[PATCH 03/11] KVM: SVM: adjust register allocation for __svm_vcpu_run

From: Paolo Bonzini
Date: Wed Nov 09 2022 - 09:55:26 EST


In preparation for moving vmload/vmsave to __svm_vcpu_run,
keep the pointer to the struct vcpu_svm in %rdi. This way
it is possible to load svm->vmcb01.pa in %rax without
clobbering the pointer to svm itself.

No functional change intended.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk")
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm/vmenter.S | 38 +++++++++++++++++++-------------------
1 file changed, 19 insertions(+), 19 deletions(-)

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
--
2.31.1