summaryrefslogtreecommitdiff
path: root/tools/testing/selftests/kvm/lib/x86_64/svm.c
blob: 6e05a8fc3fe0694fb6ab805745c841943b0e8604 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
// SPDX-License-Identifier: GPL-2.0-only
/*
 * tools/testing/selftests/kvm/lib/x86_64/svm.c
 * Helpers used for nested SVM testing
 * Largely inspired from KVM unit test svm.c
 *
 * Copyright (C) 2020, Red Hat, Inc.
 */

#include "test_util.h"
#include "kvm_util.h"
#include "../kvm_util_internal.h"
#include "processor.h"
#include "svm_util.h"

struct gpr64_regs guest_regs;
u64 rflags;

/* Allocate memory regions for nested SVM tests.
 *
 * Input Args:
 *   vm - The VM to allocate guest-virtual addresses in.
 *
 * Output Args:
 *   p_svm_gva - The guest virtual address for the struct svm_test_data.
 *
 * Return:
 *   Pointer to structure with the addresses of the SVM areas.
 */
struct svm_test_data *
vcpu_alloc_svm(struct kvm_vm *vm, vm_vaddr_t *p_svm_gva)
{
	vm_vaddr_t svm_gva = vm_vaddr_alloc(vm, getpagesize(),
					    0x10000, 0, 0);
	struct svm_test_data *svm = addr_gva2hva(vm, svm_gva);

	svm->vmcb = (void *)vm_vaddr_alloc(vm, getpagesize(),
					   0x10000, 0, 0);
	svm->vmcb_hva = addr_gva2hva(vm, (uintptr_t)svm->vmcb);
	svm->vmcb_gpa = addr_gva2gpa(vm, (uintptr_t)svm->vmcb);

	svm->save_area = (void *)vm_vaddr_alloc(vm, getpagesize(),
						0x10000, 0, 0);
	svm->save_area_hva = addr_gva2hva(vm, (uintptr_t)svm->save_area);
	svm->save_area_gpa = addr_gva2gpa(vm, (uintptr_t)svm->save_area);

	*p_svm_gva = svm_gva;
	return svm;
}

static void vmcb_set_seg(struct vmcb_seg *seg, u16 selector,
			 u64 base, u32 limit, u32 attr)
{
	seg->selector = selector;
	seg->attrib = attr;
	seg->limit = limit;
	seg->base = base;
}

void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_rsp)
{
	struct vmcb *vmcb = svm->vmcb;
	uint64_t vmcb_gpa = svm->vmcb_gpa;
	struct vmcb_save_area *save = &vmcb->save;
	struct vmcb_control_area *ctrl = &vmcb->control;
	u32 data_seg_attr = 3 | SVM_SELECTOR_S_MASK | SVM_SELECTOR_P_MASK
	      | SVM_SELECTOR_DB_MASK | SVM_SELECTOR_G_MASK;
	u32 code_seg_attr = 9 | SVM_SELECTOR_S_MASK | SVM_SELECTOR_P_MASK
		| SVM_SELECTOR_L_MASK | SVM_SELECTOR_G_MASK;
	uint64_t efer;

	efer = rdmsr(MSR_EFER);
	wrmsr(MSR_EFER, efer | EFER_SVME);
	wrmsr(MSR_VM_HSAVE_PA, svm->save_area_gpa);

	memset(vmcb, 0, sizeof(*vmcb));
	asm volatile ("vmsave\n\t" : : "a" (vmcb_gpa) : "memory");
	vmcb_set_seg(&save->es, get_es(), 0, -1U, data_seg_attr);
	vmcb_set_seg(&save->cs, get_cs(), 0, -1U, code_seg_attr);
	vmcb_set_seg(&save->ss, get_ss(), 0, -1U, data_seg_attr);
	vmcb_set_seg(&save->ds, get_ds(), 0, -1U, data_seg_attr);
	vmcb_set_seg(&save->gdtr, 0, get_gdt().address, get_gdt().size, 0);
	vmcb_set_seg(&save->idtr, 0, get_idt().address, get_idt().size, 0);

	ctrl->asid = 1;
	save->cpl = 0;
	save->efer = rdmsr(MSR_EFER);
	asm volatile ("mov %%cr4, %0" : "=r"(save->cr4) : : "memory");
	asm volatile ("mov %%cr3, %0" : "=r"(save->cr3) : : "memory");
	asm volatile ("mov %%cr0, %0" : "=r"(save->cr0) : : "memory");
	asm volatile ("mov %%dr7, %0" : "=r"(save->dr7) : : "memory");
	asm volatile ("mov %%dr6, %0" : "=r"(save->dr6) : : "memory");
	asm volatile ("mov %%cr2, %0" : "=r"(save->cr2) : : "memory");
	save->g_pat = rdmsr(MSR_IA32_CR_PAT);
	save->dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
	ctrl->intercept = (1ULL << INTERCEPT_VMRUN) |
				(1ULL << INTERCEPT_VMMCALL);

	vmcb->save.rip = (u64)guest_rip;
	vmcb->save.rsp = (u64)guest_rsp;
	guest_regs.rdi = (u64)svm;
}

/*
 * save/restore 64-bit general registers except rax, rip, rsp
 * which are directly handed through the VMCB guest processor state
 */
#define SAVE_GPR_C				\
	"xchg %%rbx, guest_regs+0x20\n\t"	\
	"xchg %%rcx, guest_regs+0x10\n\t"	\
	"xchg %%rdx, guest_regs+0x18\n\t"	\
	"xchg %%rbp, guest_regs+0x30\n\t"	\
	"xchg %%rsi, guest_regs+0x38\n\t"	\
	"xchg %%rdi, guest_regs+0x40\n\t"	\
	"xchg %%r8,  guest_regs+0x48\n\t"	\
	"xchg %%r9,  guest_regs+0x50\n\t"	\
	"xchg %%r10, guest_regs+0x58\n\t"	\
	"xchg %%r11, guest_regs+0x60\n\t"	\
	"xchg %%r12, guest_regs+0x68\n\t"	\
	"xchg %%r13, guest_regs+0x70\n\t"	\
	"xchg %%r14, guest_regs+0x78\n\t"	\
	"xchg %%r15, guest_regs+0x80\n\t"

#define LOAD_GPR_C      SAVE_GPR_C

/*
 * selftests do not use interrupts so we dropped clgi/sti/cli/stgi
 * for now. registers involved in LOAD/SAVE_GPR_C are eventually
 * unmodified so they do not need to be in the clobber list.
 */
void run_guest(struct vmcb *vmcb, uint64_t vmcb_gpa)
{
	asm volatile (
		"vmload\n\t"
		"mov rflags, %%r15\n\t"	// rflags
		"mov %%r15, 0x170(%[vmcb])\n\t"
		"mov guest_regs, %%r15\n\t"	// rax
		"mov %%r15, 0x1f8(%[vmcb])\n\t"
		LOAD_GPR_C
		"vmrun\n\t"
		SAVE_GPR_C
		"mov 0x170(%[vmcb]), %%r15\n\t"	// rflags
		"mov %%r15, rflags\n\t"
		"mov 0x1f8(%[vmcb]), %%r15\n\t"	// rax
		"mov %%r15, guest_regs\n\t"
		"vmsave\n\t"
		: : [vmcb] "r" (vmcb), [vmcb_gpa] "a" (vmcb_gpa)
		: "r15", "memory");
}

void nested_svm_check_supported(void)
{
	struct kvm_cpuid_entry2 *entry =
		kvm_get_supported_cpuid_entry(0x80000001);

	if (!(entry->ecx & CPUID_SVM)) {
		fprintf(stderr, "nested SVM not enabled, skipping test\n");
		exit(KSFT_SKIP);
	}
}