[PATCH 20/23] KVM: SVM: move VMLOAD/VMSAVE to C code

From: Paolo Bonzini
Date: Tue Mar 02 2021 - 17:38:35 EST


Thanks to the new macros that handle exception handling for SVM
instructions, it is easier to just do the VMLOAD/VMSAVE in C.
This is safe, as shown by the fact that the host reload is
already done outside the assembly source.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/svm/svm.c | 2 ++
arch/x86/kvm/svm/vmenter.S | 14 +-------------
2 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 1c62d3ec7e53..a0df44f6c239 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3719,7 +3719,9 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
} else {
struct svm_cpu_data *sd = per_cpu(svm_data, vcpu->cpu);

+ vmload(svm->vmcb_pa);
__svm_vcpu_run(svm->vmcb_pa, (unsigned long *)&vcpu->arch.regs);
+ vmsave(svm->vmcb_pa);

vmload(__sme_page_pa(sd->save_area));
}
diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 6feb8c08f45a..343108bf0f8c 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -79,12 +79,6 @@ SYM_FUNC_START(__svm_vcpu_run)

/* Enter guest mode */
sti
-1: vmload %_ASM_AX
- jmp 3f
-2: cmpb $0, kvm_rebooting
- jne 3f
- ud2
- _ASM_EXTABLE(1b, 2b)

3: vmrun %_ASM_AX
jmp 5f
@@ -93,13 +87,7 @@ SYM_FUNC_START(__svm_vcpu_run)
ud2
_ASM_EXTABLE(3b, 4b)

-5: vmsave %_ASM_AX
- jmp 7f
-6: cmpb $0, kvm_rebooting
- jne 7f
- ud2
- _ASM_EXTABLE(5b, 6b)
-7:
+5:
cli

#ifdef CONFIG_RETPOLINE
--
2.26.2