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[2003:d8:2f1b:b800:6fdb:1af2:4fbd:1fdf]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a4efe73eebsm21436129f8f.44.2025.06.04.06.02.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Jun 2025 06:02:52 -0700 (PDT) Message-ID: <0835025c-a799-4ffc-9dea-52b64ffcb96a@redhat.com> Date: Wed, 4 Jun 2025 15:02:49 +0200 Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v10 08/16] KVM: guest_memfd: Allow host to map guest_memfd pages To: Fuad Tabba Cc: kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org, pbonzini@redhat.com, chenhuacai@kernel.org, mpe@ellerman.id.au, anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, seanjc@google.com, viro@zeniv.linux.org.uk, brauner@kernel.org, willy@infradead.org, akpm@linux-foundation.org, xiaoyao.li@intel.com, yilun.xu@intel.com, chao.p.peng@linux.intel.com, jarkko@kernel.org, amoorthy@google.com, dmatlack@google.com, isaku.yamahata@intel.com, mic@digikod.net, vbabka@suse.cz, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, michael.roth@amd.com, wei.w.wang@intel.com, liam.merwick@oracle.com, isaku.yamahata@gmail.com, kirill.shutemov@linux.intel.com, suzuki.poulose@arm.com, steven.price@arm.com, quic_eberman@quicinc.com, quic_mnalajal@quicinc.com, quic_tsoni@quicinc.com, quic_svaddagi@quicinc.com, quic_cvanscha@quicinc.com, quic_pderrin@quicinc.com, quic_pheragu@quicinc.com, catalin.marinas@arm.com, james.morse@arm.com, yuzenghui@huawei.com, oliver.upton@linux.dev, maz@kernel.org, will@kernel.org, qperret@google.com, keirf@google.com, roypat@amazon.co.uk, shuah@kernel.org, hch@infradead.org, jgg@nvidia.com, rientjes@google.com, jhubbard@nvidia.com, fvdl@google.com, hughd@google.com, jthoughton@google.com, peterx@redhat.com, pankaj.gupta@amd.com, ira.weiny@intel.com References: <20250527180245.1413463-1-tabba@google.com> <20250527180245.1413463-9-tabba@google.com> From: David Hildenbrand Content-Language: en-US Autocrypt: addr=david@redhat.com; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 04.06.25 14:32, Fuad Tabba wrote: > Hi David, > > On Wed, 4 Jun 2025 at 13:26, David Hildenbrand wrote: >> >> On 27.05.25 20:02, Fuad Tabba wrote: >>> This patch enables support for shared memory in guest_memfd, including >>> mapping that memory at the host userspace. This support is gated by the >>> configuration option KVM_GMEM_SHARED_MEM, and toggled by the guest_memfd >>> flag GUEST_MEMFD_FLAG_SUPPORT_SHARED, which can be set when creating a >>> guest_memfd instance. >>> >>> Co-developed-by: Ackerley Tng >>> Signed-off-by: Ackerley Tng >>> Signed-off-by: Fuad Tabba >>> --- >>> arch/x86/include/asm/kvm_host.h | 10 ++++ >>> arch/x86/kvm/x86.c | 3 +- >> >> Nit: I would split off the x86 bits. Meaning, this patch would only >> introduce the infrastructure and a x86 KVM patch would enable it for >> selected x86 VMs. > > Will do. And probably that patch should come after/with the x86 mmu bits. -- Cheers, David / dhildenb