X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=virt%2Fkvm%2Fkvm_main.c;h=3be46841db06bb461347e819307aeb51a37bd9d6;hb=f1b9dd5eb86cec1fcf66aad17e7701d98d024a9a;hp=2679e476b6c3970f5e6479c89183a564639db257;hpb=121b018f8c74b4e0ba81b4b8ee73a82db3f24b7b;p=linux-2.6-microblaze.git

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2679e476b6c3..3be46841db06 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1133,7 +1133,7 @@ EXPORT_SYMBOL_GPL(kvm_get_dirty_log);
 #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
 /**
  * kvm_get_dirty_log_protect - get a snapshot of dirty pages, and if any pages
- *	are dirty write protect them for next write.
+ *	and reenable dirty page tracking for the corresponding pages.
  * @kvm:	pointer to kvm instance
  * @log:	slot id and address to which we copy the log
  * @is_dirty:	flag set if any page is dirty
@@ -1154,7 +1154,7 @@ EXPORT_SYMBOL_GPL(kvm_get_dirty_log);
  *
  */
 int kvm_get_dirty_log_protect(struct kvm *kvm,
-			struct kvm_dirty_log *log, bool *is_dirty)
+			struct kvm_dirty_log *log, bool *flush)
 {
 	struct kvm_memslots *slots;
 	struct kvm_memory_slot *memslot;
@@ -1176,37 +1176,114 @@ int kvm_get_dirty_log_protect(struct kvm *kvm,
 		return -ENOENT;
 
 	n = kvm_dirty_bitmap_bytes(memslot);
+	*flush = false;
+	if (kvm->manual_dirty_log_protect) {
+		/*
+		 * Unlike kvm_get_dirty_log, we always return false in *flush,
+		 * because no flush is needed until KVM_CLEAR_DIRTY_LOG.  There
+		 * is some code duplication between this function and
+		 * kvm_get_dirty_log, but hopefully all architecture
+		 * transition to kvm_get_dirty_log_protect and kvm_get_dirty_log
+		 * can be eliminated.
+		 */
+		dirty_bitmap_buffer = dirty_bitmap;
+	} else {
+		dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
+		memset(dirty_bitmap_buffer, 0, n);
+
+		spin_lock(&kvm->mmu_lock);
+		for (i = 0; i < n / sizeof(long); i++) {
+			unsigned long mask;
+			gfn_t offset;
+
+			if (!dirty_bitmap[i])
+				continue;
+
+			*flush = true;
+			mask = xchg(&dirty_bitmap[i], 0);
+			dirty_bitmap_buffer[i] = mask;
+
+			if (mask) {
+				offset = i * BITS_PER_LONG;
+				kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
+									offset, mask);
+			}
+		}
+		spin_unlock(&kvm->mmu_lock);
+	}
+
+	if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
+		return -EFAULT;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_get_dirty_log_protect);
+
+/**
+ * kvm_clear_dirty_log_protect - clear dirty bits in the bitmap
+ *	and reenable dirty page tracking for the corresponding pages.
+ * @kvm:	pointer to kvm instance
+ * @log:	slot id and address from which to fetch the bitmap of dirty pages
+ */
+int kvm_clear_dirty_log_protect(struct kvm *kvm,
+				struct kvm_clear_dirty_log *log, bool *flush)
+{
+	struct kvm_memslots *slots;
+	struct kvm_memory_slot *memslot;
+	int as_id, id, n;
+	gfn_t offset;
+	unsigned long i;
+	unsigned long *dirty_bitmap;
+	unsigned long *dirty_bitmap_buffer;
+
+	as_id = log->slot >> 16;
+	id = (u16)log->slot;
+	if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
+		return -EINVAL;
+
+	if ((log->first_page & 63) || (log->num_pages & 63))
+		return -EINVAL;
 
+	slots = __kvm_memslots(kvm, as_id);
+	memslot = id_to_memslot(slots, id);
+
+	dirty_bitmap = memslot->dirty_bitmap;
+	if (!dirty_bitmap)
+		return -ENOENT;
+
+	n = kvm_dirty_bitmap_bytes(memslot);
+	*flush = false;
 	dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
-	memset(dirty_bitmap_buffer, 0, n);
+	if (copy_from_user(dirty_bitmap_buffer, log->dirty_bitmap, n))
+		return -EFAULT;
 
 	spin_lock(&kvm->mmu_lock);
-	*is_dirty = false;
-	for (i = 0; i < n / sizeof(long); i++) {
-		unsigned long mask;
-		gfn_t offset;
-
-		if (!dirty_bitmap[i])
+	for (offset = log->first_page,
+	     i = offset / BITS_PER_LONG, n = log->num_pages / BITS_PER_LONG; n--;
+	     i++, offset += BITS_PER_LONG) {
+		unsigned long mask = *dirty_bitmap_buffer++;
+		atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i];
+		if (!mask)
 			continue;
 
-		*is_dirty = true;
-
-		mask = xchg(&dirty_bitmap[i], 0);
-		dirty_bitmap_buffer[i] = mask;
+		mask &= atomic_long_fetch_andnot(mask, p);
 
+		/*
+		 * mask contains the bits that really have been cleared.  This
+		 * never includes any bits beyond the length of the memslot (if
+		 * the length is not aligned to 64 pages), therefore it is not
+		 * a problem if userspace sets them in log->dirty_bitmap.
+		*/
 		if (mask) {
-			offset = i * BITS_PER_LONG;
+			*flush = true;
 			kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
 								offset, mask);
 		}
 	}
-
 	spin_unlock(&kvm->mmu_lock);
-	if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
-		return -EFAULT;
+
 	return 0;
 }
-EXPORT_SYMBOL_GPL(kvm_get_dirty_log_protect);
+EXPORT_SYMBOL_GPL(kvm_clear_dirty_log_protect);
 #endif
 
 bool kvm_largepages_enabled(void)
@@ -1928,32 +2005,33 @@ static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots,
 	gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
 	gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
 	gfn_t nr_pages_avail;
+	int r = start_gfn <= end_gfn ? 0 : -EINVAL;
 
 	ghc->gpa = gpa;
 	ghc->generation = slots->generation;
 	ghc->len = len;
-	ghc->memslot = __gfn_to_memslot(slots, start_gfn);
-	ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, NULL);
-	if (!kvm_is_error_hva(ghc->hva) && nr_pages_needed <= 1) {
+	ghc->hva = KVM_HVA_ERR_BAD;
+
+	/*
+	 * If the requested region crosses two memslots, we still
+	 * verify that the entire region is valid here.
+	 */
+	while (!r && start_gfn <= end_gfn) {
+		ghc->memslot = __gfn_to_memslot(slots, start_gfn);
+		ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
+					   &nr_pages_avail);
+		if (kvm_is_error_hva(ghc->hva))
+			r = -EFAULT;
+		start_gfn += nr_pages_avail;
+	}
+
+	/* Use the slow path for cross page reads and writes. */
+	if (!r && nr_pages_needed == 1)
 		ghc->hva += offset;
-	} else {
-		/*
-		 * If the requested region crosses two memslots, we still
-		 * verify that the entire region is valid here.
-		 */
-		while (start_gfn <= end_gfn) {
-			nr_pages_avail = 0;
-			ghc->memslot = __gfn_to_memslot(slots, start_gfn);
-			ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
-						   &nr_pages_avail);
-			if (kvm_is_error_hva(ghc->hva))
-				return -EFAULT;
-			start_gfn += nr_pages_avail;
-		}
-		/* Use the slow path for cross page reads and writes. */
+	else
 		ghc->memslot = NULL;
-	}
-	return 0;
+
+	return r;
 }
 
 int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
@@ -2948,6 +3026,10 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
 #endif
 	case KVM_CAP_IOEVENTFD_ANY_LENGTH:
 	case KVM_CAP_CHECK_EXTENSION_VM:
+	case KVM_CAP_ENABLE_CAP_VM:
+#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
+	case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT:
+#endif
 		return 1;
 #ifdef CONFIG_KVM_MMIO
 	case KVM_CAP_COALESCED_MMIO:
@@ -2971,6 +3053,28 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
 	return kvm_vm_ioctl_check_extension(kvm, arg);
 }
 
+int __attribute__((weak)) kvm_vm_ioctl_enable_cap(struct kvm *kvm,
+						  struct kvm_enable_cap *cap)
+{
+	return -EINVAL;
+}
+
+static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
+					   struct kvm_enable_cap *cap)
+{
+	switch (cap->cap) {
+#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
+	case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT:
+		if (cap->flags || (cap->args[0] & ~1))
+			return -EINVAL;
+		kvm->manual_dirty_log_protect = cap->args[0];
+		return 0;
+#endif
+	default:
+		return kvm_vm_ioctl_enable_cap(kvm, cap);
+	}
+}
+
 static long kvm_vm_ioctl(struct file *filp,
 			   unsigned int ioctl, unsigned long arg)
 {
@@ -2984,6 +3088,15 @@ static long kvm_vm_ioctl(struct file *filp,
 	case KVM_CREATE_VCPU:
 		r = kvm_vm_ioctl_create_vcpu(kvm, arg);
 		break;
+	case KVM_ENABLE_CAP: {
+		struct kvm_enable_cap cap;
+
+		r = -EFAULT;
+		if (copy_from_user(&cap, argp, sizeof(cap)))
+			goto out;
+		r = kvm_vm_ioctl_enable_cap_generic(kvm, &cap);
+		break;
+	}
 	case KVM_SET_USER_MEMORY_REGION: {
 		struct kvm_userspace_memory_region kvm_userspace_mem;
 
@@ -3004,6 +3117,17 @@ static long kvm_vm_ioctl(struct file *filp,
 		r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
 		break;
 	}
+#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
+	case KVM_CLEAR_DIRTY_LOG: {
+		struct kvm_clear_dirty_log log;
+
+		r = -EFAULT;
+		if (copy_from_user(&log, argp, sizeof(log)))
+			goto out;
+		r = kvm_vm_ioctl_clear_dirty_log(kvm, &log);
+		break;
+	}
+#endif
 #ifdef CONFIG_KVM_MMIO
 	case KVM_REGISTER_COALESCED_MMIO: {
 		struct kvm_coalesced_mmio_zone zone;