linux-kernel - Re: [PATCH v17 15/24] KVM: x86/mmu: Extend guest_memfd's max mapping level to shared mappings

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Message-ID: <f61594a4-5823-453c-9f1f-8bd94d3ba4a2@intel.com>
Date: Wed, 30 Jul 2025 15:36:24 +0800
From: Xiaoyao Li <xiaoyao.li@...el.com>
To: Sean Christopherson <seanjc@...gle.com>,
 Paolo Bonzini <pbonzini@...hat.com>, Marc Zyngier <maz@...nel.org>,
 Oliver Upton <oliver.upton@...ux.dev>
Cc: kvm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
 kvmarm@...ts.linux.dev, linux-kernel@...r.kernel.org,
 Ira Weiny <ira.weiny@...el.com>, Gavin Shan <gshan@...hat.com>,
 Shivank Garg <shivankg@....com>, Vlastimil Babka <vbabka@...e.cz>,
 David Hildenbrand <david@...hat.com>, Fuad Tabba <tabba@...gle.com>,
 Ackerley Tng <ackerleytng@...gle.com>, Tao Chan <chentao@...inos.cn>,
 James Houghton <jthoughton@...gle.com>
Subject: Re: [PATCH v17 15/24] KVM: x86/mmu: Extend guest_memfd's max mapping
 level to shared mappings

On 7/30/2025 6:54 AM, Sean Christopherson wrote:
> Rework kvm_mmu_max_mapping_level() to consult guest_memfd for all mappings,
> not just private mappings, so that hugepage support plays nice with the
> upcoming support for backing non-private memory with guest_memfd.
> 
> In addition to getting the max order from guest_memfd for gmem-only
> memslots, update TDX's hook to effectively ignore shared mappings, as TDX's
> restrictions on page size only apply to Secure EPT mappings.  Do nothing
> for SNP, as RMP restrictions apply to both private and shared memory.
> 
> Suggested-by: Ackerley Tng <ackerleytng@...gle.com>
> Signed-off-by: Sean Christopherson <seanjc@...gle.com>

Reviewed-by: Xiaoyao Li <xiaoyao.li@...el.com>