Commit 1395375c authored by Michael Ellerman's avatar Michael Ellerman
Browse files

Merge branch 'topic/ppc-kvm' into next 

Merge one more commit from the topic branch we shared with the kvm-ppc
tree.

This brings in a fix to the code that scans for dirty pages during
migration of a VM, which was incorrectly triggering a warning.
parents 4336b933 bf8036a4

arch/powerpc/include/asm/kvm_book3s_64.h

+10 −0
Original line number Diff line number Diff line
@@ -635,6 +635,16 @@ extern void kvmhv_remove_nest_rmap_range(struct kvm *kvm, 
				unsigned long gpa, unsigned long hpa,

				unsigned long nbytes);



static inline pte_t *

find_kvm_secondary_pte_unlocked(struct kvm *kvm, unsigned long ea,

				unsigned *hshift)

{

	pte_t *pte;



	pte = __find_linux_pte(kvm->arch.pgtable, ea, NULL, hshift);

	return pte;

}



static inline pte_t *find_kvm_secondary_pte(struct kvm *kvm, unsigned long ea,

					    unsigned *hshift)

{

arch/powerpc/kvm/book3s_64_mmu_radix.c

+29 −6
Original line number Diff line number Diff line
@@ -1040,7 +1040,7 @@ static int kvm_radix_test_clear_dirty(struct kvm *kvm, 
{

	unsigned long gfn = memslot->base_gfn + pagenum;

	unsigned long gpa = gfn << PAGE_SHIFT;

	pte_t *ptep;

	pte_t *ptep, pte;

	unsigned int shift;

	int ret = 0;

	unsigned long old, *rmapp;
@@ -1048,12 +1048,35 @@ static int kvm_radix_test_clear_dirty(struct kvm *kvm, 
	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)

		return ret;



	ptep = find_kvm_secondary_pte(kvm, gpa, &shift);

	if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) {

		ret = 1;

		if (shift)

			ret = 1 << (shift - PAGE_SHIFT);

	/*

	 * For performance reasons we don't hold kvm->mmu_lock while walking the

	 * partition scoped table.

	 */

	ptep = find_kvm_secondary_pte_unlocked(kvm, gpa, &shift);

	if (!ptep)

		return 0;



	pte = READ_ONCE(*ptep);

	if (pte_present(pte) && pte_dirty(pte)) {

		spin_lock(&kvm->mmu_lock);

		/*

		 * Recheck the pte again

		 */

		if (pte_val(pte) != pte_val(*ptep)) {

			/*

			 * We have KVM_MEM_LOG_DIRTY_PAGES enabled. Hence we can

			 * only find PAGE_SIZE pte entries here. We can continue

			 * to use the pte addr returned by above page table

			 * walk.

			 */

			if (!pte_present(*ptep) || !pte_dirty(*ptep)) {

				spin_unlock(&kvm->mmu_lock);

				return 0;

			}

		}



		ret = 1;

		VM_BUG_ON(shift);

		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0,

					      gpa, shift);

		kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid);