This is a note to let you know that I've just added the patch titled
KVM: arm/arm64: Ensure only THP is candidate for adjustment
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-arm-arm64-ensure-only-thp-is-candidate-for-adjus.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 65f71ab8ee3473657531a6be2e3ea2fb51c2ca87
Author: Punit Agrawal <punit.agrawal@xxxxxxx>
Date: Mon Oct 1 16:54:35 2018 +0100
KVM: arm/arm64: Ensure only THP is candidate for adjustment
[ Upstream commit fd2ef358282c849c193aa36dadbf4f07f7dcd29b ]
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 <punit.agrawal@xxxxxxx>
Reviewed-by: Suzuki Poulose <suzuki.poulose@xxxxxxx>
Cc: Christoffer Dall <christoffer.dall@xxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.13+
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 225dc671ae31b..1f4cac53b9234 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1068,8 +1068,14 @@ 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
