KVM: x86/mmu: Try to avoid crashing KVM if a MMU memory cache is empty

Browse source

Attempt to allocate a new object instead of crashing KVM (and likely the
kernel) if a memory cache is unexpectedly empty.  Use GFP_ATOMIC for the
allocation as the caches are used while holding mmu_lock.  The immediate
BUG_ON() makes the code unnecessarily explosive and led to confusing
minimums being used in the past, e.g. allocating 4 objects where 1 would
suffice.

Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-6-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

...

This commit is contained in:

Sean Christopherson 2020-07-02 19:35:29 -07:00 • committed by Paolo Bonzini

parent 284aa86868

commit 53a3f48771

1 changed files with 15 additions and 6 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

21

arch/x86/kvm/mmu/mmu.c

View file