Slightly improve register allocation, loading vmx only once before vmlaunch/vmresume. Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/kvm/vmx/vmenter.S | 40 +++++++++++++++++--------------------- 1 file changed, 18 insertions(+), 22 deletions(-) diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S index 1362fe5859f9..0aea6b348a96 100644 --- a/arch/x86/kvm/vmx/vmenter.S +++ b/arch/x86/kvm/vmx/vmenter.S @@ -81,13 +81,12 @@ SYM_FUNC_START(__vmx_vcpu_run) * there must not be any returns or indirect branches between this code * and vmentry. */ - movl VMX_spec_ctrl(%_ASM_DI), %edi + movl VMX_spec_ctrl(%_ASM_DI), %eax movl PER_CPU_VAR(x86_spec_ctrl_current), %esi - cmp %edi, %esi + cmp %eax, %esi je .Lspec_ctrl_done mov $MSR_IA32_SPEC_CTRL, %ecx xor %edx, %edx - mov %edi, %eax wrmsr .Lspec_ctrl_done: @@ -97,31 +96,28 @@ SYM_FUNC_START(__vmx_vcpu_run) * an LFENCE to stop speculation from skipping the wrmsr. */ - /* Load @vmx to RAX. */ - mov WORD_SIZE(%_ASM_SP), %_ASM_AX - /* Check if vmlaunch or vmresume is needed */ testb $VMX_RUN_VMRESUME, %bl /* Load guest registers. Don't clobber flags. */ - 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 + mov VCPU_RAX(%_ASM_DI), %_ASM_AX + mov VCPU_RCX(%_ASM_DI), %_ASM_CX + mov VCPU_RDX(%_ASM_DI), %_ASM_DX + mov VCPU_RBX(%_ASM_DI), %_ASM_BX + mov VCPU_RBP(%_ASM_DI), %_ASM_BP + mov VCPU_RSI(%_ASM_DI), %_ASM_SI #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 + mov VCPU_R8 (%_ASM_DI), %r8 + mov VCPU_R9 (%_ASM_DI), %r9 + mov VCPU_R10(%_ASM_DI), %r10 + mov VCPU_R11(%_ASM_DI), %r11 + mov VCPU_R12(%_ASM_DI), %r12 + mov VCPU_R13(%_ASM_DI), %r13 + mov VCPU_R14(%_ASM_DI), %r14 + mov VCPU_R15(%_ASM_DI), %r15 #endif - /* Load guest RAX. This kills the @vmx pointer! */ - mov VCPU_RAX(%_ASM_AX), %_ASM_AX + /* Load guest RDI. This kills the @vmx pointer! */ + mov VCPU_RDI(%_ASM_DI), %_ASM_DI /* Check EFLAGS.ZF from 'testb' above */ jz .Lvmlaunch -- 2.31.1
