GA17887@willie-the-truck>
On 2020-09-10 11:51, Will Deacon wrote:
> On Wed, Sep 09, 2020 at 06:12:29PM +0100, Marc Zyngier wrote:
>> On 2020-09-09 15:20, Alexandru Elisei wrote:
>> > On 9/7/20 4:23 PM, Will Deacon wrote:
>> > > @@ -1610,62 +1605,31 @@ static int user_mem_abort(struct kvm_vcpu
>> > > *vcpu, phys_addr_t fault_ipa,
>> > > if (vma_pagesize == PAGE_SIZE && !force_pte)
>> > > vma_pagesize = transparent_hugepage_adjust(memslot, hva,
>> > > &pfn, &fault_ipa);
>> > > - if (writable)
>> > > + if (writable) {
>> > > + prot |= KVM_PGTABLE_PROT_W;
>> > > kvm_set_pfn_dirty(pfn);
>> > > + mark_page_dirty(kvm, gfn);
>> >
>> > The previous code called mark_page_dirty() only if the vma_pagesize ==
>> > PAGE_SIZE
>> > (and writable was true, obviously). Is this supposed to fix a bug?
>>
>> No, this is actually introducing one. mark_page_dirty() checks that
>> there is
>> an
>> associated bitmap, and thus only happens when writing to a single
>> page, but
>> we
>> shouldn't do it for R/O memslots, which the current code avoids. It
>> should
>> be
>> guarded by logging_active.
>
> gfn_to_pfn_prot() will set "writable" to false for R/O memslots, so I
> think
> we're good here.
Ah, good point.
M.
--
Jazz is not dead. It just smells funny...
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WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Will Deacon <will@kernel.org>
Cc: kernel-team@android.com, Gavin Shan <gshan@redhat.com>,
Suzuki Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Quentin Perret <qperret@google.com>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4 17/21] KVM: arm64: Convert user_mem_abort() to generic page-table API
Date: Thu, 10 Sep 2020 11:58:03 +0100 [thread overview]
Message-ID: <8302f7defdcc90f74519024c3deea2a6@kernel.org> (raw)
In-Reply-To: <20200910105107.GA17887@willie-the-truck>
On 2020-09-10 11:51, Will Deacon wrote:
> On Wed, Sep 09, 2020 at 06:12:29PM +0100, Marc Zyngier wrote:
>> On 2020-09-09 15:20, Alexandru Elisei wrote:
>> > On 9/7/20 4:23 PM, Will Deacon wrote:
>> > > @@ -1610,62 +1605,31 @@ static int user_mem_abort(struct kvm_vcpu
>> > > *vcpu, phys_addr_t fault_ipa,
>> > > if (vma_pagesize == PAGE_SIZE && !force_pte)
>> > > vma_pagesize = transparent_hugepage_adjust(memslot, hva,
>> > > &pfn, &fault_ipa);
>> > > - if (writable)
>> > > + if (writable) {
>> > > + prot |= KVM_PGTABLE_PROT_W;
>> > > kvm_set_pfn_dirty(pfn);
>> > > + mark_page_dirty(kvm, gfn);
>> >
>> > The previous code called mark_page_dirty() only if the vma_pagesize ==
>> > PAGE_SIZE
>> > (and writable was true, obviously). Is this supposed to fix a bug?
>>
>> No, this is actually introducing one. mark_page_dirty() checks that
>> there is
>> an
>> associated bitmap, and thus only happens when writing to a single
>> page, but
>> we
>> shouldn't do it for R/O memslots, which the current code avoids. It
>> should
>> be
>> guarded by logging_active.
>
> gfn_to_pfn_prot() will set "writable" to false for R/O memslots, so I
> think
> we're good here.
Ah, good point.
M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-09-10 10:58 UTC|newest]
Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-07 15:23 [PATCH v4 00/21] KVM: arm64: Rewrite page-table code and fault handling Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 01/21] KVM: arm64: Remove kvm_mmu_free_memory_caches() Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 02/21] KVM: arm64: Add stand-alone page-table walker infrastructure Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-08 0:03 ` Gavin Shan
2020-09-08 0:03 ` Gavin Shan
2020-09-10 10:57 ` Will Deacon
2020-09-10 10:57 ` Will Deacon
2020-09-09 15:29 ` Alexandru Elisei
2020-09-09 15:29 ` Alexandru Elisei
2020-09-10 12:37 ` Will Deacon
2020-09-10 12:37 ` Will Deacon
2020-09-10 14:21 ` Andrew Scull
2020-09-10 14:21 ` Andrew Scull
2020-09-11 10:15 ` Will Deacon
2020-09-11 10:15 ` Will Deacon
2020-09-11 11:22 ` Andrew Scull
2020-09-11 11:22 ` Andrew Scull
2020-09-07 15:23 ` [PATCH v4 03/21] KVM: arm64: Add support for creating kernel-agnostic stage-1 page tables Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-08 1:09 ` Gavin Shan
2020-09-08 1:09 ` Gavin Shan
2020-09-07 15:23 ` [PATCH v4 04/21] KVM: arm64: Use generic allocator for hyp stage-1 page-tables Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-08 1:03 ` Gavin Shan
2020-09-08 1:03 ` Gavin Shan
2020-09-07 15:23 ` [PATCH v4 05/21] KVM: arm64: Add support for creating kernel-agnostic stage-2 page tables Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 06/21] KVM: arm64: Add support for stage-2 map()/unmap() in generic page-table Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-10 11:20 ` Alexandru Elisei
2020-09-10 11:20 ` Alexandru Elisei
2020-09-10 12:34 ` Will Deacon
2020-09-10 12:34 ` Will Deacon
2020-09-10 13:55 ` Alexandru Elisei
2020-09-10 13:55 ` Alexandru Elisei
2020-09-07 15:23 ` [PATCH v4 07/21] KVM: arm64: Convert kvm_phys_addr_ioremap() to generic page-table API Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 08/21] KVM: arm64: Convert kvm_set_spte_hva() " Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 09/21] KVM: arm64: Convert unmap_stage2_range() " Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 10/21] KVM: arm64: Add support for stage-2 page-aging in generic page-table Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-08 15:30 ` Alexandru Elisei
2020-09-08 15:30 ` Alexandru Elisei
2020-09-10 12:42 ` Will Deacon
2020-09-10 12:42 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 11/21] KVM: arm64: Convert page-aging and access faults to generic page-table API Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-08 15:39 ` Alexandru Elisei
2020-09-08 15:39 ` Alexandru Elisei
2020-09-07 15:23 ` [PATCH v4 12/21] KVM: arm64: Add support for stage-2 write-protect in generic page-table Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 13/21] KVM: arm64: Convert write-protect operation to generic page-table API Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 14/21] KVM: arm64: Add support for stage-2 cache flushing in generic page-table Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 15/21] KVM: arm64: Convert memslot cache-flushing code to generic page-table API Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 16/21] KVM: arm64: Add support for relaxing stage-2 perms in generic page-table code Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-08 16:37 ` Alexandru Elisei
2020-09-08 16:37 ` Alexandru Elisei
2020-09-07 15:23 ` [PATCH v4 17/21] KVM: arm64: Convert user_mem_abort() to generic page-table API Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-09 14:20 ` Alexandru Elisei
2020-09-09 14:20 ` Alexandru Elisei
2020-09-09 17:12 ` Marc Zyngier
2020-09-09 17:12 ` Marc Zyngier
2020-09-10 10:51 ` Will Deacon
2020-09-10 10:51 ` Will Deacon
2020-09-10 10:58 ` Marc Zyngier [this message]
2020-09-10 10:58 ` Marc Zyngier
2020-09-10 13:10 ` Alexandru Elisei
2020-09-10 13:10 ` Alexandru Elisei
2020-09-10 13:20 ` Alexandru Elisei
2020-09-10 13:20 ` Alexandru Elisei
2020-09-07 15:23 ` [PATCH v4 18/21] KVM: arm64: Check the pgt instead of the pgd when modifying page-table Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 19/21] KVM: arm64: Remove unused page-table code Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-08 10:33 ` Marc Zyngier
2020-09-08 10:33 ` Marc Zyngier
2020-09-10 10:54 ` Will Deacon
2020-09-10 10:54 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 20/21] KVM: arm64: Remove unused 'pgd' field from 'struct kvm_s2_mmu' Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-07 15:23 ` [PATCH v4 21/21] KVM: arm64: Don't constrain maximum IPA size based on host configuration Will Deacon
2020-09-07 15:23 ` Will Deacon
2020-09-09 14:53 ` Alexandru Elisei
2020-09-09 14:53 ` Alexandru Elisei
2020-09-07 17:16 ` [PATCH v4 00/21] KVM: arm64: Rewrite page-table code and fault handling Marc Zyngier
2020-09-07 17:16 ` Marc Zyngier
2020-09-07 17:31 ` Will Deacon
2020-09-07 17:31 ` Will Deacon
2020-09-10 4:06 ` Gavin Shan
2020-09-10 4:06 ` Gavin Shan
2020-09-10 4:11 ` Gavin Shan
2020-09-10 4:11 ` Gavin Shan
2020-09-10 10:58 ` Will Deacon
2020-09-10 10:58 ` Will Deacon
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