hyperv_svm_test.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2022, Red Hat, Inc.
  4 *
  5 * Tests for Hyper-V extensions to SVM.
  6 */
  7#include <fcntl.h>
  8#include <stdio.h>
  9#include <stdlib.h>
 10#include <string.h>
 11#include <sys/ioctl.h>
 12#include <linux/bitmap.h>
 13
 14#include "test_util.h"
 15
 16#include "kvm_util.h"
 17#include "processor.h"
 18#include "svm_util.h"
 19#include "hyperv.h"
 20
 21#define L2_GUEST_STACK_SIZE 256
 22
 23/* Exit to L1 from L2 with RDMSR instruction */
 24static inline void rdmsr_from_l2(uint32_t msr)
 25{
 26	/* Currently, L1 doesn't preserve GPRs during vmexits. */
 27	__asm__ __volatile__ ("rdmsr" : : "c"(msr) :
 28			      "rax", "rbx", "rdx", "rsi", "rdi", "r8", "r9",
 29			      "r10", "r11", "r12", "r13", "r14", "r15");
 30}
 31
 32void l2_guest_code(void)
 33{
 34	u64 unused;
 35
 36	GUEST_SYNC(3);
 37	/* Exit to L1 */
 38	vmmcall();
 39
 40	/* MSR-Bitmap tests */
 41	rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
 42	rdmsr_from_l2(MSR_FS_BASE); /* intercepted */
 43	rdmsr_from_l2(MSR_GS_BASE); /* not intercepted */
 44	vmmcall();
 45	rdmsr_from_l2(MSR_GS_BASE); /* intercepted */
 46
 47	GUEST_SYNC(5);
 48
 49	/* L2 TLB flush tests */
 50	hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE |
 51			 HV_HYPERCALL_FAST_BIT, 0x0,
 52			 HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES |
 53			 HV_FLUSH_ALL_PROCESSORS);
 54	rdmsr_from_l2(MSR_FS_BASE);
 55	/*
 56	 * Note: hypercall status (RAX) is not preserved correctly by L1 after
 57	 * synthetic vmexit, use unchecked version.
 58	 */
 59	__hyperv_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE |
 60			   HV_HYPERCALL_FAST_BIT, 0x0,
 61			   HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES |
 62			   HV_FLUSH_ALL_PROCESSORS, &unused);
 63
 64	/* Done, exit to L1 and never come back.  */
 65	vmmcall();
 66}
 67
 68static void __attribute__((__flatten__)) guest_code(struct svm_test_data *svm,
 69						    struct hyperv_test_pages *hv_pages,
 70						    vm_vaddr_t pgs_gpa)
 71{
 72	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
 73	struct vmcb *vmcb = svm->vmcb;
 74	struct hv_vmcb_enlightenments *hve = &vmcb->control.hv_enlightenments;
 75
 76	GUEST_SYNC(1);
 77
 78	wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
 79	wrmsr(HV_X64_MSR_HYPERCALL, pgs_gpa);
 80	enable_vp_assist(hv_pages->vp_assist_gpa, hv_pages->vp_assist);
 81
 82	GUEST_ASSERT(svm->vmcb_gpa);
 83	/* Prepare for L2 execution. */
 84	generic_svm_setup(svm, l2_guest_code,
 85			  &l2_guest_stack[L2_GUEST_STACK_SIZE]);
 86
 87	/* L2 TLB flush setup */
 88	hve->partition_assist_page = hv_pages->partition_assist_gpa;
 89	hve->hv_enlightenments_control.nested_flush_hypercall = 1;
 90	hve->hv_vm_id = 1;
 91	hve->hv_vp_id = 1;
 92	current_vp_assist->nested_control.features.directhypercall = 1;
 93	*(u32 *)(hv_pages->partition_assist) = 0;
 94
 95	GUEST_SYNC(2);
 96	run_guest(vmcb, svm->vmcb_gpa);
 97	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
 98	GUEST_SYNC(4);
 99	vmcb->save.rip += 3;
100
101	/* Intercept RDMSR 0xc0000100 */
102	vmcb->control.intercept |= 1ULL << INTERCEPT_MSR_PROT;
103	__set_bit(2 * (MSR_FS_BASE & 0x1fff), svm->msr + 0x800);
104	run_guest(vmcb, svm->vmcb_gpa);
105	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
106	vmcb->save.rip += 2; /* rdmsr */
107
108	/* Enable enlightened MSR bitmap */
109	hve->hv_enlightenments_control.msr_bitmap = 1;
110	run_guest(vmcb, svm->vmcb_gpa);
111	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
112	vmcb->save.rip += 2; /* rdmsr */
113
114	/* Intercept RDMSR 0xc0000101 without telling KVM about it */
115	__set_bit(2 * (MSR_GS_BASE & 0x1fff), svm->msr + 0x800);
116	/* Make sure HV_VMX_ENLIGHTENED_CLEAN_FIELD_MSR_BITMAP is set */
117	vmcb->control.clean |= HV_VMCB_NESTED_ENLIGHTENMENTS;
118	run_guest(vmcb, svm->vmcb_gpa);
119	/* Make sure we don't see SVM_EXIT_MSR here so eMSR bitmap works */
120	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
121	vmcb->save.rip += 3; /* vmcall */
122
123	/* Now tell KVM we've changed MSR-Bitmap */
124	vmcb->control.clean &= ~HV_VMCB_NESTED_ENLIGHTENMENTS;
125	run_guest(vmcb, svm->vmcb_gpa);
126	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
127	vmcb->save.rip += 2; /* rdmsr */
128
129
130	/*
131	 * L2 TLB flush test. First VMCALL should be handled directly by L0,
132	 * no VMCALL exit expected.
133	 */
134	run_guest(vmcb, svm->vmcb_gpa);
135	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_MSR);
136	vmcb->save.rip += 2; /* rdmsr */
137	/* Enable synthetic vmexit */
138	*(u32 *)(hv_pages->partition_assist) = 1;
139	run_guest(vmcb, svm->vmcb_gpa);
140	GUEST_ASSERT(vmcb->control.exit_code == HV_SVM_EXITCODE_ENL);
141	GUEST_ASSERT(vmcb->control.exit_info_1 == HV_SVM_ENL_EXITCODE_TRAP_AFTER_FLUSH);
142
143	run_guest(vmcb, svm->vmcb_gpa);
144	GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
145	GUEST_SYNC(6);
146
147	GUEST_DONE();
148}
149
150int main(int argc, char *argv[])
151{
152	vm_vaddr_t nested_gva = 0, hv_pages_gva = 0;
153	vm_vaddr_t hcall_page;
154	struct kvm_vcpu *vcpu;
155	struct kvm_vm *vm;
156	struct ucall uc;
157	int stage;
158
159	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM));
160	TEST_REQUIRE(kvm_hv_cpu_has(HV_X64_NESTED_DIRECT_FLUSH));
161
162	/* Create VM */
163	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
164	vcpu_set_hv_cpuid(vcpu);
165	vcpu_alloc_svm(vm, &nested_gva);
166	vcpu_alloc_hyperv_test_pages(vm, &hv_pages_gva);
167
168	hcall_page = vm_vaddr_alloc_pages(vm, 1);
169	memset(addr_gva2hva(vm, hcall_page), 0x0,  getpagesize());
170
171	vcpu_args_set(vcpu, 3, nested_gva, hv_pages_gva, addr_gva2gpa(vm, hcall_page));
172	vcpu_set_msr(vcpu, HV_X64_MSR_VP_INDEX, vcpu->id);
173
174	for (stage = 1;; stage++) {
175		vcpu_run(vcpu);
176		TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
177
178		switch (get_ucall(vcpu, &uc)) {
179		case UCALL_ABORT:
180			REPORT_GUEST_ASSERT(uc);
181			/* NOT REACHED */
182		case UCALL_SYNC:
183			break;
184		case UCALL_DONE:
185			goto done;
186		default:
187			TEST_FAIL("Unknown ucall %lu", uc.cmd);
188		}
189
190		/* UCALL_SYNC is handled here.  */
191		TEST_ASSERT(!strcmp((const char *)uc.args[0], "hello") &&
192			    uc.args[1] == stage, "Stage %d: Unexpected register values vmexit, got %lx",
193			    stage, (ulong)uc.args[1]);
194
195	}
196
197done:
198	kvm_vm_free(vm);
199}