Drivers: hv: vmbus: Support a vmbus API for efficiently sending page arrays
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>
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 476c685..259023a 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -57,6 +57,18 @@
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 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 @@
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,