From 3e286d39ccd799e271c215b2e6633f19d34d910b Mon Sep 17 00:00:00 2001 From: Punit Agrawal Date: Mon, 1 Oct 2018 16:54:35 +0100 Subject: [PATCH] KVM: arm/arm64: Ensure only THP is candidate for adjustment commit fd2ef358282c849c193aa36dadbf4f07f7dcd29b upstream. PageTransCompoundMap() returns true for hugetlbfs and THP hugepages. This behaviour incorrectly leads to stage 2 faults for unsupported hugepage sizes (e.g., 64K hugepage with 4K pages) to be treated as THP faults. Tighten the check to filter out hugetlbfs pages. This also leads to consistently mapping all unsupported hugepage sizes as PTE level entries at stage 2. Signed-off-by: Punit Agrawal Reviewed-by: Suzuki Poulose Cc: Christoffer Dall Cc: Marc Zyngier Cc: stable@vger.kernel.org # v4.13+ Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- virt/kvm/arm/mmu.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index ed162a6..2f405b0 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1230,8 +1230,14 @@ static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap) { kvm_pfn_t pfn = *pfnp; gfn_t gfn = *ipap >> PAGE_SHIFT; + struct page *page = pfn_to_page(pfn); - if (PageTransCompoundMap(pfn_to_page(pfn))) { + /* + * PageTransCompoungMap() returns true for THP and + * hugetlbfs. Make sure the adjustment is done only for THP + * pages. + */ + if (!PageHuge(page) && PageTransCompoundMap(page)) { unsigned long mask; /* * The address we faulted on is backed by a transparent huge -- 2.7.4