1 // SPDX-License-Identifier: GPL-2.0-only
3 * tools/testing/selftests/kvm/lib/x86_64/svm.c
4 * Helpers used for nested SVM testing
5 * Largely inspired from KVM unit test svm.c
7 * Copyright (C) 2020, Red Hat, Inc.
10 #include "test_util.h"
12 #include "processor.h"
15 #define SEV_DEV_PATH "/dev/sev"
17 struct gpr64_regs guest_regs;
20 /* Allocate memory regions for nested SVM tests.
23 * vm - The VM to allocate guest-virtual addresses in.
26 * p_svm_gva - The guest virtual address for the struct svm_test_data.
29 * Pointer to structure with the addresses of the SVM areas.
31 struct svm_test_data *
32 vcpu_alloc_svm(struct kvm_vm *vm, vm_vaddr_t *p_svm_gva)
34 vm_vaddr_t svm_gva = vm_vaddr_alloc_page(vm);
35 struct svm_test_data *svm = addr_gva2hva(vm, svm_gva);
37 svm->vmcb = (void *)vm_vaddr_alloc_page(vm);
38 svm->vmcb_hva = addr_gva2hva(vm, (uintptr_t)svm->vmcb);
39 svm->vmcb_gpa = addr_gva2gpa(vm, (uintptr_t)svm->vmcb);
41 svm->save_area = (void *)vm_vaddr_alloc_page(vm);
42 svm->save_area_hva = addr_gva2hva(vm, (uintptr_t)svm->save_area);
43 svm->save_area_gpa = addr_gva2gpa(vm, (uintptr_t)svm->save_area);
45 svm->msr = (void *)vm_vaddr_alloc_page(vm);
46 svm->msr_hva = addr_gva2hva(vm, (uintptr_t)svm->msr);
47 svm->msr_gpa = addr_gva2gpa(vm, (uintptr_t)svm->msr);
48 memset(svm->msr_hva, 0, getpagesize());
54 static void vmcb_set_seg(struct vmcb_seg *seg, u16 selector,
55 u64 base, u32 limit, u32 attr)
57 seg->selector = selector;
64 * Avoid using memset to clear the vmcb, since libc may not be
65 * available in L1 (and, even if it is, features that libc memset may
66 * want to use, like AVX, may not be enabled).
68 static void clear_vmcb(struct vmcb *vmcb)
70 int n = sizeof(*vmcb) / sizeof(u32);
72 asm volatile ("rep stosl" : "+c"(n), "+D"(vmcb) : "a"(0) : "memory");
75 void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_rsp)
77 struct vmcb *vmcb = svm->vmcb;
78 uint64_t vmcb_gpa = svm->vmcb_gpa;
79 struct vmcb_save_area *save = &vmcb->save;
80 struct vmcb_control_area *ctrl = &vmcb->control;
81 u32 data_seg_attr = 3 | SVM_SELECTOR_S_MASK | SVM_SELECTOR_P_MASK
82 | SVM_SELECTOR_DB_MASK | SVM_SELECTOR_G_MASK;
83 u32 code_seg_attr = 9 | SVM_SELECTOR_S_MASK | SVM_SELECTOR_P_MASK
84 | SVM_SELECTOR_L_MASK | SVM_SELECTOR_G_MASK;
87 efer = rdmsr(MSR_EFER);
88 wrmsr(MSR_EFER, efer | EFER_SVME);
89 wrmsr(MSR_VM_HSAVE_PA, svm->save_area_gpa);
92 asm volatile ("vmsave %0\n\t" : : "a" (vmcb_gpa) : "memory");
93 vmcb_set_seg(&save->es, get_es(), 0, -1U, data_seg_attr);
94 vmcb_set_seg(&save->cs, get_cs(), 0, -1U, code_seg_attr);
95 vmcb_set_seg(&save->ss, get_ss(), 0, -1U, data_seg_attr);
96 vmcb_set_seg(&save->ds, get_ds(), 0, -1U, data_seg_attr);
97 vmcb_set_seg(&save->gdtr, 0, get_gdt().address, get_gdt().size, 0);
98 vmcb_set_seg(&save->idtr, 0, get_idt().address, get_idt().size, 0);
102 save->efer = rdmsr(MSR_EFER);
103 asm volatile ("mov %%cr4, %0" : "=r"(save->cr4) : : "memory");
104 asm volatile ("mov %%cr3, %0" : "=r"(save->cr3) : : "memory");
105 asm volatile ("mov %%cr0, %0" : "=r"(save->cr0) : : "memory");
106 asm volatile ("mov %%dr7, %0" : "=r"(save->dr7) : : "memory");
107 asm volatile ("mov %%dr6, %0" : "=r"(save->dr6) : : "memory");
108 asm volatile ("mov %%cr2, %0" : "=r"(save->cr2) : : "memory");
109 save->g_pat = rdmsr(MSR_IA32_CR_PAT);
110 save->dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
111 ctrl->intercept = (1ULL << INTERCEPT_VMRUN) |
112 (1ULL << INTERCEPT_VMMCALL);
113 ctrl->msrpm_base_pa = svm->msr_gpa;
115 vmcb->save.rip = (u64)guest_rip;
116 vmcb->save.rsp = (u64)guest_rsp;
117 guest_regs.rdi = (u64)svm;
121 * save/restore 64-bit general registers except rax, rip, rsp
122 * which are directly handed through the VMCB guest processor state
125 "xchg %%rbx, guest_regs+0x20\n\t" \
126 "xchg %%rcx, guest_regs+0x10\n\t" \
127 "xchg %%rdx, guest_regs+0x18\n\t" \
128 "xchg %%rbp, guest_regs+0x30\n\t" \
129 "xchg %%rsi, guest_regs+0x38\n\t" \
130 "xchg %%rdi, guest_regs+0x40\n\t" \
131 "xchg %%r8, guest_regs+0x48\n\t" \
132 "xchg %%r9, guest_regs+0x50\n\t" \
133 "xchg %%r10, guest_regs+0x58\n\t" \
134 "xchg %%r11, guest_regs+0x60\n\t" \
135 "xchg %%r12, guest_regs+0x68\n\t" \
136 "xchg %%r13, guest_regs+0x70\n\t" \
137 "xchg %%r14, guest_regs+0x78\n\t" \
138 "xchg %%r15, guest_regs+0x80\n\t"
140 #define LOAD_GPR_C SAVE_GPR_C
143 * selftests do not use interrupts so we dropped clgi/sti/cli/stgi
144 * for now. registers involved in LOAD/SAVE_GPR_C are eventually
145 * unmodified so they do not need to be in the clobber list.
147 void run_guest(struct vmcb *vmcb, uint64_t vmcb_gpa)
150 "vmload %[vmcb_gpa]\n\t"
151 "mov rflags, %%r15\n\t" // rflags
152 "mov %%r15, 0x170(%[vmcb])\n\t"
153 "mov guest_regs, %%r15\n\t" // rax
154 "mov %%r15, 0x1f8(%[vmcb])\n\t"
156 "vmrun %[vmcb_gpa]\n\t"
158 "mov 0x170(%[vmcb]), %%r15\n\t" // rflags
159 "mov %%r15, rflags\n\t"
160 "mov 0x1f8(%[vmcb]), %%r15\n\t" // rax
161 "mov %%r15, guest_regs\n\t"
162 "vmsave %[vmcb_gpa]\n\t"
163 : : [vmcb] "r" (vmcb), [vmcb_gpa] "a" (vmcb_gpa)
168 * Open SEV_DEV_PATH if available, otherwise exit the entire program.
171 * The opened file descriptor of /dev/sev.
173 int open_sev_dev_path_or_exit(void)
175 return open_path_or_exit(SEV_DEV_PATH, 0);