Drivers: hv: vmbus: Give control over how the ring access is serialized (fe760e4d) · Commits · 戴 / test

drivers/hv/channel.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -639,6 +639,7 @@ int vmbus_sendpacket_ctl(struct vmbus_channel channel, void buffer,
		u64 aligned_data = 0;
		int ret;
		bool signal = false;
		bool lock = channel->acquire_ring_lock;
		int num_vecs = ((bufferlen != 0) ? 3 : 1);


		@@ -658,7 +659,7 @@ int vmbus_sendpacket_ctl(struct vmbus_channel channel, void buffer,
		bufferlist[2].iov_len = (packetlen_aligned - packetlen);

		ret = hv_ringbuffer_write(&channel->outbound, bufferlist, num_vecs,
		&signal);
		&signal, lock);

		/*
		* Signalling the host is conditional on many factors:
		@@ -738,6 +739,7 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
		struct kvec bufferlist[3];
		u64 aligned_data = 0;
		bool signal = false;
		bool lock = channel->acquire_ring_lock;

		if (pagecount > MAX_PAGE_BUFFER_COUNT)
		return -EINVAL;
		@@ -774,7 +776,8 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
		bufferlist[2].iov_base = &aligned_data;
		bufferlist[2].iov_len = (packetlen_aligned - packetlen);

		ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
		ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
		&signal, lock);

		/*
		* Signalling the host is conditional on many factors:
		@@ -837,6 +840,7 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
		struct kvec bufferlist[3];
		u64 aligned_data = 0;
		bool signal = false;
		bool lock = channel->acquire_ring_lock;

		packetlen = desc_size + bufferlen;
		packetlen_aligned = ALIGN(packetlen, sizeof(u64));
		@@ -856,7 +860,8 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
		bufferlist[2].iov_base = &aligned_data;
		bufferlist[2].iov_len = (packetlen_aligned - packetlen);

		ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
		ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
		&signal, lock);

		if (ret == 0 && signal)
		vmbus_setevent(channel);
		@@ -881,6 +886,7 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
		struct kvec bufferlist[3];
		u64 aligned_data = 0;
		bool signal = false;
		bool lock = channel->acquire_ring_lock;
		u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
		multi_pagebuffer->len);

		@@ -919,7 +925,8 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
		bufferlist[2].iov_base = &aligned_data;
		bufferlist[2].iov_len = (packetlen_aligned - packetlen);

		ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
		ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
		&signal, lock);

		if (ret == 0 && signal)
		vmbus_setevent(channel);

drivers/hv/channel_mgmt.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -259,6 +259,7 @@ static struct vmbus_channel *alloc_channel(void)
		return NULL;

		channel->id = atomic_inc_return(&chan_num);
		channel->acquire_ring_lock = true;
		spin_lock_init(&channel->inbound_lock);
		spin_lock_init(&channel->lock);

drivers/hv/hyperv_vmbus.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -529,7 +529,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);

		int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info,
		struct kvec *kv_list,
		u32 kv_count, bool *signal);
		u32 kv_count, bool *signal, bool lock);

		int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
		void buffer, u32 buflen, u32 buffer_actual_len,

drivers/hv/ring_buffer.c

+8 −5

Original line number	Diff line number	Diff line
		@@ -314,7 +314,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)

		/* Write to the ring buffer. */
		int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
		struct kvec kv_list, u32 kv_count, bool signal)
		struct kvec kv_list, u32 kv_count, bool signal, bool lock)
		{
		int i = 0;
		u32 bytes_avail_towrite;
		@@ -324,13 +324,14 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
		u32 next_write_location;
		u32 old_write;
		u64 prev_indices = 0;
		unsigned long flags;
		unsigned long flags = 0;

		for (i = 0; i < kv_count; i++)
		totalbytes_towrite += kv_list[i].iov_len;

		totalbytes_towrite += sizeof(u64);

		if (lock)
		spin_lock_irqsave(&outring_info->ring_lock, flags);

		hv_get_ringbuffer_availbytes(outring_info,
		@@ -343,6 +344,7 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
		* is empty since the read index == write index.
		*/
		if (bytes_avail_towrite <= totalbytes_towrite) {
		if (lock)
		spin_unlock_irqrestore(&outring_info->ring_lock, flags);
		return -EAGAIN;
		}
		@@ -374,6 +376,7 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
		hv_set_next_write_location(outring_info, next_write_location);


		if (lock)
		spin_unlock_irqrestore(&outring_info->ring_lock, flags);

		*signal = hv_need_to_signal(old_write, outring_info);

include/linux/hyperv.h

+16 −0

Original line number	Diff line number	Diff line
		@@ -811,8 +811,24 @@ struct vmbus_channel {
		* signaling control.
		*/
		enum hv_signal_policy signal_policy;
		/*
		* On the channel send side, many of the VMBUS
		* device drivers explicity serialize access to the
		* outgoing ring buffer. Give more control to the
		* VMBUS device drivers in terms how to serialize
		* accesss to the outgoing ring buffer.
		* The default behavior will be to aquire the
		* ring lock to preserve the current behavior.
		*/
		bool acquire_ring_lock;

		};

		static inline void set_channel_lock_state(struct vmbus_channel *c, bool state)
		{
		c->acquire_ring_lock = state;
		}

		static inline bool is_hvsock_channel(const struct vmbus_channel *c)
		{
		return !!(c->offermsg.offer.chn_flags &

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