smaller_maxphyaddr_emulation_test.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (C) 2020, Google LLC.
  4 *
  5 * Test that KVM emulates instructions in response to EPT violations when
  6 * allow_smaller_maxphyaddr is enabled and guest.MAXPHYADDR < host.MAXPHYADDR.
  7 */
  8#include "flds_emulation.h"
  9
 10#include "test_util.h"
 11#include "kvm_util.h"
 12#include "vmx.h"
 13
 14#define MAXPHYADDR 36
 15
 16#define MEM_REGION_GVA	0x0000123456789000
 17#define MEM_REGION_GPA	0x0000000700000000
 18#define MEM_REGION_SLOT	10
 19#define MEM_REGION_SIZE PAGE_SIZE
 20
 21static void guest_code(bool tdp_enabled)
 22{
 23	uint64_t error_code;
 24	uint64_t vector;
 25
 26	vector = kvm_asm_safe_ec(FLDS_MEM_EAX, error_code, "a"(MEM_REGION_GVA));
 27
 28	/*
 29	 * When TDP is enabled, flds will trigger an emulation failure, exit to
 30	 * userspace, and then the selftest host "VMM" skips the instruction.
 31	 *
 32	 * When TDP is disabled, no instruction emulation is required so flds
 33	 * should generate #PF(RSVD).
 34	 */
 35	if (tdp_enabled) {
 36		GUEST_ASSERT(!vector);
 37	} else {
 38		GUEST_ASSERT_EQ(vector, PF_VECTOR);
 39		GUEST_ASSERT(error_code & PFERR_RSVD_MASK);
 40	}
 41
 42	GUEST_DONE();
 43}
 44
 45int main(int argc, char *argv[])
 46{
 47	struct kvm_vcpu *vcpu;
 48	struct kvm_vm *vm;
 49	struct ucall uc;
 50	uint64_t *pte;
 51	uint64_t *hva;
 52	uint64_t gpa;
 53	int rc;
 54
 55	TEST_REQUIRE(kvm_has_cap(KVM_CAP_SMALLER_MAXPHYADDR));
 56
 57	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 58	vcpu_args_set(vcpu, 1, kvm_is_tdp_enabled());
 59
 60	vcpu_set_cpuid_property(vcpu, X86_PROPERTY_MAX_PHY_ADDR, MAXPHYADDR);
 61
 62	rc = kvm_check_cap(KVM_CAP_EXIT_ON_EMULATION_FAILURE);
 63	TEST_ASSERT(rc, "KVM_CAP_EXIT_ON_EMULATION_FAILURE is unavailable");
 64	vm_enable_cap(vm, KVM_CAP_EXIT_ON_EMULATION_FAILURE, 1);
 65
 66	vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
 67				    MEM_REGION_GPA, MEM_REGION_SLOT,
 68				    MEM_REGION_SIZE / PAGE_SIZE, 0);
 69	gpa = vm_phy_pages_alloc(vm, MEM_REGION_SIZE / PAGE_SIZE,
 70				 MEM_REGION_GPA, MEM_REGION_SLOT);
 71	TEST_ASSERT(gpa == MEM_REGION_GPA, "Failed vm_phy_pages_alloc");
 72	virt_map(vm, MEM_REGION_GVA, MEM_REGION_GPA, 1);
 73	hva = addr_gpa2hva(vm, MEM_REGION_GPA);
 74	memset(hva, 0, PAGE_SIZE);
 75
 76	pte = vm_get_page_table_entry(vm, MEM_REGION_GVA);
 77	*pte |= BIT_ULL(MAXPHYADDR);
 78
 79	vcpu_run(vcpu);
 80
 81	/*
 82	 * When TDP is enabled, KVM must emulate in response the guest physical
 83	 * address that is illegal from the guest's perspective, but is legal
 84	 * from hardware's perspeective.  This should result in an emulation
 85	 * failure exit to userspace since KVM doesn't support emulating flds.
 86	 */
 87	if (kvm_is_tdp_enabled()) {
 88		handle_flds_emulation_failure_exit(vcpu);
 89		vcpu_run(vcpu);
 90	}
 91
 92	switch (get_ucall(vcpu, &uc)) {
 93	case UCALL_ABORT:
 94		REPORT_GUEST_ASSERT(uc);
 95		break;
 96	case UCALL_DONE:
 97		break;
 98	default:
 99		TEST_FAIL("Unrecognized ucall: %lu", uc.cmd);
100	}
101
102	kvm_vm_free(vm);
103
104	return 0;
105}