Merge remote-tracking branch 'upstream/master' into queue

Merging critical fixes from upstream required for development.

* upstream/master: (809 commits)
  libata: Add a space to " 2GB ATA Flash Disk" DMA blacklist entry
  Revert "powerpc: Update g5_defconfig"
  powerpc/perf: Use pmc_overflow() to detect rolled back events
  powerpc: Fix VMX in interrupt check in POWER7 copy loops
  powerpc: POWER7 copy_to_user/copy_from_user patch applied twice
  powerpc: Fix personality handling in ppc64_personality()
  powerpc/dma-iommu: Fix IOMMU window check
  powerpc: Remove unnecessary ifdefs
  powerpc/kgdb: Restore current_thread_info properly
  powerpc/kgdb: Bail out of KGDB when we've been triggered
  powerpc/kgdb: Do not set kgdb_single_step on ppc
  powerpc/mpic_msgr: Add missing includes
  powerpc: Fix null pointer deref in perf hardware breakpoints
  powerpc: Fixup whitespace in xmon
  powerpc: Fix xmon dl command for new printk implementation
  xfs: check for possible overflow in xfs_ioc_trim
  xfs: unlock the AGI buffer when looping in xfs_dialloc
  xfs: fix uninitialised variable in xfs_rtbuf_get()
  powerpc/fsl: fix "Failed to mount /dev: No such device" errors
  powerpc/fsl: update defconfigs
  ...

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8e312a2e1412..399c177212b5 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4155,16 +4155,21 @@ static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc)
                 LIST_HEAD(invalid_list);
 
                 /*
+                 * Never scan more than sc->nr_to_scan VM instances.
+                 * Will not hit this condition practically since we do not try
+                 * to shrink more than one VM and it is very unlikely to see
+                 * !n_used_mmu_pages so many times.
+                 */
+                if (!nr_to_scan--)
+                        break;
+                /*
                  * n_used_mmu_pages is accessed without holding kvm->mmu_lock
                  * here. We may skip a VM instance errorneosly, but we do not
                  * want to shrink a VM that only started to populate its MMU
                  * anyway.
                  */
-                if (kvm->arch.n_used_mmu_pages > 0) {
-                        if (!nr_to_scan--)
-                                break;
+                if (!kvm->arch.n_used_mmu_pages)
                         continue;
-                }
 
                 idx = srcu_read_lock(&kvm->srcu);
                 spin_lock(&kvm->mmu_lock);