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bh=3vNAWgtLoposophLWrViaHYvvOXZ6Fk6ckKHKISBIQw=; b=5ZW/84CSiLisXbfe1r14r83e3Hy3AoEnZdshNnLemzJjOMY2dPsrs925RHSHU1mSj258Dyyz5 VMpW+WjIPY4DZdPwGAgjCBX703FNh7usPXzDd1fpjoEGG2Zj0tLFl/f X-Mailer: b4 0.14.3 Message-ID: <20260326-gmem-inplace-conversion-v4-20-e202fe950ffd@google.com> Subject: [PATCH RFC v4 20/44] KVM: selftests: Add support for mmap() on guest_memfd in core library From: Ackerley Tng To: aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, ira.weiny@intel.com, jmattson@google.com, jroedel@suse.de, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. 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 , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Jason Gunthorpe , Vlastimil Babka 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, Ackerley Tng Content-Type: text/plain; charset="utf-8" X-Rspam-User: X-Stat-Signature: geeet7irsrsqmeh5i4ase3awsu5ikff9 X-Rspamd-Queue-Id: D142180003 X-Rspamd-Server: rspam09 X-HE-Tag: 1774563906-932175 X-HE-Meta: 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 MTCuRbOE 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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. mmap() from guest_memfd using the provided gmem_flags and gmem_offset. 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. Signed-off-by: Sean Christopherson [For guest_memfds, mmap() using gmem_offset instead of 0 all the time.] Signed-off-by: Ackerley Tng --- tools/testing/selftests/kvm/include/kvm_util.h | 7 ++++++- tools/testing/selftests/kvm/lib/kvm_util.c | 19 +++++++++++-------- .../selftests/kvm/x86/private_mem_conversions_test.c | 2 +- 3 files changed, 18 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index b2d35824f2a72..4e06724cd2935 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -701,7 +701,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, uint32_t flags); void vm_mem_add(struct kvm_vm *vm, enum vm_mem_backing_src_type src_type, uint64_t gpa, uint32_t slot, uint64_t npages, uint32_t flags, - int gmem_fd, uint64_t gmem_offset); + int gmem_fd, uint64_t gmem_offset, uint64_t gmem_flags); #ifndef vm_arch_has_protected_memory static inline bool vm_arch_has_protected_memory(struct kvm_vm *vm) @@ -735,6 +735,11 @@ void *addr_gva2hva(struct kvm_vm *vm, vm_vaddr_t gva); vm_paddr_t addr_hva2gpa(struct kvm_vm *vm, void *hva); void *addr_gpa2alias(struct kvm_vm *vm, vm_paddr_t gpa); +static inline int kvm_slot_to_fd(struct kvm_vm *vm, uint32_t 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 3b64fbadcd88d..82d6945efa29a 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -979,12 +979,13 @@ void vm_set_user_memory_region2(struct kvm_vm *vm, uint32_t slot, uint32_t 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, uint64_t gpa, uint32_t slot, uint64_t npages, uint32_t flags, - int gmem_fd, uint64_t gmem_offset) + int gmem_fd, uint64_t gmem_offset, uint64_t gmem_flags) { int ret; struct userspace_mem_region *region; size_t backing_src_pagesz = get_backing_src_pagesz(src_type); size_t mem_size = npages * vm->page_size; + off_t mmap_offset = 0; size_t alignment; TEST_REQUIRE_SET_USER_MEMORY_REGION2(); @@ -1063,8 +1064,6 @@ 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) { - uint32_t 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); @@ -1085,13 +1084,17 @@ 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_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, + vm_mem_backing_src_alias(src_type)->flag, + region->fd, mmap_offset); TEST_ASSERT(!is_backing_src_hugetlb(src_type) || region->mmap_start == align_ptr_up(region->mmap_start, backing_src_pagesz), @@ -1152,7 +1155,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, uint64_t gpa, uint32_t slot, uint64_t npages, uint32_t 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 1969f4ab9b280..41f6b38f04071 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, uint32_t 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++) { uint64_t gpa = BASE_DATA_GPA + i * per_cpu_size; -- 2.53.0.1018.g2bb0e51243-goog