Commit 1b2dc736 authored by Hou Wenlong's avatar Hou Wenlong Committed by Sean Christopherson
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KVM: x86/mmu: Fix wrong start gfn of tlb flushing with range 



When a spte is dropped, the start gfn of tlb flushing should be the gfn
of spte not the base gfn of SP which contains the spte. Also introduce a
helper function to do range-based flushing when a spte is dropped, which
would help prevent future buggy use of
kvm_flush_remote_tlbs_with_address() in such case.

Fixes: c3134ce2 ("KVM: Replace old tlb flush function with new one to flush a specified range.")
Suggested-by: default avatarDavid Matlack <dmatlack@google.com>
Signed-off-by: default avatarHou Wenlong <houwenlong.hwl@antgroup.com>
Link: https://lore.kernel.org/r/72ac2169a261976f00c1703e88cda676dfb960f5.1665214747.git.houwenlong.hwl@antgroup.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 1e203847

arch/x86/kvm/mmu/mmu.c

+14 −6
Original line number Diff line number Diff line
@@ -269,6 +269,17 @@ void kvm_flush_remote_tlbs_with_address(struct kvm *kvm, 
	kvm_flush_remote_tlbs_with_range(kvm, &range);

}



static gfn_t kvm_mmu_page_get_gfn(struct kvm_mmu_page *sp, int index);



/* Flush the range of guest memory mapped by the given SPTE. */

static void kvm_flush_remote_tlbs_sptep(struct kvm *kvm, u64 *sptep)

{

	struct kvm_mmu_page *sp = sptep_to_sp(sptep);

	gfn_t gfn = kvm_mmu_page_get_gfn(sp, spte_index(sptep));



	kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level);

}



static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn,

			   unsigned int access)

{
@@ -1187,8 +1198,7 @@ static void drop_large_spte(struct kvm *kvm, u64 *sptep, bool flush) 
	drop_spte(kvm, sptep);



	if (flush)

		kvm_flush_remote_tlbs_with_address(kvm, sp->gfn,

			KVM_PAGES_PER_HPAGE(sp->role.level));

		kvm_flush_remote_tlbs_sptep(kvm, sptep);

}



/*
@@ -1639,8 +1649,7 @@ static void __rmap_add(struct kvm *kvm, 
		kvm->stat.max_mmu_rmap_size = rmap_count;

	if (rmap_count > RMAP_RECYCLE_THRESHOLD) {

		kvm_zap_all_rmap_sptes(kvm, rmap_head);

		kvm_flush_remote_tlbs_with_address(

				kvm, sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level));

		kvm_flush_remote_tlbs_gfn(kvm, gfn, sp->role.level);

	}

}
@@ -6521,8 +6530,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, 
			kvm_zap_one_rmap_spte(kvm, rmap_head, sptep);



			if (kvm_available_flush_tlb_with_range())

				kvm_flush_remote_tlbs_with_address(kvm, sp->gfn,

					KVM_PAGES_PER_HPAGE(sp->role.level));

				kvm_flush_remote_tlbs_sptep(kvm, sptep);

			else

				need_tlb_flush = 1;

arch/x86/kvm/mmu/paging_tmpl.h

+1 −2
Original line number Diff line number Diff line
@@ -927,8 +927,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa) 


			mmu_page_zap_pte(vcpu->kvm, sp, sptep, NULL);

			if (is_shadow_present_pte(old_spte))

				kvm_flush_remote_tlbs_with_address(vcpu->kvm,

					sp->gfn, KVM_PAGES_PER_HPAGE(sp->role.level));

				kvm_flush_remote_tlbs_sptep(vcpu->kvm, sptep);



			if (!rmap_can_add(vcpu))

				break;