1 files changed, 107 insertions, 81 deletions

diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 6be3462b109f..f19efad4d6f8 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -36,7 +36,6 @@
 #define DRIVER_AUTHOR	"Stephen Hemminger <sthemmin at microsoft.com>"
 #define DRIVER_DESC	"Generic UIO driver for VMBus devices"
 
-#define HV_RING_SIZE	 512	/* pages */
 #define SEND_BUFFER_SIZE (16 * 1024 * 1024)
 #define RECV_BUFFER_SIZE (31 * 1024 * 1024)
 
@@ -66,6 +65,16 @@ struct hv_uio_private_data {
 	char	send_name[32];
 };
 
+static void set_event(struct vmbus_channel *channel, s32 irq_state)
+{
+	channel->inbound.ring_buffer->interrupt_mask = !irq_state;
+	if (!channel->offermsg.monitor_allocated && irq_state) {
+		/* MB is needed for host to see the interrupt mask first */
+		virt_mb();
+		vmbus_set_event(channel);
+	}
+}
+
 /*
  * This is the irqcontrol callback to be registered to uio_info.
  * It can be used to disable/enable interrupt from user space processes.
@@ -80,9 +89,15 @@ hv_uio_irqcontrol(struct uio_info *info, s32 irq_state)
 {
 	struct hv_uio_private_data *pdata = info->priv;
 	struct hv_device *dev = pdata->device;
+	struct vmbus_channel *primary, *sc;
 
-	dev->channel->inbound.ring_buffer->interrupt_mask = !irq_state;
-	virt_mb();
+	primary = dev->channel;
+	set_event(primary, irq_state);
+
+	mutex_lock(&vmbus_connection.channel_mutex);
+	list_for_each_entry(sc, &primary->sc_list, sc_list)
+		set_event(sc, irq_state);
+	mutex_unlock(&vmbus_connection.channel_mutex);
 
 	return 0;
 }
@@ -93,21 +108,29 @@ hv_uio_irqcontrol(struct uio_info *info, s32 irq_state)
 static void hv_uio_channel_cb(void *context)
 {
 	struct vmbus_channel *chan = context;
-	struct hv_device *hv_dev = chan->device_obj;
-	struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev);
+	struct hv_device *hv_dev;
+	struct hv_uio_private_data *pdata;
 
 	chan->inbound.ring_buffer->interrupt_mask = 1;
 	virt_mb();
 
+	/*
+	 * The callback may come from a subchannel, in which case look
+	 * for the hv device in the primary channel
+	 */
+	hv_dev = chan->primary_channel ?
+		 chan->primary_channel->device_obj : chan->device_obj;
+	pdata = hv_get_drvdata(hv_dev);
 	uio_event_notify(&pdata->info);
 }
 
 /*
  * Callback from vmbus_event when channel is rescinded.
+ * It is meant for rescind of primary channels only.
  */
 static void hv_uio_rescind(struct vmbus_channel *channel)
 {
-	struct hv_device *hv_dev = channel->primary_channel->device_obj;
+	struct hv_device *hv_dev = channel->device_obj;
 	struct hv_uio_private_data *pdata = hv_get_drvdata(hv_dev);
 
 	/*
@@ -118,17 +141,22 @@ static void hv_uio_rescind(struct vmbus_channel *channel)
 
 	/* Wake up reader */
 	uio_event_notify(&pdata->info);
+
+	/*
+	 * With rescind callback registered, rescind path will not unregister the device
+	 * from vmbus when the primary channel is rescinded.
+	 * Without it, rescind handling is incomplete and next onoffer msg does not come.
+	 * Unregister the device from vmbus here.
+	 */
+	vmbus_device_unregister(channel->device_obj);
 }
 
-/* Sysfs API to allow mmap of the ring buffers
+/* Function used for mmap of ring buffer sysfs interface.
  * The ring buffer is allocated as contiguous memory by vmbus_open
  */
-static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj,
-			    struct bin_attribute *attr,
-			    struct vm_area_struct *vma)
+static int
+hv_uio_ring_mmap(struct vmbus_channel *channel, struct vm_area_struct *vma)
 {
-	struct vmbus_channel *channel
-		= container_of(kobj, struct vmbus_channel, kobj);
 	void *ring_buffer = page_address(channel->ringbuffer_page);
 
 	if (channel->state != CHANNEL_OPENED_STATE)
@@ -138,22 +166,13 @@ static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj,
 			       channel->ringbuffer_pagecount << PAGE_SHIFT);
 }
 
-static const struct bin_attribute ring_buffer_bin_attr = {
-	.attr = {
-		.name = "ring",
-		.mode = 0600,
-	},
-	.size = 2 * HV_RING_SIZE * PAGE_SIZE,
-	.mmap = hv_uio_ring_mmap,
-};
-
 /* Callback from VMBUS subsystem when new channel created. */
 static void
 hv_uio_new_channel(struct vmbus_channel *new_sc)
 {
 	struct hv_device *hv_dev = new_sc->primary_channel->device_obj;
 	struct device *device = &hv_dev->device;
-	const size_t ring_bytes = HV_RING_SIZE * PAGE_SIZE;
+	const size_t ring_bytes = SZ_2M;
 	int ret;
 
 	/* Create host communication ring */
@@ -167,8 +186,7 @@ hv_uio_new_channel(struct vmbus_channel *new_sc)
 	/* Disable interrupts on sub channel */
 	new_sc->inbound.ring_buffer->interrupt_mask = 1;
 	set_channel_read_mode(new_sc, HV_CALL_ISR);
-
-	ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr);
+	ret = hv_create_ring_sysfs(new_sc, hv_uio_ring_mmap);
 	if (ret) {
 		dev_err(device, "sysfs create ring bin file failed; %d\n", ret);
 		vmbus_close(new_sc);
@@ -240,19 +258,19 @@ hv_uio_probe(struct hv_device *dev,
 	struct hv_uio_private_data *pdata;
 	void *ring_buffer;
 	int ret;
+	size_t ring_size = hv_dev_ring_size(channel);
 
-	/* Communicating with host has to be via shared memory not hypercall */
-	if (!channel->offermsg.monitor_allocated) {
-		dev_err(&dev->device, "vmbus channel requires hypercall\n");
-		return -ENOTSUPP;
-	}
+	if (!ring_size)
+		ring_size = SZ_2M;
+
+	/* Adjust ring size if necessary to have it page aligned */
+	ring_size = VMBUS_RING_SIZE(ring_size);
 
 	pdata = devm_kzalloc(&dev->device, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
 
-	ret = vmbus_alloc_ring(channel, HV_RING_SIZE * PAGE_SIZE,
-			       HV_RING_SIZE * PAGE_SIZE);
+	ret = vmbus_alloc_ring(channel, ring_size, ring_size);
 	if (ret)
 		return ret;
 
@@ -279,60 +297,60 @@ hv_uio_probe(struct hv_device *dev,
 	pdata->info.mem[INT_PAGE_MAP].name = "int_page";
 	pdata->info.mem[INT_PAGE_MAP].addr
 		= (uintptr_t)vmbus_connection.int_page;
-	pdata->info.mem[INT_PAGE_MAP].size = PAGE_SIZE;
+	pdata->info.mem[INT_PAGE_MAP].size = HV_HYP_PAGE_SIZE;
 	pdata->info.mem[INT_PAGE_MAP].memtype = UIO_MEM_LOGICAL;
 
 	pdata->info.mem[MON_PAGE_MAP].name = "monitor_page";
 	pdata->info.mem[MON_PAGE_MAP].addr
 		= (uintptr_t)vmbus_connection.monitor_pages[1];
-	pdata->info.mem[MON_PAGE_MAP].size = PAGE_SIZE;
+	pdata->info.mem[MON_PAGE_MAP].size = HV_HYP_PAGE_SIZE;
 	pdata->info.mem[MON_PAGE_MAP].memtype = UIO_MEM_LOGICAL;
 
-	pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE);
-	if (pdata->recv_buf == NULL) {
-		ret = -ENOMEM;
-		goto fail_free_ring;
+	if (channel->device_id == HV_NIC) {
+		pdata->recv_buf = vzalloc(RECV_BUFFER_SIZE);
+		if (!pdata->recv_buf) {
+			ret = -ENOMEM;
+			goto fail_free_ring;
+		}
+
+		ret = vmbus_establish_gpadl(channel, pdata->recv_buf,
+					    RECV_BUFFER_SIZE, &pdata->recv_gpadl);
+		if (ret) {
+			if (!pdata->recv_gpadl.decrypted)
+				vfree(pdata->recv_buf);
+			goto fail_close;
+		}
+
+		/* put Global Physical Address Label in name */
+		snprintf(pdata->recv_name, sizeof(pdata->recv_name),
+			 "recv:%u", pdata->recv_gpadl.gpadl_handle);
+		pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name;
+		pdata->info.mem[RECV_BUF_MAP].addr = (uintptr_t)pdata->recv_buf;
+		pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE;
+		pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
+
+		pdata->send_buf = vzalloc(SEND_BUFFER_SIZE);
+		if (!pdata->send_buf) {
+			ret = -ENOMEM;
+			goto fail_close;
+		}
+
+		ret = vmbus_establish_gpadl(channel, pdata->send_buf,
+					    SEND_BUFFER_SIZE, &pdata->send_gpadl);
+		if (ret) {
+			if (!pdata->send_gpadl.decrypted)
+				vfree(pdata->send_buf);
+			goto fail_close;
+		}
+
+		snprintf(pdata->send_name, sizeof(pdata->send_name),
+			 "send:%u", pdata->send_gpadl.gpadl_handle);
+		pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name;
+		pdata->info.mem[SEND_BUF_MAP].addr = (uintptr_t)pdata->send_buf;
+		pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE;
+		pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
 	}
 
-	ret = vmbus_establish_gpadl(channel, pdata->recv_buf,
-				    RECV_BUFFER_SIZE, &pdata->recv_gpadl);
-	if (ret) {
-		if (!pdata->recv_gpadl.decrypted)
-			vfree(pdata->recv_buf);
-		goto fail_close;
-	}
-
-	/* put Global Physical Address Label in name */
-	snprintf(pdata->recv_name, sizeof(pdata->recv_name),
-		 "recv:%u", pdata->recv_gpadl.gpadl_handle);
-	pdata->info.mem[RECV_BUF_MAP].name = pdata->recv_name;
-	pdata->info.mem[RECV_BUF_MAP].addr
-		= (uintptr_t)pdata->recv_buf;
-	pdata->info.mem[RECV_BUF_MAP].size = RECV_BUFFER_SIZE;
-	pdata->info.mem[RECV_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
-
-	pdata->send_buf = vzalloc(SEND_BUFFER_SIZE);
-	if (pdata->send_buf == NULL) {
-		ret = -ENOMEM;
-		goto fail_close;
-	}
-
-	ret = vmbus_establish_gpadl(channel, pdata->send_buf,
-				    SEND_BUFFER_SIZE, &pdata->send_gpadl);
-	if (ret) {
-		if (!pdata->send_gpadl.decrypted)
-			vfree(pdata->send_buf);
-		goto fail_close;
-	}
-
-	snprintf(pdata->send_name, sizeof(pdata->send_name),
-		 "send:%u", pdata->send_gpadl.gpadl_handle);
-	pdata->info.mem[SEND_BUF_MAP].name = pdata->send_name;
-	pdata->info.mem[SEND_BUF_MAP].addr
-		= (uintptr_t)pdata->send_buf;
-	pdata->info.mem[SEND_BUF_MAP].size = SEND_BUFFER_SIZE;
-	pdata->info.mem[SEND_BUF_MAP].memtype = UIO_MEM_VIRTUAL;
-
 	pdata->info.priv = pdata;
 	pdata->device = dev;
 
@@ -342,10 +360,18 @@ hv_uio_probe(struct hv_device *dev,
 		goto fail_close;
 	}
 
-	ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr);
-	if (ret)
-		dev_notice(&dev->device,
-			   "sysfs create ring bin file failed; %d\n", ret);
+	/*
+	 * This internally calls sysfs_update_group, which returns a non-zero value if it executes
+	 * before sysfs_create_group. This is expected as the 'ring' will be created later in
+	 * vmbus_device_register() -> vmbus_add_channel_kobj(). Thus, no need to check the return
+	 * value and print warning.
+	 *
+	 * Creating/exposing sysfs in driver probe is not encouraged as it can lead to race
+	 * conditions with userspace. For backward compatibility, "ring" sysfs could not be removed
+	 * or decoupled from uio_hv_generic probe. Userspace programs can make use of inotify
+	 * APIs to make sure that ring is created.
+	 */
+	hv_create_ring_sysfs(channel, hv_uio_ring_mmap);
 
 	hv_set_drvdata(dev, pdata);
 
@@ -367,7 +393,7 @@ hv_uio_remove(struct hv_device *dev)
 	if (!pdata)
 		return;
 
-	sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr);
+	hv_remove_ring_sysfs(dev->channel);
 	uio_unregister_device(&pdata->info);
 	hv_uio_cleanup(dev, pdata);