[PATCH] kni: fix build on RHEL6.5

[PATCH] kni: fix build on RHEL6.5

[Jincheng Miao]

RHEL6.5 kernel is based on 2.6.32. But there are two changing
from 2.6.35:
1. socket struct is changed
It wrappered previous wait_queue_head_t of socket to
struct socket_wq. So for the kernel older than 2.6.35, we should
directly use socket->wait instead.

2. new function sk_sleep()
This function is implemented from 2.6.35 to obtain wait queue
from struct sock. This patch adds a macro in kni/compat.h
to be compatible with older kernels.

Patch is tested in RHEL6.5 and RHEL7.0 with:
CONFIG_RTE_LIBRTE_KNI=y
CONFIG_RTE_KNI_KO_DEBUG=y
CONFIG_RTE_KNI_VHOST=y
CONFIG_RTE_KNI_VHOST_MAX_CACHE_SIZE=1024
CONFIG_RTE_KNI_VHOST_VNET_HDR_EN=y
CONFIG_RTE_KNI_VHOST_DEBUG_RX=y
CONFIG_RTE_KNI_VHOST_DEBUG_TX=y


Signed-off-by: Jincheng Miao <jmiao-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
 lib/librte_eal/linuxapp/kni/compat.h    |    6 ++++++
 lib/librte_eal/linuxapp/kni/kni_vhost.c |   17 +++++++++++++++++
 2 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/lib/librte_eal/linuxapp/kni/compat.h b/lib/librte_eal/linuxapp/kni/compat.h
index 0d87421..1313523 100644
--- a/lib/librte_eal/linuxapp/kni/compat.h
+++ b/lib/librte_eal/linuxapp/kni/compat.h
@@ -13,3 +13,9 @@
 #define kstrtoul strict_strtoul
 
 #endif /* < 2.6.39 */
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,35)
+
+#define sk_sleep(s) (s)->sk_sleep
+
+#endif /* < 2.6.35 */
diff --git a/lib/librte_eal/linuxapp/kni/kni_vhost.c b/lib/librte_eal/linuxapp/kni/kni_vhost.c
index c05c868..7141f83 100644
--- a/lib/librte_eal/linuxapp/kni/kni_vhost.c
+++ b/lib/librte_eal/linuxapp/kni/kni_vhost.c
@@ -33,6 +33,7 @@
 #include <linux/if_tun.h>
 #include <linux/version.h>
 
+#include "compat.h"
 #include "kni_dev.h"
 #include "kni_fifo.h"
 
@@ -215,10 +216,19 @@ kni_sock_poll(struct file *file, struct socket *sock, poll_table * wait)
 		return POLLERR;
 
 	kni = q->kni;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35)
 	KNI_DBG("start kni_poll on group %d, wq 0x%16llx\n",
 		  kni->group_id, (uint64_t)sock->wq);
+#else
+	KNI_DBG("start kni_poll on group %d, wait at 0x%16llx\n",
+		  kni->group_id, (uint64_t)&sock->wait);
+#endif
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35)
 	poll_wait(file, &sock->wq->wait, wait);
+#else
+	poll_wait(file, &sock->wait, wait);
+#endif
 
 	if (kni_fifo_count(kni->rx_q) > 0)
 		mask |= POLLIN | POLLRDNORM;
@@ -681,10 +691,17 @@ kni_vhost_backend_init(struct kni_dev *kni)
 
 	kni->vq_status = BE_START;
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,35)
 	KNI_DBG("backend init sockfd=%d, sock->wq=0x%16llx,"
 		  "sk->sk_wq=0x%16llx",
 		  q->sockfd, (uint64_t)q->sock->wq,
 		  (uint64_t)q->sk.sk_wq);
+#else
+	KNI_DBG("backend init sockfd=%d, sock->wait at 0x%16llx,"
+		  "sk->sk_sleep=0x%16llx",
+		  q->sockfd, (uint64_t)&q->sock->wait,
+		  (uint64_t)q->sk.sk_sleep);
+#endif
 
 	return 0;
 
-- 
1.7.1

Re: [PATCH] kni: fix build on RHEL6.5

[Thomas Monjalon]

2014-12-11 13:27, Jincheng Miao:
> RHEL6.5 kernel is based on 2.6.32. But there are two changing
> from 2.6.35:
> 1. socket struct is changed
> It wrappered previous wait_queue_head_t of socket to
> struct socket_wq. So for the kernel older than 2.6.35, we should
> directly use socket->wait instead.
> 
> 2. new function sk_sleep()
> This function is implemented from 2.6.35 to obtain wait queue
> from struct sock. This patch adds a macro in kni/compat.h
> to be compatible with older kernels.

I don't understand the relation between RHEL-6.5 and the kernel 2.6.35.
The patch seems not related to RHEL at all.
Please start your explanations by describing what is the problem
you want to solve.

Thanks
-- 
Thomas

Re: [PATCH] kni: fix build on RHEL6.5

[Jincheng Miao]

On 12/16/2014 11:21 PM, Thomas Monjalon wrote:
> 2014-12-11 13:27, Jincheng Miao:
>> RHEL6.5 kernel is based on 2.6.32. But there are two changing
>> from 2.6.35:
>> 1. socket struct is changed
>> It wrappered previous wait_queue_head_t of socket to
>> struct socket_wq. So for the kernel older than 2.6.35, we should
>> directly use socket->wait instead.
>>
>> 2. new function sk_sleep()
>> This function is implemented from 2.6.35 to obtain wait queue
>> from struct sock. This patch adds a macro in kni/compat.h
>> to be compatible with older kernels.
> I don't understand the relation between RHEL-6.5 and the kernel 2.6.35.
> The patch seems not related to RHEL at all.
> Please start your explanations by describing what is the problem
> you want to solve.

Hi Thomas,

This patch is working for resolving the problem I found on RHEL6.5:
http://dpdk.org/ml/archives/dev/2014-December/009827.html

Because the root cause is socket struct change from 2.6.35, so this
patch also fits for all kernels older than 2.6.35.

Sorry for the ambiguous description, I think the title should be:
"kni: more compatibility for kernel older than 2.6.35"

Regards,
Jincheng Miao

>
> Thanks

Re: [PATCH] kni: fix build on RHEL6.5

[Thomas Monjalon]

2014-12-17 11:26, Jincheng Miao:
> On 12/16/2014 11:21 PM, Thomas Monjalon wrote:
> > 2014-12-11 13:27, Jincheng Miao:
> >> RHEL6.5 kernel is based on 2.6.32. But there are two changing
> >> from 2.6.35:
> >> 1. socket struct is changed
> >> It wrappered previous wait_queue_head_t of socket to
> >> struct socket_wq. So for the kernel older than 2.6.35, we should
> >> directly use socket->wait instead.
> >>
> >> 2. new function sk_sleep()
> >> This function is implemented from 2.6.35 to obtain wait queue
> >> from struct sock. This patch adds a macro in kni/compat.h
> >> to be compatible with older kernels.
> > I don't understand the relation between RHEL-6.5 and the kernel 2.6.35.
> > The patch seems not related to RHEL at all.
> > Please start your explanations by describing what is the problem
> > you want to solve.
> 
> Hi Thomas,
> 
> This patch is working for resolving the problem I found on RHEL6.5:
> http://dpdk.org/ml/archives/dev/2014-December/009827.html
> 
> Because the root cause is socket struct change from 2.6.35, so this
> patch also fits for all kernels older than 2.6.35.
> 
> Sorry for the ambiguous description, I think the title should be:
> "kni: more compatibility for kernel older than 2.6.35"

Applied with title "kni: fix build with kernel < 2.6.35 and vhost debug enabled"
and error log.

Thanks
-- 
Thomas