Introduce a set of APIs to execute VM with private memslots.
Host userspace APIs for:
1) Setting up and executing VM having private memslots
2) Backing/unbacking guest private memory
Guest APIs for:
1) Changing memory access type and memory type
2) Setting ucall page access type as shared
Signed-off-by: Vishal Annapurve <vannapurve@xxxxxxxxxx>
---
tools/testing/selftests/kvm/Makefile | 1 +
.../kvm/include/x86_64/private_mem.h | 51 +++
.../selftests/kvm/lib/x86_64/private_mem.c | 297 ++++++++++++++++++
3 files changed, 349 insertions(+)
create mode 100644 tools/testing/selftests/kvm/include/x86_64/private_mem.h
create mode 100644 tools/testing/selftests/kvm/lib/x86_64/private_mem.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 41fd1171fbd8..8fe72a60aef0 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -51,6 +51,7 @@ LIBKVM += lib/ucall_common.c
LIBKVM_x86_64 += lib/x86_64/apic.c
LIBKVM_x86_64 += lib/x86_64/handlers.S
LIBKVM_x86_64 += lib/x86_64/perf_test_util.c
+LIBKVM_x86_64 += lib/x86_64/private_mem.c
LIBKVM_x86_64 += lib/x86_64/processor.c
LIBKVM_x86_64 += lib/x86_64/svm.c
LIBKVM_x86_64 += lib/x86_64/ucall.c
diff --git a/tools/testing/selftests/kvm/include/x86_64/private_mem.h b/tools/testing/selftests/kvm/include/x86_64/private_mem.h
new file mode 100644
index 000000000000..00cab7b84f2c
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/x86_64/private_mem.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2022, Google LLC.
+ */
+
+#ifndef SELFTEST_KVM_PRIVATE_MEM_H
+#define SELFTEST_KVM_PRIVATE_MEM_H
+
+#include <stdint.h>
+#include <kvm_util.h>
+
+enum mem_conversion_type {
+ TO_PRIVATE,
+ TO_SHARED
+};
+
+void guest_update_mem_access(enum mem_conversion_type type, uint64_t gpa,
+ uint64_t size);
+void guest_update_mem_map(enum mem_conversion_type type, uint64_t gpa,
+ uint64_t size);
+
+void guest_map_ucall_page_shared(void);
+
+enum mem_op {
+ ALLOCATE_MEM,
+ UNBACK_MEM
+};
+
+void vm_update_private_mem(struct kvm_vm *vm, uint64_t gpa, uint64_t size,
+ enum mem_op op);
+
+typedef void (*guest_code_fn)(void);
+typedef void (*io_exit_handler)(struct kvm_vm *vm, uint32_t uc_arg1);
+
+struct test_setup_info {
+ uint64_t test_area_gpa;
+ uint64_t test_area_size;
+ uint32_t test_area_slot;
+};
+
+struct vm_setup_info {
+ enum vm_mem_backing_src_type vm_mem_src;
+ uint32_t memslot0_pages;
+ struct test_setup_info test_info;
+ guest_code_fn guest_fn;
+ io_exit_handler ioexit_cb;
+};
+
+void execute_vm_with_private_mem(struct vm_setup_info *info);
+
+#endif /* SELFTEST_KVM_PRIVATE_MEM_H */
diff --git a/tools/testing/selftests/kvm/lib/x86_64/private_mem.c b/tools/testing/selftests/kvm/lib/x86_64/private_mem.c
new file mode 100644
index 000000000000..000584219045
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/x86_64/private_mem.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * tools/testing/selftests/kvm/lib/kvm_util.c
+ *
+ * Copyright (C) 2022, Google LLC.
+ */
+#define _GNU_SOURCE /* for program_invocation_name */
+#include <fcntl.h>
+#include <limits.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+#include <linux/kvm_para.h>
+
+#include <test_util.h>
+#include <kvm_util.h>
+#include <private_mem.h>
+#include <processor.h>
+
+/*
+ * Execute KVM hypercall to change memory access type for a given gpa range.
+ *
+ * Input Args:
+ * type - memory conversion type TO_SHARED/TO_PRIVATE
+ * gpa - starting gpa address
+ * size - size of the range starting from gpa for which memory access needs
+ * to be changed
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Function called by guest logic in selftests to update the memory access type
+ * for a given gpa range. This API is useful in exercising implicit conversion
+ * path.
+ */
+void guest_update_mem_access(enum mem_conversion_type type, uint64_t gpa,
+ uint64_t size)
+{
+ int ret = kvm_hypercall(KVM_HC_MAP_GPA_RANGE, gpa, size >> MIN_PAGE_SHIFT,
+ type == TO_PRIVATE ? KVM_MARK_GPA_RANGE_ENC_ACCESS :
+ KVM_CLR_GPA_RANGE_ENC_ACCESS, 0);
+ GUEST_ASSERT_1(!ret, ret);
+}
+
+/*
+ * Execute KVM hypercall to change memory type for a given gpa range.
+ *
+ * Input Args:
+ * type - memory conversion type TO_SHARED/TO_PRIVATE
+ * gpa - starting gpa address
+ * size - size of the range starting from gpa for which memory type needs
+ * to be changed
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Function called by guest logic in selftests to update the memory type for a
+ * given gpa range. This API is useful in exercising explicit conversion path.
+ */
+void guest_update_mem_map(enum mem_conversion_type type, uint64_t gpa,
+ uint64_t size)
+{
+ int ret = kvm_hypercall(KVM_HC_MAP_GPA_RANGE, gpa, size >> MIN_PAGE_SHIFT,
+ type == TO_PRIVATE ? KVM_MAP_GPA_RANGE_ENCRYPTED :
+ KVM_MAP_GPA_RANGE_DECRYPTED, 0);
+ GUEST_ASSERT_1(!ret, ret);
+}
+
+/*
+ * Execute KVM hypercall to change memory access type for ucall page.
+ *
+ * Input Args: None
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Function called by guest logic in selftests to update the memory access type
+ * for ucall page since by default all the accesses from guest to private
+ * memslot are treated as private accesses.
+ */
+void guest_map_ucall_page_shared(void)
+{
+ vm_paddr_t ucall_paddr = get_ucall_pool_paddr();
+
+ guest_update_mem_access(TO_SHARED, ucall_paddr, 1 << MIN_PAGE_SHIFT);
+}
+
+/*
+ * Execute KVM ioctl to back/unback private memory for given gpa range.
+ *
+ * Input Args:
+ * vm - kvm_vm handle
+ * gpa - starting gpa address
+ * size - size of the gpa range
+ * op - mem_op indicating whether private memory needs to be allocated or
+ * unbacked
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Function called by host userspace logic in selftests to back/unback private
+ * memory for gpa ranges. This function is useful to setup initial boot private
+ * memory and then convert memory during runtime.
+ */
+void vm_update_private_mem(struct kvm_vm *vm, uint64_t gpa, uint64_t size,
+ enum mem_op op)
+{
+ int priv_memfd;
+ uint64_t priv_offset, guest_phys_base, fd_offset;
+ struct kvm_enc_region enc_region;
+ struct kvm_userspace_memory_region_ext *region_ext;
+ struct kvm_userspace_memory_region *region;
+ int fallocate_mode = 0;
+ int ret;
+
+ region_ext = kvm_userspace_memory_region_ext_find(vm, gpa, gpa + size);
+ TEST_ASSERT(region_ext != NULL, "Region not found");
+ region = ®ion_ext->region;
+ TEST_ASSERT(region->flags & KVM_MEM_PRIVATE,
+ "Can not update private memfd for non-private memslot\n");
+ priv_memfd = region_ext->private_fd;
+ priv_offset = region_ext->private_offset;
+ guest_phys_base = region->guest_phys_addr;
+ fd_offset = priv_offset + (gpa - guest_phys_base);
+
+ if (op == UNBACK_MEM)
+ fallocate_mode = (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE);
+
+ printf("priv_memfd %d fallocate_mode 0x%x for offset 0x%lx size 0x%lx\n",
+ priv_memfd, fallocate_mode, fd_offset, size);
+ ret = fallocate(priv_memfd, fallocate_mode, fd_offset, size);
+ TEST_ASSERT(ret == 0, "fallocate failed\n");
+ enc_region.addr = gpa;
+ enc_region.size = size;
+ if (op == ALLOCATE_MEM) {
+ printf("doing encryption for gpa 0x%lx size 0x%lx\n", gpa, size);
+ vm_ioctl(vm, KVM_MEMORY_ENCRYPT_REG_REGION, &enc_region);
+ } else {
+ printf("undoing encryption for gpa 0x%lx size 0x%lx\n", gpa, size);
+ vm_ioctl(vm, KVM_MEMORY_ENCRYPT_UNREG_REGION, &enc_region);
+ }
+}
+
+static void handle_vm_exit_map_gpa_hypercall(struct kvm_vm *vm,
+ volatile struct kvm_run *run)
+{
+ uint64_t gpa, npages, attrs, size;
+
+ TEST_ASSERT(run->hypercall.nr == KVM_HC_MAP_GPA_RANGE,
+ "Unhandled Hypercall %lld\n", run->hypercall.nr);
+ gpa = run->hypercall.args[0];
+ npages = run->hypercall.args[1];
+ size = npages << MIN_PAGE_SHIFT;
+ attrs = run->hypercall.args[2];
+ pr_info("Explicit conversion off 0x%lx size 0x%lx to %s\n", gpa, size,
+ (attrs & KVM_MAP_GPA_RANGE_ENCRYPTED) ? "private" : "shared");
+
+ if (attrs & KVM_MAP_GPA_RANGE_ENCRYPTED)
+ vm_update_private_mem(vm, gpa, size, ALLOCATE_MEM);
+ else
+ vm_update_private_mem(vm, gpa, size, UNBACK_MEM);
+
+ run->hypercall.ret = 0;
+}
+
+static void handle_vm_exit_memory_error(struct kvm_vm *vm, volatile struct kvm_run *run)
+{
+ uint64_t gpa, size, flags;
+
+ gpa = run->memory.gpa;
+ size = run->memory.size;
+ flags = run->memory.flags;
+ pr_info("Implicit conversion off 0x%lx size 0x%lx to %s\n", gpa, size,
+ (flags & KVM_MEMORY_EXIT_FLAG_PRIVATE) ? "private" : "shared");
+ if (flags & KVM_MEMORY_EXIT_FLAG_PRIVATE)
+ vm_update_private_mem(vm, gpa, size, ALLOCATE_MEM);
+ else
+ vm_update_private_mem(vm, gpa, size, UNBACK_MEM);
+}
+
+static void vcpu_work(struct kvm_vm *vm, struct kvm_vcpu *vcpu,
+ struct vm_setup_info *info)
+{
+ volatile struct kvm_run *run;
+ struct ucall uc;
+ uint64_t cmd;
+
+ /*
+ * Loop until the guest is done.
+ */
+ run = vcpu->run;
+
+ while (true) {
+ vcpu_run(vcpu);
+
+ if (run->exit_reason == KVM_EXIT_IO) {
+ cmd = get_ucall(vcpu, &uc);
+ if (cmd != UCALL_SYNC)
+ break;
+
+ TEST_ASSERT(info->ioexit_cb, "ioexit cb not present");
+ info->ioexit_cb(vm, uc.args[1]);
+ continue;
+ }
+
+ if (run->exit_reason == KVM_EXIT_HYPERCALL) {
+ handle_vm_exit_map_gpa_hypercall(vm, run);
+ continue;
+ }
+
+ if (run->exit_reason == KVM_EXIT_MEMORY_FAULT) {
+ handle_vm_exit_memory_error(vm, run);
+ continue;
+ }
+
+ TEST_FAIL("Unhandled VCPU exit reason %d\n", run->exit_reason);
+ break;
+ }
+
+ if (run->exit_reason == KVM_EXIT_IO && cmd == UCALL_ABORT)
+ TEST_FAIL("%s at %s:%ld, val = %lu", (const char *)uc.args[0],
+ __FILE__, uc.args[1], uc.args[2]);
+}
+
+/*
+ * Execute guest vm with private memory memslots.
+ *
+ * Input Args:
+ * info - pointer to a structure containing information about setting up a VM
+ * with private memslots
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Function called by host userspace logic in selftests to execute guest vm
+ * logic. It will install two memslots:
+ * 1) memslot 0 : containing all the boot code/stack pages
+ * 2) test_mem_slot : containing the region of memory that would be used to test
+ * private/shared memory accesses to a memory backed by private memslots
+ */
+void execute_vm_with_private_mem(struct vm_setup_info *info)
+{
+ struct kvm_vm *vm;
+ struct kvm_enable_cap cap;
+ struct kvm_vcpu *vcpu;
+ uint32_t memslot0_pages = info->memslot0_pages;
+ uint64_t test_area_gpa, test_area_size;
+ struct test_setup_info *test_info = &info->test_info;
+
+ vm = vm_create_barebones();
+ vm_set_memory_encryption(vm, true, false, 0);
+ vm->use_ucall_pool = true;
+ vm_userspace_mem_region_add(vm, info->vm_mem_src, 0, 0,
+ memslot0_pages, KVM_MEM_PRIVATE);
+ kvm_vm_elf_load(vm, program_invocation_name);
+ vm_create_irqchip(vm);
+ TEST_ASSERT(info->guest_fn, "guest_fn not present");
+ vcpu = vm_vcpu_add(vm, 0, info->guest_fn);
+
+ vm_check_cap(vm, KVM_CAP_EXIT_HYPERCALL);
+ cap.cap = KVM_CAP_EXIT_HYPERCALL;
+ cap.flags = 0;
+ cap.args[0] = (1 << KVM_HC_MAP_GPA_RANGE);
+ vm_ioctl(vm, KVM_ENABLE_CAP, &cap);
+
+ TEST_ASSERT(test_info->test_area_size, "Test mem size not present");
+
+ test_area_size = test_info->test_area_size;
+ test_area_gpa = test_info->test_area_gpa;
+ vm_userspace_mem_region_add(vm, info->vm_mem_src, test_area_gpa,
+ test_info->test_area_slot, test_area_size / vm->page_size,
+ KVM_MEM_PRIVATE);
+ vm_update_private_mem(vm, test_area_gpa, test_area_size, ALLOCATE_MEM);
+
+ pr_info("Mapping test memory pages 0x%zx page_size 0x%x\n",
+ test_area_size/vm->page_size, vm->page_size);
+ virt_map(vm, test_area_gpa, test_area_gpa, test_area_size/vm->page_size);
+
+ ucall_init(vm, NULL);
+ vm_update_private_mem(vm, 0, (memslot0_pages << MIN_PAGE_SHIFT), ALLOCATE_MEM);
+
+ vcpu_work(vm, vcpu, info);
+
+ ucall_uninit(vm);
+ kvm_vm_free(vm);
+}
--
2.37.1.595.g718a3a8f04-goog
