165 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * tools/testing/selftests/kvm/lib/x86_64/svm.c4 * Helpers used for nested SVM testing5 * Largely inspired from KVM unit test svm.c6 *7 * Copyright (C) 2020, Red Hat, Inc.8 */9 10#include "test_util.h"11#include "kvm_util.h"12#include "processor.h"13#include "svm_util.h"14 15#define SEV_DEV_PATH "/dev/sev"16 17struct gpr64_regs guest_regs;18u64 rflags;19 20/* Allocate memory regions for nested SVM tests.21 *22 * Input Args:23 * vm - The VM to allocate guest-virtual addresses in.24 *25 * Output Args:26 * p_svm_gva - The guest virtual address for the struct svm_test_data.27 *28 * Return:29 * Pointer to structure with the addresses of the SVM areas.30 */31struct svm_test_data *32vcpu_alloc_svm(struct kvm_vm *vm, vm_vaddr_t *p_svm_gva)33{34 vm_vaddr_t svm_gva = vm_vaddr_alloc_page(vm);35 struct svm_test_data *svm = addr_gva2hva(vm, svm_gva);36 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);40 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);44 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());49 50 *p_svm_gva = svm_gva;51 return svm;52}53 54static void vmcb_set_seg(struct vmcb_seg *seg, u16 selector,55 u64 base, u32 limit, u32 attr)56{57 seg->selector = selector;58 seg->attrib = attr;59 seg->limit = limit;60 seg->base = base;61}62 63void generic_svm_setup(struct svm_test_data *svm, void *guest_rip, void *guest_rsp)64{65 struct vmcb *vmcb = svm->vmcb;66 uint64_t vmcb_gpa = svm->vmcb_gpa;67 struct vmcb_save_area *save = &vmcb->save;68 struct vmcb_control_area *ctrl = &vmcb->control;69 u32 data_seg_attr = 3 | SVM_SELECTOR_S_MASK | SVM_SELECTOR_P_MASK70 | SVM_SELECTOR_DB_MASK | SVM_SELECTOR_G_MASK;71 u32 code_seg_attr = 9 | SVM_SELECTOR_S_MASK | SVM_SELECTOR_P_MASK72 | SVM_SELECTOR_L_MASK | SVM_SELECTOR_G_MASK;73 uint64_t efer;74 75 efer = rdmsr(MSR_EFER);76 wrmsr(MSR_EFER, efer | EFER_SVME);77 wrmsr(MSR_VM_HSAVE_PA, svm->save_area_gpa);78 79 memset(vmcb, 0, sizeof(*vmcb));80 asm volatile ("vmsave %0\n\t" : : "a" (vmcb_gpa) : "memory");81 vmcb_set_seg(&save->es, get_es(), 0, -1U, data_seg_attr);82 vmcb_set_seg(&save->cs, get_cs(), 0, -1U, code_seg_attr);83 vmcb_set_seg(&save->ss, get_ss(), 0, -1U, data_seg_attr);84 vmcb_set_seg(&save->ds, get_ds(), 0, -1U, data_seg_attr);85 vmcb_set_seg(&save->gdtr, 0, get_gdt().address, get_gdt().size, 0);86 vmcb_set_seg(&save->idtr, 0, get_idt().address, get_idt().size, 0);87 88 ctrl->asid = 1;89 save->cpl = 0;90 save->efer = rdmsr(MSR_EFER);91 asm volatile ("mov %%cr4, %0" : "=r"(save->cr4) : : "memory");92 asm volatile ("mov %%cr3, %0" : "=r"(save->cr3) : : "memory");93 asm volatile ("mov %%cr0, %0" : "=r"(save->cr0) : : "memory");94 asm volatile ("mov %%dr7, %0" : "=r"(save->dr7) : : "memory");95 asm volatile ("mov %%dr6, %0" : "=r"(save->dr6) : : "memory");96 asm volatile ("mov %%cr2, %0" : "=r"(save->cr2) : : "memory");97 save->g_pat = rdmsr(MSR_IA32_CR_PAT);98 save->dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);99 ctrl->intercept = (1ULL << INTERCEPT_VMRUN) |100 (1ULL << INTERCEPT_VMMCALL);101 ctrl->msrpm_base_pa = svm->msr_gpa;102 103 vmcb->save.rip = (u64)guest_rip;104 vmcb->save.rsp = (u64)guest_rsp;105 guest_regs.rdi = (u64)svm;106}107 108/*109 * save/restore 64-bit general registers except rax, rip, rsp110 * which are directly handed through the VMCB guest processor state111 */112#define SAVE_GPR_C \113 "xchg %%rbx, guest_regs+0x20\n\t" \114 "xchg %%rcx, guest_regs+0x10\n\t" \115 "xchg %%rdx, guest_regs+0x18\n\t" \116 "xchg %%rbp, guest_regs+0x30\n\t" \117 "xchg %%rsi, guest_regs+0x38\n\t" \118 "xchg %%rdi, guest_regs+0x40\n\t" \119 "xchg %%r8, guest_regs+0x48\n\t" \120 "xchg %%r9, guest_regs+0x50\n\t" \121 "xchg %%r10, guest_regs+0x58\n\t" \122 "xchg %%r11, guest_regs+0x60\n\t" \123 "xchg %%r12, guest_regs+0x68\n\t" \124 "xchg %%r13, guest_regs+0x70\n\t" \125 "xchg %%r14, guest_regs+0x78\n\t" \126 "xchg %%r15, guest_regs+0x80\n\t"127 128#define LOAD_GPR_C SAVE_GPR_C129 130/*131 * selftests do not use interrupts so we dropped clgi/sti/cli/stgi132 * for now. registers involved in LOAD/SAVE_GPR_C are eventually133 * unmodified so they do not need to be in the clobber list.134 */135void run_guest(struct vmcb *vmcb, uint64_t vmcb_gpa)136{137 asm volatile (138 "vmload %[vmcb_gpa]\n\t"139 "mov rflags, %%r15\n\t" // rflags140 "mov %%r15, 0x170(%[vmcb])\n\t"141 "mov guest_regs, %%r15\n\t" // rax142 "mov %%r15, 0x1f8(%[vmcb])\n\t"143 LOAD_GPR_C144 "vmrun %[vmcb_gpa]\n\t"145 SAVE_GPR_C146 "mov 0x170(%[vmcb]), %%r15\n\t" // rflags147 "mov %%r15, rflags\n\t"148 "mov 0x1f8(%[vmcb]), %%r15\n\t" // rax149 "mov %%r15, guest_regs\n\t"150 "vmsave %[vmcb_gpa]\n\t"151 : : [vmcb] "r" (vmcb), [vmcb_gpa] "a" (vmcb_gpa)152 : "r15", "memory");153}154 155/*156 * Open SEV_DEV_PATH if available, otherwise exit the entire program.157 *158 * Return:159 * The opened file descriptor of /dev/sev.160 */161int open_sev_dev_path_or_exit(void)162{163 return open_path_or_exit(SEV_DEV_PATH, 0);164}165