From: Marcelo Tosatti <mtosatti@redhat.com>
Date: Mon, 28 Jun 2010 15:04:20 +0000 (-0300)
Subject: Revert "KVM: cleanup: remove kvm_get_dirty_log()"
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=6cd154e66b144f50bd490eb2eb70fe8b05a8fc79;p=users%2Fdwmw2%2Flinux.git

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 da0c133ea7f88..5cb58655cd5f9 100644
--- 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 bea6f7cf81efb..801d9f3c70aec 100644
--- 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 b51e6b2fcb47b..e796326f36462 100644
--- 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 9eaea28e0da52..ec2e3c6ac7ed9 100644
--- 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;