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Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Baoquan He , Jason Gunthorpe , John Hubbard , Peter Xu , tarunsahu@google.com, Randy Dunlap , Lorenzo Stoakes , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jason Gunthorpe , Fuad Tabba , Vlastimil Babka , Baoquan He Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1789084533; l=6307; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=Y0/M8zFLRVYzxfNZnbsRQ1DqeXpThQossdoX7qTMEj8=; b=XAsQUFepWY5SR8UbbaaDfFFPDICKe52oWYXSPLiOrFWLVzrN7Qo78he0P9VmecuIgGWz1M8Px ylx4ksESxALBPxOuNv/z1PyhY6JUf4Y2zlZCtSdZ31i4crJFpFV36ch X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 84E3C40008 X-Stat-Signature: 7adwcjqmqf61zb1gk84tzgz7hpy51t37 X-HE-Tag: 1789084548-141043 X-HE-Meta: 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 SELnLUQi 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Sean Christopherson Accept gmem_flags in vm_mem_add() to be able to create a guest_memfd within vm_mem_add(). When vm_mem_add() is used to set up a guest_memfd for a memslot, set up the provided (or created) gmem_fd as the fd for the user memory region. This makes it available to be mmap()-ed from just like fds from other memory sources. For guest_memfds, mmap() using gmem_offset instead of 0 all the time. Always use MAP_SHARED if mmap-ing from guest_memfd instead of reading flag from the configured src_type, which doesn't include guest_memfd. Add a kvm_slot_to_fd() helper to provide convenient access to the file descriptor of a memslot. Update existing callers of vm_mem_add() to pass 0 for gmem_flags to preserve existing behavior. Co-developed-by: Ackerley Tng Signed-off-by: Ackerley Tng Signed-off-by: Sean Christopherson Tested-by: Shivank Garg Reviewed-by: Fuad Tabba --- tools/testing/selftests/kvm/include/kvm_util.h | 7 +++++- tools/testing/selftests/kvm/lib/kvm_util.c | 28 ++++++++++++---------- .../kvm/x86/private_mem_conversions_test.c | 2 +- 3 files changed, 23 insertions(+), 14 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index cf49a84de02e8..a091c495442a1 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -700,7 +700,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, gpa_t gpa, u32 slot, u64 npages, u32 flags); void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type, gpa_t gpa, u32 slot, u64 npages, u32 flags, - int gmem_fd, u64 gmem_offset); + int gmem_fd, u64 gmem_offset, u64 gmem_flags); #ifndef vm_arch_has_protected_memory static inline bool vm_arch_has_protected_memory(struct kvm_vm *vm) @@ -732,6 +732,11 @@ void *addr_gva2hva(struct kvm_vm *vm, gva_t gva); gpa_t addr_hva2gpa(struct kvm_vm *vm, void *hva); void *addr_gpa2alias(struct kvm_vm *vm, gpa_t gpa); +static inline int kvm_slot_to_fd(struct kvm_vm *vm, u32 slot) +{ + return memslot2region(vm, slot)->fd; +} + #ifndef vcpu_arch_put_guest #define vcpu_arch_put_guest(mem, val) do { (mem) = (val); } while (0) #endif diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index af501a27211a2..08d0bbcd421ea 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1002,12 +1002,14 @@ void vm_set_user_memory_region2(struct kvm_vm *vm, u32 slot, u32 flags, /* FIXME: This thing needs to be ripped apart and rewritten. */ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type, gpa_t gpa, u32 slot, u64 npages, u32 flags, - int gmem_fd, u64 gmem_offset) + int gmem_fd, u64 gmem_offset, u64 gmem_flags) { int ret; struct userspace_mem_region *region; size_t backing_src_pagesz = get_backing_src_pagesz(src_type); + int mmap_flags = vm_mem_backing_src_alias(src_type)->flag; size_t mem_size = npages * vm->page_size; + off_t mmap_offset = 0; size_t alignment = 1; TEST_REQUIRE_SET_USER_MEMORY_REGION2(); @@ -1079,8 +1081,6 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type, if (flags & KVM_MEM_GUEST_MEMFD) { if (gmem_fd < 0) { - u32 gmem_flags = 0; - TEST_ASSERT(!gmem_offset, "Offset must be zero when creating new guest_memfd"); gmem_fd = vm_create_guest_memfd(vm, mem_size, gmem_flags); @@ -1101,13 +1101,17 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type, } region->fd = -1; - if (backing_src_is_shared(src_type)) + if (flags & KVM_MEM_GUEST_MEMFD && gmem_flags & GUEST_MEMFD_FLAG_MMAP) { + region->fd = kvm_dup(gmem_fd); + mmap_flags = MAP_SHARED; + mmap_offset = gmem_offset; + } else if (backing_src_is_shared(src_type)) { region->fd = kvm_memfd_alloc(region->mmap_size, src_type == VM_MEM_SRC_SHARED_HUGETLB); + } - region->mmap_start = kvm_mmap(region->mmap_size, PROT_READ | PROT_WRITE, - vm_mem_backing_src_alias(src_type)->flag, - region->fd); + region->mmap_start = __kvm_mmap(region->mmap_size, PROT_READ | PROT_WRITE, + mmap_flags, region->fd, mmap_offset); TEST_ASSERT(!is_backing_src_hugetlb(src_type) || region->mmap_start == align_ptr_up(region->mmap_start, backing_src_pagesz), @@ -1153,10 +1157,10 @@ void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type, /* If shared memory, create an alias. */ if (region->fd >= 0) { - region->mmap_alias = kvm_mmap(region->mmap_size, - PROT_READ | PROT_WRITE, - vm_mem_backing_src_alias(src_type)->flag, - region->fd); + region->mmap_alias = __kvm_mmap(region->mmap_size, + PROT_READ | PROT_WRITE, + mmap_flags, region->fd, + mmap_offset); /* Align host alias address */ region->host_alias = align_ptr_up(region->mmap_alias, alignment); @@ -1167,7 +1171,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type, gpa_t gpa, u32 slot, u64 npages, u32 flags) { - vm_mem_add(vm, src_type, gpa, slot, npages, flags, -1, 0); + vm_mem_add(vm, src_type, gpa, slot, npages, flags, -1, 0, 0); } /* diff --git a/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c b/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c index 3aa0673f79f33..f3de2a4ab0551 100644 --- a/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c +++ b/tools/testing/selftests/kvm/x86/private_mem_conversions_test.c @@ -399,7 +399,7 @@ static void test_mem_conversions(enum vm_mem_backing_src_type src_type, u32 nr_v for (i = 0; i < nr_memslots; i++) vm_mem_add(vm, src_type, BASE_DATA_GPA + slot_size * i, BASE_DATA_SLOT + i, slot_size / vm->page_size, - KVM_MEM_GUEST_MEMFD, memfd, slot_size * i); + KVM_MEM_GUEST_MEMFD, memfd, slot_size * i, 0); for (i = 0; i < nr_vcpus; i++) { gpa_t gpa = BASE_DATA_GPA + i * per_cpu_size; -- 2.55.0.1007.g17ff1f9808-goog