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AJvYcCWFx1p+J87mjCqxGW/egHwc+1jDYYXjZ9CNkNlWVQjflVUlrRIhTT+LV+IORXszmCEhMUxLm3VwNddS3ji0@vger.kernel.org X-Gm-Message-State: AOJu0Yzl4+XDD4lxZKZDi+2yl4TxOSF2B0q8mWBO5yb1FaE67S18sxMB GkTo/OqfXKFuDP5mTMT8wHU+xf0P+f/SDAJYWvZVCNdaJJjdWs5U7gySzZA/7CE/PYAsLU6Xqd6 71w== X-Google-Smtp-Source: AGHT+IGgV5ke5hXPrHMuRnrP+wv3u6Tkx21fI8p6ntOfTtgrw4d762tpa+/9V2HMZqsC7PIFnB4sz/aRjw== X-Received: from wrbdr8.prod.google.com ([2002:a5d:5f88:0:b0:3a4:ead6:8232]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a5d:5f49:0:b0:3a4:eb7a:2cda with SMTP id ffacd0b85a97d-3a51d95dcd5mr6346937f8f.30.1749137907542; Thu, 05 Jun 2025 08:38:27 -0700 (PDT) Date: Thu, 5 Jun 2025 16:37:54 +0100 In-Reply-To: <20250605153800.557144-1-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: <20250605153800.557144-1-tabba@google.com> X-Mailer: git-send-email 2.49.0.1266.g31b7d2e469-goog Message-ID: <20250605153800.557144-13-tabba@google.com> Subject: [PATCH v11 12/18] KVM: x86: Enable guest_memfd shared memory for SW-protected VMs From: Fuad Tabba To: kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org, kvmarm@lists.linux.dev 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, peterx@redhat.com, pankaj.gupta@amd.com, ira.weiny@intel.com, tabba@google.com Define the architecture-specific macro to enable shared memory support in guest_memfd for relevant software-only VM types, specifically KVM_X86_DEFAULT_VM and KVM_X86_SW_PROTECTED_VM. Enable the KVM_GMEM_SHARED_MEM Kconfig option if KVM_SW_PROTECTED_VM is enabled. 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/Kconfig | 1 + arch/x86/kvm/x86.c | 3 ++- 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 709cc2a7ba66..ce9ad4cd93c5 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -2255,8 +2255,18 @@ void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level, #ifdef CONFIG_KVM_GMEM #define kvm_arch_supports_gmem(kvm) ((kvm)->arch.supports_gmem) + +/* + * CoCo VMs with hardware support that use guest_memfd only for backing private + * memory, e.g., TDX, cannot use guest_memfd with userspace mapping enabled. + */ +#define kvm_arch_supports_gmem_shared_mem(kvm) \ + (IS_ENABLED(CONFIG_KVM_GMEM_SHARED_MEM) && \ + ((kvm)->arch.vm_type == KVM_X86_SW_PROTECTED_VM || \ + (kvm)->arch.vm_type == KVM_X86_DEFAULT_VM)) #else #define kvm_arch_supports_gmem(kvm) false +#define kvm_arch_supports_gmem_shared_mem(kvm) false #endif #define kvm_arch_has_readonly_mem(kvm) (!(kvm)->arch.has_protected_state) diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig index b37258253543..fdf24b50af9d 100644 --- a/arch/x86/kvm/Kconfig +++ b/arch/x86/kvm/Kconfig @@ -47,6 +47,7 @@ config KVM_X86 select KVM_GENERIC_HARDWARE_ENABLING select KVM_GENERIC_PRE_FAULT_MEMORY select KVM_GENERIC_GMEM_POPULATE if KVM_SW_PROTECTED_VM + select KVM_GMEM_SHARED_MEM if KVM_SW_PROTECTED_VM select KVM_WERROR if WERROR config KVM diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 035ced06b2dd..2a02f2457c42 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12718,7 +12718,8 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) return -EINVAL; kvm->arch.vm_type = type; - kvm->arch.supports_gmem = (type == KVM_X86_SW_PROTECTED_VM); + kvm->arch.supports_gmem = + type == KVM_X86_DEFAULT_VM || type == KVM_X86_SW_PROTECTED_VM; /* Decided by the vendor code for other VM types. */ kvm->arch.pre_fault_allowed = type == KVM_X86_DEFAULT_VM || type == KVM_X86_SW_PROTECTED_VM;