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AJvYcCXXV+1yEw8PT/cA/RXlo2mE8xWNozyxH+0jaKt3Red6J2FbVXXNL8e0eBKjtkulWlAbe41WGyZZpZRMDlPH@vger.kernel.org X-Gm-Message-State: AOJu0YxKb/DLnm+AFAzXGca36/tHxdUnraAL+Ina14enitcQduAfpzHH /W5xNL/sT9AO7ZdhxTBXxM/8TsxFIWFIhUXJwG2QHBJgvNXT8dXcOK+4CvdcVODEuIXnPnXccQ= = X-Google-Smtp-Source: AGHT+IHuQgBmWKLX/iaLAIhwX+Ygl7SCrjQmYq5mlPdxwxv1m1H3cuEySvE1kherBoZWNYm/GzLxu4kvpQ== X-Received: from wmsd12.prod.google.com ([2002:a05:600c:3acc:b0:439:3df1:f296]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:1550:b0:439:9377:fa17 with SMTP id 5b1f17b1804b1-4399377fb82mr36630915e9.18.1739899510991; Tue, 18 Feb 2025 09:25:10 -0800 (PST) Date: Tue, 18 Feb 2025 17:24:54 +0000 In-Reply-To: <20250218172500.807733-1-tabba@google.com> Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250218172500.807733-1-tabba@google.com> X-Mailer: git-send-email 2.48.1.601.g30ceb7b040-goog Message-ID: <20250218172500.807733-5-tabba@google.com> Subject: [PATCH v4 04/10] KVM: guest_memfd: Add KVM capability to check if guest_memfd is shared From: Fuad Tabba To: kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org Cc: 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, david@redhat.com, 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, tabba@google.com Add the KVM capability KVM_CAP_GMEM_SHARED_MEM, which indicates that the VM supports shared memory in guest_memfd, or that the host can create VMs that support shared memory. Supporting shared memory implies that memory can be mapped when shared with the host. Signed-off-by: Fuad Tabba --- include/uapi/linux/kvm.h | 1 + virt/kvm/kvm_main.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 45e6d8fca9b9..117937a895da 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -929,6 +929,7 @@ struct kvm_enable_cap { #define KVM_CAP_PRE_FAULT_MEMORY 236 #define KVM_CAP_X86_APIC_BUS_CYCLES_NS 237 #define KVM_CAP_X86_GUEST_MODE 238 +#define KVM_CAP_GMEM_SHARED_MEM 239 struct kvm_irq_routing_irqchip { __u32 irqchip; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index ba0327e2d0d3..38f0f402ea46 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4830,6 +4830,10 @@ static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) #ifdef CONFIG_KVM_PRIVATE_MEM case KVM_CAP_GUEST_MEMFD: return !kvm || kvm_arch_has_private_mem(kvm); +#endif +#ifdef CONFIG_KVM_GMEM_SHARED_MEM + case KVM_CAP_GMEM_SHARED_MEM: + return !kvm || kvm_arch_gmem_supports_shared_mem(kvm); #endif default: break;