* Re: [RFC] act_cpu: redirect skb receiving to a special CPU.
From: Changli Gao @ 2010-06-05 13:26 UTC (permalink / raw)
To: hadi; +Cc: Eric Dumazet, David S. Miller, Tom Herbert, Linux Netdev List
In-Reply-To: <1275743224.3490.44.camel@bigi>
On Sat, Jun 5, 2010 at 9:07 PM, jamal <hadi@cyberus.ca> wrote:
> Changli,
>
> I like the idea..
>
> My preference would be to not change ingress qdisc to have queues.
ingress doesn't have any qdisc, but a class tree. The ingress_queue
will be sth. like this:
while (1) {
result = tc_classify(..., &res);
cl = ingress_find(res.classid, ...);
if (!cl->level)
break;
...
}
Then we can classify skbs in tree manner.
> The cpuid should be sufficient to map to a remote cpu queue, no?
It should be sufficient, but it isn't efficient. With map option, we
can use cls_flow to map traffic to classid, and use act_cpu map to map
classid to cpuid.
> Now, if you could represent each cpu as a netdevice, then we wouldnt
> need any change;-> And we could have multiple types of ways to redirect
> to cpus instead of just doing IPIs - example, ive always thought of
> sending over something like HT (I think it would be a lot cheaper).
I won't implement a new netdevice, but reuse the softnet. Even, I'll
reuse the enqueue_to_backlog() introduced by RPS, and of course, use
IPIs as RPS. Is there another way to trigger an IRQ of the remote CPU?
>
> I didnt queit understand the map OFFSET part. is this part of rfs?
>
No. As class IDs are started from 1, but CPU IDs are started from 0, I
need to minus/add a number from/to class IDs to map class IDs from CPU
IDs.
--
Regards,
Changli Gao(xiaosuo@gmail.com)
^ permalink raw reply
* Re: [PATCH] act_mirred: don't clone skb when skb isn't shared
From: jamal @ 2010-06-05 13:24 UTC (permalink / raw)
To: Changli Gao; +Cc: David S. Miller, netdev
In-Reply-To: <AANLkTikHqzIr-SjPZe-iiMPxVG9PRR9-0A9qeMwzfLYp@mail.gmail.com>
On Sat, 2010-06-05 at 21:07 +0800, Changli Gao wrote:
> Thanks. BTW: act_nat.c doesn't obey the following rule, and you plan
> to remove TC_MUNGED and TC_OK2MUNGE?
> 2) If you munge any packet thou shalt call pskb_expand_head in the case
> someone else is referencing the skb. After that you "own" the skb.
> You must also tell us if it is ok to munge the packet (TC_OK2MUNGE),
> this way any action downstream can stomp on the packet.
That rule still applies but it is upto the discretion of the action.
i.e if the act_nat thinks it is ok for others down the street to trample
on the packet, it should tell us so. Maybe i should change the wording
to use the word "may" in that 3rd sentence.
[I will kill (low prio) TC_OK2MUNGE but not TC_MUNGED.]
cheers,
jamal
^ permalink raw reply
* Re: [PATCH] act_mirred: don't clone skb when skb isn't shared
From: Changli Gao @ 2010-06-05 13:07 UTC (permalink / raw)
To: hadi; +Cc: David S. Miller, netdev
In-Reply-To: <1275742435.3490.31.camel@bigi>
On Sat, Jun 5, 2010 at 8:53 PM, jamal <hadi@cyberus.ca> wrote:
> On Fri, 2010-06-04 at 21:43 +0800, Changli Gao wrote:
>> don't clone skb when skb isn't shared
>>
>> When the tcf_action is TC_ACT_STOLEN, and the skb isn't shared, we don't need
>> to clone a new skb. As the skb will be freed after this function returns, we
>> can use it freely once we get a reference to it.
>
> It looks like a good optimization - but i am not a big fan of one-offs
> [because usability goes down and I am forced to explain it longer in the
> rules (refer to: Documentation/networking/tc-actions-env-rules.txt)]
Thanks. BTW: act_nat.c doesn't obey the following rule, and you plan
to remove TC_MUNGED and TC_OK2MUNGE?
2) If you munge any packet thou shalt call pskb_expand_head in the case
someone else is referencing the skb. After that you "own" the skb.
You must also tell us if it is ok to munge the packet (TC_OK2MUNGE),
this way any action downstream can stomp on the packet.
>
> How about you update skb_act_clone to take take the action code as well
> and do the check the if stolen/queued it does a skb_get otherwise it
> calls skb_clone?
>
Good idea. Thanks.
--
Regards,
Changli Gao(xiaosuo@gmail.com)
^ permalink raw reply
* Re: [RFC] act_cpu: redirect skb receiving to a special CPU.
From: jamal @ 2010-06-05 13:07 UTC (permalink / raw)
To: Changli Gao; +Cc: Eric Dumazet, David S. Miller, Tom Herbert, Linux Netdev List
In-Reply-To: <AANLkTikskTWJrULj2IKYhebxh9O_XTOMBy3i0wPY8thq@mail.gmail.com>
Changli,
I like the idea..
My preference would be to not change ingress qdisc to have queues.
The cpuid should be sufficient to map to a remote cpu queue, no?
Now, if you could represent each cpu as a netdevice, then we wouldnt
need any change;-> And we could have multiple types of ways to redirect
to cpus instead of just doing IPIs - example, ive always thought of
sending over something like HT (I think it would be a lot cheaper).
I didnt queit understand the map OFFSET part. is this part of rfs?
cheers,
jamal
On Sat, 2010-06-05 at 18:56 +0800, Changli Gao wrote:
> I am going to implement a CPU action, which can be used with ingress
> qdisc to redirect skb receiving to a special cpu. It is much like RPS,
> but more flexible:
>
> * choose the hash function with the help of cls_flow.c
> * pin special traffic to a dedicate CPU
> * weighted packets distributing
>
> act_cpu will use the function enqueue_to_backlog() supplied by RPS to
> redirect skb receiving, and have two kind paramter:
>
> * cpu CPUID - the ID of CPU, which handles this traffic
> * map OFFSET - map the mirror class ID to CPUID: CPUID = mirror class ID + CPUID
>
> sch_ingress will be enhanced to support class tree.
>
^ permalink raw reply
* Re: [PATCH] act_mirred: don't clone skb when skb isn't shared
From: jamal @ 2010-06-05 12:53 UTC (permalink / raw)
To: Changli Gao; +Cc: David S. Miller, netdev
In-Reply-To: <1275658990-15838-1-git-send-email-xiaosuo@gmail.com>
On Fri, 2010-06-04 at 21:43 +0800, Changli Gao wrote:
> don't clone skb when skb isn't shared
>
> When the tcf_action is TC_ACT_STOLEN, and the skb isn't shared, we don't need
> to clone a new skb. As the skb will be freed after this function returns, we
> can use it freely once we get a reference to it.
It looks like a good optimization - but i am not a big fan of one-offs
[because usability goes down and I am forced to explain it longer in the
rules (refer to: Documentation/networking/tc-actions-env-rules.txt)]
How about you update skb_act_clone to take take the action code as well
and do the check the if stolen/queued it does a skb_get otherwise it
calls skb_clone?
cheers,
jamal
^ permalink raw reply
* Re: [PATCH] r8169: fix random mdio_write failures
From: Francois Romieu @ 2010-06-05 12:41 UTC (permalink / raw)
To: Timo Teräs; +Cc: netdev, Edward Hsu, Hayes, davem
In-Reply-To: <1275733273-28321-1-git-send-email-timo.teras@iki.fi>
Timo Teräs <timo.teras@iki.fi> :
[...]
> diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
> index 217e709..03a8318 100644
> --- a/drivers/net/r8169.c
> +++ b/drivers/net/r8169.c
> @@ -559,6 +559,11 @@ static void mdio_write(void __iomem *ioaddr, int reg_addr, int value)
> break;
> udelay(25);
> }
> + /*
> + * Some configurations require a small delay even after the write
> + * completed indication or the next write might fail.
> + */
> + udelay(25);
Acked-off-by: Francois Romieu <romieu@fr.zoreil.com>
Good work.
I wonder if increasing the in-loop delay as well would help the write
succeed faster (or slower ?).
--
Ueimor
^ permalink raw reply
* Re: 2.6.32 and Multicast group membership
From: Mark Smith @ 2010-06-05 11:33 UTC (permalink / raw)
To: Mr. Berkley Shands; +Cc: Net Dev
In-Reply-To: <4C057DF4.3000305@exegy.com>
On Tue, 01 Jun 2010 16:39:00 -0500
"Mr. Berkley Shands" <bshands@exegy.com> wrote:
> starting in 2.6.32, my multicast connections stop getting data after
> 60-100 seconds.
> The identical user code works fine under 2.6.22 through 2.6.31.
>
> The NIC (an intel 82586) has two ports on the same subnet
> (eth0 at 172.16.21.55/24 and eth1 at 172.16.21.56/24)
>
> if (setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*)&req,
> sizeof(req)))
> {
> perror("setsockopt IP_ADD_MEMBERSHIP failed");
> ::exit(-1);
> }
>
> If I do ADD_MEMBERSHIP on just one of these interfaces, the sockets
> still get data.
> But if I join on both interfaces, one or both will stop getting packets
> after 60-100 seconds. Sniffing with tcpdump shows the Cisco layer 3 switch
> is not getting its responses back to keep the multicast group open.
While it could be a kernel change, that sounds like it might also be
related to IGMP snooping on the Cisco switch. Any changes made to that
recently?
> The HP layer 2 switch does not seem to care, it keeps the data flowing
> regardless
> of which physical port the join is executed on.
>
This is expected behaviour on a 'dumb' layer 2 switch i.e. one that
doesn't perform IGMP snooping and therefore doesn't suppress multicasts
towards end-nodes that aren't subscribed. That further suggests a
change on the Cisco.
FWIW, I'm having no trouble with IPv4 multicast under 2.6.33, plugged
into Cisco switch, with IGMP snooping, but not multicast suppression,
enabled.
> Changing IP_MULTICAST_ALL has no effect :-(
> Did I miss something? New code that I have to specify to keep the Cisco
> happy?
>
> tia
>
> Berkley
>
>
> --
>
> // E. F. Berkley Shands, MSc//
>
> ** Exegy Inc.**
>
> 349 Marshall Road, Suite 100
>
> St. Louis , MO 63119
>
> Direct: (314) 218-3600 X450
>
> Cell: (314) 303-2546
>
> Office: (314) 218-3600
>
> Fax: (314) 218-3601
>
>
>
> The Usual Disclaimer follows...
>
>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply
* [RFC] act_cpu: redirect skb receiving to a special CPU.
From: Changli Gao @ 2010-06-05 10:56 UTC (permalink / raw)
To: Eric Dumazet, David S. Miller, Tom Herbert, Jamal Hadi Salim
Cc: Linux Netdev List
I am going to implement a CPU action, which can be used with ingress
qdisc to redirect skb receiving to a special cpu. It is much like RPS,
but more flexible:
* choose the hash function with the help of cls_flow.c
* pin special traffic to a dedicate CPU
* weighted packets distributing
act_cpu will use the function enqueue_to_backlog() supplied by RPS to
redirect skb receiving, and have two kind paramter:
* cpu CPUID - the ID of CPU, which handles this traffic
* map OFFSET - map the mirror class ID to CPUID: CPUID = mirror class ID + CPUID
sch_ingress will be enhanced to support class tree.
--
Regards,
Changli Gao(xiaosuo@gmail.com)
^ permalink raw reply
* [PATCH] r8169: fix random mdio_write failures
From: Timo Teräs @ 2010-06-05 10:21 UTC (permalink / raw)
To: netdev; +Cc: Timo Teräs, françois romieu, Edward Hsu
In-Reply-To: <4C0A1736.9030209@iki.fi>
Some configurations need delay between the "write completed" indication
and new write to work reliably.
Realtek driver seems to use longer delay when polling the "write complete"
bit, so it waits long enough between writes with high probability (but
could probably break too). This patch adds a new udelay to make sure we
wait unconditionally some time after the write complete indication.
This caused a regression with XID 18000000 boards when the board specific
phy configuration writing many mdio registers was added in commit
2e955856ff (r8169: phy init for the 8169scd). Some of the configration
mdio writes would almost always fail, and depending on failure might leave
the PHY in non-working state.
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Cc: françois romieu <romieu@fr.zoreil.com>
Cc: Edward Hsu <edward_hsu@realtek.com.tw>
---
drivers/net/r8169.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index 217e709..03a8318 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -559,6 +559,11 @@ static void mdio_write(void __iomem *ioaddr, int reg_addr, int value)
break;
udelay(25);
}
+ /*
+ * Some configurations require a small delay even after the write
+ * completed indication or the next write might fail.
+ */
+ udelay(25);
}
static int mdio_read(void __iomem *ioaddr, int reg_addr)
--
1.7.0.4
^ permalink raw reply related
* [RFC PATCH v7 00/19] Provide a zero-copy method on KVM virtio-net.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike
In-Reply-To: <1275732899-5423-19-git-send-email-xiaohui.xin@intel.com>
We provide an zero-copy method which driver side may get external
buffers to DMA. Here external means driver don't use kernel space
to allocate skb buffers. Currently the external buffer can be from
guest virtio-net driver.
The idea is simple, just to pin the guest VM user space and then
let host NIC driver has the chance to directly DMA to it.
The patches are based on vhost-net backend driver. We add a device
which provides proto_ops as sendmsg/recvmsg to vhost-net to
send/recv directly to/from the NIC driver. KVM guest who use the
vhost-net backend may bind any ethX interface in the host side to
get copyless data transfer thru guest virtio-net frontend.
patch 01-13: net core changes.
patch 14-18: new device as interface to mantpulate external buffers.
patch 19: for vhost-net.
The guest virtio-net driver submits multiple requests thru vhost-net
backend driver to the kernel. And the requests are queued and then
completed after corresponding actions in h/w are done.
For read, user space buffers are dispensed to NIC driver for rx when
a page constructor API is invoked. Means NICs can allocate user buffers
from a page constructor. We add a hook in netif_receive_skb() function
to intercept the incoming packets, and notify the zero-copy device.
For write, the zero-copy deivce may allocates a new host skb and puts
payload on the skb_shinfo(skb)->frags, and copied the header to skb->data.
The request remains pending until the skb is transmitted by h/w.
Here, we have ever considered 2 ways to utilize the page constructor
API to dispense the user buffers.
One: Modify __alloc_skb() function a bit, it can only allocate a
structure of sk_buff, and the data pointer is pointing to a
user buffer which is coming from a page constructor API.
Then the shinfo of the skb is also from guest.
When packet is received from hardware, the skb->data is filled
directly by h/w. What we have done is in this way.
Pros: We can avoid any copy here.
Cons: Guest virtio-net driver needs to allocate skb as almost
the same method with the host NIC drivers, say the size
of netdev_alloc_skb() and the same reserved space in the
head of skb. Many NIC drivers are the same with guest and
ok for this. But some lastest NIC drivers reserves special
room in skb head. To deal with it, we suggest to provide
a method in guest virtio-net driver to ask for parameter
we interest from the NIC driver when we know which device
we have bind to do zero-copy. Then we ask guest to do so.
Two: Modify driver to get user buffer allocated from a page constructor
API(to substitute alloc_page()), the user buffer are used as payload
buffers and filled by h/w directly when packet is received. Driver
should associate the pages with skb (skb_shinfo(skb)->frags). For
the head buffer side, let host allocates skb, and h/w fills it.
After that, the data filled in host skb header will be copied into
guest header buffer which is submitted together with the payload buffer.
Pros: We could less care the way how guest or host allocates their
buffers.
Cons: We still need a bit copy here for the skb header.
We are not sure which way is the better here. This is the first thing we want
to get comments from the community. We wish the modification to the network
part will be generic which not used by vhost-net backend only, but a user
application may use it as well when the zero-copy device may provides async
read/write operations later.
We have got comments from Michael. And he said the first method will break
the compatiblity of virtio-net driver and may complicate the qemu live
migration. Currently, we tried to ignore the skb_reserve() if the device
is doing zero-copy. Then guest virtio-net driver wil not changed. So we now
continue to go with the first way.
But comments about the two ways are still appreicated.
We provide multiple submits and asynchronous notifiicaton to
vhost-net too.
Our goal is to improve the bandwidth and reduce the CPU usage.
Exact performance data will be provided later. But for simple
test with netperf, we found bindwidth up and CPU % up too,
but the bindwidth up ratio is much more than CPU % up ratio.
What we have not done yet:
packet split support
To support GRO
Performance tuning
what we have done in v1:
polish the RCU usage
deal with write logging in asynchroush mode in vhost
add notifier block for mp device
rename page_ctor to mp_port in netdevice.h to make it looks generic
add mp_dev_change_flags() for mp device to change NIC state
add CONIFG_VHOST_MPASSTHRU to limit the usage when module is not load
a small fix for missing dev_put when fail
using dynamic minor instead of static minor number
a __KERNEL__ protect to mp_get_sock()
what we have done in v2:
remove most of the RCU usage, since the ctor pointer is only
changed by BIND/UNBIND ioctl, and during that time, NIC will be
stopped to get good cleanup(all outstanding requests are finished),
so the ctor pointer cannot be raced into wrong situation.
Remove the struct vhost_notifier with struct kiocb.
Let vhost-net backend to alloc/free the kiocb and transfer them
via sendmsg/recvmsg.
use get_user_pages_fast() and set_page_dirty_lock() when read.
Add some comments for netdev_mp_port_prep() and handle_mpassthru().
what we have done in v3:
the async write logging is rewritten
a drafted synchronous write function for qemu live migration
a limit for locked pages from get_user_pages_fast() to prevent Dos
by using RLIMIT_MEMLOCK
what we have done in v4:
add iocb completion callback from vhost-net to queue iocb in mp device
replace vq->receiver by mp_sock_data_ready()
remove stuff in mp device which access structures from vhost-net
modify skb_reserve() to ignore host NIC driver reserved space
rebase to the latest vhost tree
split large patches into small pieces, especially for net core part.
what we have done in v5:
address Arnd Bergmann's comments
-remove IFF_MPASSTHRU_EXCL flag in mp device
-Add CONFIG_COMPAT macro
-remove mp_release ops
move dev_is_mpassthru() as inline func
fix a bug in memory relinquish
Apply to current git (2.6.34-rc6) tree.
what we have done in v6:
move create_iocb() out of page_dtor which may happen in interrupt context
-This remove the potential issues which lock called in interrupt context
make the cache used by mp, vhost as static, and created/destoryed during
modules init/exit functions.
-This makes multiple mp guest created at the same time.
what we have done in v7:
some cleanup prepared to suppprt PS mode
performance:
using netperf with GSO/TSO disabled, 10G NIC,
disabled packet split mode, with raw socket case compared to vhost.
bindwidth will be from 1.1Gbps to 1.7Gbps
CPU % from 120%-140% to 140%-160%
We have retested the performance based on 2.6.34-rc6 in above situtation.
BW CPU %
vhost 1.4Gbps 120% ~ 130%
vhost + zero-copy 2.7Gbps 160% ~ 180%
^ permalink raw reply
* [RFC PATCH v7 18/19] Add a kconfig entry and make entry for mp device.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-17-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
drivers/vhost/Kconfig | 10 ++++++++++
drivers/vhost/Makefile | 2 ++
2 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig
index e4e2fd1..a6b8cbf 100644
--- a/drivers/vhost/Kconfig
+++ b/drivers/vhost/Kconfig
@@ -9,3 +9,13 @@ config VHOST_NET
To compile this driver as a module, choose M here: the module will
be called vhost_net.
+config MEDIATE_PASSTHRU
+ tristate "mediate passthru network driver (EXPERIMENTAL)"
+ depends on VHOST_NET
+ ---help---
+ zerocopy network I/O support, we call it as mediate passthru to
+ be distiguish with hardare passthru.
+
+ To compile this driver as a module, choose M here: the module will
+ be called mpassthru.
+
diff --git a/drivers/vhost/Makefile b/drivers/vhost/Makefile
index 72dd020..c18b9fc 100644
--- a/drivers/vhost/Makefile
+++ b/drivers/vhost/Makefile
@@ -1,2 +1,4 @@
obj-$(CONFIG_VHOST_NET) += vhost_net.o
vhost_net-y := vhost.o net.o
+
+obj-$(CONFIG_MEDIATE_PASSTHRU) += mpassthru.o
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 16/19] Manipulate external buffers in mp device.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xiaohui Xin
In-Reply-To: <1275732899-5423-15-git-send-email-xiaohui.xin@intel.com>
From: Xiaohui Xin<xiaohui.xin@intel.com>
How external buffer comes from, how to destroy.
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
drivers/vhost/mpassthru.c | 253 ++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 251 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/mpassthru.c b/drivers/vhost/mpassthru.c
index 25e2f3e..8c48898 100644
--- a/drivers/vhost/mpassthru.c
+++ b/drivers/vhost/mpassthru.c
@@ -161,6 +161,39 @@ static int mp_dev_change_flags(struct net_device *dev, unsigned flags)
return ret;
}
+/* The main function to allocate external buffers */
+static struct skb_external_page *page_ctor(struct mpassthru_port *port,
+ struct sk_buff *skb, int npages)
+{
+ int i;
+ unsigned long flags;
+ struct page_ctor *ctor;
+ struct page_info *info = NULL;
+
+ ctor = container_of(port, struct page_ctor, port);
+
+ spin_lock_irqsave(&ctor->read_lock, flags);
+ if (!list_empty(&ctor->readq)) {
+ info = list_first_entry(&ctor->readq, struct page_info, list);
+ list_del(&info->list);
+ }
+ spin_unlock_irqrestore(&ctor->read_lock, flags);
+ if (!info)
+ return NULL;
+
+ for (i = 0; i < info->pnum; i++) {
+ get_page(info->pages[i]);
+ info->frag[i].page = info->pages[i];
+ info->frag[i].page_offset = i ? 0 : info->offset;
+ info->frag[i].size = port->npages > 1 ? PAGE_SIZE :
+ port->data_len;
+ }
+ info->skb = skb;
+ info->ext_page.frags = info->frag;
+ info->ext_page.ushinfo = &info->ushinfo;
+ return &info->ext_page;
+}
+
static int page_ctor_attach(struct mp_struct *mp)
{
int rc;
@@ -186,7 +219,7 @@ static int page_ctor_attach(struct mp_struct *mp)
dev_hold(dev);
ctor->dev = dev;
- ctor->port.ctor = NULL;
+ ctor->port.ctor = page_ctor;
ctor->port.sock = &mp->socket;
ctor->lock_pages = 0;
rc = netdev_mp_port_attach(dev, &ctor->port);
@@ -252,11 +285,66 @@ static int set_memlock_rlimit(struct page_ctor *ctor, int resource,
return 0;
}
+static void relinquish_resource(struct page_ctor *ctor)
+{
+ if (!(ctor->dev->flags & IFF_UP) &&
+ !(ctor->wq_len + ctor->rq_len))
+ printk(KERN_INFO "relinquish_resource\n");
+}
+
+static void mp_ki_dtor(struct kiocb *iocb)
+{
+ struct page_info *info = (struct page_info *)(iocb->private);
+ int i;
+
+ if (info->flags == INFO_READ) {
+ for (i = 0; i < info->pnum; i++) {
+ if (info->pages[i]) {
+ set_page_dirty_lock(info->pages[i]);
+ put_page(info->pages[i]);
+ }
+ }
+ info->skb->destructor = NULL;
+ kfree_skb(info->skb);
+ info->ctor->rq_len--;
+ } else
+ info->ctor->wq_len--;
+ /* Decrement the number of locked pages */
+ info->ctor->lock_pages -= info->pnum;
+ kmem_cache_free(ext_page_info_cache, info);
+ relinquish_resource(info->ctor);
+
+ return;
+}
+
+static struct kiocb *create_iocb(struct page_info *info, int size)
+{
+ struct kiocb *iocb = NULL;
+
+ iocb = info->iocb;
+ if (!iocb)
+ return iocb;
+ iocb->ki_flags = 0;
+ iocb->ki_users = 1;
+ iocb->ki_key = 0;
+ iocb->ki_ctx = NULL;
+ iocb->ki_cancel = NULL;
+ iocb->ki_retry = NULL;
+ iocb->ki_iovec = NULL;
+ iocb->ki_eventfd = NULL;
+ iocb->ki_pos = info->desc_pos;
+ iocb->ki_nbytes = size;
+ iocb->ki_dtor(iocb);
+ iocb->private = (void *)info;
+ iocb->ki_dtor = mp_ki_dtor;
+
+ return iocb;
+}
+
static int page_ctor_detach(struct mp_struct *mp)
{
struct page_ctor *ctor;
struct page_info *info;
- struct kiocb *iocb = NULL;
int i;
/* locked by mp_mutex */
@@ -268,11 +356,17 @@ static int page_ctor_detach(struct mp_struct *mp)
for (i = 0; i < info->pnum; i++)
if (info->pages[i])
put_page(info->pages[i]);
+ create_iocb(info, 0);
+ ctor->rq_len--;
kmem_cache_free(ext_page_info_cache, info);
}
+
+ relinquish_resource(ctor);
+
set_memlock_rlimit(ctor, RLIMIT_MEMLOCK,
ctor->o_rlim.rlim_cur,
ctor->o_rlim.rlim_max);
+
netdev_mp_port_detach(ctor->dev);
dev_put(ctor->dev);
@@ -320,6 +414,161 @@ static void mp_put(struct mp_file *mfile)
mp_detach(mfile->mp);
}
+/* The callback to destruct the external buffers or skb */
+static void page_dtor(struct skb_external_page *ext_page)
+{
+ struct page_info *info;
+ struct page_ctor *ctor;
+ struct sock *sk;
+ struct sk_buff *skb;
+ unsigned long flags;
+
+ if (!ext_page)
+ return;
+ info = container_of(ext_page, struct page_info, ext_page);
+ if (!info)
+ return;
+ ctor = info->ctor;
+ skb = info->skb;
+
+ if ((info->flags == INFO_READ) && info->skb)
+ info->skb->head = NULL;
+
+ /* If the info->total is 0, make it to be reused */
+ if (!info->total) {
+ spin_lock_irqsave(&ctor->read_lock, flags);
+ list_add(&info->list, &ctor->readq);
+ spin_unlock_irqrestore(&ctor->read_lock, flags);
+ return;
+ }
+
+ if (info->flags == INFO_READ)
+ return;
+
+ /* For transmit, we should wait for the DMA finish by hardware.
+ * Queue the notifier to wake up the backend driver
+ */
+
+ create_iocb(info, info->total);
+
+ sk = ctor->port.sock->sk;
+ sk->sk_write_space(sk);
+
+ return;
+}
+
+/* For small exteranl buffers transmit, we don't need to call
+ * get_user_pages().
+ */
+static struct page_info *alloc_small_page_info(struct page_ctor *ctor,
+ struct kiocb *iocb, int total)
+{
+ struct page_info *info =
+ kmem_cache_zalloc(ext_page_info_cache, GFP_KERNEL);
+
+ if (!info)
+ return NULL;
+ info->total = total;
+ info->ext_page.dtor = page_dtor;
+ info->ctor = ctor;
+ info->flags = INFO_WRITE;
+ info->iocb = iocb;
+ return info;
+}
+
+/* The main function to transform the guest user space address
+ * to host kernel address via get_user_pages(). Thus the hardware
+ * can do DMA directly to the external buffer address.
+ */
+static struct page_info *alloc_page_info(struct page_ctor *ctor,
+ struct kiocb *iocb, struct iovec *iov,
+ int count, struct frag *frags,
+ int npages, int total)
+{
+ int rc;
+ int i, j, n = 0;
+ int len;
+ unsigned long base, lock_limit;
+ struct page_info *info = NULL;
+
+ lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit >>= PAGE_SHIFT;
+
+ if (ctor->lock_pages + count > lock_limit && npages) {
+ printk(KERN_INFO "exceed the locked memory rlimit.");
+ return NULL;
+ }
+
+ info = kmem_cache_zalloc(ext_page_info_cache, GFP_KERNEL);
+
+ if (!info)
+ return NULL;
+
+ for (i = j = 0; i < count; i++) {
+ base = (unsigned long)iov[i].iov_base;
+ len = iov[i].iov_len;
+
+ if (!len)
+ continue;
+ n = ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
+
+ rc = get_user_pages_fast(base, n, npages ? 1 : 0,
+ &info->pages[j]);
+ if (rc != n)
+ goto failed;
+
+ while (n--) {
+ frags[j].offset = base & ~PAGE_MASK;
+ frags[j].size = min_t(int, len,
+ PAGE_SIZE - frags[j].offset);
+ len -= frags[j].size;
+ base += frags[j].size;
+ j++;
+ }
+ }
+
+#ifdef CONFIG_HIGHMEM
+ if (npages && !(dev->features & NETIF_F_HIGHDMA)) {
+ for (i = 0; i < j; i++) {
+ if (PageHighMem(info->pages[i]))
+ goto failed;
+ }
+ }
+#endif
+
+ info->total = total;
+ info->ext_page.dtor = page_dtor;
+ info->ctor = ctor;
+ info->pnum = j;
+ info->iocb = iocb;
+ if (!npages)
+ info->flags = INFO_WRITE;
+ if (info->flags == INFO_READ) {
+ info->ext_page.start = (u8 *)(((unsigned long)
+ (pfn_to_kaddr(page_to_pfn(info->pages[0]))) +
+ frags[0].offset));
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+ info->ext_page.size = SKB_DATA_ALIGN(
+ iov[0].iov_len + NET_IP_ALIGN + NET_SKB_PAD);
+#else
+ info->ext_page.size = SKB_DATA_ALIGN(
+ iov[0].iov_len + NET_IP_ALIGN + NET_SKB_PAD) -
+ NET_IP_ALIGN - NET_SKB_PAD;
+#endif
+ }
+ /* increment the number of locked pages */
+ ctor->lock_pages += j;
+ return info;
+
+failed:
+ for (i = 0; i < j; i++)
+ put_page(info->pages[i]);
+
+ kmem_cache_free(ext_page_info_cache, info);
+
+ return NULL;
+}
+
/* Ops structure to mimic raw sockets with mp device */
static const struct proto_ops mp_socket_ops = {
};
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 15/19] Add basic funcs and ioctl to mp device.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-14-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
The ioctl is used by mp device to bind an underlying
NIC, it will query hardware capability and declare the
NIC to use external buffers.
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
memory leak fixed,
kconfig made,
do_unbind() made,
mp_chr_ioctl() cleanup
by Jeff Dike <jdike@linux.intel.com>
drivers/vhost/mpassthru.c | 681 +++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 681 insertions(+), 0 deletions(-)
create mode 100644 drivers/vhost/mpassthru.c
diff --git a/drivers/vhost/mpassthru.c b/drivers/vhost/mpassthru.c
new file mode 100644
index 0000000..25e2f3e
--- /dev/null
+++ b/drivers/vhost/mpassthru.c
@@ -0,0 +1,681 @@
+/*
+ * MPASSTHRU - Mediate passthrough device.
+ * Copyright (C) 2009 ZhaoYu, XinXiaohui, Dike, Jeffery G
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#define DRV_NAME "mpassthru"
+#define DRV_DESCRIPTION "Mediate passthru device driver"
+#define DRV_COPYRIGHT "(C) 2009 ZhaoYu, XinXiaohui, Dike, Jeffery G"
+
+#include <linux/compat.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/poll.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/aio.h>
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/miscdevice.h>
+#include <linux/ethtool.h>
+#include <linux/rtnetlink.h>
+#include <linux/if.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/crc32.h>
+#include <linux/nsproxy.h>
+#include <linux/uaccess.h>
+#include <linux/virtio_net.h>
+#include <linux/mpassthru.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/rtnetlink.h>
+#include <net/sock.h>
+
+#include <asm/system.h>
+
+/* Uncomment to enable debugging */
+/* #define MPASSTHRU_DEBUG 1 */
+
+#ifdef MPASSTHRU_DEBUG
+static int debug;
+
+#define DBG if (mp->debug) printk
+#define DBG1 if (debug == 2) printk
+#else
+#define DBG(a...)
+#define DBG1(a...)
+#endif
+
+#define COPY_THRESHOLD (L1_CACHE_BYTES * 4)
+#define COPY_HDR_LEN (L1_CACHE_BYTES < 64 ? 64 : L1_CACHE_BYTES)
+
+struct frag {
+ u16 offset;
+ u16 size;
+};
+
+struct page_info {
+ struct list_head list;
+ int header;
+ /* indicate the actual length of bytes
+ * send/recv in the external buffers
+ */
+ int total;
+ int offset;
+ struct page *pages[MAX_SKB_FRAGS+1];
+ struct skb_frag_struct frag[MAX_SKB_FRAGS+1];
+ struct sk_buff *skb;
+ struct page_ctor *ctor;
+
+ /* The pointer relayed to skb, to indicate
+ * it's a external allocated skb or kernel
+ */
+ struct skb_external_page ext_page;
+ struct skb_shared_info ushinfo;
+
+#define INFO_READ 0
+#define INFO_WRITE 1
+ unsigned flags;
+ unsigned pnum;
+
+ /* It's meaningful for receive, means
+ * the max length allowed
+ */
+ size_t len;
+
+ /* The fields after that is for backend
+ * driver, now for vhost-net.
+ */
+
+ struct kiocb *iocb;
+ unsigned int desc_pos;
+ struct iovec hdr[MAX_SKB_FRAGS + 2];
+ struct iovec iov[MAX_SKB_FRAGS + 2];
+};
+
+static struct kmem_cache *ext_page_info_cache;
+
+struct page_ctor {
+ struct list_head readq;
+ int wq_len;
+ int rq_len;
+ spinlock_t read_lock;
+ /* record the locked pages */
+ int lock_pages;
+ struct rlimit o_rlim;
+ struct net_device *dev;
+ struct mpassthru_port port;
+};
+
+struct mp_struct {
+ struct mp_file *mfile;
+ struct net_device *dev;
+ struct page_ctor *ctor;
+ struct socket socket;
+
+#ifdef MPASSTHRU_DEBUG
+ int debug;
+#endif
+};
+
+struct mp_file {
+ atomic_t count;
+ struct mp_struct *mp;
+ struct net *net;
+};
+
+struct mp_sock {
+ struct sock sk;
+ struct mp_struct *mp;
+};
+
+static int mp_dev_change_flags(struct net_device *dev, unsigned flags)
+{
+ int ret = 0;
+
+ rtnl_lock();
+ ret = dev_change_flags(dev, flags);
+ rtnl_unlock();
+
+ if (ret < 0)
+ printk(KERN_ERR "failed to change dev state of %s", dev->name);
+
+ return ret;
+}
+
+static int page_ctor_attach(struct mp_struct *mp)
+{
+ int rc;
+ struct page_ctor *ctor;
+ struct net_device *dev = mp->dev;
+
+ /* locked by mp_mutex */
+ if (rcu_dereference(mp->ctor))
+ return -EBUSY;
+
+ ctor = kzalloc(sizeof(*ctor), GFP_KERNEL);
+ if (!ctor)
+ return -ENOMEM;
+ rc = netdev_mp_port_prep(dev, &ctor->port);
+ if (rc)
+ goto fail;
+
+ INIT_LIST_HEAD(&ctor->readq);
+ spin_lock_init(&ctor->read_lock);
+
+ ctor->rq_len = 0;
+ ctor->wq_len = 0;
+
+ dev_hold(dev);
+ ctor->dev = dev;
+ ctor->port.ctor = NULL;
+ ctor->port.sock = &mp->socket;
+ ctor->lock_pages = 0;
+ rc = netdev_mp_port_attach(dev, &ctor->port);
+ if (rc)
+ goto fail;
+
+ /* locked by mp_mutex */
+ rcu_assign_pointer(mp->ctor, ctor);
+
+ /* XXX:Need we do set_offload here ? */
+
+ return 0;
+
+fail:
+ kfree(ctor);
+ dev_put(dev);
+
+ return rc;
+}
+
+struct page_info *info_dequeue(struct page_ctor *ctor)
+{
+ unsigned long flags;
+ struct page_info *info = NULL;
+ spin_lock_irqsave(&ctor->read_lock, flags);
+ if (!list_empty(&ctor->readq)) {
+ info = list_first_entry(&ctor->readq,
+ struct page_info, list);
+ list_del(&info->list);
+ }
+ spin_unlock_irqrestore(&ctor->read_lock, flags);
+ return info;
+}
+
+static int set_memlock_rlimit(struct page_ctor *ctor, int resource,
+ unsigned long cur, unsigned long max)
+{
+ struct rlimit new_rlim, *old_rlim;
+ int retval;
+
+ if (resource != RLIMIT_MEMLOCK)
+ return -EINVAL;
+ new_rlim.rlim_cur = cur;
+ new_rlim.rlim_max = max;
+
+ old_rlim = current->signal->rlim + resource;
+
+ /* remember the old rlimit value when backend enabled */
+ ctor->o_rlim.rlim_cur = old_rlim->rlim_cur;
+ ctor->o_rlim.rlim_max = old_rlim->rlim_max;
+
+ if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
+ !capable(CAP_SYS_RESOURCE))
+ return -EPERM;
+
+ retval = security_task_setrlimit(resource, &new_rlim);
+ if (retval)
+ return retval;
+
+ task_lock(current->group_leader);
+ *old_rlim = new_rlim;
+ task_unlock(current->group_leader);
+ return 0;
+}
+
+static int page_ctor_detach(struct mp_struct *mp)
+{
+ struct page_ctor *ctor;
+ struct page_info *info;
+ struct kiocb *iocb = NULL;
+ int i;
+
+ /* locked by mp_mutex */
+ ctor = rcu_dereference(mp->ctor);
+ if (!ctor)
+ return -ENODEV;
+
+ while ((info = info_dequeue(ctor))) {
+ for (i = 0; i < info->pnum; i++)
+ if (info->pages[i])
+ put_page(info->pages[i]);
+ kmem_cache_free(ext_page_info_cache, info);
+ }
+ set_memlock_rlimit(ctor, RLIMIT_MEMLOCK,
+ ctor->o_rlim.rlim_cur,
+ ctor->o_rlim.rlim_max);
+ netdev_mp_port_detach(ctor->dev);
+ dev_put(ctor->dev);
+
+ /* locked by mp_mutex */
+ rcu_assign_pointer(mp->ctor, NULL);
+ synchronize_rcu();
+
+ kfree(ctor);
+ return 0;
+}
+
+static void __mp_detach(struct mp_struct *mp)
+{
+ mp->mfile = NULL;
+
+ mp_dev_change_flags(mp->dev, mp->dev->flags & ~IFF_UP);
+ page_ctor_detach(mp);
+ mp_dev_change_flags(mp->dev, mp->dev->flags | IFF_UP);
+
+ /* Drop the extra count on the net device */
+ dev_put(mp->dev);
+}
+
+static DEFINE_MUTEX(mp_mutex);
+
+static void mp_detach(struct mp_struct *mp)
+{
+ mutex_lock(&mp_mutex);
+ __mp_detach(mp);
+ mutex_unlock(&mp_mutex);
+}
+
+static struct mp_struct *mp_get(struct mp_file *mfile)
+{
+ struct mp_struct *mp = NULL;
+ if (atomic_inc_not_zero(&mfile->count))
+ mp = mfile->mp;
+
+ return mp;
+}
+
+static void mp_put(struct mp_file *mfile)
+{
+ if (atomic_dec_and_test(&mfile->count))
+ mp_detach(mfile->mp);
+}
+
+/* Ops structure to mimic raw sockets with mp device */
+static const struct proto_ops mp_socket_ops = {
+};
+
+static struct proto mp_proto = {
+ .name = "mp",
+ .owner = THIS_MODULE,
+ .obj_size = sizeof(struct mp_sock),
+};
+
+static int mp_chr_open(struct inode *inode, struct file * file)
+{
+ struct mp_file *mfile;
+ cycle_kernel_lock();
+ DBG1(KERN_INFO "mp: mp_chr_open\n");
+
+ mfile = kzalloc(sizeof(*mfile), GFP_KERNEL);
+ if (!mfile)
+ return -ENOMEM;
+ atomic_set(&mfile->count, 0);
+ mfile->mp = NULL;
+ mfile->net = get_net(current->nsproxy->net_ns);
+ file->private_data = mfile;
+ return 0;
+}
+
+static int mp_attach(struct mp_struct *mp, struct file *file)
+{
+ struct mp_file *mfile = file->private_data;
+ int err;
+
+ netif_tx_lock_bh(mp->dev);
+
+ err = -EINVAL;
+
+ if (mfile->mp)
+ goto out;
+
+ err = -EBUSY;
+ if (mp->mfile)
+ goto out;
+
+ err = 0;
+ mfile->mp = mp;
+ mp->mfile = mfile;
+ mp->socket.file = file;
+ dev_hold(mp->dev);
+ sock_hold(mp->socket.sk);
+ atomic_inc(&mfile->count);
+
+out:
+ netif_tx_unlock_bh(mp->dev);
+ return err;
+}
+
+static int do_unbind(struct mp_file *mfile)
+{
+ struct mp_struct *mp = mp_get(mfile);
+
+ if (!mp)
+ return -EINVAL;
+
+ mp_detach(mp);
+ sock_put(mp->socket.sk);
+ mp_put(mfile);
+ return 0;
+}
+
+static long mp_chr_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct mp_file *mfile = file->private_data;
+ struct mp_struct *mp;
+ struct net_device *dev;
+ void __user* argp = (void __user *)arg;
+ struct ifreq ifr;
+ struct sock *sk;
+ int ret;
+
+ ret = -EINVAL;
+
+ switch (cmd) {
+ case MPASSTHRU_BINDDEV:
+ ret = -EFAULT;
+ if (copy_from_user(&ifr, argp, sizeof ifr))
+ break;
+
+ ifr.ifr_name[IFNAMSIZ-1] = '\0';
+
+ ret = -ENODEV;
+ dev = dev_get_by_name(mfile->net, ifr.ifr_name);
+ if (!dev)
+ break;
+
+ mutex_lock(&mp_mutex);
+
+ ret = -EBUSY;
+
+ /* the device can be only bind once */
+ if (dev_is_mpassthru(dev))
+ goto err_dev_put;
+
+ mp = mfile->mp;
+ if (mp)
+ goto err_dev_put;
+
+ mp = kzalloc(sizeof(*mp), GFP_KERNEL);
+ if (!mp) {
+ ret = -ENOMEM;
+ goto err_dev_put;
+ }
+ mp->dev = dev;
+ ret = -ENOMEM;
+
+ sk = sk_alloc(mfile->net, AF_UNSPEC, GFP_KERNEL, &mp_proto);
+ if (!sk)
+ goto err_free_mp;
+
+ init_waitqueue_head(&mp->socket.wait);
+ mp->socket.ops = &mp_socket_ops;
+ sock_init_data(&mp->socket, sk);
+ sk->sk_sndbuf = INT_MAX;
+ container_of(sk, struct mp_sock, sk)->mp = mp;
+
+ sk->sk_destruct = NULL;
+ sk->sk_data_ready = NULL;
+ sk->sk_write_space = NULL;
+ sk->sk_state_change = NULL;
+ ret = mp_attach(mp, file);
+ if (ret < 0)
+ goto err_free_sk;
+
+ ret = page_ctor_attach(mp);
+ if (ret < 0)
+ goto err_free_sk;
+
+ mp_dev_change_flags(mp->dev, mp->dev->flags | IFF_UP);
+out:
+ mutex_unlock(&mp_mutex);
+ break;
+err_free_sk:
+ sk_free(sk);
+err_free_mp:
+ kfree(mp);
+err_dev_put:
+ dev_put(dev);
+ goto out;
+
+ case MPASSTHRU_UNBINDDEV:
+ ret = do_unbind(mfile);
+ break;
+
+ default:
+ break;
+ }
+ return ret;
+}
+
+static unsigned int mp_chr_poll(struct file *file, poll_table * wait)
+{
+ struct mp_file *mfile = file->private_data;
+ struct mp_struct *mp = mp_get(mfile);
+ struct sock *sk;
+ unsigned int mask = 0;
+
+ if (!mp)
+ return POLLERR;
+
+ sk = mp->socket.sk;
+
+ poll_wait(file, &mp->socket.wait, wait);
+
+ if (!skb_queue_empty(&sk->sk_receive_queue))
+ mask |= POLLIN | POLLRDNORM;
+
+ if (sock_writeable(sk) ||
+ (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
+ sock_writeable(sk)))
+ mask |= POLLOUT | POLLWRNORM;
+
+ if (mp->dev->reg_state != NETREG_REGISTERED)
+ mask = POLLERR;
+
+ mp_put(mfile);
+ return mask;
+}
+
+static ssize_t mp_chr_aio_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long count, loff_t pos)
+{
+ struct file *file = iocb->ki_filp;
+ struct mp_struct *mp = mp_get(file->private_data);
+ struct sock *sk = mp->socket.sk;
+ struct sk_buff *skb;
+ int len, err;
+ ssize_t result = 0;
+
+ if (!mp)
+ return -EBADFD;
+
+ /* currently, async is not supported.
+ * but we may support real async aio from user application,
+ * maybe qemu virtio-net backend.
+ */
+ if (!is_sync_kiocb(iocb))
+ return -EFAULT;
+
+ len = iov_length(iov, count);
+
+ if (unlikely(len) < ETH_HLEN)
+ return -EINVAL;
+
+ skb = sock_alloc_send_skb(sk, len + NET_IP_ALIGN,
+ file->f_flags & O_NONBLOCK, &err);
+
+ if (!skb)
+ return -EFAULT;
+
+ skb_reserve(skb, NET_IP_ALIGN);
+ skb_put(skb, len);
+
+ if (skb_copy_datagram_from_iovec(skb, 0, iov, 0, len)) {
+ kfree_skb(skb);
+ return -EAGAIN;
+ }
+
+ skb->protocol = eth_type_trans(skb, mp->dev);
+ skb->dev = mp->dev;
+
+ dev_queue_xmit(skb);
+
+ mp_put(file->private_data);
+ return result;
+}
+
+static int mp_chr_close(struct inode *inode, struct file *file)
+{
+ struct mp_file *mfile = file->private_data;
+
+ /*
+ * Ignore return value since an error only means there was nothing to
+ * do
+ */
+ do_unbind(mfile);
+
+ put_net(mfile->net);
+ kfree(mfile);
+
+ return 0;
+}
+
+#ifdef CONFIG_COMPAT
+static long mp_chr_compat_ioctl(struct file *f, unsigned int ioctl,
+ unsigned long arg)
+{
+ return mp_chr_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+static const struct file_operations mp_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = do_sync_write,
+ .aio_write = mp_chr_aio_write,
+ .poll = mp_chr_poll,
+ .unlocked_ioctl = mp_chr_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = mp_chr_compat_ioctl,
+#endif
+ .open = mp_chr_open,
+ .release = mp_chr_close,
+};
+
+static struct miscdevice mp_miscdev = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "mp",
+ .nodename = "net/mp",
+ .fops = &mp_fops,
+};
+
+static int mp_device_event(struct notifier_block *unused,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = ptr;
+ struct mpassthru_port *port;
+ struct mp_struct *mp = NULL;
+ struct socket *sock = NULL;
+
+ port = dev->mp_port;
+ if (port == NULL)
+ return NOTIFY_DONE;
+
+ switch (event) {
+ case NETDEV_UNREGISTER:
+ sock = dev->mp_port->sock;
+ mp = container_of(sock->sk, struct mp_sock, sk)->mp;
+ do_unbind(mp->mfile);
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block mp_notifier_block __read_mostly = {
+ .notifier_call = mp_device_event,
+};
+
+static int mp_init(void)
+{
+ int err = 0;
+
+ ext_page_info_cache = kmem_cache_create("skb_page_info",
+ sizeof(struct page_info),
+ 0, SLAB_HWCACHE_ALIGN, NULL);
+ if (!ext_page_info_cache)
+ return -ENOMEM;
+
+ err = misc_register(&mp_miscdev);
+ if (err) {
+ printk(KERN_ERR "mp: Can't register misc device\n");
+ kmem_cache_destroy(ext_page_info_cache);
+ } else {
+ printk(KERN_INFO "Registering mp misc device - minor = %d\n",
+ mp_miscdev.minor);
+ register_netdevice_notifier(&mp_notifier_block);
+ }
+ return err;
+}
+
+void mp_exit(void)
+{
+ unregister_netdevice_notifier(&mp_notifier_block);
+ misc_deregister(&mp_miscdev);
+ kmem_cache_destroy(ext_page_info_cache);
+}
+
+/* Get an underlying socket object from mp file. Returns error unless file is
+ * attached to a device. The returned object works like a packet socket, it
+ * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
+ * holding a reference to the file for as long as the socket is in use. */
+struct socket *mp_get_socket(struct file *file)
+{
+ struct mp_file *mfile = file->private_data;
+ struct mp_struct *mp;
+
+ if (file->f_op != &mp_fops)
+ return ERR_PTR(-EINVAL);
+ mp = mp_get(mfile);
+ if (!mp)
+ return ERR_PTR(-EBADFD);
+ mp_put(mfile);
+ return &mp->socket;
+}
+EXPORT_SYMBOL_GPL(mp_get_socket);
+
+module_init(mp_init);
+module_exit(mp_exit);
+MODULE_AUTHOR(DRV_COPYRIGHT);
+MODULE_DESCRIPTION(DRV_DESCRIPTION);
+MODULE_LICENSE("GPL v2");
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 13/19] To skip GRO if buffer is external currently.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-12-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
net/core/dev.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index dc2f225..6c6b2fe 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2787,6 +2787,10 @@ enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
if (skb_is_gso(skb) || skb_has_frags(skb))
goto normal;
+ /* currently GRO is not supported by mediate passthru */
+ if (dev_is_mpassthru(skb->dev))
+ goto normal;
+
rcu_read_lock();
list_for_each_entry_rcu(ptype, head, list) {
if (ptype->type != type || ptype->dev || !ptype->gro_receive)
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 12/19] Add a hook to intercept external buffers from NIC driver.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-11-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
The hook is called in netif_receive_skb().
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
net/core/dev.c | 35 +++++++++++++++++++++++++++++++++++
1 files changed, 35 insertions(+), 0 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index 37b389a..dc2f225 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2548,6 +2548,37 @@ err:
EXPORT_SYMBOL(netdev_mp_port_prep);
#endif
+#if defined(CONFIG_MEDIATE_PASSTHRU) || defined(CONFIG_MEDIATE_PASSTHRU_MODULE)
+/* Add a hook to intercept mediate passthru(zero-copy) packets,
+ * and insert it to the socket queue owned by mp_port specially.
+ */
+static inline struct sk_buff *handle_mpassthru(struct sk_buff *skb,
+ struct packet_type **pt_prev,
+ int *ret,
+ struct net_device *orig_dev)
+{
+ struct mpassthru_port *mp_port = NULL;
+ struct sock *sk = NULL;
+
+ if (!dev_is_mpassthru(skb->dev))
+ return skb;
+ mp_port = skb->dev->mp_port;
+
+ if (*pt_prev) {
+ *ret = deliver_skb(skb, *pt_prev, orig_dev);
+ *pt_prev = NULL;
+ }
+
+ sk = mp_port->sock->sk;
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_state_change(sk);
+
+ return NULL;
+}
+#else
+#define handle_mpassthru(skb, pt_prev, ret, orig_dev) (skb)
+#endif
+
/**
* netif_receive_skb - process receive buffer from network
* @skb: buffer to process
@@ -2629,6 +2660,10 @@ int netif_receive_skb(struct sk_buff *skb)
ncls:
#endif
+ /* To intercept mediate passthru(zero-copy) packets here */
+ skb = handle_mpassthru(skb, &pt_prev, &ret, orig_dev);
+ if (!skb)
+ goto out;
skb = handle_bridge(skb, &pt_prev, &ret, orig_dev);
if (!skb)
goto out;
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 11/19] Use callback to deal with skb_release_data() specially.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-10-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
If buffer is external, then use the callback to destruct
buffers.
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
net/core/skbuff.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 37587f0..418457c 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -385,6 +385,11 @@ static void skb_clone_fraglist(struct sk_buff *skb)
static void skb_release_data(struct sk_buff *skb)
{
+ /* check if the skb has external buffers, we have use destructor_arg
+ * here to indicate
+ */
+ struct skb_external_page *ext_page = skb_shinfo(skb)->destructor_arg;
+
if (!skb->cloned ||
!atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1,
&skb_shinfo(skb)->dataref)) {
@@ -397,6 +402,12 @@ static void skb_release_data(struct sk_buff *skb)
if (skb_has_frags(skb))
skb_drop_fraglist(skb);
+ /* if the skb has external buffers, use destructor here,
+ * since after that skb->head will be kfree, in case skb->head
+ * from external buffer cannot use kfree to destroy.
+ */
+ if (dev_is_mpassthru(skb->dev) && ext_page && ext_page->dtor)
+ ext_page->dtor(ext_page);
kfree(skb->head);
}
}
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 10/19] Don't do skb recycle, if device use external buffer.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-9-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
net/core/skbuff.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 38d19d0..37587f0 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -553,6 +553,12 @@ int skb_recycle_check(struct sk_buff *skb, int skb_size)
if (skb_shared(skb) || skb_cloned(skb))
return 0;
+ /* if the device wants to do mediate passthru, the skb may
+ * get external buffer, so don't recycle
+ */
+ if (dev_is_mpassthru(skb->dev))
+ return 0;
+
skb_release_head_state(skb);
shinfo = skb_shinfo(skb);
atomic_set(&shinfo->dataref, 1);
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 07/19] Add interface to get external buffers.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-6-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
Currently, it can get external buffers from mp device.
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
include/linux/skbuff.h | 12 ++++++++++++
net/core/skbuff.c | 16 ++++++++++++++++
2 files changed, 28 insertions(+), 0 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index cf309c9..281a1c0 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1519,6 +1519,18 @@ static inline void netdev_free_page(struct net_device *dev, struct page *page)
__free_page(page);
}
+extern struct skb_external_page *netdev_alloc_external_pages(
+ struct net_device *dev,
+ struct sk_buff *skb, int npages);
+
+static inline struct skb_external_page *netdev_alloc_external_page(
+ struct net_device *dev,
+ struct sk_buff *skb, unsigned int size)
+{
+ return netdev_alloc_external_pages(dev, skb,
+ DIV_ROUND_UP(size, PAGE_SIZE));
+}
+
/**
* skb_clone_writable - is the header of a clone writable
* @skb: buffer to check
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 93c4e06..fbdb1f1 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -278,6 +278,22 @@ struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask)
}
EXPORT_SYMBOL(__netdev_alloc_page);
+struct skb_external_page *netdev_alloc_external_pages(struct net_device *dev,
+ struct sk_buff *skb, int npages)
+{
+ struct mpassthru_port *port;
+ struct skb_external_page *ext_page = NULL;
+
+ port = rcu_dereference(dev->mp_port);
+ if (!port)
+ goto out;
+ WARN_ON(npages > port->npages);
+ ext_page = port->ctor(port, skb, npages);
+out:
+ return ext_page;
+}
+EXPORT_SYMBOL(netdev_alloc_external_pages);
+
void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
int size)
{
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 06/19] Add a function to indicate if device use external buffer.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-5-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
include/linux/netdevice.h | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 31d9c4a..0cb78f4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1602,6 +1602,11 @@ extern void netdev_mp_port_detach(struct net_device *dev);
extern int netdev_mp_port_prep(struct net_device *dev,
struct mpassthru_port *port);
+static inline bool dev_is_mpassthru(struct net_device *dev)
+{
+ return (dev && dev->mp_port);
+}
+
static inline void napi_free_frags(struct napi_struct *napi)
{
kfree_skb(napi->skb);
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 04/19] Add a ndo_mp_port_prep pointer to net_device_ops.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-3-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
If the driver want to allocate external buffers,
then it can export it's capability, as the skb
buffer header length, the page length can be DMA, etc.
The external buffers owner may utilize this.
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
include/linux/netdevice.h | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index efb575a..183c786 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -707,6 +707,10 @@ struct net_device_ops {
int (*ndo_fcoe_get_wwn)(struct net_device *dev,
u64 *wwn, int type);
#endif
+#if defined(CONFIG_MEDIATE_PASSTHRU) || defined(CONFIG_MEDIATE_PASSTHRU_MODULE)
+ int (*ndo_mp_port_prep)(struct net_device *dev,
+ struct mpassthru_port *port);
+#endif
};
/*
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 03/19] Export 2 func for device to assign/deassign new strucure
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-2-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
include/linux/netdevice.h | 3 +++
net/core/dev.c | 28 ++++++++++++++++++++++++++++
2 files changed, 31 insertions(+), 0 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index bae725c..efb575a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1592,6 +1592,9 @@ extern gro_result_t napi_frags_finish(struct napi_struct *napi,
gro_result_t ret);
extern struct sk_buff * napi_frags_skb(struct napi_struct *napi);
extern gro_result_t napi_gro_frags(struct napi_struct *napi);
+extern int netdev_mp_port_attach(struct net_device *dev,
+ struct mpassthru_port *port);
+extern void netdev_mp_port_detach(struct net_device *dev);
static inline void napi_free_frags(struct napi_struct *napi)
{
diff --git a/net/core/dev.c b/net/core/dev.c
index f769098..ecbb6b1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2469,6 +2469,34 @@ void netif_nit_deliver(struct sk_buff *skb)
rcu_read_unlock();
}
+/* Export two functions to assign/de-assign mp_port pointer
+ * to a net device.
+ */
+
+int netdev_mp_port_attach(struct net_device *dev,
+ struct mpassthru_port *port)
+{
+ /* locked by mp_mutex */
+ if (rcu_dereference(dev->mp_port))
+ return -EBUSY;
+
+ rcu_assign_pointer(dev->mp_port, port);
+
+ return 0;
+}
+EXPORT_SYMBOL(netdev_mp_port_attach);
+
+void netdev_mp_port_detach(struct net_device *dev)
+{
+ /* locked by mp_mutex */
+ if (!rcu_dereference(dev->mp_port))
+ return;
+
+ rcu_assign_pointer(dev->mp_port, NULL);
+ synchronize_rcu();
+}
+EXPORT_SYMBOL(netdev_mp_port_detach);
+
/**
* netif_receive_skb - process receive buffer from network
* @skb: buffer to process
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 02/19] Add a new struct for device to manipulate external buffer.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-1-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
include/linux/netdevice.h | 19 ++++++++++++++++++-
1 files changed, 18 insertions(+), 1 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index fa8b476..bae725c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -530,6 +530,22 @@ struct netdev_queue {
unsigned long tx_dropped;
} ____cacheline_aligned_in_smp;
+/* Add a structure in structure net_device, the new field is
+ * named as mp_port. It's for mediate passthru (zero-copy).
+ * It contains the capability for the net device driver,
+ * a socket, and an external buffer creator, external means
+ * skb buffer belongs to the device may not be allocated from
+ * kernel space.
+ */
+struct mpassthru_port {
+ int hdr_len;
+ int data_len;
+ int npages;
+ unsigned flags;
+ struct socket *sock;
+ struct skb_external_page *(*ctor)(struct mpassthru_port *,
+ struct sk_buff *, int);
+};
/*
* This structure defines the management hooks for network devices.
@@ -952,7 +968,8 @@ struct net_device {
struct macvlan_port *macvlan_port;
/* GARP */
struct garp_port *garp_port;
-
+ /* mpassthru */
+ struct mpassthru_port *mp_port;
/* class/net/name entry */
struct device dev;
/* space for optional device, statistics, and wireless sysfs groups */
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 01/19] Add a new structure for skb buffer from external.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
From: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
include/linux/skbuff.h | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 124f90c..cf309c9 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -203,6 +203,18 @@ struct skb_shared_info {
void * destructor_arg;
};
+/* The structure is for a skb which skb->data may point to
+ * an external buffer, which is not allocated from kernel space.
+ * Since the buffer is external, then the shinfo or frags are
+ * also extern too. It also contains a destructor for itself.
+ */
+struct skb_external_page {
+ u8 *start;
+ int size;
+ struct skb_frag_struct *frags;
+ struct skb_shared_info *ushinfo;
+ void (*dtor)(struct skb_external_page *);
+};
/* We divide dataref into two halves. The higher 16 bits hold references
* to the payload part of skb->data. The lower 16 bits hold references to
* the entire skb->data. A clone of a headerless skb holds the length of
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 19/19] Provides multiple submits and asynchronous notifications.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-18-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
The vhost-net backend now only supports synchronous send/recv
operations. The patch provides multiple submits and asynchronous
notifications. This is needed for zero-copy case.
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
---
drivers/vhost/net.c | 255 ++++++++++++++++++++++++++++++++++++++++++++++++-
drivers/vhost/vhost.c | 120 +++++++++++++----------
drivers/vhost/vhost.h | 14 +++
3 files changed, 333 insertions(+), 56 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 9777583..9a0d162 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -24,6 +24,8 @@
#include <linux/if_arp.h>
#include <linux/if_tun.h>
#include <linux/if_macvlan.h>
+#include <linux/mpassthru.h>
+#include <linux/aio.h>
#include <net/sock.h>
@@ -45,10 +47,13 @@ enum vhost_net_poll_state {
VHOST_NET_POLL_STOPPED = 2,
};
+static struct kmem_cache *notify_cache;
+
struct vhost_net {
struct vhost_dev dev;
struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
struct vhost_poll poll[VHOST_NET_VQ_MAX];
+ struct kmem_cache *cache;
/* Tells us whether we are polling a socket for TX.
* We only do this when socket buffer fills up.
* Protected by tx vq lock. */
@@ -93,11 +98,146 @@ static void tx_poll_start(struct vhost_net *net, struct socket *sock)
net->tx_poll_state = VHOST_NET_POLL_STARTED;
}
+struct kiocb *notify_dequeue(struct vhost_virtqueue *vq)
+{
+ struct kiocb *iocb = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vq->notify_lock, flags);
+ if (!list_empty(&vq->notifier)) {
+ iocb = list_first_entry(&vq->notifier,
+ struct kiocb, ki_list);
+ list_del(&iocb->ki_list);
+ }
+ spin_unlock_irqrestore(&vq->notify_lock, flags);
+ return iocb;
+}
+
+static void handle_iocb(struct kiocb *iocb)
+{
+ struct vhost_virtqueue *vq = iocb->private;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vq->notify_lock, flags);
+ list_add_tail(&iocb->ki_list, &vq->notifier);
+ spin_unlock_irqrestore(&vq->notify_lock, flags);
+}
+
+static int is_async_vq(struct vhost_virtqueue *vq)
+{
+ return (vq->link_state == VHOST_VQ_LINK_ASYNC);
+}
+
+static void handle_async_rx_events_notify(struct vhost_net *net,
+ struct vhost_virtqueue *vq,
+ struct socket *sock)
+{
+ struct kiocb *iocb = NULL;
+ struct vhost_log *vq_log = NULL;
+ int rx_total_len = 0;
+ unsigned int head, log, in, out;
+ int size;
+
+ if (!is_async_vq(vq))
+ return;
+
+ if (sock->sk->sk_data_ready)
+ sock->sk->sk_data_ready(sock->sk, 0);
+
+ vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
+ vq->log : NULL;
+
+ while ((iocb = notify_dequeue(vq)) != NULL) {
+ vhost_add_used_and_signal(&net->dev, vq,
+ iocb->ki_pos, iocb->ki_nbytes);
+ size = iocb->ki_nbytes;
+ head = iocb->ki_pos;
+ rx_total_len += iocb->ki_nbytes;
+
+ if (iocb->ki_dtor)
+ iocb->ki_dtor(iocb);
+ kmem_cache_free(net->cache, iocb);
+
+ /* when log is enabled, recomputing the log info is needed,
+ * since these buffers are in async queue, and may not get
+ * the log info before.
+ */
+ if (unlikely(vq_log)) {
+ if (!log)
+ __vhost_get_vq_desc(&net->dev, vq, vq->iov,
+ ARRAY_SIZE(vq->iov),
+ &out, &in, vq_log,
+ &log, head);
+ vhost_log_write(vq, vq_log, log, size);
+ }
+ if (unlikely(rx_total_len >= VHOST_NET_WEIGHT)) {
+ vhost_poll_queue(&vq->poll);
+ break;
+ }
+ }
+}
+
+static void handle_async_tx_events_notify(struct vhost_net *net,
+ struct vhost_virtqueue *vq)
+{
+ struct kiocb *iocb = NULL;
+ struct list_head *entry, *tmp;
+ unsigned long flags;
+ int tx_total_len = 0;
+
+ if (!is_async_vq(vq))
+ return;
+ spin_lock_irqsave(&vq->notify_lock, flags);
+ list_for_each_safe(entry, tmp, &vq->notifier) {
+ iocb = list_entry(entry,
+ struct kiocb, ki_list);
+ if (!iocb->ki_flags)
+ continue;
+ list_del(&iocb->ki_list);
+ vhost_add_used_and_signal(&net->dev, vq,
+ iocb->ki_pos, 0);
+ tx_total_len += iocb->ki_nbytes;
+
+ if (iocb->ki_dtor)
+ iocb->ki_dtor(iocb);
+
+ kmem_cache_free(net->cache, iocb);
+ if (unlikely(tx_total_len >= VHOST_NET_WEIGHT)) {
+ vhost_poll_queue(&vq->poll);
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&vq->notify_lock, flags);
+}
+
+static struct kiocb *create_iocb(struct vhost_net *net,
+ struct vhost_virtqueue *vq,
+ unsigned head)
+{
+ struct kiocb *iocb = NULL;
+
+ if (!is_async_vq(vq))
+ return NULL;
+
+ iocb = kmem_cache_zalloc(net->cache, GFP_KERNEL);
+ if (!iocb)
+ return NULL;
+ iocb->private = vq;
+ iocb->ki_pos = head;
+ iocb->ki_dtor = handle_iocb;
+ if (vq == &net->dev.vqs[VHOST_NET_VQ_RX]) {
+ iocb->ki_user_data = vq->num;
+ iocb->ki_iovec = vq->hdr;
+ }
+ return iocb;
+}
+
/* Expects to be always run from workqueue - which acts as
* read-size critical section for our kind of RCU. */
static void handle_tx(struct vhost_net *net)
{
struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
+ struct kiocb *iocb = NULL;
unsigned head, out, in, s;
struct msghdr msg = {
.msg_name = NULL,
@@ -130,6 +270,8 @@ static void handle_tx(struct vhost_net *net)
tx_poll_stop(net);
hdr_size = vq->hdr_size;
+ handle_async_tx_events_notify(net, vq);
+
for (;;) {
head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
ARRAY_SIZE(vq->iov),
@@ -157,6 +299,13 @@ static void handle_tx(struct vhost_net *net)
/* Skip header. TODO: support TSO. */
s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out);
msg.msg_iovlen = out;
+
+ if (is_async_vq(vq)) {
+ iocb = create_iocb(net, vq, head);
+ if (!iocb)
+ break;
+ }
+
len = iov_length(vq->iov, out);
/* Sanity check */
if (!len) {
@@ -166,12 +315,18 @@ static void handle_tx(struct vhost_net *net)
break;
}
/* TODO: Check specific error and bomb out unless ENOBUFS? */
- err = sock->ops->sendmsg(NULL, sock, &msg, len);
+ err = sock->ops->sendmsg(iocb, sock, &msg, len);
if (unlikely(err < 0)) {
+ if (is_async_vq(vq))
+ kmem_cache_free(net->cache, iocb);
vhost_discard_vq_desc(vq);
tx_poll_start(net, sock);
break;
}
+
+ if (is_async_vq(vq))
+ continue;
+
if (err != len)
pr_err("Truncated TX packet: "
" len %d != %zd\n", err, len);
@@ -183,6 +338,8 @@ static void handle_tx(struct vhost_net *net)
}
}
+ handle_async_tx_events_notify(net, vq);
+
mutex_unlock(&vq->mutex);
unuse_mm(net->dev.mm);
}
@@ -192,6 +349,7 @@ static void handle_tx(struct vhost_net *net)
static void handle_rx(struct vhost_net *net)
{
struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
+ struct kiocb *iocb = NULL;
unsigned head, out, in, log, s;
struct vhost_log *vq_log;
struct msghdr msg = {
@@ -212,7 +370,8 @@ static void handle_rx(struct vhost_net *net)
int err;
size_t hdr_size;
struct socket *sock = rcu_dereference(vq->private_data);
- if (!sock || skb_queue_empty(&sock->sk->sk_receive_queue))
+ if (!sock || (skb_queue_empty(&sock->sk->sk_receive_queue) &&
+ vq->link_state == VHOST_VQ_LINK_SYNC))
return;
use_mm(net->dev.mm);
@@ -220,9 +379,17 @@ static void handle_rx(struct vhost_net *net)
vhost_disable_notify(vq);
hdr_size = vq->hdr_size;
+ /* In async cases, when write log is enabled, in case the submitted
+ * buffers did not get log info before the log enabling, so we'd
+ * better recompute the log info when needed. We do this in
+ * handle_async_rx_events_notify().
+ */
+
vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
vq->log : NULL;
+ handle_async_rx_events_notify(net, vq, sock);
+
for (;;) {
head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
ARRAY_SIZE(vq->iov),
@@ -251,6 +418,13 @@ static void handle_rx(struct vhost_net *net)
s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, in);
msg.msg_iovlen = in;
len = iov_length(vq->iov, in);
+
+ if (is_async_vq(vq)) {
+ iocb = create_iocb(net, vq, head);
+ if (!iocb)
+ break;
+ }
+
/* Sanity check */
if (!len) {
vq_err(vq, "Unexpected header len for RX: "
@@ -258,13 +432,20 @@ static void handle_rx(struct vhost_net *net)
iov_length(vq->hdr, s), hdr_size);
break;
}
- err = sock->ops->recvmsg(NULL, sock, &msg,
+
+ err = sock->ops->recvmsg(iocb, sock, &msg,
len, MSG_DONTWAIT | MSG_TRUNC);
/* TODO: Check specific error and bomb out unless EAGAIN? */
if (err < 0) {
+ if (is_async_vq(vq))
+ kmem_cache_free(net->cache, iocb);
vhost_discard_vq_desc(vq);
break;
}
+
+ if (is_async_vq(vq))
+ continue;
+
/* TODO: Should check and handle checksum. */
if (err > len) {
pr_err("Discarded truncated rx packet: "
@@ -290,6 +471,8 @@ static void handle_rx(struct vhost_net *net)
}
}
+ handle_async_rx_events_notify(net, vq, sock);
+
mutex_unlock(&vq->mutex);
unuse_mm(net->dev.mm);
}
@@ -343,6 +526,7 @@ static int vhost_net_open(struct inode *inode, struct file *f)
vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT);
vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN);
n->tx_poll_state = VHOST_NET_POLL_DISABLED;
+ n->cache = NULL;
f->private_data = n;
@@ -406,6 +590,21 @@ static void vhost_net_flush(struct vhost_net *n)
vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
}
+static void vhost_async_cleanup(struct vhost_net *n)
+{
+ /* clean the notifier */
+ struct vhost_virtqueue *vq;
+ struct kiocb *iocb = NULL;
+ if (n->cache) {
+ vq = &n->dev.vqs[VHOST_NET_VQ_RX];
+ while ((iocb = notify_dequeue(vq)) != NULL)
+ kmem_cache_free(n->cache, iocb);
+ vq = &n->dev.vqs[VHOST_NET_VQ_TX];
+ while ((iocb = notify_dequeue(vq)) != NULL)
+ kmem_cache_free(n->cache, iocb);
+ }
+}
+
static int vhost_net_release(struct inode *inode, struct file *f)
{
struct vhost_net *n = f->private_data;
@@ -422,6 +621,7 @@ static int vhost_net_release(struct inode *inode, struct file *f)
/* We do an extra flush before freeing memory,
* since jobs can re-queue themselves. */
vhost_net_flush(n);
+ vhost_async_cleanup(n);
kfree(n);
return 0;
}
@@ -473,21 +673,58 @@ static struct socket *get_tap_socket(int fd)
return sock;
}
-static struct socket *get_socket(int fd)
+static struct socket *get_mp_socket(int fd)
+{
+ struct file *file = fget(fd);
+ struct socket *sock;
+ if (!file)
+ return ERR_PTR(-EBADF);
+ sock = mp_get_socket(file);
+ if (IS_ERR(sock))
+ fput(file);
+ return sock;
+}
+
+static struct socket *get_socket(struct vhost_virtqueue *vq, int fd,
+ enum vhost_vq_link_state *state)
{
struct socket *sock;
/* special case to disable backend */
if (fd == -1)
return NULL;
+
+ *state = VHOST_VQ_LINK_SYNC;
+
sock = get_raw_socket(fd);
if (!IS_ERR(sock))
return sock;
sock = get_tap_socket(fd);
if (!IS_ERR(sock))
return sock;
+ /* If we dont' have notify_cache, then dont do mpassthru */
+ if (!notify_cache)
+ return ERR_PTR(-ENOTSOCK);
+ sock = get_mp_socket(fd);
+ if (!IS_ERR(sock)) {
+ *state = VHOST_VQ_LINK_ASYNC;
+ return sock;
+ }
return ERR_PTR(-ENOTSOCK);
}
+static void vhost_init_link_state(struct vhost_net *n, int index)
+{
+ struct vhost_virtqueue *vq = n->vqs + index;
+
+ WARN_ON(!mutex_is_locked(&vq->mutex));
+ if (vq->link_state == VHOST_VQ_LINK_ASYNC) {
+ INIT_LIST_HEAD(&vq->notifier);
+ spin_lock_init(&vq->notify_lock);
+ if (!n->cache)
+ n->cache = notify_cache;
+ }
+}
+
static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
{
struct socket *sock, *oldsock;
@@ -511,12 +748,14 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
r = -EFAULT;
goto err_vq;
}
- sock = get_socket(fd);
+ sock = get_socket(vq, fd, &vq->link_state);
if (IS_ERR(sock)) {
r = PTR_ERR(sock);
goto err_vq;
}
+ vhost_init_link_state(n, index);
+
/* start polling new socket */
oldsock = vq->private_data;
if (sock == oldsock)
@@ -650,6 +889,10 @@ int vhost_net_init(void)
r = misc_register(&vhost_net_misc);
if (r)
goto err_reg;
+
+ notify_cache = kmem_cache_create("vhost_kiocb",
+ sizeof(struct kiocb), 0,
+ SLAB_HWCACHE_ALIGN, NULL);
return 0;
err_reg:
vhost_cleanup();
@@ -663,6 +906,8 @@ void vhost_net_exit(void)
{
misc_deregister(&vhost_net_misc);
vhost_cleanup();
+ if (notify_cache)
+ kmem_cache_destroy(notify_cache);
}
module_exit(vhost_net_exit);
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index e69d238..ad3779c 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -861,61 +861,17 @@ static unsigned get_indirect(struct vhost_dev *dev, struct vhost_virtqueue *vq,
return 0;
}
-/* This looks in the virtqueue and for the first available buffer, and converts
- * it to an iovec for convenient access. Since descriptors consist of some
- * number of output then some number of input descriptors, it's actually two
- * iovecs, but we pack them into one and note how many of each there were.
- *
- * This function returns the descriptor number found, or vq->num (which
- * is never a valid descriptor number) if none was found. */
-unsigned vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq,
- struct iovec iov[], unsigned int iov_size,
- unsigned int *out_num, unsigned int *in_num,
- struct vhost_log *log, unsigned int *log_num)
+/* This computes the log info according to the index of buffer */
+unsigned __vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num,
+ unsigned int head)
{
struct vring_desc desc;
- unsigned int i, head, found = 0;
- u16 last_avail_idx;
+ unsigned int i = head, found = 0;
int ret;
- /* Check it isn't doing very strange things with descriptor numbers. */
- last_avail_idx = vq->last_avail_idx;
- if (get_user(vq->avail_idx, &vq->avail->idx)) {
- vq_err(vq, "Failed to access avail idx at %p\n",
- &vq->avail->idx);
- return vq->num;
- }
-
- if ((u16)(vq->avail_idx - last_avail_idx) > vq->num) {
- vq_err(vq, "Guest moved used index from %u to %u",
- last_avail_idx, vq->avail_idx);
- return vq->num;
- }
-
- /* If there's nothing new since last we looked, return invalid. */
- if (vq->avail_idx == last_avail_idx)
- return vq->num;
-
- /* Only get avail ring entries after they have been exposed by guest. */
- smp_rmb();
-
- /* Grab the next descriptor number they're advertising, and increment
- * the index we've seen. */
- if (get_user(head, &vq->avail->ring[last_avail_idx % vq->num])) {
- vq_err(vq, "Failed to read head: idx %d address %p\n",
- last_avail_idx,
- &vq->avail->ring[last_avail_idx % vq->num]);
- return vq->num;
- }
-
- /* If their number is silly, that's an error. */
- if (head >= vq->num) {
- vq_err(vq, "Guest says index %u > %u is available",
- head, vq->num);
- return vq->num;
- }
-
- /* When we start there are none of either input nor output. */
*out_num = *in_num = 0;
if (unlikely(log))
*log_num = 0;
@@ -979,8 +935,70 @@ unsigned vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq,
*out_num += ret;
}
} while ((i = next_desc(&desc)) != -1);
+ return head;
+}
+
+/* This looks in the virtqueue and for the first available buffer, and converts
+ * it to an iovec for convenient access. Since descriptors consist of some
+ * number of output then some number of input descriptors, it's actually two
+ * iovecs, but we pack them into one and note how many of each there were.
+ *
+ * This function returns the descriptor number found, or vq->num (which
+ * is never a valid descriptor number) if none was found. */
+unsigned vhost_get_vq_desc(struct vhost_dev *dev, struct vhost_virtqueue *vq,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num)
+{
+ struct vring_desc desc;
+ unsigned int i, head, found = 0;
+ u16 last_avail_idx;
+ int ret;
+
+ /* Check it isn't doing very strange things with descriptor numbers. */
+ last_avail_idx = vq->last_avail_idx;
+ if (get_user(vq->avail_idx, &vq->avail->idx)) {
+ vq_err(vq, "Failed to access avail idx at %p\n",
+ &vq->avail->idx);
+ return vq->num;
+ }
+
+ if ((u16)(vq->avail_idx - last_avail_idx) > vq->num) {
+ vq_err(vq, "Guest moved used index from %u to %u",
+ last_avail_idx, vq->avail_idx);
+ return vq->num;
+ }
+
+ /* If there's nothing new since last we looked, return invalid. */
+ if (vq->avail_idx == last_avail_idx)
+ return vq->num;
+
+ /* Only get avail ring entries after they have been exposed by guest. */
+ smp_rmb();
+
+ /* Grab the next descriptor number they're advertising, and increment
+ * the index we've seen. */
+ if (get_user(head, &vq->avail->ring[last_avail_idx % vq->num])) {
+ vq_err(vq, "Failed to read head: idx %d address %p\n",
+ last_avail_idx,
+ &vq->avail->ring[last_avail_idx % vq->num]);
+ return vq->num;
+ }
+
+ /* If their number is silly, that's an error. */
+ if (head >= vq->num) {
+ vq_err(vq, "Guest says index %u > %u is available",
+ head, vq->num);
+ return vq->num;
+ }
+
+ ret = __vhost_get_vq_desc(dev, vq, iov, iov_size,
+ out_num, in_num,
+ log, log_num, head);
/* On success, increment avail index. */
+ if (ret == vq->num)
+ return ret;
vq->last_avail_idx++;
return head;
}
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 44591ba..3c9cbce 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -43,6 +43,11 @@ struct vhost_log {
u64 len;
};
+enum vhost_vq_link_state {
+ VHOST_VQ_LINK_SYNC = 0,
+ VHOST_VQ_LINK_ASYNC = 1,
+};
+
/* The virtqueue structure describes a queue attached to a device. */
struct vhost_virtqueue {
struct vhost_dev *dev;
@@ -96,6 +101,10 @@ struct vhost_virtqueue {
/* Log write descriptors */
void __user *log_base;
struct vhost_log log[VHOST_NET_MAX_SG];
+ /* Differiate async socket for 0-copy from normal */
+ enum vhost_vq_link_state link_state;
+ struct list_head notifier;
+ spinlock_t notify_lock;
};
struct vhost_dev {
@@ -124,6 +133,11 @@ unsigned vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *,
struct iovec iov[], unsigned int iov_count,
unsigned int *out_num, unsigned int *in_num,
struct vhost_log *log, unsigned int *log_num);
+unsigned __vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *,
+ struct iovec iov[], unsigned int iov_count,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num,
+ unsigned int head);
void vhost_discard_vq_desc(struct vhost_virtqueue *);
int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
--
1.5.4.4
^ permalink raw reply related
* [RFC PATCH v7 17/19] Export proto_ops to vhost-net driver.
From: xiaohui.xin @ 2010-06-05 10:14 UTC (permalink / raw)
To: netdev, kvm, linux-kernel, mst, mingo, davem, herbert, jdike; +Cc: Xin Xiaohui
In-Reply-To: <1275732899-5423-16-git-send-email-xiaohui.xin@intel.com>
From: Xin Xiaohui <xiaohui.xin@intel.com>
Currently, vhost-net is only user to the mp device.
Signed-off-by: Xin Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Zhao Yu <yzhao81new@gmail.com>
Reviewed-by: Jeff Dike <jdike@linux.intel.com>
---
drivers/vhost/mpassthru.c | 295 ++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 290 insertions(+), 5 deletions(-)
diff --git a/drivers/vhost/mpassthru.c b/drivers/vhost/mpassthru.c
index 8c48898..23755ba 100644
--- a/drivers/vhost/mpassthru.c
+++ b/drivers/vhost/mpassthru.c
@@ -414,6 +414,11 @@ static void mp_put(struct mp_file *mfile)
mp_detach(mfile->mp);
}
+static void iocb_tag(struct kiocb *iocb)
+{
+ iocb->ki_flags = 1;
+}
+
/* The callback to destruct the external buffers or skb */
static void page_dtor(struct skb_external_page *ext_page)
{
@@ -449,7 +454,7 @@ static void page_dtor(struct skb_external_page *ext_page)
* Queue the notifier to wake up the backend driver
*/
- create_iocb(info, info->total);
+ iocb_tag(info->iocb);
sk = ctor->port.sock->sk;
sk->sk_write_space(sk);
@@ -569,8 +574,288 @@ failed:
return NULL;
}
+static void mp_sock_destruct(struct sock *sk)
+{
+ struct mp_struct *mp = container_of(sk, struct mp_sock, sk)->mp;
+ kfree(mp);
+}
+
+static void mp_sock_state_change(struct sock *sk)
+{
+ if (sk_has_sleeper(sk))
+ wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN);
+}
+
+static void mp_sock_write_space(struct sock *sk)
+{
+ if (sk_has_sleeper(sk))
+ wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT);
+}
+
+static void mp_sock_data_ready(struct sock *sk, int coming)
+{
+ struct mp_struct *mp = container_of(sk, struct mp_sock, sk)->mp;
+ struct page_ctor *ctor = NULL;
+ struct sk_buff *skb = NULL;
+ struct page_info *info = NULL;
+ struct ethhdr *eth;
+ struct kiocb *iocb = NULL;
+ int len, i;
+
+ struct virtio_net_hdr hdr = {
+ .flags = 0,
+ .gso_type = VIRTIO_NET_HDR_GSO_NONE
+ };
+
+ ctor = rcu_dereference(mp->ctor);
+ if (!ctor)
+ return;
+
+ while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+ if (skb_shinfo(skb)->destructor_arg) {
+ info = container_of(skb_shinfo(skb)->destructor_arg,
+ struct page_info, ext_page);
+ info->skb = skb;
+ if (skb->len > info->len) {
+ mp->dev->stats.rx_dropped++;
+ DBG(KERN_INFO "Discarded truncated rx packet: "
+ " len %d > %zd\n", skb->len, info->len);
+ info->total = skb->len;
+ goto clean;
+ } else {
+ eth = eth_hdr(skb);
+ skb_push(skb, ETH_HLEN);
+ info->total = skb->len;
+ }
+ } else {
+ /* The skb composed with kernel buffers
+ * in case external buffers are not sufficent.
+ * The case should be rare.
+ */
+ unsigned long flags;
+ int i;
+ info = NULL;
+
+ spin_lock_irqsave(&ctor->read_lock, flags);
+ if (!list_empty(&ctor->readq)) {
+ info = list_first_entry(&ctor->readq,
+ struct page_info, list);
+ list_del(&info->list);
+ }
+ spin_unlock_irqrestore(&ctor->read_lock, flags);
+ if (!info) {
+ DBG(KERN_INFO
+ "No external buffer avaliable %p\n",
+ skb);
+ skb_queue_head(&sk->sk_receive_queue,
+ skb);
+ break;
+ }
+ info->skb = skb;
+ eth = eth_hdr(skb);
+ skb_push(skb, ETH_HLEN);
+ info->total = skb->len;
+ skb_copy_datagram_iovec(skb, 0, info->iov, skb->len);
+ }
+
+ len = memcpy_toiovec(info->hdr, (unsigned char *)&hdr,
+ sizeof hdr);
+ if (len) {
+ DBG(KERN_INFO
+ "Unable to write vnet_hdr at addr %p: %d\n",
+ info->hdr->iov_base, len);
+ goto clean;
+ }
+
+ iocb = create_iocb(info, skb->len + sizeof(hdr));
+ continue;
+
+clean:
+ kfree_skb(skb);
+ for (i = 0; info->pages[i]; i++)
+ put_page(info->pages[i]);
+ kmem_cache_free(ext_page_info_cache, info);
+ }
+ return;
+}
+
+static int mp_sendmsg(struct kiocb *iocb, struct socket *sock,
+ struct msghdr *m, size_t total_len)
+{
+ struct mp_struct *mp = container_of(sock->sk, struct mp_sock, sk)->mp;
+ struct page_ctor *ctor;
+ struct iovec *iov = m->msg_iov;
+ struct page_info *info = NULL;
+ struct frag frags[MAX_SKB_FRAGS];
+ struct sk_buff *skb;
+ int count = m->msg_iovlen;
+ int total = 0, header, n, i, len, rc;
+ unsigned long base;
+
+ ctor = rcu_dereference(mp->ctor);
+ if (!ctor)
+ return -ENODEV;
+
+ total = iov_length(iov, count);
+
+ if (total < ETH_HLEN)
+ return -EINVAL;
+
+ if (total <= COPY_THRESHOLD)
+ goto copy;
+
+ n = 0;
+ for (i = 0; i < count; i++) {
+ base = (unsigned long)iov[i].iov_base;
+ len = iov[i].iov_len;
+ if (!len)
+ continue;
+ n += ((base & ~PAGE_MASK) + len + ~PAGE_MASK) >> PAGE_SHIFT;
+ if (n > MAX_SKB_FRAGS)
+ return -EINVAL;
+ }
+
+copy:
+ header = total > COPY_THRESHOLD ? COPY_HDR_LEN : total;
+
+ skb = alloc_skb(header + NET_IP_ALIGN, GFP_ATOMIC);
+ if (!skb)
+ goto drop;
+
+ skb_reserve(skb, NET_IP_ALIGN);
+
+ skb_set_network_header(skb, ETH_HLEN);
+
+ memcpy_fromiovec(skb->data, iov, header);
+ skb_put(skb, header);
+ skb->protocol = *((__be16 *)(skb->data) + ETH_ALEN);
+
+ if (header == total) {
+ rc = total;
+ info = alloc_small_page_info(ctor, iocb, total);
+ } else {
+ info = alloc_page_info(ctor, iocb, iov, count, frags, 0, total);
+ if (info)
+ for (i = 0; info->pages[i]; i++) {
+ skb_add_rx_frag(skb, i, info->pages[i],
+ frags[i].offset, frags[i].size);
+ info->pages[i] = NULL;
+ }
+ }
+ if (info != NULL) {
+ info->desc_pos = iocb->ki_pos;
+ info->total = total;
+ info->skb = skb;
+ skb_shinfo(skb)->destructor_arg = &info->ext_page;
+ skb->dev = mp->dev;
+ ctor->wq_len++;
+ create_iocb(info, info->total);
+ dev_queue_xmit(skb);
+ return 0;
+ }
+drop:
+ kfree_skb(skb);
+ if (info) {
+ for (i = 0; info->pages[i]; i++)
+ put_page(info->pages[i]);
+ kmem_cache_free(ext_page_info_cache, info);
+ }
+ mp->dev->stats.tx_dropped++;
+ return -ENOMEM;
+}
+
+static int mp_recvmsg(struct kiocb *iocb, struct socket *sock,
+ struct msghdr *m, size_t total_len,
+ int flags)
+{
+ struct mp_struct *mp = container_of(sock->sk, struct mp_sock, sk)->mp;
+ struct page_ctor *ctor;
+ struct iovec *iov = m->msg_iov;
+ int count = m->msg_iovlen;
+ int npages, payload;
+ struct page_info *info;
+ struct frag frags[MAX_SKB_FRAGS];
+ unsigned long base;
+ int i, len;
+ unsigned long flag;
+
+ if (!(flags & MSG_DONTWAIT))
+ return -EINVAL;
+
+ ctor = rcu_dereference(mp->ctor);
+ if (!ctor)
+ return -EINVAL;
+
+ /* Error detections in case invalid external buffer */
+ if (count > 2 && iov[1].iov_len < ctor->port.hdr_len &&
+ mp->dev->features & NETIF_F_SG) {
+ return -EINVAL;
+ }
+
+ npages = ctor->port.npages;
+ payload = ctor->port.data_len;
+
+ /* If KVM guest virtio-net FE driver use SG feature */
+ if (count > 2) {
+ for (i = 2; i < count; i++) {
+ base = (unsigned long)iov[i].iov_base & ~PAGE_MASK;
+ len = iov[i].iov_len;
+ if (npages == 1)
+ len = min_t(int, len, PAGE_SIZE - base);
+ else if (base)
+ break;
+ payload -= len;
+ if (payload <= 0)
+ goto proceed;
+ if (npages == 1 || (len & ~PAGE_MASK))
+ break;
+ }
+ }
+
+ if ((((unsigned long)iov[1].iov_base & ~PAGE_MASK)
+ - NET_SKB_PAD - NET_IP_ALIGN) >= 0)
+ goto proceed;
+
+ return -EINVAL;
+
+proceed:
+ /* skip the virtnet head */
+ iov++;
+ count--;
+
+ if (!ctor->lock_pages || !ctor->rq_len)
+ set_memlock_rlimit(ctor, RLIMIT_MEMLOCK,
+ iocb->ki_user_data * 4096 * 2,
+ iocb->ki_user_data * 4096 * 2);
+
+ /* Translate address to kernel */
+ info = alloc_page_info(ctor, iocb, iov, count, frags, npages, 0);
+ if (!info)
+ return -ENOMEM;
+ info->len = total_len;
+ info->hdr[0].iov_base = iocb->ki_iovec[0].iov_base;
+ info->hdr[0].iov_len = iocb->ki_iovec[0].iov_len;
+ info->offset = frags[0].offset;
+ info->desc_pos = iocb->ki_pos;
+
+ iov--;
+ count++;
+
+ memcpy(info->iov, iov, sizeof(struct iovec) * count);
+
+ spin_lock_irqsave(&ctor->read_lock, flag);
+ list_add_tail(&info->list, &ctor->readq);
+ spin_unlock_irqrestore(&ctor->read_lock, flag);
+
+ ctor->rq_len++;
+
+ return 0;
+}
+
/* Ops structure to mimic raw sockets with mp device */
static const struct proto_ops mp_socket_ops = {
+ .sendmsg = mp_sendmsg,
+ .recvmsg = mp_recvmsg,
};
static struct proto mp_proto = {
@@ -693,10 +978,10 @@ static long mp_chr_ioctl(struct file *file, unsigned int cmd,
sk->sk_sndbuf = INT_MAX;
container_of(sk, struct mp_sock, sk)->mp = mp;
- sk->sk_destruct = NULL;
- sk->sk_data_ready = NULL;
- sk->sk_write_space = NULL;
- sk->sk_state_change = NULL;
+ sk->sk_destruct = mp_sock_destruct;
+ sk->sk_data_ready = mp_sock_data_ready;
+ sk->sk_write_space = mp_sock_write_space;
+ sk->sk_state_change = mp_sock_state_change;
ret = mp_attach(mp, file);
if (ret < 0)
goto err_free_sk;
--
1.5.4.4
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