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Commit bc32ce21 authored by Xiao Guangrong's avatar Xiao Guangrong Committed by Avi Kivity
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KVM: MMU: fix wrong not write protected sp report 



The audit code reports some sp not write protected in current code, it's just the
bug in audit_write_protection(), since:

- the invalid sp not need write protected
- using uninitialize local variable('gfn')
- call kvm_mmu_audit() out of mmu_lock's protection

Signed-off-by: default avatarXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 0beb8d66

arch/x86/kvm/mmu.c

+3 −2
Original line number Diff line number Diff line
@@ -3708,16 +3708,17 @@ static void audit_write_protection(struct kvm_vcpu *vcpu) 
	struct kvm_memory_slot *slot;

	unsigned long *rmapp;

	u64 *spte;

	gfn_t gfn;



	list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {

		if (sp->role.direct)

			continue;

		if (sp->unsync)

			continue;

		if (sp->role.invalid)

			continue;



		slot = gfn_to_memslot(vcpu->kvm, sp->gfn);

		rmapp = &slot->rmap[gfn - slot->base_gfn];

		rmapp = &slot->rmap[sp->gfn - slot->base_gfn];



		spte = rmap_next(vcpu->kvm, rmapp, NULL);

		while (spte) {

arch/x86/kvm/paging_tmpl.h

+2 −1
Original line number Diff line number Diff line
@@ -504,7 +504,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, 
	unsigned long mmu_seq;



	pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);

	kvm_mmu_audit(vcpu, "pre page fault");



	r = mmu_topup_memory_caches(vcpu);

	if (r)
@@ -542,6 +541,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, 
	spin_lock(&vcpu->kvm->mmu_lock);

	if (mmu_notifier_retry(vcpu, mmu_seq))

		goto out_unlock;



	kvm_mmu_audit(vcpu, "pre page fault");

	kvm_mmu_free_some_pages(vcpu);

	sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,

			     level, &write_pt, pfn);