Revert "KVM: cleanup: remove kvm_get_dirty_log()"

This reverts commit 7e2c227d82232327c43e25fa98a132c000faa005, as it
breaks dirty logging on PPC.

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

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index da0c133ea7f88deea4c5fc19beb4936ac5de29f8..5cb58655cd5f98d482895b51e9251852a70c1236 100644 (file)
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1818,10 +1818,10 @@ static void kvm_ia64_sync_dirty_log(struct kvm *kvm,
 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
                struct kvm_dirty_log *log)
 {
-       int r, i;
+       int r;
        unsigned long n;
        struct kvm_memory_slot *memslot;
-       unsigned long is_dirty = 0;
+       int is_dirty = 0;
 
        mutex_lock(&kvm->slots_lock);
 
@@ -1835,23 +1835,15 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
                goto out;
 
        kvm_ia64_sync_dirty_log(kvm, memslot);
-
-       n = kvm_dirty_bitmap_bytes(memslot);
-
-       for (i = 0; !is_dirty && i < n/sizeof(long); ++i)
-               is_dirty = memslot->dirty_bitmap[i];
+       r = kvm_get_dirty_log(kvm, log, &is_dirty);
+       if (r)
+               goto out;
 
        /* If nothing is dirty, don't bother messing with page tables. */
        if (is_dirty) {
                kvm_flush_remote_tlbs(kvm);
-               r = -EFAULT;
-               if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
-                       goto out;
+               n = kvm_dirty_bitmap_bytes(memslot);
                memset(memslot->dirty_bitmap, 0, n);
-       } else {
-               r = -EFAULT;
-               if (clear_user(log->dirty_bitmap, n))
-                       goto out;
        }
        r = 0;
 out:

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index bea6f7cf81efb3682aa4546681b041694537f95d..801d9f3c70aec7ab9d3dd057f882d5b632695c2d 100644 (file)
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -1185,43 +1185,28 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
        struct kvm_memory_slot *memslot;
        struct kvm_vcpu *vcpu;
        ulong ga, ga_end;
-       unsigned long is_dirty = 0;
-       int r, i;
+       int is_dirty = 0;
+       int r;
        unsigned long n;
 
        mutex_lock(&kvm->slots_lock);
 
-       r = -EINVAL;
-       if (log->slot >= KVM_MEMORY_SLOTS)
-               goto out;
-
-       memslot = &kvm->memslots->memslots[log->slot];
-       r = -ENOENT;
-       if (!memslot->dirty_bitmap)
+       r = kvm_get_dirty_log(kvm, log, &is_dirty);
+       if (r)
                goto out;
 
-       n = kvm_dirty_bitmap_bytes(memslot);
-
-       for (i = 0; !is_dirty && i < n/sizeof(long); ++i)
-               is_dirty = memslot->dirty_bitmap[i];
-
        /* If nothing is dirty, don't bother messing with page tables. */
        if (is_dirty) {
+               memslot = &kvm->memslots->memslots[log->slot];
+
                ga = memslot->base_gfn << PAGE_SHIFT;
                ga_end = ga + (memslot->npages << PAGE_SHIFT);
 
                kvm_for_each_vcpu(n, vcpu, kvm)
                        kvmppc_mmu_pte_pflush(vcpu, ga, ga_end);
 
-               r = -EFAULT;
-               if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
-                       goto out;
-
+               n = kvm_dirty_bitmap_bytes(memslot);
                memset(memslot->dirty_bitmap, 0, n);
-       } else {
-               r = -EFAULT;
-               if (clear_user(log->dirty_bitmap, n))
-                       goto out;
        }
 
        r = 0;

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index b51e6b2fcb47b0c77a0adfc203c72f30b9af20e5..e796326f364628935e690b20f09c6e606ad7eb4e 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -336,6 +336,8 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 
 int kvm_dev_ioctl_check_extension(long ext);
 
+int kvm_get_dirty_log(struct kvm *kvm,
+                       struct kvm_dirty_log *log, int *is_dirty);
 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
                                struct kvm_dirty_log *log);
 

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9eaea28e0da5201c13c95280f5e493abb4e75c41..ec2e3c6ac7ed9985cc7505a502c6c1c357d3fc33 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -773,6 +773,40 @@ int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
        return kvm_set_memory_region(kvm, mem, user_alloc);
 }
 
+int kvm_get_dirty_log(struct kvm *kvm,
+                       struct kvm_dirty_log *log, int *is_dirty)
+{
+       struct kvm_memory_slot *memslot;
+       int r, i;
+       unsigned long n;
+       unsigned long any = 0;
+
+       r = -EINVAL;
+       if (log->slot >= KVM_MEMORY_SLOTS)
+               goto out;
+
+       memslot = &kvm->memslots->memslots[log->slot];
+       r = -ENOENT;
+       if (!memslot->dirty_bitmap)
+               goto out;
+
+       n = kvm_dirty_bitmap_bytes(memslot);
+
+       for (i = 0; !any && i < n/sizeof(long); ++i)
+               any = memslot->dirty_bitmap[i];
+
+       r = -EFAULT;
+       if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
+               goto out;
+
+       if (any)
+               *is_dirty = 1;
+
+       r = 0;
+out:
+       return r;
+}
+
 void kvm_disable_largepages(void)
 {
        largepages_enabled = false;