[PATCH 1/5] KVM: SVM: Drop stale comment from svm_hv_vmcb_dirty_nested_enlightenments()

Vitaly Kuznetsov
2021-12-20T15:22:43Z

Commit 3fa5e8fd0a0e4 ("KVM: SVM: delay svm_vcpu_init_msrpm after
svm->vmcb is initialized") re-arranged svm_vcpu_init_msrpm() call in
svm_create_vcpu() making the comment about vmcb being NULL
obsolete. Drop it.

While on it, drop superfluous vmcb_is_clean() check: vmcb_mark_dirty()
is a bit flip, an extra check is unlikely to bring any performance gain.
Drop now-unneeded vmcb_is_clean() helper as well.

Fixes: 3fa5e8fd0a0e4 ("KVM: SVM: delay svm_vcpu_init_msrpm after svm->vmcb is initialized")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/svm/svm.h | 5 -----
arch/x86/kvm/svm/svm_onhyperv.h | 9 +--------
2 files changed, 1 insertion(+), 13 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index daa8ca84afcc..5d197aae3a19 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -305,11 +305,6 @@ static inline void vmcb_mark_all_clean(struct vmcb *vmcb)
& ~VMCB_ALWAYS_DIRTY_MASK;
}

-static inline bool vmcb_is_clean(struct vmcb *vmcb, int bit)
-{
- return (vmcb->control.clean & (1 << bit));
-}
-
static inline void vmcb_mark_dirty(struct vmcb *vmcb, int bit)
{
vmcb->control.clean &= ~(1 << bit);
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index c53b8bf8d013..cdbcfc63d171 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -83,14 +83,7 @@ static inline void svm_hv_vmcb_dirty_nested_enlightenments(
struct hv_enlightenments *hve =
(struct hv_enlightenments *)vmcb->control.reserved_sw;

- /*
- * vmcb can be NULL if called during early vcpu init.
- * And its okay not to mark vmcb dirty during vcpu init
- * as we mark it dirty unconditionally towards end of vcpu
- * init phase.
- */
- if (vmcb_is_clean(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS) &&
- hve->hv_enlightenments_control.msr_bitmap)
+ if (hve->hv_enlightenments_control.msr_bitmap)
vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS);
}

--
2.33.1