KVM: x86/mmu: Voluntarily reschedule as needed when zapping MMIO sptes
authorSean Christopherson <sean.j.christopherson@intel.com>
Tue, 5 Feb 2019 21:01:24 +0000 (13:01 -0800)
committerPaolo Bonzini <pbonzini@redhat.com>
Wed, 20 Feb 2019 21:48:40 +0000 (22:48 +0100)
commit571c5af06e303b4a69016193fd6b5afbc96eac40
treeaddd30f7a8b18519c9444a86ece7516c4affdccc
parent4771450c345dc5e3e3417d82aff62e0d88e7eee6
KVM: x86/mmu: Voluntarily reschedule as needed when zapping MMIO sptes

Call cond_resched_lock() when zapping MMIO to reschedule if needed or to
release and reacquire mmu_lock in case of contention.  There is no need
to flush or zap when temporarily dropping mmu_lock as zapping MMIO sptes
is done when holding the memslots lock and with the "update in-progress"
bit set in the memslots generation, which disables MMIO spte caching.
The walk does need to be restarted if mmu_lock is dropped as the active
pages list may be modified.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/mmu.c