Commit 061dc93e authored Sep 16, 2020 by Boqun Feng Committed by Wei Liu Sep 28, 2020

Driver: hv: util: Use VMBUS_RING_SIZE() for ringbuffer sizes



For a Hyper-V vmbus, the size of the ringbuffer has two requirements:

1) it has to take one PAGE_SIZE for the header

2) it has to be PAGE_SIZE aligned so that double-mapping can work

VMBUS_RING_SIZE() could calculate a correct ringbuffer size which
fulfills both requirements, therefore use it to make sure vmbus work
when PAGE_SIZE != HV_HYP_PAGE_SIZE (4K).

Note that since the argument for VMBUS_RING_SIZE() is the size of
payload (data part), so it will be minus 4k (the size of header when
PAGE_SIZE = 4k) than the original value to keep the ringbuffer total
size unchanged when PAGE_SIZE = 4k.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-11-boqun.feng@gmail.com


Signed-off-by: Wei Liu <wei.liu@kernel.org>

parent d02a2699

drivers/hv/hv_util.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -461,6 +461,9 @@ static void heartbeat_onchannelcallback(void *context)
		}
		}

		#define HV_UTIL_RING_SEND_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)
		#define HV_UTIL_RING_RECV_SIZE VMBUS_RING_SIZE(3 * HV_HYP_PAGE_SIZE)

		static int util_probe(struct hv_device *dev,
		const struct hv_vmbus_device_id *dev_id)
		{
		@@ -491,8 +494,8 @@ static int util_probe(struct hv_device *dev,

		hv_set_drvdata(dev, srv);

		ret = vmbus_open(dev->channel, 4 * HV_HYP_PAGE_SIZE,
		4 * HV_HYP_PAGE_SIZE, NULL, 0, srv->util_cb,
		ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
		HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
		dev->channel);
		if (ret)
		goto error;
		@@ -551,8 +554,8 @@ static int util_resume(struct hv_device *dev)
		return ret;
		}

		ret = vmbus_open(dev->channel, 4 * HV_HYP_PAGE_SIZE,
		4 * HV_HYP_PAGE_SIZE, NULL, 0, srv->util_cb,
		ret = vmbus_open(dev->channel, HV_UTIL_RING_SEND_SIZE,
		HV_UTIL_RING_RECV_SIZE, NULL, 0, srv->util_cb,
		dev->channel);
		return ret;
		}

Admin message