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authorPaolo Bonzini <pbonzini@redhat.com>2022-10-29 00:30:07 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2022-11-09 20:16:46 +0300
commitf7ef280132f9bf6f82acf5aa5c3c837206eef501 (patch)
tree661b83bdff9781276aa6b07eee33780e8653bd41 /arch
parent16fdc1de169ee0a4e59a8c02244414ec7acd55c3 (diff)
downloadlinux-f7ef280132f9bf6f82acf5aa5c3c837206eef501.tar.xz
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 <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/svm/vmenter.S38
1 files 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