Commit eeb87272 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86/mmu: Don't rely on page-track mechanism to flush on memslot change 

Call kvm_mmu_zap_all_fast() directly when flushing a memslot instead of
bouncing through the page-track mechanism.  KVM (unfortunately) needs to
zap and flush all page tables on memslot DELETE/MOVE irrespective of
whether KVM is shadowing guest page tables.

This will allow changing KVM to register a page-track notifier on the
first shadow root allocation, and will also allow deleting the misguided
kvm_page_track_flush_slot() hook itself once KVM-GT also moves to a
different method for reacting to memslot changes.

No functional change intended.

Cc: Yan Zhao <yan.y.zhao@intel.com>
Link: https://lore.kernel.org/r/20221110014821.1548347-2-seanjc@google.com


Reviewed-by: default avatarYan Zhao <yan.y.zhao@intel.com>
Tested-by: default avatarYongwei Ma <yongwei.ma@intel.com>
Link: https://lore.kernel.org/r/20230729013535.1070024-14-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent db0d70e6

arch/x86/kvm/mmu/mmu.c

+2 −8
Original line number Diff line number Diff line
@@ -6159,13 +6159,6 @@ static bool kvm_has_zapped_obsolete_pages(struct kvm *kvm) 
	return unlikely(!list_empty_careful(&kvm->arch.zapped_obsolete_pages));

}



static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm,

			struct kvm_memory_slot *slot,

			struct kvm_page_track_notifier_node *node)

{

	kvm_mmu_zap_all_fast(kvm);

}



int kvm_mmu_init_vm(struct kvm *kvm)

{

	struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker;
@@ -6183,7 +6176,6 @@ int kvm_mmu_init_vm(struct kvm *kvm) 
	}



	node->track_write = kvm_mmu_pte_write;

	node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot;

	kvm_page_track_register_notifier(kvm, node);



	kvm->arch.split_page_header_cache.kmem_cache = mmu_page_header_cache;
@@ -6711,6 +6703,8 @@ void kvm_arch_flush_shadow_all(struct kvm *kvm) 
void kvm_arch_flush_shadow_memslot(struct kvm *kvm,

				   struct kvm_memory_slot *slot)

{

	kvm_mmu_zap_all_fast(kvm);



	kvm_page_track_flush_slot(kvm, slot);

}