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 821: vmload %_ASM_AX 83 jmp 3f 842: cmpb $0, kvm_rebooting 85 jne 3f 86 ud2 87 _ASM_EXTABLE(1b, 2b) 88 893: vmrun %_ASM_AX 90 jmp 5f 914: cmpb $0, kvm_rebooting 92 jne 5f 93 ud2 94 _ASM_EXTABLE(3b, 4b) 95 965: vmsave %_ASM_AX 97 jmp 7f 986: cmpb $0, kvm_rebooting 99 jne 7f 100 ud2 101 _ASM_EXTABLE(5b, 6b) 1027: 103 cli 104 105#ifdef CONFIG_RETPOLINE 106 /* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */ 107 FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE 108#endif 109 110 /* "POP" @regs to RAX. */ 111 pop %_ASM_AX 112 113 /* Save all guest registers. */ 114 mov %_ASM_CX, VCPU_RCX(%_ASM_AX) 115 mov %_ASM_DX, VCPU_RDX(%_ASM_AX) 116 mov %_ASM_BX, VCPU_RBX(%_ASM_AX) 117 mov %_ASM_BP, VCPU_RBP(%_ASM_AX) 118 mov %_ASM_SI, VCPU_RSI(%_ASM_AX) 119 mov %_ASM_DI, VCPU_RDI(%_ASM_AX) 120#ifdef CONFIG_X86_64 121 mov %r8, VCPU_R8 (%_ASM_AX) 122 mov %r9, VCPU_R9 (%_ASM_AX) 123 mov %r10, VCPU_R10(%_ASM_AX) 124 mov %r11, VCPU_R11(%_ASM_AX) 125 mov %r12, VCPU_R12(%_ASM_AX) 126 mov %r13, VCPU_R13(%_ASM_AX) 127 mov %r14, VCPU_R14(%_ASM_AX) 128 mov %r15, VCPU_R15(%_ASM_AX) 129#endif 130 131 /* 132 * Clear all general purpose registers except RSP and RAX to prevent 133 * speculative use of the guest's values, even those that are reloaded 134 * via the stack. In theory, an L1 cache miss when restoring registers 135 * could lead to speculative execution with the guest's values. 136 * Zeroing XORs are dirt cheap, i.e. the extra paranoia is essentially 137 * free. RSP and RAX are exempt as they are restored by hardware 138 * during VM-Exit. 139 */ 140 xor %ecx, %ecx 141 xor %edx, %edx 142 xor %ebx, %ebx 143 xor %ebp, %ebp 144 xor %esi, %esi 145 xor %edi, %edi 146#ifdef CONFIG_X86_64 147 xor %r8d, %r8d 148 xor %r9d, %r9d 149 xor %r10d, %r10d 150 xor %r11d, %r11d 151 xor %r12d, %r12d 152 xor %r13d, %r13d 153 xor %r14d, %r14d 154 xor %r15d, %r15d 155#endif 156 157 pop %_ASM_BX 158 159#ifdef CONFIG_X86_64 160 pop %r12 161 pop %r13 162 pop %r14 163 pop %r15 164#else 165 pop %esi 166 pop %edi 167#endif 168 pop %_ASM_BP 169 ret 170SYM_FUNC_END(__svm_vcpu_run) 171