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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | /* SPDX-License-Identifier: GPL-2.0 */ #include <linux/linkage.h> #include <asm/asm.h> #include <asm/bitsperlong.h> #include <asm/kvm_vcpu_regs.h> #include <asm/nospec-branch.h> #define WORD_SIZE (BITS_PER_LONG / 8) /* Intentionally omit RAX as it's context switched by hardware */ #define VCPU_RCX __VCPU_REGS_RCX * WORD_SIZE #define VCPU_RDX __VCPU_REGS_RDX * WORD_SIZE #define VCPU_RBX __VCPU_REGS_RBX * WORD_SIZE /* Intentionally omit RSP as it's context switched by hardware */ #define VCPU_RBP __VCPU_REGS_RBP * WORD_SIZE #define VCPU_RSI __VCPU_REGS_RSI * WORD_SIZE #define VCPU_RDI __VCPU_REGS_RDI * WORD_SIZE #ifdef CONFIG_X86_64 #define VCPU_R8 __VCPU_REGS_R8 * WORD_SIZE #define VCPU_R9 __VCPU_REGS_R9 * WORD_SIZE #define VCPU_R10 __VCPU_REGS_R10 * WORD_SIZE #define VCPU_R11 __VCPU_REGS_R11 * WORD_SIZE #define VCPU_R12 __VCPU_REGS_R12 * WORD_SIZE #define VCPU_R13 __VCPU_REGS_R13 * WORD_SIZE #define VCPU_R14 __VCPU_REGS_R14 * WORD_SIZE #define VCPU_R15 __VCPU_REGS_R15 * WORD_SIZE #endif .section .noinstr.text, "ax" /** * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode * @vmcb_pa: unsigned long * @regs: unsigned long * (to guest registers) */ SYM_FUNC_START(__svm_vcpu_run) push %_ASM_BP #ifdef CONFIG_X86_64 push %r15 push %r14 push %r13 push %r12 #else push %edi push %esi #endif push %_ASM_BX /* Save @regs. */ push %_ASM_ARG2 /* Save @vmcb. */ push %_ASM_ARG1 /* Move @regs to RAX. */ mov %_ASM_ARG2, %_ASM_AX /* Load guest registers. */ mov VCPU_RCX(%_ASM_AX), %_ASM_CX mov VCPU_RDX(%_ASM_AX), %_ASM_DX mov VCPU_RBX(%_ASM_AX), %_ASM_BX mov VCPU_RBP(%_ASM_AX), %_ASM_BP mov VCPU_RSI(%_ASM_AX), %_ASM_SI mov VCPU_RDI(%_ASM_AX), %_ASM_DI #ifdef CONFIG_X86_64 mov VCPU_R8 (%_ASM_AX), %r8 mov VCPU_R9 (%_ASM_AX), %r9 mov VCPU_R10(%_ASM_AX), %r10 mov VCPU_R11(%_ASM_AX), %r11 mov VCPU_R12(%_ASM_AX), %r12 mov VCPU_R13(%_ASM_AX), %r13 mov VCPU_R14(%_ASM_AX), %r14 mov VCPU_R15(%_ASM_AX), %r15 #endif /* "POP" @vmcb to RAX. */ pop %_ASM_AX /* Enter guest mode */ sti 1: vmload %_ASM_AX jmp 3f 2: cmpb $0, kvm_rebooting jne 3f ud2 _ASM_EXTABLE(1b, 2b) 3: vmrun %_ASM_AX jmp 5f 4: cmpb $0, kvm_rebooting jne 5f ud2 _ASM_EXTABLE(3b, 4b) 5: vmsave %_ASM_AX jmp 7f 6: cmpb $0, kvm_rebooting jne 7f ud2 _ASM_EXTABLE(5b, 6b) 7: cli #ifdef CONFIG_RETPOLINE /* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */ FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE #endif /* "POP" @regs to RAX. */ pop %_ASM_AX /* Save all guest registers. */ mov %_ASM_CX, VCPU_RCX(%_ASM_AX) mov %_ASM_DX, VCPU_RDX(%_ASM_AX) mov %_ASM_BX, VCPU_RBX(%_ASM_AX) mov %_ASM_BP, VCPU_RBP(%_ASM_AX) mov %_ASM_SI, VCPU_RSI(%_ASM_AX) mov %_ASM_DI, VCPU_RDI(%_ASM_AX) #ifdef CONFIG_X86_64 mov %r8, VCPU_R8 (%_ASM_AX) mov %r9, VCPU_R9 (%_ASM_AX) mov %r10, VCPU_R10(%_ASM_AX) mov %r11, VCPU_R11(%_ASM_AX) mov %r12, VCPU_R12(%_ASM_AX) mov %r13, VCPU_R13(%_ASM_AX) mov %r14, VCPU_R14(%_ASM_AX) mov %r15, VCPU_R15(%_ASM_AX) #endif /* * Clear all general purpose registers except RSP and RAX to prevent * speculative use of the guest's values, even those that are reloaded * via the stack. In theory, an L1 cache miss when restoring registers * could lead to speculative execution with the guest's values. * Zeroing XORs are dirt cheap, i.e. the extra paranoia is essentially * free. RSP and RAX are exempt as they are restored by hardware * during VM-Exit. */ xor %ecx, %ecx xor %edx, %edx xor %ebx, %ebx xor %ebp, %ebp xor %esi, %esi xor %edi, %edi #ifdef CONFIG_X86_64 xor %r8d, %r8d xor %r9d, %r9d xor %r10d, %r10d xor %r11d, %r11d xor %r12d, %r12d xor %r13d, %r13d xor %r14d, %r14d xor %r15d, %r15d #endif pop %_ASM_BX #ifdef CONFIG_X86_64 pop %r12 pop %r13 pop %r14 pop %r15 #else pop %esi pop %edi #endif pop %_ASM_BP ret SYM_FUNC_END(__svm_vcpu_run) |