On 17/06/2020 15:38, Catalin Marinas wrote:
On Wed, Jun 17, 2020 at 01:38:44PM +0100, Steven Price wrote:
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index e3b9ee268823..040a7fffaa93 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1783,6 +1783,17 @@ static int user_mem_abort(struct kvm_vcpu *vcpu,
phys_addr_t fault_ipa,
vma_pagesize = PMD_SIZE;
}
+ if (system_supports_mte() && kvm->arch.vcpu_has_mte) {
+ /*
+ * VM will be able to see the page's tags, so we must ensure
+ * they have been initialised.
+ */
+ struct page *page = pfn_to_page(pfn);
+
+ if (!test_and_set_bit(PG_mte_tagged, &page->flags))
+ mte_clear_page_tags(page_address(page),
page_size(page));
+ }
Are all the guest pages always mapped via a Stage 2 fault? It may be
better if we did that via kvm_set_spte_hva().
I was under the impression that pages are always faulted into the stage
2, but I have to admit I'm not 100% sure about that.
kvm_set_spte_hva() may be more appropriate, although on first look I
don't understand how that function deals with huge pages. Is it actually
called for normal mappings or only for changes due to the likes of KSM?
Steve
