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AJvYcCX+FVncEk9QklWYLnbuP4epgA3bQa2ZEb0sFWRGlwXt9NTwYRKxLHwDveZasS0Pnf/ZwdhQmAoS7RFKyYYu@vger.kernel.org X-Gm-Message-State: AOJu0YytYb3H6Lzxd6aiWjpRON6nx8XpnTpXWKDNcAWqTmXYQTxtjUN4 9LsVcEhe1yqUPxI6bhOyVZeJFeuVyTNjT5jDW0G5jcFTg2cUsTb/KrYFaHLzlnrXGKTuVDcStKK bPA== X-Google-Smtp-Source: AGHT+IEcdVpCbp8MjJf64q8k5e/VTPJ3pw7BA2+dZtfA0ZF4gfu1Oso/b3kULdysXS+hJCL6sJ2jnEhvsg== X-Received: from wmrn12.prod.google.com ([2002:a05:600c:500c:b0:441:bc26:4d3f]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:820a:b0:43d:762:e0c4 with SMTP id 5b1f17b1804b1-44c959b79fdmr129129035e9.27.1748368995587; Tue, 27 May 2025 11:03:15 -0700 (PDT) Date: Tue, 27 May 2025 19:02:43 +0100 In-Reply-To: <20250527180245.1413463-1-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: <20250527180245.1413463-1-tabba@google.com> X-Mailer: git-send-email 2.49.0.1164.gab81da1b16-goog Message-ID: <20250527180245.1413463-15-tabba@google.com> Subject: [PATCH v10 14/16] KVM: arm64: Enable mapping guest_memfd in arm64 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, peterx@redhat.com, pankaj.gupta@amd.com, ira.weiny@intel.com, tabba@google.com Enable mapping guest_memfd backed memory at the host in arm64. For now, it applies to all arm64 VM types in arm64 that use guest_memfd. In the future, new VM types can restrict this via kvm_arch_gmem_supports_shared_mem(). Signed-off-by: Fuad Tabba --- arch/arm64/include/asm/kvm_host.h | 5 +++++ arch/arm64/kvm/Kconfig | 1 + arch/arm64/kvm/mmu.c | 7 +++++++ 3 files changed, 13 insertions(+) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 08ba91e6fb03..8add94929711 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1593,4 +1593,9 @@ static inline bool kvm_arch_has_irq_bypass(void) return true; } +#ifdef CONFIG_KVM_GMEM +#define kvm_arch_supports_gmem(kvm) true +#define kvm_arch_supports_gmem_shared_mem(kvm) IS_ENABLED(CONFIG_KVM_GMEM_SHARED_MEM) +#endif + #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 096e45acadb2..8c1e1964b46a 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -38,6 +38,7 @@ menuconfig KVM select HAVE_KVM_VCPU_RUN_PID_CHANGE select SCHED_INFO select GUEST_PERF_EVENTS if PERF_EVENTS + select KVM_GMEM_SHARED_MEM help Support hosting virtualized guest machines. diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 896c56683d88..03da08390bf0 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -2264,6 +2264,13 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, if ((new->base_gfn + new->npages) > (kvm_phys_size(&kvm->arch.mmu) >> PAGE_SHIFT)) return -EFAULT; + /* + * Only support guest_memfd backed memslots with shared memory, since + * there aren't any CoCo VMs that support only private memory on arm64. + */ + if (kvm_slot_has_gmem(new) && !kvm_gmem_memslot_supports_shared(new)) + return -EINVAL; + hva = new->userspace_addr; reg_end = hva + (new->npages << PAGE_SHIFT);