Commit cd4c7183 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: arm64: Convert to the gfn-based MMU notifier callbacks 



Move arm64 to the gfn-base MMU notifier APIs, which do the hva->gfn
lookup in common code.

No meaningful functional change intended, though the exact order of
operations is slightly different since the memslot lookups occur before
calling into arch code.

Reviewed-by: default avatarMarc Zyngier <maz@kernel.org>
Tested-by: default avatarMarc Zyngier <maz@kernel.org>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210402005658.3024832-4-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 3039bcc7

arch/arm64/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -586,6 +586,7 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu, 
			      struct kvm_vcpu_events *events);



#define KVM_ARCH_WANT_MMU_NOTIFIER

#define KVM_ARCH_WANT_NEW_MMU_NOTIFIER_APIS



void kvm_arm_halt_guest(struct kvm *kvm);

void kvm_arm_resume_guest(struct kvm *kvm);

arch/arm64/kvm/mmu.c

+31 −84
Original line number Diff line number Diff line
@@ -839,7 +839,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, 
	 * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk

	 * the page we just got a reference to gets unmapped before we have a

	 * chance to grab the mmu_lock, which ensure that if the page gets

	 * unmapped afterwards, the call to kvm_unmap_hva will take it away

	 * unmapped afterwards, the call to kvm_unmap_gfn will take it away

	 * from us again properly. This smp_rmb() interacts with the smp_wmb()

	 * in kvm_mmu_notifier_invalidate_<page|range_end>.

	 */
@@ -1064,123 +1064,70 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu) 
	return ret;

}



static int handle_hva_to_gpa(struct kvm *kvm,

			     unsigned long start,

			     unsigned long end,

			     int (*handler)(struct kvm *kvm,

					    gpa_t gpa, u64 size,

					    void *data),

			     void *data)

bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)

{

	struct kvm_memslots *slots;

	struct kvm_memory_slot *memslot;

	int ret = 0;



	slots = kvm_memslots(kvm);



	/* we only care about the pages that the guest sees */

	kvm_for_each_memslot(memslot, slots) {

		unsigned long hva_start, hva_end;

		gfn_t gpa;



		hva_start = max(start, memslot->userspace_addr);

		hva_end = min(end, memslot->userspace_addr +

					(memslot->npages << PAGE_SHIFT));

		if (hva_start >= hva_end)

			continue;



		gpa = hva_to_gfn_memslot(hva_start, memslot) << PAGE_SHIFT;

		ret |= handler(kvm, gpa, (u64)(hva_end - hva_start), data);

	}



	return ret;

}

	if (!kvm->arch.mmu.pgt)

		return 0;



static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)

{

	unsigned flags = *(unsigned *)data;

	bool may_block = flags & MMU_NOTIFIER_RANGE_BLOCKABLE;

	__unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT,

			     (range->end - range->start) << PAGE_SHIFT,

			     range->may_block);



	__unmap_stage2_range(&kvm->arch.mmu, gpa, size, may_block);

	return 0;

}



int kvm_unmap_hva_range(struct kvm *kvm,

			unsigned long start, unsigned long end, unsigned flags)

bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)

{

	if (!kvm->arch.mmu.pgt)

		return 0;

	kvm_pfn_t pfn = pte_pfn(range->pte);



	handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, &flags);

	if (!kvm->arch.mmu.pgt)

		return 0;

}



static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)

{

	kvm_pfn_t *pfn = (kvm_pfn_t *)data;

	WARN_ON(range->end - range->start != 1);



	WARN_ON(size != PAGE_SIZE);

	/*

	 * We've moved a page around, probably through CoW, so let's treat it

	 * just like a translation fault and clean the cache to the PoC.

	 */

	clean_dcache_guest_page(pfn, PAGE_SIZE);



	/*

	 * The MMU notifiers will have unmapped a huge PMD before calling

	 * ->change_pte() (which in turn calls kvm_set_spte_hva()) and

	 * ->change_pte() (which in turn calls kvm_set_spte_gfn()) and

	 * therefore we never need to clear out a huge PMD through this

	 * calling path and a memcache is not required.

	 */

	kvm_pgtable_stage2_map(kvm->arch.mmu.pgt, gpa, PAGE_SIZE,

			       __pfn_to_phys(*pfn), KVM_PGTABLE_PROT_R, NULL);

	kvm_pgtable_stage2_map(kvm->arch.mmu.pgt, range->start << PAGE_SHIFT,

			       PAGE_SIZE, __pfn_to_phys(pfn),

			       KVM_PGTABLE_PROT_R, NULL);



	return 0;

}



int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)

bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)

{

	unsigned long end = hva + PAGE_SIZE;

	kvm_pfn_t pfn = pte_pfn(pte);

	u64 size = (range->end - range->start) << PAGE_SHIFT;

	kvm_pte_t kpte;

	pte_t pte;



	if (!kvm->arch.mmu.pgt)

		return 0;



	/*

	 * We've moved a page around, probably through CoW, so let's treat it

	 * just like a translation fault and clean the cache to the PoC.

	 */

	clean_dcache_guest_page(pfn, PAGE_SIZE);

	handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &pfn);

	return 0;

}



static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)

{

	pte_t pte;

	kvm_pte_t kpte;



	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);

	kpte = kvm_pgtable_stage2_mkold(kvm->arch.mmu.pgt, gpa);



	kpte = kvm_pgtable_stage2_mkold(kvm->arch.mmu.pgt,

					range->start << PAGE_SHIFT);

	pte = __pte(kpte);

	return pte_valid(pte) && pte_young(pte);

}



static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)

{

	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);

	return kvm_pgtable_stage2_is_young(kvm->arch.mmu.pgt, gpa);

}



int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)

{

	if (!kvm->arch.mmu.pgt)

		return 0;



	return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);

}



int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)

bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)

{

	if (!kvm->arch.mmu.pgt)

		return 0;



	return handle_hva_to_gpa(kvm, hva, hva + PAGE_SIZE,

				 kvm_test_age_hva_handler, NULL);

	return kvm_pgtable_stage2_is_young(kvm->arch.mmu.pgt,

					   range->start << PAGE_SHIFT);

}



phys_addr_t kvm_mmu_get_httbr(void)