On Mon, Dec 05, 2022, Vishal Annapurve wrote:
Add support for registering private memory with kvm using KVM_SET_USER_MEMORY_REGION ioctl.
Helper function to query extended userspace mem region is introduced to allow memory conversion.
vm_mem_backing_src types is extended to contain additional guest memory source types to cover the cases where guest memory can be backed by both anonymous memory and restricted memfd.
Signed-off-by: Vishal Annapurve vannapurve@google.com
.../selftests/kvm/include/kvm_util_base.h | 12 +++- .../testing/selftests/kvm/include/test_util.h | 4 ++ tools/testing/selftests/kvm/lib/kvm_util.c | 58 +++++++++++++++++-- tools/testing/selftests/kvm/lib/test_util.c | 11 ++++ 4 files changed, 78 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index c7685c7038ff..4ad99f295f2a 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -31,7 +31,10 @@ 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;
As discussed in the UPM series, we're trending towards adding an entirely new struct+ioctl(), kvm_userspace_memory_region2, instead of extending the existing struct. The == -> >= hack you had to add in kvm_do_ioctl() below is one of the reason for that change.
- }; struct sparsebit *unused_phy_pages; int fd; off_t offset;
@@ -196,7 +199,7 @@ 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); \
}) @@ -384,6 +387,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags); void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa); void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot);
struct kvm_vcpu *__vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id); vm_vaddr_t vm_vaddr_unused_gap(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min); vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min); @@ -715,6 +719,10 @@ struct kvm_userspace_memory_region * kvm_userspace_memory_region_find(struct kvm_vm *vm, uint64_t start, uint64_t end); +struct kvm_userspace_memory_region_ext * +kvm_userspace_memory_region_ext_find(struct kvm_vm *vm, uint64_t start,
uint64_t end);#define sync_global_to_guest(vm, g) ({ \ typeof(g) *_p = addr_gva2hva(vm, (vm_vaddr_t)&(g)); \ memcpy(_p, &(g), sizeof(g)); \ diff --git a/tools/testing/selftests/kvm/include/test_util.h b/tools/testing/selftests/kvm/include/test_util.h index 80d6416f3012..aea80071f2b8 100644 --- a/tools/testing/selftests/kvm/include/test_util.h +++ b/tools/testing/selftests/kvm/include/test_util.h @@ -103,6 +103,8 @@ enum vm_mem_backing_src_type { VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB, VM_MEM_SRC_SHMEM, VM_MEM_SRC_SHARED_HUGETLB,
- VM_MEM_SRC_ANONYMOUS_AND_RESTRICTED_MEMFD,
- VM_MEM_SRC_ANON_HTLB2M_AND_RESTRICTED_MEMFD,
There's no need for a dedicated flag in the backing type, vm_userspace_mem_region_add() already takes the memslot's flags and can simply key off KVM_MEM_PRIVATE.
@@ -881,6 +915,7 @@ 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;
No need to initialize to -1, KVM is supposed to ignore the restrictedmem fd if !KVM_MEM_PRIVATE, and if KVM_MEM_PRIVATE is set, selftests must provide a valid fd.
TEST_ASSERT(vm_adjust_num_guest_pages(vm->mode, npages) == npages, "Number of guest pages is not compatible with the host. "
This is what I ended up with after splitting out the conversion to KVM_SET_USER_MEMORY_REGION2 to a separate patch.
-- diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 7c1f81f93ba3..26c6830c1aa1 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -32,6 +32,11 @@ int open_path_or_exit(const char *path, int flags) return fd; }
+static int memfd_restricted(unsigned int flags) +{ + return syscall(__NR_memfd_restricted, flags); +} + /* * Open KVM_DEV_PATH if available, otherwise exit the entire program. * @@ -980,6 +985,15 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, }
region->backing_src_type = src_type; + + if (flags & KVM_MEM_PRIVATE) { + region->region.restricted_fd = memfd_restricted(0); + region->region.restricted_offset = 0; + + TEST_ASSERT(region->region.restricted_fd >= 0, + "Failed to create restricted memfd"); + } + region->unused_phy_pages = sparsebit_alloc(); sparsebit_set_num(region->unused_phy_pages, guest_paddr >> vm->page_shift, npages); @@ -992,9 +1006,10 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION2 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\n", ret, errno, slot, flags, - guest_paddr, (uint64_t) region->region.memory_size); + guest_paddr, (uint64_t) region->region.memory_size, + region->region.restricted_fd);
/* Add to quick lookup data structures */ vm_userspace_mem_region_gpa_insert(&vm->regions.gpa_tree, region);