Merge branch kvm-arm64/misc into kvmarm/next

* kvm-arm64/misc:
  : Miscellaneous updates
  :
  :  - Put an upper bound on the number of I-cache invalidations by
  :    cacheline to avoid soft lockups
  :
  :  - Get rid of bogus refererence count transfer for THP mappings
  :
  :  - Do a local TLB invalidation on permission fault race
  :
  :  - Fixes for page_fault_test KVM selftest
  :
  :  - Add a tracepoint for detecting MMIO instructions unsupported by KVM
  KVM: arm64: Add tracepoint for MMIO accesses where ISV==0
  KVM: arm64: selftest: Perform ISB before reading PAR_EL1
  KVM: arm64: selftest: Add the missing .guest_prepare()
  KVM: arm64: Always invalidate TLB for stage-2 permission faults
  KVM: arm64: Do not transfer page refcount for THP adjustment
  KVM: arm64: Avoid soft lockups due to I-cache maintenance
  arm64: tlbflush: Rename MAX_TLBI_OPS
  KVM: arm64: Don't use kerneldoc comment for arm64_check_features()

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

1 files changed, 0 insertions, 20 deletions

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 482280fe22d7..2358dd0b9589 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1298,28 +1298,8 @@ transparent_hugepage_adjust(struct kvm *kvm, struct kvm_memory_slot *memslot,
 		if (sz < PMD_SIZE)
 			return PAGE_SIZE;
 
-		/*
-		 * The address we faulted on is backed by a transparent huge
-		 * page.  However, because we map the compound huge page and
-		 * not the individual tail page, we need to transfer the
-		 * refcount to the head page.  We have to be careful that the
-		 * THP doesn't start to split while we are adjusting the
-		 * refcounts.
-		 *
-		 * We are sure this doesn't happen, because mmu_invalidate_retry
-		 * was successful and we are holding the mmu_lock, so if this
-		 * THP is trying to split, it will be blocked in the mmu
-		 * notifier before touching any of the pages, specifically
-		 * before being able to call __split_huge_page_refcount().
-		 *
-		 * We can therefore safely transfer the refcount from PG_tail
-		 * to PG_head and switch the pfn from a tail page to the head
-		 * page accordingly.
-		 */
 		*ipap &= PMD_MASK;
-		kvm_release_pfn_clean(pfn);
 		pfn &= ~(PTRS_PER_PMD - 1);
-		get_page(pfn_to_page(pfn));
 		*pfnp = pfn;
 
 		return PMD_SIZE;