From: Sean Christopherson <[email protected]> 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 <[email protected]> [For guest_memfds, mmap() using gmem_offset instead of 0 all the time.] Signed-off-by: Ackerley Tng <[email protected]> --- tools/testing/selftests/kvm/include/kvm_util.h | 7 ++++++- tools/testing/selftests/kvm/lib/kvm_util.c | 18 ++++++++++-------- .../kvm/x86/private_mem_conversions_test.c | 2 +- 3 files changed, 17 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index 45159638d5dde..de8ae9be19067 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -678,7 +678,7 @@ 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 guest_memfd_fd, uint64_t guest_memfd_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) @@ -711,6 +711,11 @@ 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 8b714270cf381..19c0445c0b296 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -944,12 +944,13 @@ 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; size_t alignment; TEST_REQUIRE_SET_USER_MEMORY_REGION2(); @@ -1028,8 +1029,6 @@ 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); @@ -1050,13 +1049,16 @@ 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); + 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); + mmap_offset = flags & KVM_MEM_GUEST_MEMFD ? gmem_offset : 0; + 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), @@ -1117,7 +1119,7 @@ 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; -- 2.51.0.858.gf9c4a03a3a-goog
