With this, vm_userspace_mem_region_add() can use restricted memory to back guest memory.
Signed-off-by: Ackerley Tng ackerleytng@google.com --- .../selftests/kvm/include/kvm_util_base.h | 7 ++- .../testing/selftests/kvm/include/test_util.h | 2 + tools/testing/selftests/kvm/lib/kvm_util.c | 48 ++++++++++++++++--- tools/testing/selftests/kvm/lib/test_util.c | 7 +++ 4 files changed, 55 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index 30453e2de8396..950fd337898e1 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -33,7 +33,10 @@ typedef uint64_t vm_paddr_t; /* Virtual Machine (Guest) physical address */ typedef uint64_t vm_vaddr_t; /* Virtual Machine (Guest) virtual address */
struct userspace_mem_region { - struct kvm_userspace_memory_region region; + union { + struct kvm_userspace_memory_region region; + struct kvm_userspace_memory_region_ext region_ext; + }; struct sparsebit *unused_phy_pages; struct sparsebit *protected_phy_pages; int fd; @@ -214,7 +217,7 @@ static inline bool kvm_has_cap(long cap)
#define kvm_do_ioctl(fd, cmd, arg) \ ({ \ - static_assert(!_IOC_SIZE(cmd) || sizeof(*arg) == _IOC_SIZE(cmd), ""); \ + static_assert(!_IOC_SIZE(cmd) || sizeof(*arg) >= _IOC_SIZE(cmd), ""); \ ioctl(fd, cmd, arg); \ })
diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index befc754ce9b3b..01456a78b3a2e 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -94,6 +94,7 @@ enum vm_mem_backing_src_type { VM_MEM_SRC_ANONYMOUS_HUGETLB_1GB, VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB, VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB, + VM_MEM_SRC_ANONYMOUS_AND_RESTRICTED_MEMFD, VM_MEM_SRC_SHMEM, VM_MEM_SRC_SHARED_HUGETLB, NUM_SRC_TYPES, @@ -104,6 +105,7 @@ enum vm_mem_backing_src_type { struct vm_mem_backing_src_alias { const char *name; uint32_t flag; + bool need_restricted_memfd; };
#define MIN_RUN_DELAY_NS 200000UL diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 6673be2f49c31..4e5928fa71c44 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -15,7 +15,6 @@ #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> -#include <linux/kernel.h>
#define KVM_UTIL_MIN_PFN 2
@@ -799,6 +798,27 @@ void vm_set_user_memory_region(struct kvm_vm *vm, uint32_t slot, uint32_t flags, errno, strerror(errno)); }
+/** + * Initialize memory in restricted_fd with size @memory_region_size and return + * the fd. + * + * Errors out if there's any error + */ +static int initialize_restricted_memfd(uint64_t memory_region_size) +{ + int ret; + int mfd = -1; + + mfd = syscall(__NR_memfd_restricted, 0); + TEST_ASSERT(mfd != -1, "Failed to create private memfd"); + ret = ftruncate(mfd, memory_region_size); + TEST_ASSERT(ret != -1, "Failed to resize memfd %d to %lx", mfd, memory_region_size); + ret = fallocate(mfd, 0, 0, memory_region_size); + TEST_ASSERT(ret != -1, "Failed to allocate %lx bytes in memfd %d", memory_region_size, mfd); + + return mfd; +} + /* * VM Userspace Memory Region Add * @@ -830,6 +850,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, struct userspace_mem_region *region; size_t backing_src_pagesz = get_backing_src_pagesz(src_type); size_t alignment; + int restricted_memfd = -1;
TEST_ASSERT(vm_adjust_num_guest_pages(vm->mode, npages) == npages, "Number of guest pages is not compatible with the host. " @@ -927,14 +948,24 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
/* As needed perform madvise */ if ((src_type == VM_MEM_SRC_ANONYMOUS || - src_type == VM_MEM_SRC_ANONYMOUS_THP) && thp_configured()) { - ret = madvise(region->host_mem, npages * vm->page_size, - src_type == VM_MEM_SRC_ANONYMOUS ? MADV_NOHUGEPAGE : MADV_HUGEPAGE); + src_type == VM_MEM_SRC_ANONYMOUS_THP || + src_type == VM_MEM_SRC_ANONYMOUS_AND_RESTRICTED_MEMFD) && thp_configured()) { + int advice = src_type == VM_MEM_SRC_ANONYMOUS_THP + ? MADV_HUGEPAGE + : MADV_NOHUGEPAGE; + ret = madvise(region->host_mem, npages * vm->page_size, advice); TEST_ASSERT(ret == 0, "madvise failed, addr: %p length: 0x%lx src_type: %s", region->host_mem, npages * vm->page_size, vm_mem_backing_src_alias(src_type)->name); }
+ if (vm_mem_backing_src_alias(src_type)->need_restricted_memfd) { + restricted_memfd = initialize_restricted_memfd(npages * vm->page_size); + TEST_ASSERT(restricted_memfd != -1, + "Failed to create restricted memfd"); + flags |= KVM_MEM_PRIVATE; + } + region->unused_phy_pages = sparsebit_alloc(); region->protected_phy_pages = sparsebit_alloc(); sparsebit_set_num(region->unused_phy_pages, @@ -944,13 +975,16 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, region->region.guest_phys_addr = guest_paddr; region->region.memory_size = npages * vm->page_size; region->region.userspace_addr = (uintptr_t) region->host_mem; - ret = __vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION, ®ion->region); + region->region_ext.restricted_fd = restricted_memfd; + region->region_ext.restricted_offset = 0; + ret = __vm_ioctl(vm, KVM_SET_USER_MEMORY_REGION, ®ion->region_ext); TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION IOCTL failed,\n" " rc: %i errno: %i\n" " slot: %u flags: 0x%x\n" - " guest_phys_addr: 0x%lx size: 0x%lx", + " guest_phys_addr: 0x%lx size: 0x%lx restricted_fd: %d", ret, errno, slot, flags, - guest_paddr, (uint64_t) region->region.memory_size); + guest_paddr, (uint64_t) region->region.memory_size, + restricted_memfd);
/* Add to quick lookup data structures */ vm_userspace_mem_region_gpa_insert(&vm->regions.gpa_tree, region); diff --git a/tools/testing/selftests/kvm/lib/test_util.c b/tools/testing/selftests/kvm/lib/test_util.c index 6d23878bbfe1a..2d53e55d13565 100644 --- a/tools/testing/selftests/kvm/lib/test_util.c +++ b/tools/testing/selftests/kvm/lib/test_util.c @@ -8,6 +8,7 @@ #include <assert.h> #include <ctype.h> #include <limits.h> +#include <stdbool.h> #include <stdlib.h> #include <time.h> #include <sys/stat.h> @@ -254,6 +255,11 @@ const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i) */ .flag = MAP_SHARED, }, + [VM_MEM_SRC_ANONYMOUS_AND_RESTRICTED_MEMFD] = { + .name = "anonymous_and_restricted_memfd", + .flag = ANON_FLAGS, + .need_restricted_memfd = true, + }, }; _Static_assert(ARRAY_SIZE(aliases) == NUM_SRC_TYPES, "Missing new backing src types?"); @@ -272,6 +278,7 @@ size_t get_backing_src_pagesz(uint32_t i) switch (i) { case VM_MEM_SRC_ANONYMOUS: case VM_MEM_SRC_SHMEM: + case VM_MEM_SRC_ANONYMOUS_AND_RESTRICTED_MEMFD: return getpagesize(); case VM_MEM_SRC_ANONYMOUS_THP: return get_trans_hugepagesz();