KVM: Allow reading aliases with mmu_lock

This allows the mmu notifier code to run unalias_gfn with only the
mmu_lock held.  Only alias writes need the mmu_lock held. Readers will
either take the slots_lock in read mode or the mmu_lock.

Signed-off-by: Andrea Arcangeli <andrea@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Andrea Arcangeli 2008-07-25 16:26:39 +02:00 committed by Avi Kivity
parent 6e86841d05
commit a1708ce8a3

View File

@ -1495,6 +1495,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
goto out;
down_write(&kvm->slots_lock);
spin_lock(&kvm->mmu_lock);
p = &kvm->arch.aliases[alias->slot];
p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
@ -1506,6 +1507,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
break;
kvm->arch.naliases = n;
spin_unlock(&kvm->mmu_lock);
kvm_mmu_zap_all(kvm);
up_write(&kvm->slots_lock);