DPDK patches and discussions
 help / color / mirror / Atom feed
* [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
@ 2015-03-25 18:43 Zoltan Kiss
  2015-03-26  1:20 ` Ananyev, Konstantin
  0 siblings, 1 reply; 6+ messages in thread
From: Zoltan Kiss @ 2015-03-25 18:43 UTC (permalink / raw)
  To: dev; +Cc: Zoltan Kiss

This macro and function were copies from the mbuf library, no reason to keep
them.

Signed-off-by: Zoltan Kiss <zoltan.kiss@linaro.org>
---
 examples/vhost/main.c | 38 +++++---------------------------------
 1 file changed, 5 insertions(+), 33 deletions(-)

diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index c3fcb80..1c998a5 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -139,8 +139,6 @@
 /* Number of descriptors per cacheline. */
 #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
 
-#define MBUF_EXT_MEM(mb)   (RTE_MBUF_FROM_BADDR((mb)->buf_addr) != (mb))
-
 /* mask of enabled ports */
 static uint32_t enabled_port_mask = 0;
 
@@ -1538,32 +1536,6 @@ attach_rxmbuf_zcp(struct virtio_net *dev)
 	return;
 }
 
-/*
- * Detach an attched packet mbuf -
- *  - restore original mbuf address and length values.
- *  - reset pktmbuf data and data_len to their default values.
- *  All other fields of the given packet mbuf will be left intact.
- *
- * @param m
- *   The attached packet mbuf.
- */
-static inline void pktmbuf_detach_zcp(struct rte_mbuf *m)
-{
-	const struct rte_mempool *mp = m->pool;
-	void *buf = RTE_MBUF_TO_BADDR(m);
-	uint32_t buf_ofs;
-	uint32_t buf_len = mp->elt_size - sizeof(*m);
-	m->buf_physaddr = rte_mempool_virt2phy(mp, m) + sizeof(*m);
-
-	m->buf_addr = buf;
-	m->buf_len = (uint16_t)buf_len;
-
-	buf_ofs = (RTE_PKTMBUF_HEADROOM <= m->buf_len) ?
-			RTE_PKTMBUF_HEADROOM : m->buf_len;
-	m->data_off = buf_ofs;
-
-	m->data_len = 0;
-}
 
 /*
  * This function is called after packets have been transimited. It fetchs mbuf
@@ -1590,8 +1562,8 @@ txmbuf_clean_zcp(struct virtio_net *dev, struct vpool *vpool)
 
 	for (index = 0; index < mbuf_count; index++) {
 		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
-		if (likely(MBUF_EXT_MEM(mbuf)))
-			pktmbuf_detach_zcp(mbuf);
+		if (likely(RTE_MBUF_INDIRECT(mbuf)))
+			rte_pktmbuf_detach(mbuf);
 		rte_ring_sp_enqueue(vpool->ring, mbuf);
 
 		/* Update used index buffer information. */
@@ -1653,8 +1625,8 @@ static void mbuf_destroy_zcp(struct vpool *vpool)
 	for (index = 0; index < mbuf_count; index++) {
 		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
 		if (likely(mbuf != NULL)) {
-			if (likely(MBUF_EXT_MEM(mbuf)))
-				pktmbuf_detach_zcp(mbuf);
+			if (likely(RTE_MBUF_INDIRECT(mbuf)))
+				rte_pktmbuf_detach(mbuf);
 			rte_ring_sp_enqueue(vpool->ring, (void *)mbuf);
 		}
 	}
@@ -2149,7 +2121,7 @@ switch_worker_zcp(__attribute__((unused)) void *arg)
 					}
 					while (likely(rx_count)) {
 						rx_count--;
-						pktmbuf_detach_zcp(
+						rte_pktmbuf_detach(
 							pkts_burst[rx_count]);
 						rte_ring_sp_enqueue(
 							vpool_array[index].ring,
-- 
1.9.1

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
  2015-03-25 18:43 [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies Zoltan Kiss
@ 2015-03-26  1:20 ` Ananyev, Konstantin
  2015-03-26  3:32   ` Ouyang, Changchun
  2015-03-26 16:46   ` Zoltan Kiss
  0 siblings, 2 replies; 6+ messages in thread
From: Ananyev, Konstantin @ 2015-03-26  1:20 UTC (permalink / raw)
  To: Zoltan Kiss, dev



> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Zoltan Kiss
> Sent: Wednesday, March 25, 2015 6:43 PM
> To: dev@dpdk.org
> Cc: Zoltan Kiss
> Subject: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
> 
> This macro and function were copies from the mbuf library, no reason to keep
> them.

NACK
You can't use RTE_MBUF_INDIRECT macro here.
If you'll look at vhost code carefully, you'll realise that we don't use standard rte_pktmbuf_attach() here.
As we attach mbuf not to another mbuf but to external memory buffer, passed to us by virtio device.
Look at attach_rxmbuf_zcp().
Though I suppose, we can replace pktmbuf_detach_zcp() , with  rte_pktmbuf_detach() - they are doing identical things.
BTW, I wonder did you ever  test your patch?
My guess it would cause vhost with '--zero-copy' to crash or  corrupt the packets straightway. 

Konstantin

> 
> Signed-off-by: Zoltan Kiss <zoltan.kiss@linaro.org>
> ---
>  examples/vhost/main.c | 38 +++++---------------------------------
>  1 file changed, 5 insertions(+), 33 deletions(-)
> 
> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
> index c3fcb80..1c998a5 100644
> --- a/examples/vhost/main.c
> +++ b/examples/vhost/main.c
> @@ -139,8 +139,6 @@
>  /* Number of descriptors per cacheline. */
>  #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
> 
> -#define MBUF_EXT_MEM(mb)   (RTE_MBUF_FROM_BADDR((mb)->buf_addr) != (mb))
> -
>  /* mask of enabled ports */
>  static uint32_t enabled_port_mask = 0;
> 
> @@ -1538,32 +1536,6 @@ attach_rxmbuf_zcp(struct virtio_net *dev)
>  	return;
>  }
> 
> -/*
> - * Detach an attched packet mbuf -
> - *  - restore original mbuf address and length values.
> - *  - reset pktmbuf data and data_len to their default values.
> - *  All other fields of the given packet mbuf will be left intact.
> - *
> - * @param m
> - *   The attached packet mbuf.
> - */
> -static inline void pktmbuf_detach_zcp(struct rte_mbuf *m)
> -{
> -	const struct rte_mempool *mp = m->pool;
> -	void *buf = RTE_MBUF_TO_BADDR(m);
> -	uint32_t buf_ofs;
> -	uint32_t buf_len = mp->elt_size - sizeof(*m);
> -	m->buf_physaddr = rte_mempool_virt2phy(mp, m) + sizeof(*m);
> -
> -	m->buf_addr = buf;
> -	m->buf_len = (uint16_t)buf_len;
> -
> -	buf_ofs = (RTE_PKTMBUF_HEADROOM <= m->buf_len) ?
> -			RTE_PKTMBUF_HEADROOM : m->buf_len;
> -	m->data_off = buf_ofs;
> -
> -	m->data_len = 0;
> -}
> 
>  /*
>   * This function is called after packets have been transimited. It fetchs mbuf
> @@ -1590,8 +1562,8 @@ txmbuf_clean_zcp(struct virtio_net *dev, struct vpool *vpool)
> 
>  	for (index = 0; index < mbuf_count; index++) {
>  		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
> -		if (likely(MBUF_EXT_MEM(mbuf)))
> -			pktmbuf_detach_zcp(mbuf);
> +		if (likely(RTE_MBUF_INDIRECT(mbuf)))
> +			rte_pktmbuf_detach(mbuf);
>  		rte_ring_sp_enqueue(vpool->ring, mbuf);
> 
>  		/* Update used index buffer information. */
> @@ -1653,8 +1625,8 @@ static void mbuf_destroy_zcp(struct vpool *vpool)
>  	for (index = 0; index < mbuf_count; index++) {
>  		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
>  		if (likely(mbuf != NULL)) {
> -			if (likely(MBUF_EXT_MEM(mbuf)))
> -				pktmbuf_detach_zcp(mbuf);
> +			if (likely(RTE_MBUF_INDIRECT(mbuf)))
> +				rte_pktmbuf_detach(mbuf);
>  			rte_ring_sp_enqueue(vpool->ring, (void *)mbuf);
>  		}
>  	}
> @@ -2149,7 +2121,7 @@ switch_worker_zcp(__attribute__((unused)) void *arg)
>  					}
>  					while (likely(rx_count)) {
>  						rx_count--;
> -						pktmbuf_detach_zcp(
> +						rte_pktmbuf_detach(
>  							pkts_burst[rx_count]);
>  						rte_ring_sp_enqueue(
>  							vpool_array[index].ring,
> --
> 1.9.1

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
  2015-03-26  1:20 ` Ananyev, Konstantin
@ 2015-03-26  3:32   ` Ouyang, Changchun
  2015-03-26 16:46   ` Zoltan Kiss
  1 sibling, 0 replies; 6+ messages in thread
From: Ouyang, Changchun @ 2015-03-26  3:32 UTC (permalink / raw)
  To: Ananyev, Konstantin, Zoltan Kiss, dev



> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Ananyev,
> Konstantin
> Sent: Thursday, March 26, 2015 9:21 AM
> To: Zoltan Kiss; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] examples/vhost: use library routines
> instead of local copies
> 
> 
> 
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Zoltan Kiss
> > Sent: Wednesday, March 25, 2015 6:43 PM
> > To: dev@dpdk.org
> > Cc: Zoltan Kiss
> > Subject: [dpdk-dev] [PATCH] examples/vhost: use library routines
> > instead of local copies
> >
> > This macro and function were copies from the mbuf library, no reason
> > to keep them.
> 
> NACK
> You can't use RTE_MBUF_INDIRECT macro here.
> If you'll look at vhost code carefully, you'll realise that we don't use standard
> rte_pktmbuf_attach() here.
> As we attach mbuf not to another mbuf but to external memory buffer,
> passed to us by virtio device.
> Look at attach_rxmbuf_zcp().
> Though I suppose, we can replace pktmbuf_detach_zcp() , with
> rte_pktmbuf_detach() - they are doing identical things.
> BTW, I wonder did you ever  test your patch?
> My guess it would cause vhost with '--zero-copy' to crash or  corrupt the
> packets straightway.
> 
> Konstantin
> 
> >
> > Signed-off-by: Zoltan Kiss <zoltan.kiss@linaro.org>

NACK this patch,
Same reason with Konstantin.
Changchun

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
  2015-03-26  1:20 ` Ananyev, Konstantin
  2015-03-26  3:32   ` Ouyang, Changchun
@ 2015-03-26 16:46   ` Zoltan Kiss
  2015-03-26 17:34     ` Ananyev, Konstantin
  1 sibling, 1 reply; 6+ messages in thread
From: Zoltan Kiss @ 2015-03-26 16:46 UTC (permalink / raw)
  To: Ananyev, Konstantin, dev



On 26/03/15 01:20, Ananyev, Konstantin wrote:
>
>
>> -----Original Message-----
>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Zoltan Kiss
>> Sent: Wednesday, March 25, 2015 6:43 PM
>> To: dev@dpdk.org
>> Cc: Zoltan Kiss
>> Subject: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
>>
>> This macro and function were copies from the mbuf library, no reason to keep
>> them.
>
> NACK
> You can't use RTE_MBUF_INDIRECT macro here.
> If you'll look at vhost code carefully, you'll realise that we don't use standard rte_pktmbuf_attach() here.
> As we attach mbuf not to another mbuf but to external memory buffer, passed to us by virtio device.
> Look at attach_rxmbuf_zcp().
Yes, I think the proper fix is to set the flag in attach_rxmbuf_zcp() 
and virtio_tx_route_zcp(), then you can use the library macro here.

> Though I suppose, we can replace pktmbuf_detach_zcp() , with  rte_pktmbuf_detach() - they are doing identical things.
Yes, the only difference is that the latter do "m->ol_flags = 0" as well.

> BTW, I wonder did you ever  test your patch?
Indeed I did not, shame on me. I don't have a KVM setup at hand. This 
fix were born as a side effect of the cleaning up in the library,
and I'm afraid I don't have the time right now to create a KVM setup. 
Could anyone who has it at hand help out to run a quick test? (for the 
v2 of this patch, which I'll send in shortly)

Regards,

Zoltan

> My guess it would cause vhost with '--zero-copy' to crash or  corrupt the packets straightway.
>
> Konstantin
>
>>
>> Signed-off-by: Zoltan Kiss <zoltan.kiss@linaro.org>
>> ---
>>   examples/vhost/main.c | 38 +++++---------------------------------
>>   1 file changed, 5 insertions(+), 33 deletions(-)
>>
>> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
>> index c3fcb80..1c998a5 100644
>> --- a/examples/vhost/main.c
>> +++ b/examples/vhost/main.c
>> @@ -139,8 +139,6 @@
>>   /* Number of descriptors per cacheline. */
>>   #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
>>
>> -#define MBUF_EXT_MEM(mb)   (RTE_MBUF_FROM_BADDR((mb)->buf_addr) != (mb))
>> -
>>   /* mask of enabled ports */
>>   static uint32_t enabled_port_mask = 0;
>>
>> @@ -1538,32 +1536,6 @@ attach_rxmbuf_zcp(struct virtio_net *dev)
>>   	return;
>>   }
>>
>> -/*
>> - * Detach an attched packet mbuf -
>> - *  - restore original mbuf address and length values.
>> - *  - reset pktmbuf data and data_len to their default values.
>> - *  All other fields of the given packet mbuf will be left intact.
>> - *
>> - * @param m
>> - *   The attached packet mbuf.
>> - */
>> -static inline void pktmbuf_detach_zcp(struct rte_mbuf *m)
>> -{
>> -	const struct rte_mempool *mp = m->pool;
>> -	void *buf = RTE_MBUF_TO_BADDR(m);
>> -	uint32_t buf_ofs;
>> -	uint32_t buf_len = mp->elt_size - sizeof(*m);
>> -	m->buf_physaddr = rte_mempool_virt2phy(mp, m) + sizeof(*m);
>> -
>> -	m->buf_addr = buf;
>> -	m->buf_len = (uint16_t)buf_len;
>> -
>> -	buf_ofs = (RTE_PKTMBUF_HEADROOM <= m->buf_len) ?
>> -			RTE_PKTMBUF_HEADROOM : m->buf_len;
>> -	m->data_off = buf_ofs;
>> -
>> -	m->data_len = 0;
>> -}
>>
>>   /*
>>    * This function is called after packets have been transimited. It fetchs mbuf
>> @@ -1590,8 +1562,8 @@ txmbuf_clean_zcp(struct virtio_net *dev, struct vpool *vpool)
>>
>>   	for (index = 0; index < mbuf_count; index++) {
>>   		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
>> -		if (likely(MBUF_EXT_MEM(mbuf)))
>> -			pktmbuf_detach_zcp(mbuf);
>> +		if (likely(RTE_MBUF_INDIRECT(mbuf)))
>> +			rte_pktmbuf_detach(mbuf);
>>   		rte_ring_sp_enqueue(vpool->ring, mbuf);
>>
>>   		/* Update used index buffer information. */
>> @@ -1653,8 +1625,8 @@ static void mbuf_destroy_zcp(struct vpool *vpool)
>>   	for (index = 0; index < mbuf_count; index++) {
>>   		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
>>   		if (likely(mbuf != NULL)) {
>> -			if (likely(MBUF_EXT_MEM(mbuf)))
>> -				pktmbuf_detach_zcp(mbuf);
>> +			if (likely(RTE_MBUF_INDIRECT(mbuf)))
>> +				rte_pktmbuf_detach(mbuf);
>>   			rte_ring_sp_enqueue(vpool->ring, (void *)mbuf);
>>   		}
>>   	}
>> @@ -2149,7 +2121,7 @@ switch_worker_zcp(__attribute__((unused)) void *arg)
>>   					}
>>   					while (likely(rx_count)) {
>>   						rx_count--;
>> -						pktmbuf_detach_zcp(
>> +						rte_pktmbuf_detach(
>>   							pkts_burst[rx_count]);
>>   						rte_ring_sp_enqueue(
>>   							vpool_array[index].ring,
>> --
>> 1.9.1
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
  2015-03-26 16:46   ` Zoltan Kiss
@ 2015-03-26 17:34     ` Ananyev, Konstantin
  2015-03-26 18:01       ` Zoltan Kiss
  0 siblings, 1 reply; 6+ messages in thread
From: Ananyev, Konstantin @ 2015-03-26 17:34 UTC (permalink / raw)
  To: Zoltan Kiss, dev



> -----Original Message-----
> From: Zoltan Kiss [mailto:zoltan.kiss@linaro.org]
> Sent: Thursday, March 26, 2015 4:46 PM
> To: Ananyev, Konstantin; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
> 
> 
> 
> On 26/03/15 01:20, Ananyev, Konstantin wrote:
> >
> >
> >> -----Original Message-----
> >> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Zoltan Kiss
> >> Sent: Wednesday, March 25, 2015 6:43 PM
> >> To: dev@dpdk.org
> >> Cc: Zoltan Kiss
> >> Subject: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
> >>
> >> This macro and function were copies from the mbuf library, no reason to keep
> >> them.
> >
> > NACK
> > You can't use RTE_MBUF_INDIRECT macro here.
> > If you'll look at vhost code carefully, you'll realise that we don't use standard rte_pktmbuf_attach() here.
> > As we attach mbuf not to another mbuf but to external memory buffer, passed to us by virtio device.
> > Look at attach_rxmbuf_zcp().
> Yes, I think the proper fix is to set the flag in attach_rxmbuf_zcp()
> and virtio_tx_route_zcp(), then you can use the library macro here.

No, it is not.
IND_ATTACHED_MBUF flag indicates that that mbuf attached to another mbuf and __rte_pktmbuf_prefree_seg()
would try to do mbuf detach.
We definetly don't want to set IND_ATTACHED_MBUF here.
I think there is no need to fix anything here.

Konstantin

> 
> > Though I suppose, we can replace pktmbuf_detach_zcp() , with  rte_pktmbuf_detach() - they are doing identical things.
> Yes, the only difference is that the latter do "m->ol_flags = 0" as well.
> 
> > BTW, I wonder did you ever  test your patch?
> Indeed I did not, shame on me. I don't have a KVM setup at hand. This
> fix were born as a side effect of the cleaning up in the library,
> and I'm afraid I don't have the time right now to create a KVM setup.
> Could anyone who has it at hand help out to run a quick test? (for the
> v2 of this patch, which I'll send in shortly)


> 
> Regards,
> 
> Zoltan
> 
> > My guess it would cause vhost with '--zero-copy' to crash or  corrupt the packets straightway.
> >
> > Konstantin
> >
> >>
> >> Signed-off-by: Zoltan Kiss <zoltan.kiss@linaro.org>
> >> ---
> >>   examples/vhost/main.c | 38 +++++---------------------------------
> >>   1 file changed, 5 insertions(+), 33 deletions(-)
> >>
> >> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
> >> index c3fcb80..1c998a5 100644
> >> --- a/examples/vhost/main.c
> >> +++ b/examples/vhost/main.c
> >> @@ -139,8 +139,6 @@
> >>   /* Number of descriptors per cacheline. */
> >>   #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
> >>
> >> -#define MBUF_EXT_MEM(mb)   (RTE_MBUF_FROM_BADDR((mb)->buf_addr) != (mb))
> >> -
> >>   /* mask of enabled ports */
> >>   static uint32_t enabled_port_mask = 0;
> >>
> >> @@ -1538,32 +1536,6 @@ attach_rxmbuf_zcp(struct virtio_net *dev)
> >>   	return;
> >>   }
> >>
> >> -/*
> >> - * Detach an attched packet mbuf -
> >> - *  - restore original mbuf address and length values.
> >> - *  - reset pktmbuf data and data_len to their default values.
> >> - *  All other fields of the given packet mbuf will be left intact.
> >> - *
> >> - * @param m
> >> - *   The attached packet mbuf.
> >> - */
> >> -static inline void pktmbuf_detach_zcp(struct rte_mbuf *m)
> >> -{
> >> -	const struct rte_mempool *mp = m->pool;
> >> -	void *buf = RTE_MBUF_TO_BADDR(m);
> >> -	uint32_t buf_ofs;
> >> -	uint32_t buf_len = mp->elt_size - sizeof(*m);
> >> -	m->buf_physaddr = rte_mempool_virt2phy(mp, m) + sizeof(*m);
> >> -
> >> -	m->buf_addr = buf;
> >> -	m->buf_len = (uint16_t)buf_len;
> >> -
> >> -	buf_ofs = (RTE_PKTMBUF_HEADROOM <= m->buf_len) ?
> >> -			RTE_PKTMBUF_HEADROOM : m->buf_len;
> >> -	m->data_off = buf_ofs;
> >> -
> >> -	m->data_len = 0;
> >> -}
> >>
> >>   /*
> >>    * This function is called after packets have been transimited. It fetchs mbuf
> >> @@ -1590,8 +1562,8 @@ txmbuf_clean_zcp(struct virtio_net *dev, struct vpool *vpool)
> >>
> >>   	for (index = 0; index < mbuf_count; index++) {
> >>   		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
> >> -		if (likely(MBUF_EXT_MEM(mbuf)))
> >> -			pktmbuf_detach_zcp(mbuf);
> >> +		if (likely(RTE_MBUF_INDIRECT(mbuf)))
> >> +			rte_pktmbuf_detach(mbuf);
> >>   		rte_ring_sp_enqueue(vpool->ring, mbuf);
> >>
> >>   		/* Update used index buffer information. */
> >> @@ -1653,8 +1625,8 @@ static void mbuf_destroy_zcp(struct vpool *vpool)
> >>   	for (index = 0; index < mbuf_count; index++) {
> >>   		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
> >>   		if (likely(mbuf != NULL)) {
> >> -			if (likely(MBUF_EXT_MEM(mbuf)))
> >> -				pktmbuf_detach_zcp(mbuf);
> >> +			if (likely(RTE_MBUF_INDIRECT(mbuf)))
> >> +				rte_pktmbuf_detach(mbuf);
> >>   			rte_ring_sp_enqueue(vpool->ring, (void *)mbuf);
> >>   		}
> >>   	}
> >> @@ -2149,7 +2121,7 @@ switch_worker_zcp(__attribute__((unused)) void *arg)
> >>   					}
> >>   					while (likely(rx_count)) {
> >>   						rx_count--;
> >> -						pktmbuf_detach_zcp(
> >> +						rte_pktmbuf_detach(
> >>   							pkts_burst[rx_count]);
> >>   						rte_ring_sp_enqueue(
> >>   							vpool_array[index].ring,
> >> --
> >> 1.9.1
> >

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
  2015-03-26 17:34     ` Ananyev, Konstantin
@ 2015-03-26 18:01       ` Zoltan Kiss
  0 siblings, 0 replies; 6+ messages in thread
From: Zoltan Kiss @ 2015-03-26 18:01 UTC (permalink / raw)
  To: Ananyev, Konstantin, dev



On 26/03/15 17:34, Ananyev, Konstantin wrote:
>
>
>> -----Original Message-----
>> From: Zoltan Kiss [mailto:zoltan.kiss@linaro.org]
>> Sent: Thursday, March 26, 2015 4:46 PM
>> To: Ananyev, Konstantin; dev@dpdk.org
>> Subject: Re: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
>>
>>
>>
>> On 26/03/15 01:20, Ananyev, Konstantin wrote:
>>>
>>>
>>>> -----Original Message-----
>>>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Zoltan Kiss
>>>> Sent: Wednesday, March 25, 2015 6:43 PM
>>>> To: dev@dpdk.org
>>>> Cc: Zoltan Kiss
>>>> Subject: [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies
>>>>
>>>> This macro and function were copies from the mbuf library, no reason to keep
>>>> them.
>>>
>>> NACK
>>> You can't use RTE_MBUF_INDIRECT macro here.
>>> If you'll look at vhost code carefully, you'll realise that we don't use standard rte_pktmbuf_attach() here.
>>> As we attach mbuf not to another mbuf but to external memory buffer, passed to us by virtio device.
>>> Look at attach_rxmbuf_zcp().
>> Yes, I think the proper fix is to set the flag in attach_rxmbuf_zcp()
>> and virtio_tx_route_zcp(), then you can use the library macro here.
>
> No, it is not.
> IND_ATTACHED_MBUF flag indicates that that mbuf attached to another mbuf and __rte_pktmbuf_prefree_seg()
> would try to do mbuf detach.
> We definetly don't want to set IND_ATTACHED_MBUF here.
I see. Quite confusing how vhost reuse some library code to do something 
slightly different.

> I think there is no need to fix anything here.
>
> Konstantin
>
>>
>>> Though I suppose, we can replace pktmbuf_detach_zcp() , with  rte_pktmbuf_detach() - they are doing identical things.
>> Yes, the only difference is that the latter do "m->ol_flags = 0" as well.
>>
>>> BTW, I wonder did you ever  test your patch?
>> Indeed I did not, shame on me. I don't have a KVM setup at hand. This
>> fix were born as a side effect of the cleaning up in the library,
>> and I'm afraid I don't have the time right now to create a KVM setup.
>> Could anyone who has it at hand help out to run a quick test? (for the
>> v2 of this patch, which I'll send in shortly)
>
>
>>
>> Regards,
>>
>> Zoltan
>>
>>> My guess it would cause vhost with '--zero-copy' to crash or  corrupt the packets straightway.
>>>
>>> Konstantin
>>>
>>>>
>>>> Signed-off-by: Zoltan Kiss <zoltan.kiss@linaro.org>
>>>> ---
>>>>    examples/vhost/main.c | 38 +++++---------------------------------
>>>>    1 file changed, 5 insertions(+), 33 deletions(-)
>>>>
>>>> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
>>>> index c3fcb80..1c998a5 100644
>>>> --- a/examples/vhost/main.c
>>>> +++ b/examples/vhost/main.c
>>>> @@ -139,8 +139,6 @@
>>>>    /* Number of descriptors per cacheline. */
>>>>    #define DESC_PER_CACHELINE (RTE_CACHE_LINE_SIZE / sizeof(struct vring_desc))
>>>>
>>>> -#define MBUF_EXT_MEM(mb)   (RTE_MBUF_FROM_BADDR((mb)->buf_addr) != (mb))
>>>> -
>>>>    /* mask of enabled ports */
>>>>    static uint32_t enabled_port_mask = 0;
>>>>
>>>> @@ -1538,32 +1536,6 @@ attach_rxmbuf_zcp(struct virtio_net *dev)
>>>>    	return;
>>>>    }
>>>>
>>>> -/*
>>>> - * Detach an attched packet mbuf -
>>>> - *  - restore original mbuf address and length values.
>>>> - *  - reset pktmbuf data and data_len to their default values.
>>>> - *  All other fields of the given packet mbuf will be left intact.
>>>> - *
>>>> - * @param m
>>>> - *   The attached packet mbuf.
>>>> - */
>>>> -static inline void pktmbuf_detach_zcp(struct rte_mbuf *m)
>>>> -{
>>>> -	const struct rte_mempool *mp = m->pool;
>>>> -	void *buf = RTE_MBUF_TO_BADDR(m);
>>>> -	uint32_t buf_ofs;
>>>> -	uint32_t buf_len = mp->elt_size - sizeof(*m);
>>>> -	m->buf_physaddr = rte_mempool_virt2phy(mp, m) + sizeof(*m);
>>>> -
>>>> -	m->buf_addr = buf;
>>>> -	m->buf_len = (uint16_t)buf_len;
>>>> -
>>>> -	buf_ofs = (RTE_PKTMBUF_HEADROOM <= m->buf_len) ?
>>>> -			RTE_PKTMBUF_HEADROOM : m->buf_len;
>>>> -	m->data_off = buf_ofs;
>>>> -
>>>> -	m->data_len = 0;
>>>> -}
>>>>
>>>>    /*
>>>>     * This function is called after packets have been transimited. It fetchs mbuf
>>>> @@ -1590,8 +1562,8 @@ txmbuf_clean_zcp(struct virtio_net *dev, struct vpool *vpool)
>>>>
>>>>    	for (index = 0; index < mbuf_count; index++) {
>>>>    		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
>>>> -		if (likely(MBUF_EXT_MEM(mbuf)))
>>>> -			pktmbuf_detach_zcp(mbuf);
>>>> +		if (likely(RTE_MBUF_INDIRECT(mbuf)))
>>>> +			rte_pktmbuf_detach(mbuf);
>>>>    		rte_ring_sp_enqueue(vpool->ring, mbuf);
>>>>
>>>>    		/* Update used index buffer information. */
>>>> @@ -1653,8 +1625,8 @@ static void mbuf_destroy_zcp(struct vpool *vpool)
>>>>    	for (index = 0; index < mbuf_count; index++) {
>>>>    		mbuf = __rte_mbuf_raw_alloc(vpool->pool);
>>>>    		if (likely(mbuf != NULL)) {
>>>> -			if (likely(MBUF_EXT_MEM(mbuf)))
>>>> -				pktmbuf_detach_zcp(mbuf);
>>>> +			if (likely(RTE_MBUF_INDIRECT(mbuf)))
>>>> +				rte_pktmbuf_detach(mbuf);
>>>>    			rte_ring_sp_enqueue(vpool->ring, (void *)mbuf);
>>>>    		}
>>>>    	}
>>>> @@ -2149,7 +2121,7 @@ switch_worker_zcp(__attribute__((unused)) void *arg)
>>>>    					}
>>>>    					while (likely(rx_count)) {
>>>>    						rx_count--;
>>>> -						pktmbuf_detach_zcp(
>>>> +						rte_pktmbuf_detach(
>>>>    							pkts_burst[rx_count]);
>>>>    						rte_ring_sp_enqueue(
>>>>    							vpool_array[index].ring,
>>>> --
>>>> 1.9.1
>>>

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2015-03-26 18:01 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-03-25 18:43 [dpdk-dev] [PATCH] examples/vhost: use library routines instead of local copies Zoltan Kiss
2015-03-26  1:20 ` Ananyev, Konstantin
2015-03-26  3:32   ` Ouyang, Changchun
2015-03-26 16:46   ` Zoltan Kiss
2015-03-26 17:34     ` Ananyev, Konstantin
2015-03-26 18:01       ` Zoltan Kiss

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).