[PATCH v3 02/20] KVM: SVM: Macrofy 64-bit GPR swapping in __svm_vcpu_run()

Chang S. Bae
2026-04-28T05:26:17Z

Convert the register save/restore sequences in SVM entry code to macros,
following VMX code. Drop the now-redundant register offset defines.

No functional change intended.

Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
---
V2 -> V3: New patch
---
arch/x86/kvm/svm/vmenter.S | 38 +++-----------------------------------
arch/x86/kvm/vmenter.h | 10 ++++++++++
2 files changed, 13 insertions(+), 35 deletions(-)

diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 358236557454..5f3d2400c60a 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -17,17 +17,6 @@
#define VCPU_RSI (SVM_vcpu_arch_regs + __VCPU_REGS_RSI * WORD_SIZE)
#define VCPU_RDI (SVM_vcpu_arch_regs + __VCPU_REGS_RDI * WORD_SIZE)

-#ifdef CONFIG_X86_64
-#define VCPU_R8 (SVM_vcpu_arch_regs + __VCPU_REGS_R8 * WORD_SIZE)
-#define VCPU_R9 (SVM_vcpu_arch_regs + __VCPU_REGS_R9 * WORD_SIZE)
-#define VCPU_R10 (SVM_vcpu_arch_regs + __VCPU_REGS_R10 * WORD_SIZE)
-#define VCPU_R11 (SVM_vcpu_arch_regs + __VCPU_REGS_R11 * WORD_SIZE)
-#define VCPU_R12 (SVM_vcpu_arch_regs + __VCPU_REGS_R12 * WORD_SIZE)
-#define VCPU_R13 (SVM_vcpu_arch_regs + __VCPU_REGS_R13 * WORD_SIZE)
-#define VCPU_R14 (SVM_vcpu_arch_regs + __VCPU_REGS_R14 * WORD_SIZE)
-#define VCPU_R15 (SVM_vcpu_arch_regs + __VCPU_REGS_R15 * WORD_SIZE)
-#endif
-
#define SVM_vmcb01_pa (SVM_vmcb01 + KVM_VMCB_pa)

.section .noinstr.text, "ax"
@@ -115,14 +104,7 @@ SYM_FUNC_START(__svm_vcpu_run)
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
+ SVM_LOAD_REGS %_ASM_DI, 8,9,10,11,12,13,14,15
#endif
mov VCPU_RDI(%_ASM_DI), %_ASM_DI

@@ -143,14 +125,7 @@ SYM_FUNC_START(__svm_vcpu_run)
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)
+ SVM_STORE_REGS %_ASM_AX, 8,9,10,11,12,13,14,15
#endif

/* @svm can stay in RDI from now on. */
@@ -200,14 +175,7 @@ SYM_FUNC_START(__svm_vcpu_run)
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
+ CLEAR_REGS 8d,9d,10d,11d,12d,13d,14d,15d
#endif

/* "Pop" @enter_flags. */
diff --git a/arch/x86/kvm/vmenter.h b/arch/x86/kvm/vmenter.h
index 03e4067c188b..11bfc2729c68 100644
--- a/arch/x86/kvm/vmenter.h
+++ b/arch/x86/kvm/vmenter.h
@@ -96,6 +96,16 @@
mov %r\i, (VMX_vcpu_arch_regs + \i * WORD_SIZE)(\dst)
.endr
.endm
+.macro SVM_LOAD_REGS src:req, regs:vararg
+ .irp i, \regs
+ mov (SVM_vcpu_arch_regs + \i * WORD_SIZE)(\src), %r\i
+ .endr
+.endm
+.macro SVM_STORE_REGS dst:req, regs:vararg
+ .irp i, \regs
+ mov %r\i, (SVM_vcpu_arch_regs + \i * WORD_SIZE)(\dst)
+ .endr
+.endm
#endif

#endif /* __ASSEMBLER__ */
--
2.51.0