diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile index e5a71aa0967b..a789759b7261 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -14,7 +14,7 @@ kvm-y += x86.o emulate.o i8259.o irq.o lapic.o \ hyperv.o debugfs.o mmu/mmu.o mmu/page_track.o kvm-intel-y += vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o vmx/evmcs.o vmx/nested.o -kvm-amd-y += svm/svm.o svm/pmu.o svm/nested.o svm/avic.o svm/sev.o +kvm-amd-y += svm/svm.o svm/vmenter.o svm/pmu.o svm/nested.o svm/avic.o svm/sev.o obj-$(CONFIG_KVM) += kvm.o obj-$(CONFIG_KVM_INTEL) += kvm-intel.o diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 05d77b395fc1..2be5bbae3a40 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3276,6 +3276,8 @@ static void svm_cancel_injection(struct kvm_vcpu *vcpu) svm_complete_interrupts(svm); } +bool __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs); + static void svm_vcpu_run(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -3330,95 +3332,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu) local_irq_enable(); - asm volatile ( - "push %%" _ASM_BP "; \n\t" - "mov %c[rbx](%[svm]), %%" _ASM_BX " \n\t" - "mov %c[rcx](%[svm]), %%" _ASM_CX " \n\t" - "mov %c[rdx](%[svm]), %%" _ASM_DX " \n\t" - "mov %c[rsi](%[svm]), %%" _ASM_SI " \n\t" - "mov %c[rdi](%[svm]), %%" _ASM_DI " \n\t" - "mov %c[rbp](%[svm]), %%" _ASM_BP " \n\t" -#ifdef CONFIG_X86_64 - "mov %c[r8](%[svm]), %%r8 \n\t" - "mov %c[r9](%[svm]), %%r9 \n\t" - "mov %c[r10](%[svm]), %%r10 \n\t" - "mov %c[r11](%[svm]), %%r11 \n\t" - "mov %c[r12](%[svm]), %%r12 \n\t" - "mov %c[r13](%[svm]), %%r13 \n\t" - "mov %c[r14](%[svm]), %%r14 \n\t" - "mov %c[r15](%[svm]), %%r15 \n\t" -#endif - - /* Enter guest mode */ - "push %%" _ASM_AX " \n\t" - "mov %c[vmcb](%[svm]), %%" _ASM_AX " \n\t" - __ex("vmload %%" _ASM_AX) "\n\t" - __ex("vmrun %%" _ASM_AX) "\n\t" - __ex("vmsave %%" _ASM_AX) "\n\t" - "pop %%" _ASM_AX " \n\t" - - /* Save guest registers, load host registers */ - "mov %%" _ASM_BX ", %c[rbx](%[svm]) \n\t" - "mov %%" _ASM_CX ", %c[rcx](%[svm]) \n\t" - "mov %%" _ASM_DX ", %c[rdx](%[svm]) \n\t" - "mov %%" _ASM_SI ", %c[rsi](%[svm]) \n\t" - "mov %%" _ASM_DI ", %c[rdi](%[svm]) \n\t" - "mov %%" _ASM_BP ", %c[rbp](%[svm]) \n\t" -#ifdef CONFIG_X86_64 - "mov %%r8, %c[r8](%[svm]) \n\t" - "mov %%r9, %c[r9](%[svm]) \n\t" - "mov %%r10, %c[r10](%[svm]) \n\t" - "mov %%r11, %c[r11](%[svm]) \n\t" - "mov %%r12, %c[r12](%[svm]) \n\t" - "mov %%r13, %c[r13](%[svm]) \n\t" - "mov %%r14, %c[r14](%[svm]) \n\t" - "mov %%r15, %c[r15](%[svm]) \n\t" - /* - * Clear host registers marked as clobbered to prevent - * speculative use. - */ - "xor %%r8d, %%r8d \n\t" - "xor %%r9d, %%r9d \n\t" - "xor %%r10d, %%r10d \n\t" - "xor %%r11d, %%r11d \n\t" - "xor %%r12d, %%r12d \n\t" - "xor %%r13d, %%r13d \n\t" - "xor %%r14d, %%r14d \n\t" - "xor %%r15d, %%r15d \n\t" -#endif - "xor %%ebx, %%ebx \n\t" - "xor %%ecx, %%ecx \n\t" - "xor %%edx, %%edx \n\t" - "xor %%esi, %%esi \n\t" - "xor %%edi, %%edi \n\t" - "pop %%" _ASM_BP - : - : [svm]"a"(svm), - [vmcb]"i"(offsetof(struct vcpu_svm, vmcb_pa)), - [rbx]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RBX])), - [rcx]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RCX])), - [rdx]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RDX])), - [rsi]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RSI])), - [rdi]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RDI])), - [rbp]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_RBP])) -#ifdef CONFIG_X86_64 - , [r8]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R8])), - [r9]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R9])), - [r10]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R10])), - [r11]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R11])), - [r12]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R12])), - [r13]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R13])), - [r14]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R14])), - [r15]"i"(offsetof(struct vcpu_svm, vcpu.arch.regs[VCPU_REGS_R15])) -#endif - : "cc", "memory" -#ifdef CONFIG_X86_64 - , "rbx", "rcx", "rdx", "rsi", "rdi" - , "r8", "r9", "r10", "r11" , "r12", "r13", "r14", "r15" -#else - , "ebx", "ecx", "edx", "esi", "edi" -#endif - ); + __svm_vcpu_run(svm->vmcb_pa, (unsigned long *)&svm->vcpu.arch.regs); /* Eliminate branch target predictions from guest mode */ vmexit_fill_RSB(); diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S new file mode 100644 index 000000000000..fa1af90067e9 --- /dev/null +++ b/arch/x86/kvm/svm/vmenter.S @@ -0,0 +1,162 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include +#include +#include +#include + +#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 + + .text + +/** + * __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 + mov %_ASM_SP, %_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 */ +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: + /* "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)