The idea behind this is: we don't want to keep tracking of huge pages when logging_active is true, which will result in performance degradation. We still need to set vma_pagesize to PAGE_SIZE, so that we can make use of it to force a PTE mapping.
Cc: Suzuki K Poulose <suzuki.poul...@arm.com> Cc: Punit Agrawal <punit.agra...@arm.com> Signed-off-by: Zenghui Yu <yuzeng...@huawei.com> --- Atfer looking into https://patchwork.codeaurora.org/patch/647985/ , the "vma_pagesize = PAGE_SIZE" logic was not intended to be deleted. As far as I can tell, we used to have "hugetlb" to force the PTE mapping, but we have "vma_pagesize" currently instead. We should set it properly for performance reasons (e.g, in VM migration). Did I miss something important? --- virt/kvm/arm/mmu.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 30251e2..7d41b16 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1705,6 +1705,13 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, (vma_pagesize == PUD_SIZE && kvm_stage2_has_pmd(kvm))) && !force_pte) { gfn = (fault_ipa & huge_page_mask(hstate_vma(vma))) >> PAGE_SHIFT; + } else { + /* + * Fallback to PTE if it's not one of the stage2 + * supported hugepage sizes or the corresponding level + * doesn't exist, or logging is enabled. + */ + vma_pagesize = PAGE_SIZE; } up_read(¤t->mm->mmap_sem); -- 1.8.3.1
