similar to: [PATCH] vhost: max s/g to match qemu

qemu supports up to UIO_MAXIOV s/g so we have to match that. Apparently windows guests rely on this (more precisely, they want to fill all of vq with s/g entries of a single descriptor). Allocate indirect and log arrays dynamically to avoid using too much contigious memory. hdr array is used to store the virtio header. Since each iovec entry has >= 1 byte length, we never need more than header

qemu supports up to UIO_MAXIOV s/g so we have to match that. Apparently windows guests rely on this (more precisely, they want to fill all of vq with s/g entries of a single descriptor). Allocate indirect and log arrays dynamically to avoid using too much contigious memory. hdr array is used to store the virtio header. Since each iovec entry has >= 1 byte length, we never need more than header

This patch generalizes buffer handling functions to support multiple buffer heads. In-line for viewing, attached for applying. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruN net-next-p0/drivers/vhost/net.c net-next-p1/drivers/vhost/net.c --- net-next-p0/drivers/vhost/net.c 2010-02-24 12:59:24.000000000 -0800 +++ net-next-p1/drivers/vhost/net.c 2010-03-01

This patch generalizes buffer handling functions to support multiple buffer heads. In-line for viewing, attached for applying. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruN net-next-p0/drivers/vhost/net.c net-next-p1/drivers/vhost/net.c --- net-next-p0/drivers/vhost/net.c 2010-02-24 12:59:24.000000000 -0800 +++ net-next-p1/drivers/vhost/net.c 2010-03-01

This patch adds the mergeable RX buffers feature to vhost. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-p0/drivers/vhost/net.c net-next-v4/drivers/vhost/net.c --- net-next-p0/drivers/vhost/net.c 2010-03-22 12:04:38.000000000 -0700 +++ net-next-v4/drivers/vhost/net.c 2010-04-19 14:23:38.000000000 -0700 @@ -108,7 +108,7 @@ static void handle_tx(struct

This patch adds the mergeable RX buffers feature to vhost. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-p0/drivers/vhost/net.c net-next-v4/drivers/vhost/net.c --- net-next-p0/drivers/vhost/net.c 2010-03-22 12:04:38.000000000 -0700 +++ net-next-v4/drivers/vhost/net.c 2010-04-19 14:23:38.000000000 -0700 @@ -108,7 +108,7 @@ static void handle_tx(struct

This patch adds mergeable receive buffers support to vhost. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-v0/drivers/vhost/net.c net-next-v5/drivers/vhost/net.c --- net-next-v0/drivers/vhost/net.c 2010-04-22 11:31:57.000000000 -0700 +++ net-next-v5/drivers/vhost/net.c 2010-04-22 12:41:17.000000000 -0700 @@ -109,7 +109,7 @@ static void handle_tx(struct

This patch adds mergeable receive buffers support to vhost. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-v0/drivers/vhost/net.c net-next-v5/drivers/vhost/net.c --- net-next-v0/drivers/vhost/net.c 2010-04-22 11:31:57.000000000 -0700 +++ net-next-v5/drivers/vhost/net.c 2010-04-22 12:41:17.000000000 -0700 @@ -109,7 +109,7 @@ static void handle_tx(struct

This patch adds mergeable receive buffer support to vhost_net. +-DLS Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-v0/drivers/vhost/net.c net-next-v6/drivers/vhost/net.c --- net-next-v0/drivers/vhost/net.c 2010-04-24 21:36:54.000000000 -0700 +++ net-next-v6/drivers/vhost/net.c 2010-04-26 01:13:04.000000000 -0700 @@ -109,7 +109,7 @@ static void

This patch adds mergeable receive buffer support to vhost_net. +-DLS Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-v0/drivers/vhost/net.c net-next-v6/drivers/vhost/net.c --- net-next-v0/drivers/vhost/net.c 2010-04-24 21:36:54.000000000 -0700 +++ net-next-v6/drivers/vhost/net.c 2010-04-26 01:13:04.000000000 -0700 @@ -109,7 +109,7 @@ static void

From: Shirley Ma <mashirle at us.ibm.com> This adds experimental zero copy support in vhost-net, disabled by default. To enable, set the zerocopytx module option to 1. This patch maintains the outstanding userspace buffers in the sequence it is delivered to vhost. The outstanding userspace buffers will be marked as done once the lower device buffers DMA has finished. This is monitored

From: Shirley Ma <mashirle at us.ibm.com> This adds experimental zero copy support in vhost-net, disabled by default. To enable, set the zerocopytx module option to 1. This patch maintains the outstanding userspace buffers in the sequence it is delivered to vhost. The outstanding userspace buffers will be marked as done once the lower device buffers DMA has finished. This is monitored

>From: Shirley Ma <mashirle at us.ibm.com> This adds experimental zero copy support in vhost-net, disabled by default. To enable, set experimental_zcopytx module option to 1. This patch maintains the outstanding userspace buffers in the sequence it is delivered to vhost. The outstanding userspace buffers will be marked as done once the lower device buffers DMA has finished. This is

>From: Shirley Ma <mashirle at us.ibm.com> This adds experimental zero copy support in vhost-net, disabled by default. To enable, set experimental_zcopytx module option to 1. This patch maintains the outstanding userspace buffers in the sequence it is delivered to vhost. The outstanding userspace buffers will be marked as done once the lower device buffers DMA has finished. This is

This patch adds vnet_hdr processing for mergeable buffer support to vhost-net. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruN net-next-p1/drivers/vhost/net.c net-next-p2/drivers/vhost/net.c --- net-next-p1/drivers/vhost/net.c 2010-03-01 11:44:22.000000000 -0800 +++ net-next-p2/drivers/vhost/net.c 2010-03-02 13:01:34.000000000 -0800 @@ -109,7 +109,6 @@

This patch adds vnet_hdr processing for mergeable buffer support to vhost-net. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruN net-next-p1/drivers/vhost/net.c net-next-p2/drivers/vhost/net.c --- net-next-p1/drivers/vhost/net.c 2010-03-01 11:44:22.000000000 -0800 +++ net-next-p2/drivers/vhost/net.c 2010-03-02 13:01:34.000000000 -0800 @@ -109,7 +109,6 @@

This patch adds support for the Mergeable Receive Buffers feature to vhost_net. +-DLS Changes from previous revision: 1) renamed: vhost_discard_vq_desc -> vhost_discard_desc vhost_get_heads -> vhost_get_desc_n vhost_get_vq_desc -> vhost_get_desc 2) added heads as argument to ghost_get_desc_n 3) changed "vq->heads" from iovec to vring_used_elem, removed casts 4)

This patch adds support for the Mergeable Receive Buffers feature to vhost_net. +-DLS Changes from previous revision: 1) renamed: vhost_discard_vq_desc -> vhost_discard_desc vhost_get_heads -> vhost_get_desc_n vhost_get_vq_desc -> vhost_get_desc 2) added heads as argument to ghost_get_desc_n 3) changed "vq->heads" from iovec to vring_used_elem, removed casts 4)

This patch adds mergeable receive buffer support to vhost_net. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-v0/drivers/vhost/net.c net-next-v7/drivers/vhost/net.c --- net-next-v0/drivers/vhost/net.c 2010-04-24 21:36:54.000000000 -0700 +++ net-next-v7/drivers/vhost/net.c 2010-04-28 12:26:18.000000000 -0700 @@ -74,6 +74,23 @@ static int move_iovec_hdr(struct

This patch adds mergeable receive buffer support to vhost_net. Signed-off-by: David L Stevens <dlstevens at us.ibm.com> diff -ruNp net-next-v0/drivers/vhost/net.c net-next-v7/drivers/vhost/net.c --- net-next-v0/drivers/vhost/net.c 2010-04-24 21:36:54.000000000 -0700 +++ net-next-v7/drivers/vhost/net.c 2010-04-28 12:26:18.000000000 -0700 @@ -74,6 +74,23 @@ static int move_iovec_hdr(struct