KVM: split kvm_arch_set_memory_region into prepare and commit

Required for SRCU convertion later.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 29 insertions, 22 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1ce833191430..43da65feed49 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5228,13 +5228,13 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
         kfree(kvm);
 }
 
-int kvm_arch_set_memory_region(struct kvm *kvm,
-                                struct kvm_userspace_memory_region *mem,
+int kvm_arch_prepare_memory_region(struct kvm *kvm,
+                                struct kvm_memory_slot *memslot,
                                 struct kvm_memory_slot old,
+                                struct kvm_userspace_memory_region *mem,
                                 int user_alloc)
 {
-        int npages = mem->memory_size >> PAGE_SHIFT;
-        struct kvm_memory_slot *memslot = &kvm->memslots->memslots[mem->slot];
+        int npages = memslot->npages;
 
         /*To keep backward compatibility with older userspace,
          *x86 needs to hanlde !user_alloc case.
@@ -5254,26 +5254,35 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
                         if (IS_ERR((void *)userspace_addr))
                                 return PTR_ERR((void *)userspace_addr);
 
-                        /* set userspace_addr atomically for kvm_hva_to_rmapp */
-                        spin_lock(&kvm->mmu_lock);
                         memslot->userspace_addr = userspace_addr;
-                        spin_unlock(&kvm->mmu_lock);
-                } else {
-                        if (!old.user_alloc && old.rmap) {
-                                int ret;
-
-                                down_write(&current->mm->mmap_sem);
-                                ret = do_munmap(current->mm, old.userspace_addr,
-                                                old.npages * PAGE_SIZE);
-                                up_write(&current->mm->mmap_sem);
-                                if (ret < 0)
-                                        printk(KERN_WARNING
-                                       "kvm_vm_ioctl_set_memory_region: "
-                                       "failed to munmap memory\n");
-                        }
                 }
         }
 
+
+        return 0;
+}
+
+void kvm_arch_commit_memory_region(struct kvm *kvm,
+                                struct kvm_userspace_memory_region *mem,
+                                struct kvm_memory_slot old,
+                                int user_alloc)
+{
+
+        int npages = mem->memory_size >> PAGE_SHIFT;
+
+        if (!user_alloc && !old.user_alloc && old.rmap && !npages) {
+                int ret;
+
+                down_write(&current->mm->mmap_sem);
+                ret = do_munmap(current->mm, old.userspace_addr,
+                                old.npages * PAGE_SIZE);
+                up_write(&current->mm->mmap_sem);
+                if (ret < 0)
+                        printk(KERN_WARNING
+                               "kvm_vm_ioctl_set_memory_region: "
+                               "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);
@@ -5282,8 +5291,6 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
 
         kvm_mmu_slot_remove_write_access(kvm, mem->slot);
         spin_unlock(&kvm->mmu_lock);
-
-        return 0;
 }
 
 void kvm_arch_flush_shadow(struct kvm *kvm)