1/* SPDX-License-Identifier: GPL-2.0 */ 2#include <linux/linkage.h> 3#include <asm/asm.h> 4#include <asm/bitsperlong.h> 5#include <asm/kvm_vcpu_regs.h> 6#include <asm/nospec-branch.h> 7 8#define WORD_SIZE (BITS_PER_LONG / 8) 9 10/* Intentionally omit RAX as it's context switched by hardware */ 11#define VCPU_RCX __VCPU_REGS_RCX * WORD_SIZE 12#define VCPU_RDX __VCPU_REGS_RDX * WORD_SIZE 13#define VCPU_RBX __VCPU_REGS_RBX * WORD_SIZE 14/* Intentionally omit RSP as it's context switched by hardware */ 15#define VCPU_RBP __VCPU_REGS_RBP * WORD_SIZE 16#define VCPU_RSI __VCPU_REGS_RSI * WORD_SIZE 17#define VCPU_RDI __VCPU_REGS_RDI * WORD_SIZE 18 19#ifdef CONFIG_X86_64 20#define VCPU_R8 __VCPU_REGS_R8 * WORD_SIZE 21#define VCPU_R9 __VCPU_REGS_R9 * WORD_SIZE 22#define VCPU_R10 __VCPU_REGS_R10 * WORD_SIZE 23#define VCPU_R11 __VCPU_REGS_R11 * WORD_SIZE 24#define VCPU_R12 __VCPU_REGS_R12 * WORD_SIZE 25#define VCPU_R13 __VCPU_REGS_R13 * WORD_SIZE 26#define VCPU_R14 __VCPU_REGS_R14 * WORD_SIZE 27#define VCPU_R15 __VCPU_REGS_R15 * WORD_SIZE 28#endif 29 30.section .noinstr.text, "ax" 31 32/** 33 * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode 34 * @vmcb_pa: unsigned long 35 * @regs: unsigned long * (to guest registers) 36 */ 37SYM_FUNC_START(__svm_vcpu_run) 38 push %_ASM_BP 39#ifdef CONFIG_X86_64 40 push %r15 41 push %r14 42 push %r13 43 push %r12 44#else 45 push %edi 46 push %esi 47#endif 48 push %_ASM_BX 49 50 /* Save @regs. */ 51 push %_ASM_ARG2 52 53 /* Save @vmcb. */ 54 push %_ASM_ARG1 55 56 /* Move @regs to RAX. */ 57 mov %_ASM_ARG2, %_ASM_AX 58 59 /* Load guest registers. */ 60 mov VCPU_RCX(%_ASM_AX), %_ASM_CX 61 mov VCPU_RDX(%_ASM_AX), %_ASM_DX 62 mov VCPU_RBX(%_ASM_AX), %_ASM_BX 63 mov VCPU_RBP(%_ASM_AX), %_ASM_BP 64 mov VCPU_RSI(%_ASM_AX), %_ASM_SI 65 mov VCPU_RDI(%_ASM_AX), %_ASM_DI 66#ifdef CONFIG_X86_64 67 mov VCPU_R8 (%_ASM_AX), %r8 68 mov VCPU_R9 (%_ASM_AX), %r9 69 mov VCPU_R10(%_ASM_AX), %r10 70 mov VCPU_R11(%_ASM_AX), %r11 71 mov VCPU_R12(%_ASM_AX), %r12 72 mov VCPU_R13(%_ASM_AX), %r13 73 mov VCPU_R14(%_ASM_AX), %r14 74 mov VCPU_R15(%_ASM_AX), %r15 75#endif 76 77 /* "POP" @vmcb to RAX. */ 78 pop %_ASM_AX 79 80 /* Enter guest mode */ 81 sti 82 831: vmrun %_ASM_AX 84 852: cli 86 87#ifdef CONFIG_RETPOLINE 88 /* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */ 89 FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE 90#endif 91 92 /* "POP" @regs to RAX. */ 93 pop %_ASM_AX 94 95 /* Save all guest registers. */ 96 mov %_ASM_CX, VCPU_RCX(%_ASM_AX) 97 mov %_ASM_DX, VCPU_RDX(%_ASM_AX) 98 mov %_ASM_BX, VCPU_RBX(%_ASM_AX) 99 mov %_ASM_BP, VCPU_RBP(%_ASM_AX) 100 mov %_ASM_SI, VCPU_RSI(%_ASM_AX) 101 mov %_ASM_DI, VCPU_RDI(%_ASM_AX) 102#ifdef CONFIG_X86_64 103 mov %r8, VCPU_R8 (%_ASM_AX) 104 mov %r9, VCPU_R9 (%_ASM_AX) 105 mov %r10, VCPU_R10(%_ASM_AX) 106 mov %r11, VCPU_R11(%_ASM_AX) 107 mov %r12, VCPU_R12(%_ASM_AX) 108 mov %r13, VCPU_R13(%_ASM_AX) 109 mov %r14, VCPU_R14(%_ASM_AX) 110 mov %r15, VCPU_R15(%_ASM_AX) 111#endif 112 113 /* 114 * Clear all general purpose registers except RSP and RAX to prevent 115 * speculative use of the guest's values, even those that are reloaded 116 * via the stack. In theory, an L1 cache miss when restoring registers 117 * could lead to speculative execution with the guest's values. 118 * Zeroing XORs are dirt cheap, i.e. the extra paranoia is essentially 119 * free. RSP and RAX are exempt as they are restored by hardware 120 * during VM-Exit. 121 */ 122 xor %ecx, %ecx 123 xor %edx, %edx 124 xor %ebx, %ebx 125 xor %ebp, %ebp 126 xor %esi, %esi 127 xor %edi, %edi 128#ifdef CONFIG_X86_64 129 xor %r8d, %r8d 130 xor %r9d, %r9d 131 xor %r10d, %r10d 132 xor %r11d, %r11d 133 xor %r12d, %r12d 134 xor %r13d, %r13d 135 xor %r14d, %r14d 136 xor %r15d, %r15d 137#endif 138 139 pop %_ASM_BX 140 141#ifdef CONFIG_X86_64 142 pop %r12 143 pop %r13 144 pop %r14 145 pop %r15 146#else 147 pop %esi 148 pop %edi 149#endif 150 pop %_ASM_BP 151 ret 152 1533: cmpb $0, kvm_rebooting 154 jne 2b 155 ud2 156 157 _ASM_EXTABLE(1b, 3b) 158 159SYM_FUNC_END(__svm_vcpu_run) 160 161/** 162 * __svm_sev_es_vcpu_run - Run a SEV-ES vCPU via a transition to SVM guest mode 163 * @vmcb_pa: unsigned long 164 */ 165SYM_FUNC_START(__svm_sev_es_vcpu_run) 166 push %_ASM_BP 167#ifdef CONFIG_X86_64 168 push %r15 169 push %r14 170 push %r13 171 push %r12 172#else 173 push %edi 174 push %esi 175#endif 176 push %_ASM_BX 177 178 /* Move @vmcb to RAX. */ 179 mov %_ASM_ARG1, %_ASM_AX 180 181 /* Enter guest mode */ 182 sti 183 1841: vmrun %_ASM_AX 185 1862: cli 187 188#ifdef CONFIG_RETPOLINE 189 /* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */ 190 FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE 191#endif 192 193 pop %_ASM_BX 194 195#ifdef CONFIG_X86_64 196 pop %r12 197 pop %r13 198 pop %r14 199 pop %r15 200#else 201 pop %esi 202 pop %edi 203#endif 204 pop %_ASM_BP 205 ret 206 2073: cmpb $0, kvm_rebooting 208 jne 2b 209 ud2 210 211 _ASM_EXTABLE(1b, 3b) 212 213SYM_FUNC_END(__svm_sev_es_vcpu_run) 214