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Subject[PATCH 1/8] KVM: SVM: Create a stack frame in __svm_vcpu_run() for unwinding
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Unconditionally create a stack frame in __svm_vcpu_run() to play nice with
unwinding via frame pointers, at least until the point where RBP is loaded
with the guest's value. Don't bother conditioning the code on
CONFIG_FRAME_POINTER=y, as RBP needs to be saved and restored anyways (due
to it being clobbered with the guest's value); omitting the "MOV RSP, RBP"
is not worth the extra #ifdef.

Creating a stack frame will allow removing the OBJECT_FILES_NON_STANDARD
tag from vmenter.S once __svm_sev_es_vcpu_run() is fixed to not stomp all
over RBP for no reason.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/vmenter.S | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 9499f9c6b077..ee5d5a30da88 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -99,6 +99,7 @@
*/
SYM_FUNC_START(__svm_vcpu_run)
push %_ASM_BP
+ mov %_ASM_SP, %_ASM_BP
#ifdef CONFIG_X86_64
push %r15
push %r14
--
2.44.0.rc0.258.g7320e95886-goog

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