Now that the fast invalidate mechanism has been reintroduced, restore
the performance tweaks for fast invalidation that existed prior to its
removal.
Paraphrasing the original changelog (commit 5ff0568374ed2 was itself a
partial revert):
Don't force reloading the remote mmu when zapping an obsolete page, as
a MMU_RELOAD request has already been issued by kvm_mmu_zap_all_fast()
immediately after incrementing mmu_valid_gen, i.e. after marking pages
obsolete.
This reverts commit 5ff0568374ed2e585376a3832857ade5daccd381.
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/mmu.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 84d916674529..bce19918ca5a 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2752,7 +2752,12 @@ static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm,
} else {
list_move(&sp->link, &kvm->arch.active_mmu_pages);
- if (!sp->role.invalid)
+ /*
+ * Obsolete pages cannot be used on any vCPUs, see the comment
+ * in kvm_mmu_zap_all_fast(). Note, is_obsolete_sp() also
+ * treats invalid shadow pages as being obsolete.
+ */
+ if (!is_obsolete_sp(kvm, sp))
kvm_reload_remote_mmus(kvm);
}
--
2.22.0
