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 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6105,7 +6105,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
                                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 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
                               "failed to munmap memory\n");
        }
 
+       if (!kvm->arch.n_requested_mmu_pages)
+               nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
+
        spin_lock(&kvm->mmu_lock);
-       if (!kvm->arch.n_requested_mmu_pages) {
-               unsigned int nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
+       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);
 }