KVM: MMU: move mmu pages calculated out of mmu lock
kvm_mmu_calculate_mmu_pages need to walk all memslots and it's protected by
kvm->slots_lock, so move it out of mmu spinlock
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 785ae0c..b9c2b8e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6105,7 +6105,7 @@
int user_alloc)
{
- int npages = mem->memory_size >> PAGE_SHIFT;
+ int nr_mmu_pages = 0, npages = mem->memory_size >> PAGE_SHIFT;
if (!user_alloc && !old.user_alloc && old.rmap && !npages) {
int ret;
@@ -6120,12 +6120,12 @@
"failed to munmap memory\n");
}
- spin_lock(&kvm->mmu_lock);
- if (!kvm->arch.n_requested_mmu_pages) {
- unsigned int nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
- kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
- }
+ if (!kvm->arch.n_requested_mmu_pages)
+ nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
+ spin_lock(&kvm->mmu_lock);
+ if (nr_mmu_pages)
+ kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
kvm_mmu_slot_remove_write_access(kvm, mem->slot);
spin_unlock(&kvm->mmu_lock);
}