VM implementations that make use of encrypted memory need a way to configure things like the encryption/shared bit position for page table handling, the default encryption policy for internal allocations made by the core library, and a way to fetch the list/bitmap of encrypted pages to do the actual memory encryption. Add an interface to configure these parameters. Also introduce a sparsebit map to track allocations/mappings that should be treated as encrypted, and provide a way for VM implementations to retrieve it to handle operations related memory encryption.
Signed-off-by: Michael Roth michael.roth@amd.com --- .../testing/selftests/kvm/include/kvm_util.h | 6 ++ tools/testing/selftests/kvm/lib/kvm_util.c | 63 +++++++++++++++++-- .../selftests/kvm/lib/kvm_util_internal.h | 10 +++ 3 files changed, 75 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index 010b59b13917..f417de80596c 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -348,6 +348,12 @@ int vm_create_device(struct kvm_vm *vm, struct kvm_create_device *cd);
void assert_on_unhandled_exception(struct kvm_vm *vm, uint32_t vcpuid);
+void vm_set_memory_encryption(struct kvm_vm *vm, bool enc_by_default, bool has_enc_bit, + uint8_t enc_bit); +struct sparsebit *vm_get_encrypted_phy_pages(struct kvm_vm *vm, int slot, + vm_paddr_t *gpa_start, + uint64_t *size); + /* Common ucalls */ enum { UCALL_NONE, diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 92f59adddebe..c58f930dedd2 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -631,6 +631,7 @@ static void __vm_mem_region_delete(struct kvm_vm *vm, "rc: %i errno: %i", ret, errno);
sparsebit_free(®ion->unused_phy_pages); + sparsebit_free(®ion->encrypted_phy_pages); ret = munmap(region->mmap_start, region->mmap_size); TEST_ASSERT(ret == 0, "munmap failed, rc: %i errno: %i", ret, errno);
@@ -924,6 +925,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, }
region->unused_phy_pages = sparsebit_alloc(); + region->encrypted_phy_pages = sparsebit_alloc(); sparsebit_set_num(region->unused_phy_pages, guest_paddr >> vm->page_shift, npages); region->region.slot = slot; @@ -1153,6 +1155,7 @@ void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid) * num - number of pages * paddr_min - Physical address minimum * memslot - Memory region to allocate page from + * encrypt - Whether to treat the pages as encrypted * * Output Args: None * @@ -1164,11 +1167,13 @@ void vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpuid) * and their base address is returned. A TEST_ASSERT failure occurs if * not enough pages are available at or above paddr_min. */ -vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num, - vm_paddr_t paddr_min, uint32_t memslot) +static vm_paddr_t +_vm_phy_pages_alloc(struct kvm_vm *vm, size_t num, vm_paddr_t paddr_min, + uint32_t memslot, bool encrypt) { struct userspace_mem_region *region; sparsebit_idx_t pg, base; + vm_paddr_t gpa;
TEST_ASSERT(num > 0, "Must allocate at least one page");
@@ -1198,10 +1203,25 @@ vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num, abort(); }
- for (pg = base; pg < base + num; ++pg) + for (pg = base; pg < base + num; ++pg) { sparsebit_clear(region->unused_phy_pages, pg); + if (encrypt) + sparsebit_set(region->encrypted_phy_pages, pg); + } + + gpa = base * vm->page_size;
- return base * vm->page_size; + if (encrypt && vm->memcrypt.has_enc_bit) + gpa |= (1ULL << vm->memcrypt.enc_bit); + + return gpa; +} + +vm_paddr_t vm_phy_pages_alloc(struct kvm_vm *vm, size_t num, + vm_paddr_t paddr_min, uint32_t memslot) +{ + return _vm_phy_pages_alloc(vm, 1, paddr_min, memslot, + vm->memcrypt.enc_by_default); }
vm_paddr_t vm_phy_page_alloc(struct kvm_vm *vm, vm_paddr_t paddr_min, @@ -2146,6 +2166,10 @@ void vm_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent) region->host_mem); fprintf(stream, "%*sunused_phy_pages: ", indent + 2, ""); sparsebit_dump(stream, region->unused_phy_pages, 0); + if (vm->memcrypt.enabled) { + fprintf(stream, "%*sencrypted_phy_pages: ", indent + 2, ""); + sparsebit_dump(stream, region->encrypted_phy_pages, 0); + } } fprintf(stream, "%*sMapped Virtual Pages:\n", indent, ""); sparsebit_dump(stream, vm->vpages_mapped, indent + 2); @@ -2343,3 +2367,34 @@ int vcpu_get_stats_fd(struct kvm_vm *vm, uint32_t vcpuid)
return ioctl(vcpu->fd, KVM_GET_STATS_FD, NULL); } + +void vm_set_memory_encryption(struct kvm_vm *vm, bool enc_by_default, bool has_enc_bit, + uint8_t enc_bit) +{ + vm->memcrypt.enabled = true; + vm->memcrypt.enc_by_default = enc_by_default; + vm->memcrypt.has_enc_bit = has_enc_bit; + vm->memcrypt.enc_bit = enc_bit; +} + +struct sparsebit * +vm_get_encrypted_phy_pages(struct kvm_vm *vm, int slot, vm_paddr_t *gpa_start, + uint64_t *size) +{ + struct userspace_mem_region *region; + struct sparsebit *encrypted_phy_pages; + + if (!vm->memcrypt.enabled) + return NULL; + + region = memslot2region(vm, slot); + if (!region) + return NULL; + + encrypted_phy_pages = sparsebit_alloc(); + sparsebit_copy(encrypted_phy_pages, region->encrypted_phy_pages); + *size = region->region.memory_size; + *gpa_start = region->region.guest_phys_addr; + + return encrypted_phy_pages; +} diff --git a/tools/testing/selftests/kvm/lib/kvm_util_internal.h b/tools/testing/selftests/kvm/lib/kvm_util_internal.h index a03febc24ba6..99ccab86115c 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util_internal.h +++ b/tools/testing/selftests/kvm/lib/kvm_util_internal.h @@ -16,6 +16,7 @@ struct userspace_mem_region { struct kvm_userspace_memory_region region; struct sparsebit *unused_phy_pages; + struct sparsebit *encrypted_phy_pages; int fd; off_t offset; void *host_mem; @@ -44,6 +45,14 @@ struct userspace_mem_regions { DECLARE_HASHTABLE(slot_hash, 9); };
+/* Memory encryption policy/configuration. */ +struct vm_memcrypt { + bool enabled; + int8_t enc_by_default; + bool has_enc_bit; + int8_t enc_bit; +}; + struct kvm_vm { int mode; unsigned long type; @@ -67,6 +76,7 @@ struct kvm_vm { vm_vaddr_t idt; vm_vaddr_t handlers; uint32_t dirty_ring_size; + struct vm_memcrypt memcrypt; };
struct vcpu *vcpu_find(struct kvm_vm *vm, uint32_t vcpuid);