Hi Steven, On Mon, Oct 26, 2020 at 03:57:27PM +0000, Steven Price wrote: > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index 19aacc7d64de..38fe25310ca1 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c > @@ -862,6 +862,26 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, > phys_addr_t fault_ipa, > if (vma_pagesize == PAGE_SIZE && !force_pte) > vma_pagesize = transparent_hugepage_adjust(memslot, hva, > &pfn, &fault_ipa); > + > + /* > + * The otherwise redundant test for system_supports_mte() allows the > + * code to be compiled out when CONFIG_ARM64_MTE is not present. > + */ > + if (system_supports_mte() && kvm->arch.mte_enabled && pfn_valid(pfn)) { > + /* > + * 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); > + long i, nr_pages = compound_nr(page); > + > + /* if PG_mte_tagged is set, tags have already been initialised > */ > + for (i = 0; i < nr_pages; i++, page++) { > + if (!test_and_set_bit(PG_mte_tagged, &page->flags)) > + mte_clear_page_tags(page_address(page)); > + } > + }
If this page was swapped out and mapped back in, where does the restoring from swap happen? I may have asked in the past, is user_mem_abort() the only path for mapping Normal pages into stage 2? -- Catalin