From fd2ef358282c849c193aa36dadbf4f07f7dcd29b 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 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 --- 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 7e477b3cae5b..c23a1b323aad 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1231,8 +1231,14 @@ 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