linux-kernel - [PATCH 5/7] KVM: SVM: adjust register allocation for __svm_vcpu

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Message-Id: <20221028230723.3254250-6-pbonzini@redhat.com>
Date:   Fri, 28 Oct 2022 19:07:21 -0400
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     jmattson@...gle.com, seanjc@...gle.com, jpoimboe@...nel.org
Subject: [PATCH 5/7] KVM: SVM: adjust register allocation for __svm_vcpu_run

In preparation for moving SPEC_CTRL access to __svm_vcpu_run,
keep the pointer to the struct vcpu_svm in %rdi, which is not
used by rdmsr/wrmsr.

Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
---
 arch/x86/kvm/svm/vmenter.S | 39 +++++++++++++++++++-------------------
 1 file changed, 20 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 8fac744361e5..51a63a47d74f 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -53,30 +53,31 @@ 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
 
-	/* 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
 
+	/* Load guest registers. */
+	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_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
+	mov VCPU_RDI(%_ASM_DI), %_ASM_DI
+
 	/* Enter guest mode */
 	sti
 
-- 
2.31.1