From: Sean Christopherson <seanjc@google.com>
To: "Jörg Rödel" <joro@8bytes.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
x86@kernel.org, Kiryl Shutsemau <kas@kernel.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
Ashish Kalra <ashish.kalra@amd.com>,
Michael Roth <michael.roth@amd.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-coco@lists.linux.dev, Joerg Roedel <joerg.roedel@amd.com>
Subject: Re: [PATCH 3/4] KVM: guest_memfd: Add `write` parameter to kvm_gmem_populate()
Date: Tue, 23 Jun 2026 05:57:58 -0700 [thread overview]
Message-ID: <ajqC1k1VV23_Xe5F@google.com> (raw)
In-Reply-To: <20260623091556.1500930-4-joro@8bytes.org>
On Tue, Jun 23, 2026, Jörg Rödel wrote:
> From: Joerg Roedel <joerg.roedel@amd.com>
>
> The call-path of kvm_gmem_populate() might subsequently write to the
> page provided by user-space. This is used to provide detailed error
> information in case the page population failed.
>
> But since kvm_gmem_populate() only acquires a read-only reference to
> the user-space page via get_user_pages_fast(), the error information
> might be written to a read-only page later on.
>
> Add a parameter to kvm_gmem_populate() to optionally acquire a
> writeable reference to the source page to make sure page permissions
> can be enforced.
Already fixed, commit f13e90059908 ("KVM: SEV: Pin source page for write when
adding CPUID data for SNP guest").
next prev parent reply other threads:[~2026-06-23 12:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-23 9:15 [PATCH 0/4] kvm: sev: Fix issues reported by Sashiko Jörg Rödel
2026-06-23 9:15 ` [PATCH 1/4] kvm: sev: Fix user-space triggerable WARN_ON on snp_launch_update path Jörg Rödel
2026-06-23 14:46 ` Sean Christopherson
2026-06-23 9:15 ` [PATCH 2/4] kvm: sev: Unmap pages in correct order in sev_gmem_post_populate() Jörg Rödel
2026-06-23 9:15 ` [PATCH 3/4] KVM: guest_memfd: Add `write` parameter to kvm_gmem_populate() Jörg Rödel
2026-06-23 12:57 ` Sean Christopherson [this message]
2026-06-23 9:15 ` [PATCH 4/4] kvm: sev: Acquire a writeable page reference for CPUID pages Jörg Rödel
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