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authorWei Liu <wei.liu@kernel.org>2021-02-15 10:44:58 +0000
committerWei Liu <wei.liu@kernel.org>2021-02-15 10:49:11 +0000
commit3019270282a175defc02c8331786c73e082cd2a8 (patch)
tree13a9b1c1be5030db044227dc12ff0b074443326d /drivers/hv
parentfb5ef35165a37ca63ef0227657eabd06f0a39cf9 (diff)
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Revert "Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer"
This reverts commit a8c3209998afb5c4941b49e35b513cea9050cb4a. It is reported that the said commit caused regression in netvsc. Reported-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/channel.c9
-rw-r--r--drivers/hv/hv_fcopy.c1
-rw-r--r--drivers/hv/hv_kvp.c1
-rw-r--r--drivers/hv/hyperv_vmbus.h2
-rw-r--r--drivers/hv/ring_buffer.c82
5 files changed, 15 insertions, 80 deletions
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 9aa789e5f22b..0bd202de7960 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -597,15 +597,12 @@ static int __vmbus_open(struct vmbus_channel *newchannel,
newchannel->onchannel_callback = onchannelcallback;
newchannel->channel_callback_context = context;
- if (!newchannel->max_pkt_size)
- newchannel->max_pkt_size = VMBUS_DEFAULT_MAX_PKT_SIZE;
-
- err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages, 0);
+ err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages);
if (err)
goto error_clean_ring;
- err = hv_ringbuffer_init(&newchannel->inbound, &page[send_pages],
- recv_pages, newchannel->max_pkt_size);
+ err = hv_ringbuffer_init(&newchannel->inbound,
+ &page[send_pages], recv_pages);
if (err)
goto error_clean_ring;
diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c
index 660036da7449..59ce85e00a02 100644
--- a/drivers/hv/hv_fcopy.c
+++ b/drivers/hv/hv_fcopy.c
@@ -349,7 +349,6 @@ int hv_fcopy_init(struct hv_util_service *srv)
{
recv_buffer = srv->recv_buffer;
fcopy_transaction.recv_channel = srv->channel;
- fcopy_transaction.recv_channel->max_pkt_size = HV_HYP_PAGE_SIZE * 2;
/*
* When this driver loads, the user level daemon that
diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index c698592b83e4..b49962d312ce 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -757,7 +757,6 @@ hv_kvp_init(struct hv_util_service *srv)
{
recv_buffer = srv->recv_buffer;
kvp_transaction.recv_channel = srv->channel;
- kvp_transaction.recv_channel->max_pkt_size = HV_HYP_PAGE_SIZE * 4;
/*
* When this driver loads, the user level daemon that
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 42f3d9d123a1..9416e09ebd58 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -174,7 +174,7 @@ extern int hv_synic_cleanup(unsigned int cpu);
void hv_ringbuffer_pre_init(struct vmbus_channel *channel);
int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
- struct page *pages, u32 pagecnt, u32 max_pkt_size);
+ struct page *pages, u32 pagecnt);
void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 29e90477363a..35833d4d1a1d 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -190,7 +190,7 @@ void hv_ringbuffer_pre_init(struct vmbus_channel *channel)
/* Initialize the ring buffer. */
int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
- struct page *pages, u32 page_cnt, u32 max_pkt_size)
+ struct page *pages, u32 page_cnt)
{
int i;
struct page **pages_wraparound;
@@ -232,14 +232,6 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
sizeof(struct hv_ring_buffer);
ring_info->priv_read_index = 0;
- /* Initialize buffer that holds copies of incoming packets */
- if (max_pkt_size) {
- ring_info->pkt_buffer = kzalloc(max_pkt_size, GFP_KERNEL);
- if (!ring_info->pkt_buffer)
- return -ENOMEM;
- ring_info->pkt_buffer_size = max_pkt_size;
- }
-
spin_lock_init(&ring_info->ring_lock);
return 0;
@@ -252,9 +244,6 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
vunmap(ring_info->ring_buffer);
ring_info->ring_buffer = NULL;
mutex_unlock(&ring_info->ring_buffer_mutex);
-
- kfree(ring_info->pkt_buffer);
- ring_info->pkt_buffer_size = 0;
}
/* Write to the ring buffer. */
@@ -396,7 +385,7 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
memcpy(buffer, (const char *)desc + offset, packetlen);
/* Advance ring index to next packet descriptor */
- __hv_pkt_iter_next(channel, desc, true);
+ __hv_pkt_iter_next(channel, desc);
/* Notify host of update */
hv_pkt_iter_close(channel);
@@ -423,22 +412,6 @@ static u32 hv_pkt_iter_avail(const struct hv_ring_buffer_info *rbi)
}
/*
- * Get first vmbus packet without copying it out of the ring buffer
- */
-struct vmpacket_descriptor *hv_pkt_iter_first_raw(struct vmbus_channel *channel)
-{
- struct hv_ring_buffer_info *rbi = &channel->inbound;
-
- hv_debug_delay_test(channel, MESSAGE_DELAY);
-
- if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor))
- return NULL;
-
- return (struct vmpacket_descriptor *)(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
-}
-EXPORT_SYMBOL_GPL(hv_pkt_iter_first_raw);
-
-/*
* Get first vmbus packet from ring buffer after read_index
*
* If ring buffer is empty, returns NULL and no other action needed.
@@ -446,49 +419,17 @@ EXPORT_SYMBOL_GPL(hv_pkt_iter_first_raw);
struct vmpacket_descriptor *hv_pkt_iter_first(struct vmbus_channel *channel)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
- struct vmpacket_descriptor *desc, *desc_copy;
- u32 bytes_avail, pkt_len, pkt_offset;
+ struct vmpacket_descriptor *desc;
- desc = hv_pkt_iter_first_raw(channel);
- if (!desc)
+ hv_debug_delay_test(channel, MESSAGE_DELAY);
+ if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor))
return NULL;
- bytes_avail = min(rbi->pkt_buffer_size, hv_pkt_iter_avail(rbi));
-
- /*
- * Ensure the compiler does not use references to incoming Hyper-V values (which
- * could change at any moment) when reading local variables later in the code
- */
- pkt_len = READ_ONCE(desc->len8) << 3;
- pkt_offset = READ_ONCE(desc->offset8) << 3;
-
- /*
- * If pkt_len is invalid, set it to the smaller of hv_pkt_iter_avail() and
- * rbi->pkt_buffer_size
- */
- if (pkt_len < sizeof(struct vmpacket_descriptor) || pkt_len > bytes_avail)
- pkt_len = bytes_avail;
-
- /*
- * If pkt_offset is invalid, arbitrarily set it to
- * the size of vmpacket_descriptor
- */
- if (pkt_offset < sizeof(struct vmpacket_descriptor) || pkt_offset > pkt_len)
- pkt_offset = sizeof(struct vmpacket_descriptor);
-
- /* Copy the Hyper-V packet out of the ring buffer */
- desc_copy = (struct vmpacket_descriptor *)rbi->pkt_buffer;
- memcpy(desc_copy, desc, pkt_len);
-
- /*
- * Hyper-V could still change len8 and offset8 after the earlier read.
- * Ensure that desc_copy has legal values for len8 and offset8 that
- * are consistent with the copy we just made
- */
- desc_copy->len8 = pkt_len >> 3;
- desc_copy->offset8 = pkt_offset >> 3;
+ desc = hv_get_ring_buffer(rbi) + rbi->priv_read_index;
+ if (desc)
+ prefetch((char *)desc + (desc->len8 << 3));
- return desc_copy;
+ return desc;
}
EXPORT_SYMBOL_GPL(hv_pkt_iter_first);
@@ -500,8 +441,7 @@ EXPORT_SYMBOL_GPL(hv_pkt_iter_first);
*/
struct vmpacket_descriptor *
__hv_pkt_iter_next(struct vmbus_channel *channel,
- const struct vmpacket_descriptor *desc,
- bool copy)
+ const struct vmpacket_descriptor *desc)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
u32 packetlen = desc->len8 << 3;
@@ -514,7 +454,7 @@ __hv_pkt_iter_next(struct vmbus_channel *channel,
rbi->priv_read_index -= dsize;
/* more data? */
- return copy ? hv_pkt_iter_first(channel) : hv_pkt_iter_first_raw(channel);
+ return hv_pkt_iter_first(channel);
}
EXPORT_SYMBOL_GPL(__hv_pkt_iter_next);