Re: [PATCH 3/4] KVM: guest_memfd: Add `write` parameter to kvm_gmem_populate()

[Sean Christopherson]

On Tue, Jun 23, 2026, Jörg Rödel wrote:
> From: Joerg Roedel <joerg.roedel@xxxxxxx>
> 
> 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").