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-rw-r--r--tools/testing/selftests/kvm/.gitignore1
-rw-r--r--tools/testing/selftests/kvm/Makefile1
-rw-r--r--tools/testing/selftests/kvm/include/x86_64/processor.h4
-rw-r--r--tools/testing/selftests/kvm/lib/x86_64/processor.c92
-rw-r--r--tools/testing/selftests/kvm/x86_64/emulator_error_test.c219
5 files changed, 317 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index 14c550d64d3c..d5bc9bf3b528 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -8,6 +8,7 @@
/x86_64/cr4_cpuid_sync_test
/x86_64/debug_regs
/x86_64/evmcs_test
+/x86_64/emulator_error_test
/x86_64/get_cpuid_test
/x86_64/get_msr_index_features
/x86_64/kvm_pv_test
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 279051fb901c..bc65c57ae40d 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -41,6 +41,7 @@ LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_ha
TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test
TEST_GEN_PROGS_x86_64 += x86_64/get_msr_index_features
TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
+TEST_GEN_PROGS_x86_64 += x86_64/emulator_error_test
TEST_GEN_PROGS_x86_64 += x86_64/get_cpuid_test
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_clock
TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h
index 914b0d16929c..6d27a5435971 100644
--- a/tools/testing/selftests/kvm/include/x86_64/processor.h
+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h
@@ -399,6 +399,10 @@ void vcpu_init_descriptor_tables(struct kvm_vm *vm, uint32_t vcpuid);
void vm_handle_exception(struct kvm_vm *vm, int vector,
void (*handler)(struct ex_regs *));
+uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr);
+void vm_set_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr,
+ uint64_t pte);
+
/*
* set_cpuid() - overwrites a matching cpuid entry with the provided value.
* matches based on ent->function && ent->index. returns true
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index 5e0e3a131dad..3114b18454d5 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -282,6 +282,98 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr)
__virt_pg_map(vm, vaddr, paddr, X86_PAGE_SIZE_4K);
}
+static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid,
+ uint64_t vaddr)
+{
+ uint16_t index[4];
+ struct pageUpperEntry *pml4e, *pdpe, *pde;
+ struct pageTableEntry *pte;
+ struct kvm_cpuid_entry2 *entry;
+ struct kvm_sregs sregs;
+ int max_phy_addr;
+ /* Set the bottom 52 bits. */
+ uint64_t rsvd_mask = 0x000fffffffffffff;
+
+ entry = kvm_get_supported_cpuid_index(0x80000008, 0);
+ max_phy_addr = entry->eax & 0x000000ff;
+ /* Clear the bottom bits of the reserved mask. */
+ rsvd_mask = (rsvd_mask >> max_phy_addr) << max_phy_addr;
+
+ /*
+ * SDM vol 3, fig 4-11 "Formats of CR3 and Paging-Structure Entries
+ * with 4-Level Paging and 5-Level Paging".
+ * If IA32_EFER.NXE = 0 and the P flag of a paging-structure entry is 1,
+ * the XD flag (bit 63) is reserved.
+ */
+ vcpu_sregs_get(vm, vcpuid, &sregs);
+ if ((sregs.efer & EFER_NX) == 0) {
+ rsvd_mask |= (1ull << 63);
+ }
+
+ TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use "
+ "unknown or unsupported guest mode, mode: 0x%x", vm->mode);
+ TEST_ASSERT(sparsebit_is_set(vm->vpages_valid,
+ (vaddr >> vm->page_shift)),
+ "Invalid virtual address, vaddr: 0x%lx",
+ vaddr);
+ /*
+ * Based on the mode check above there are 48 bits in the vaddr, so
+ * shift 16 to sign extend the last bit (bit-47),
+ */
+ TEST_ASSERT(vaddr == (((int64_t)vaddr << 16) >> 16),
+ "Canonical check failed. The virtual address is invalid.");
+
+ index[0] = (vaddr >> 12) & 0x1ffu;
+ index[1] = (vaddr >> 21) & 0x1ffu;
+ index[2] = (vaddr >> 30) & 0x1ffu;
+ index[3] = (vaddr >> 39) & 0x1ffu;
+
+ pml4e = addr_gpa2hva(vm, vm->pgd);
+ TEST_ASSERT(pml4e[index[3]].present,
+ "Expected pml4e to be present for gva: 0x%08lx", vaddr);
+ TEST_ASSERT((*(uint64_t*)(&pml4e[index[3]]) &
+ (rsvd_mask | (1ull << 7))) == 0,
+ "Unexpected reserved bits set.");
+
+ pdpe = addr_gpa2hva(vm, pml4e[index[3]].pfn * vm->page_size);
+ TEST_ASSERT(pdpe[index[2]].present,
+ "Expected pdpe to be present for gva: 0x%08lx", vaddr);
+ TEST_ASSERT(pdpe[index[2]].page_size == 0,
+ "Expected pdpe to map a pde not a 1-GByte page.");
+ TEST_ASSERT((*(uint64_t*)(&pdpe[index[2]]) & rsvd_mask) == 0,
+ "Unexpected reserved bits set.");
+
+ pde = addr_gpa2hva(vm, pdpe[index[2]].pfn * vm->page_size);
+ TEST_ASSERT(pde[index[1]].present,
+ "Expected pde to be present for gva: 0x%08lx", vaddr);
+ TEST_ASSERT(pde[index[1]].page_size == 0,
+ "Expected pde to map a pte not a 2-MByte page.");
+ TEST_ASSERT((*(uint64_t*)(&pde[index[1]]) & rsvd_mask) == 0,
+ "Unexpected reserved bits set.");
+
+ pte = addr_gpa2hva(vm, pde[index[1]].pfn * vm->page_size);
+ TEST_ASSERT(pte[index[0]].present,
+ "Expected pte to be present for gva: 0x%08lx", vaddr);
+
+ return &pte[index[0]];
+}
+
+uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr)
+{
+ struct pageTableEntry *pte = _vm_get_page_table_entry(vm, vcpuid, vaddr);
+
+ return *(uint64_t *)pte;
+}
+
+void vm_set_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr,
+ uint64_t pte)
+{
+ struct pageTableEntry *new_pte = _vm_get_page_table_entry(vm, vcpuid,
+ vaddr);
+
+ *(uint64_t *)new_pte = pte;
+}
+
void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
{
struct pageUpperEntry *pml4e, *pml4e_start;
diff --git a/tools/testing/selftests/kvm/x86_64/emulator_error_test.c b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
new file mode 100644
index 000000000000..f070ff0224fa
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/emulator_error_test.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020, Google LLC.
+ *
+ * Tests for KVM_CAP_EXIT_ON_EMULATION_FAILURE capability.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+
+#include "test_util.h"
+#include "kvm_util.h"
+#include "vmx.h"
+
+#define VCPU_ID 1
+#define PAGE_SIZE 4096
+#define MAXPHYADDR 36
+
+#define MEM_REGION_GVA 0x0000123456789000
+#define MEM_REGION_GPA 0x0000000700000000
+#define MEM_REGION_SLOT 10
+#define MEM_REGION_SIZE PAGE_SIZE
+
+static void guest_code(void)
+{
+ __asm__ __volatile__("flds (%[addr])"
+ :: [addr]"r"(MEM_REGION_GVA));
+
+ GUEST_DONE();
+}
+
+static void run_guest(struct kvm_vm *vm)
+{
+ int rc;
+
+ rc = _vcpu_run(vm, VCPU_ID);
+ TEST_ASSERT(rc == 0, "vcpu_run failed: %d\n", rc);
+}
+
+/*
+ * Accessors to get R/M, REG, and Mod bits described in the SDM vol 2,
+ * figure 2-2 "Table Interpretation of ModR/M Byte (C8H)".
+ */
+#define GET_RM(insn_byte) (insn_byte & 0x7)
+#define GET_REG(insn_byte) ((insn_byte & 0x38) >> 3)
+#define GET_MOD(insn_byte) ((insn_byte & 0xc) >> 6)
+
+/* Ensure we are dealing with a simple 2-byte flds instruction. */
+static bool is_flds(uint8_t *insn_bytes, uint8_t insn_size)
+{
+ return insn_size >= 2 &&
+ insn_bytes[0] == 0xd9 &&
+ GET_REG(insn_bytes[1]) == 0x0 &&
+ GET_MOD(insn_bytes[1]) == 0x0 &&
+ /* Ensure there is no SIB byte. */
+ GET_RM(insn_bytes[1]) != 0x4 &&
+ /* Ensure there is no displacement byte. */
+ GET_RM(insn_bytes[1]) != 0x5;
+}
+
+static void process_exit_on_emulation_error(struct kvm_vm *vm)
+{
+ struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+ struct kvm_regs regs;
+ uint8_t *insn_bytes;
+ uint8_t insn_size;
+ uint64_t flags;
+
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_INTERNAL_ERROR,
+ "Unexpected exit reason: %u (%s)",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+
+ TEST_ASSERT(run->emulation_failure.suberror == KVM_INTERNAL_ERROR_EMULATION,
+ "Unexpected suberror: %u",
+ run->emulation_failure.suberror);
+
+ if (run->emulation_failure.ndata >= 1) {
+ flags = run->emulation_failure.flags;
+ if ((flags & KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES) &&
+ run->emulation_failure.ndata >= 3) {
+ insn_size = run->emulation_failure.insn_size;
+ insn_bytes = run->emulation_failure.insn_bytes;
+
+ TEST_ASSERT(insn_size <= 15 && insn_size > 0,
+ "Unexpected instruction size: %u",
+ insn_size);
+
+ TEST_ASSERT(is_flds(insn_bytes, insn_size),
+ "Unexpected instruction. Expected 'flds' (0xd9 /0)");
+
+ /*
+ * If is_flds() succeeded then the instruction bytes
+ * contained an flds instruction that is 2-bytes in
+ * length (ie: no prefix, no SIB, no displacement).
+ */
+ vcpu_regs_get(vm, VCPU_ID, &regs);
+ regs.rip += 2;
+ vcpu_regs_set(vm, VCPU_ID, &regs);
+ }
+ }
+}
+
+static void do_guest_assert(struct kvm_vm *vm, struct ucall *uc)
+{
+ TEST_FAIL("%s at %s:%ld", (const char *)uc->args[0], __FILE__,
+ uc->args[1]);
+}
+
+static void check_for_guest_assert(struct kvm_vm *vm)
+{
+ struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+ struct ucall uc;
+
+ if (run->exit_reason == KVM_EXIT_IO &&
+ get_ucall(vm, VCPU_ID, &uc) == UCALL_ABORT) {
+ do_guest_assert(vm, &uc);
+ }
+}
+
+static void process_ucall_done(struct kvm_vm *vm)
+{
+ struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+ struct ucall uc;
+
+ check_for_guest_assert(vm);
+
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+ "Unexpected exit reason: %u (%s)",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+
+ TEST_ASSERT(get_ucall(vm, VCPU_ID, &uc) == UCALL_DONE,
+ "Unexpected ucall command: %lu, expected UCALL_DONE (%d)",
+ uc.cmd, UCALL_DONE);
+}
+
+static uint64_t process_ucall(struct kvm_vm *vm)
+{
+ struct kvm_run *run = vcpu_state(vm, VCPU_ID);
+ struct ucall uc;
+
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+ "Unexpected exit reason: %u (%s)",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+
+ switch (get_ucall(vm, VCPU_ID, &uc)) {
+ case UCALL_SYNC:
+ break;
+ case UCALL_ABORT:
+ do_guest_assert(vm, &uc);
+ break;
+ case UCALL_DONE:
+ process_ucall_done(vm);
+ break;
+ default:
+ TEST_ASSERT(false, "Unexpected ucall");
+ }
+
+ return uc.cmd;
+}
+
+int main(int argc, char *argv[])
+{
+ struct kvm_enable_cap emul_failure_cap = {
+ .cap = KVM_CAP_EXIT_ON_EMULATION_FAILURE,
+ .args[0] = 1,
+ };
+ struct kvm_cpuid_entry2 *entry;
+ struct kvm_cpuid2 *cpuid;
+ struct kvm_vm *vm;
+ uint64_t gpa, pte;
+ uint64_t *hva;
+ int rc;
+
+ /* Tell stdout not to buffer its content */
+ setbuf(stdout, NULL);
+
+ vm = vm_create_default(VCPU_ID, 0, guest_code);
+
+ if (!kvm_check_cap(KVM_CAP_SMALLER_MAXPHYADDR)) {
+ printf("module parameter 'allow_smaller_maxphyaddr' is not set. Skipping test.\n");
+ return 0;
+ }
+
+ cpuid = kvm_get_supported_cpuid();
+
+ entry = kvm_get_supported_cpuid_index(0x80000008, 0);
+ entry->eax = (entry->eax & 0xffffff00) | MAXPHYADDR;
+ set_cpuid(cpuid, entry);
+
+ vcpu_set_cpuid(vm, VCPU_ID, cpuid);
+
+ rc = kvm_check_cap(KVM_CAP_EXIT_ON_EMULATION_FAILURE);
+ TEST_ASSERT(rc, "KVM_CAP_EXIT_ON_EMULATION_FAILURE is unavailable");
+ vm_enable_cap(vm, &emul_failure_cap);
+
+ vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
+ MEM_REGION_GPA, MEM_REGION_SLOT,
+ MEM_REGION_SIZE / PAGE_SIZE, 0);
+ gpa = vm_phy_pages_alloc(vm, MEM_REGION_SIZE / PAGE_SIZE,
+ MEM_REGION_GPA, MEM_REGION_SLOT);
+ TEST_ASSERT(gpa == MEM_REGION_GPA, "Failed vm_phy_pages_alloc\n");
+ virt_map(vm, MEM_REGION_GVA, MEM_REGION_GPA, 1);
+ hva = addr_gpa2hva(vm, MEM_REGION_GPA);
+ memset(hva, 0, PAGE_SIZE);
+ pte = vm_get_page_table_entry(vm, VCPU_ID, MEM_REGION_GVA);
+ vm_set_page_table_entry(vm, VCPU_ID, MEM_REGION_GVA, pte | (1ull << 36));
+
+ run_guest(vm);
+ process_exit_on_emulation_error(vm);
+ run_guest(vm);
+
+ TEST_ASSERT(process_ucall(vm) == UCALL_DONE, "Expected UCALL_DONE");
+
+ kvm_vm_free(vm);
+
+ return 0;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.