Commit cc38d61c authored by Quentin Perret's avatar Quentin Perret Committed by Marc Zyngier
Browse files

KVM: arm64: Convert write-protect operation to generic page-table API 



Convert stage2_wp_range() to call the kvm_pgtable_stage2_wrprotect()
function of the generic page-table code instead of walking the page-table
directly.

Signed-off-by: default avatarQuentin Perret <qperret@google.com>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200911132529.19844-14-will@kernel.org
parent 73d49df2

arch/arm64/kvm/mmu.c

+4 −21
Original line number Diff line number Diff line
@@ -71,6 +71,9 @@ static int stage2_apply_range(struct kvm *kvm, phys_addr_t addr, 
	return ret;

}



#define stage2_apply_range_resched(kvm, addr, end, fn)			\

	stage2_apply_range(kvm, addr, end, fn, true)



static bool memslot_is_logging(struct kvm_memory_slot *memslot)

{

	return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
@@ -1302,27 +1305,7 @@ static void stage2_wp_p4ds(struct kvm_s2_mmu *mmu, pgd_t *pgd, 
static void stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)

{

	struct kvm *kvm = mmu->kvm;

	pgd_t *pgd;

	phys_addr_t next;



	pgd = mmu->pgd + stage2_pgd_index(kvm, addr);

	do {

		/*

		 * Release kvm_mmu_lock periodically if the memory region is

		 * large. Otherwise, we may see kernel panics with

		 * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,

		 * CONFIG_LOCKDEP. Additionally, holding the lock too long

		 * will also starve other vCPUs. We have to also make sure

		 * that the page tables are not freed while we released

		 * the lock.

		 */

		cond_resched_lock(&kvm->mmu_lock);

		if (!READ_ONCE(mmu->pgd))

			break;

		next = stage2_pgd_addr_end(kvm, addr, end);

		if (stage2_pgd_present(kvm, *pgd))

			stage2_wp_p4ds(mmu, pgd, addr, next);

	} while (pgd++, addr = next, addr != end);

	stage2_apply_range_resched(kvm, addr, end, kvm_pgtable_stage2_wrprotect);

}



/**