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Drivers: hv: vmbus: Support a vmbus API for efficiently sending page arrays

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Currently, the API for sending a multi-page buffer over VMBUS is limited to
a maximum pfn array of MAX_MULTIPAGE_BUFFER_COUNT. This limitation is
not imposed by the host and unnecessarily limits the maximum payload
that can be sent. Implement an API that does not have this restriction.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
K. Y. Srinivasan 2015-01-09 23:54:34 -08:00 committed by Greg Kroah-Hartman
parent 9f52a16309
commit d61031ee8d
2 changed files with 75 additions and 0 deletions
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44
drivers/hv/channel.c
View File

@ -683,6 +683,50 @@ int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
}
EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
/*
* vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
* using a GPADL Direct packet type.
* The buffer includes the vmbus descriptor.
*/
int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
struct vmbus_packet_mpb_array *desc,
u32 desc_size,
void *buffer, u32 bufferlen, u64 requestid)
{
int ret;
u32 packetlen;
u32 packetlen_aligned;
struct kvec bufferlist[3];
u64 aligned_data = 0;
bool signal = false;
packetlen = desc_size + bufferlen;
packetlen_aligned = ALIGN(packetlen, sizeof(u64));
/* Setup the descriptor */
desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
desc->length8 = (u16)(packetlen_aligned >> 3);
desc->transactionid = requestid;
desc->rangecount = 1;
bufferlist[0].iov_base = desc;
bufferlist[0].iov_len = desc_size;
bufferlist[1].iov_base = buffer;
bufferlist[1].iov_len = bufferlen;
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
if (ret == 0 && signal)
vmbus_setevent(channel);
return ret;
}
EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
/*
* vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
* using a GPADL Direct packet type.

31
include/linux/hyperv.h
View File

@ -57,6 +57,18 @@ struct hv_multipage_buffer {
u64 pfn_array[MAX_MULTIPAGE_BUFFER_COUNT];
};
/*
* Multiple-page buffer array; the pfn array is variable size:
* The number of entries in the PFN array is determined by
* "len" and "offset".
*/
struct hv_mpb_array {
/* Length and Offset determines the # of pfns in the array */
u32 len;
u32 offset;
u64 pfn_array[];
};
/* 0x18 includes the proprietary packet header */
#define MAX_PAGE_BUFFER_PACKET (0x18 + \
(sizeof(struct hv_page_buffer) * \
@ -814,6 +826,18 @@ struct vmbus_channel_packet_multipage_buffer {
struct hv_multipage_buffer range;
} __packed;
/* The format must be the same as struct vmdata_gpa_direct */
struct vmbus_packet_mpb_array {
u16 type;
u16 dataoffset8;
u16 length8;
u16 flags;
u64 transactionid;
u32 reserved;
u32 rangecount; /* Always 1 in this case */
struct hv_mpb_array range;
} __packed;
extern int vmbus_open(struct vmbus_channel *channel,
u32 send_ringbuffersize,
@ -845,6 +869,13 @@ extern int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
u32 bufferlen,
u64 requestid);
extern int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
struct vmbus_packet_mpb_array *mpb,
u32 desc_size,
void *buffer,
u32 bufferlen,
u64 requestid);
extern int vmbus_establish_gpadl(struct vmbus_channel *channel,
void *kbuffer,
u32 size,