From f7ef280132f9bf6f82acf5aa5c3c837206eef501 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 28 Oct 2022 17:30:07 -0400 Subject: KVM: SVM: adjust register allocation for __svm_vcpu_run() 32-bit ABI uses RAX/RCX/RDX as its argument registers, so they are in the way of instructions that hardcode their operands such as RDMSR/WRMSR or VMLOAD/VMRUN/VMSAVE. In preparation for moving vmload/vmsave to __svm_vcpu_run(), keep the pointer to the struct vcpu_svm in %rdi. In particular, it is now possible to load svm->vmcb01.pa in %rax without clobbering the struct vcpu_svm pointer. No functional change intended. Cc: stable@vger.kernel.org Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk") Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/vmenter.S | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-) (limited to 'arch/x86/kvm/svm/vmenter.S') diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index f0ff41103e4c..531510ab6072 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -54,29 +54,29 @@ SYM_FUNC_START(__svm_vcpu_run) /* Save @vmcb. */ push %_ASM_ARG1 - /* Move @svm to RAX. */ - mov %_ASM_ARG2, %_ASM_AX + /* Move @svm to RDI. */ + mov %_ASM_ARG2, %_ASM_DI + + /* "POP" @vmcb to RAX. */ + pop %_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 + 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 - - /* "POP" @vmcb to RAX. */ - pop %_ASM_AX + mov VCPU_RDI(%_ASM_DI), %_ASM_DI /* Enter guest mode */ sti -- cgit v1.2.3-59-g8ed1b