[PATCH RFC 0/1] Return -EINVAL if device's ack is VIRTIO_NET_ERR

[PATCH RFC 0/1] Return -EINVAL if device's ack is VIRTIO_NET_ERR

[Hawkins Jiawei]

This patch fixes the problem that vhost_net_start_one() doesn't cancel
the device startup and returns 0 even if the device's ack is VIRTIO_NET_ERR
in net->nc->info->load().

Note that this problem also exists in
patch "vdpa: Add vhost_vdpa_net_load_offloads()" at [1].
Because this patch has not been merged yet, so I will submit the v2 patch
to fix the problem in that patch once the pending patch
has been successfully merged.

[1]. https://lists.nongnu.org/archive/html/qemu-devel/2023-06/msg00504.html

Hawkins Jiawei (1):
  vdpa: Return -EINVAL if device's ack is VIRTIO_NET_ERR

 net/vhost-vdpa.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

-- 
2.25.1

[PATCH RFC 1/1] vdpa: Return -EINVAL if device's ack is VIRTIO_NET_ERR

[Hawkins Jiawei]

According to VirtIO standard, "The class, command and
command-specific-data are set by the driver,
and the device sets the ack byte.
There is little it can do except issue a diagnostic
if ack is not VIRTIO_NET_OK."

Therefore, QEMU should stop sending the queued SVQ commands and
cancel the device startup if the device's ack is not VIRTIO_NET_OK.

Yet the problem is that, vhost_vdpa_net_load_x() returns 1 based on
`*s->status != VIRTIO_NET_OK` when the device's ack is VIRTIO_NET_ERR.
As a result, net->nc->info->load() also returns 1, this makes
vhost_net_start_one() incorrectly assume the device state is
successfully loaded by vhost_vdpa_net_load() and return 0, instead of
goto `fail` label to cancel the device startup, as vhost_net_start_one()
only cancels the device startup when net->nc->info->load() returns a
negative value.

This patch fixes this problem by returning -EINVAL when the device's
ack is not VIRTIO_NET_OK.

Fixes: f73c0c43ac ("vdpa: extract vhost_vdpa_net_load_mac from vhost_vdpa_net_load")
Fixes: f64c7cda69 ("vdpa: Add vhost_vdpa_net_load_mq")
Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
---
 net/vhost-vdpa.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 37cdc84562..630c9bf71e 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -651,8 +651,9 @@ static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n)
         if (unlikely(dev_written < 0)) {
             return dev_written;
         }
-
-        return *s->status != VIRTIO_NET_OK;
+        if (*s->status != VIRTIO_NET_OK) {
+            return -EINVAL;
+        }
     }
 
     return 0;
@@ -676,8 +677,11 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
     if (unlikely(dev_written < 0)) {
         return dev_written;
     }
+    if (*s->status != VIRTIO_NET_OK) {
+        return -EINVAL;
+    }
 
-    return *s->status != VIRTIO_NET_OK;
+    return 0;
 }
 
 static int vhost_vdpa_net_load(NetClientState *nc)
-- 
2.25.1

Re: [PATCH RFC 1/1] vdpa: Return -EINVAL if device's ack is VIRTIO_NET_ERR

[Eugenio Perez Martin]

On Wed, Jun 14, 2023 at 3:02 PM Hawkins Jiawei <yin31149@gmail.com> wrote:
>
> According to VirtIO standard, "The class, command and
> command-specific-data are set by the driver,
> and the device sets the ack byte.
> There is little it can do except issue a diagnostic
> if ack is not VIRTIO_NET_OK."
>
> Therefore, QEMU should stop sending the queued SVQ commands and
> cancel the device startup if the device's ack is not VIRTIO_NET_OK.
>
> Yet the problem is that, vhost_vdpa_net_load_x() returns 1 based on
> `*s->status != VIRTIO_NET_OK` when the device's ack is VIRTIO_NET_ERR.
> As a result, net->nc->info->load() also returns 1, this makes
> vhost_net_start_one() incorrectly assume the device state is
> successfully loaded by vhost_vdpa_net_load() and return 0, instead of
> goto `fail` label to cancel the device startup, as vhost_net_start_one()
> only cancels the device startup when net->nc->info->load() returns a
> negative value.
>
> This patch fixes this problem by returning -EINVAL when the device's
> ack is not VIRTIO_NET_OK.
>
> Fixes: f73c0c43ac ("vdpa: extract vhost_vdpa_net_load_mac from vhost_vdpa_net_load")
> Fixes: f64c7cda69 ("vdpa: Add vhost_vdpa_net_load_mq")
> Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>

Maybe we could split the fixes? Either way:

Acked-by: Eugenio Pérez <eperezma@redhat.com>

Thanks!

> ---
>  net/vhost-vdpa.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 37cdc84562..630c9bf71e 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -651,8 +651,9 @@ static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n)
>          if (unlikely(dev_written < 0)) {
>              return dev_written;
>          }
> -
> -        return *s->status != VIRTIO_NET_OK;
> +        if (*s->status != VIRTIO_NET_OK) {
> +            return -EINVAL;
> +        }
>      }
>
>      return 0;
> @@ -676,8 +677,11 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
>      if (unlikely(dev_written < 0)) {
>          return dev_written;
>      }
> +    if (*s->status != VIRTIO_NET_OK) {
> +        return -EINVAL;
> +    }
>
> -    return *s->status != VIRTIO_NET_OK;
> +    return 0;
>  }
>
>  static int vhost_vdpa_net_load(NetClientState *nc)
> --
> 2.25.1
>

Re: [PATCH RFC 1/1] vdpa: Return -EINVAL if device's ack is VIRTIO_NET_ERR

[Michael S. Tsirkin]

On Wed, Jun 14, 2023 at 09:01:47PM +0800, Hawkins Jiawei wrote:
> According to VirtIO standard, "The class, command and
> command-specific-data are set by the driver,
> and the device sets the ack byte.
> There is little it can do except issue a diagnostic
> if ack is not VIRTIO_NET_OK."
> 
> Therefore, QEMU should stop sending the queued SVQ commands and
> cancel the device startup if the device's ack is not VIRTIO_NET_OK.
> 
> Yet the problem is that, vhost_vdpa_net_load_x() returns 1 based on
> `*s->status != VIRTIO_NET_OK` when the device's ack is VIRTIO_NET_ERR.
> As a result, net->nc->info->load() also returns 1, this makes
> vhost_net_start_one() incorrectly assume the device state is
> successfully loaded by vhost_vdpa_net_load() and return 0, instead of
> goto `fail` label to cancel the device startup, as vhost_net_start_one()
> only cancels the device startup when net->nc->info->load() returns a
> negative value.
> 
> This patch fixes this problem by returning -EINVAL when the device's
> ack is not VIRTIO_NET_OK.
> 
> Fixes: f73c0c43ac ("vdpa: extract vhost_vdpa_net_load_mac from vhost_vdpa_net_load")
> Fixes: f64c7cda69 ("vdpa: Add vhost_vdpa_net_load_mq")
> Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
> ---
>  net/vhost-vdpa.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 37cdc84562..630c9bf71e 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -651,8 +651,9 @@ static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n)
>          if (unlikely(dev_written < 0)) {
>              return dev_written;
>          }
> -
> -        return *s->status != VIRTIO_NET_OK;
> +        if (*s->status != VIRTIO_NET_OK) {
> +            return -EINVAL;
> +        }
>      }
>  
>      return 0;
> @@ -676,8 +677,11 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
>      if (unlikely(dev_written < 0)) {
>          return dev_written;
>      }
> +    if (*s->status != VIRTIO_NET_OK) {
> +        return -EINVAL;
> +    }
>  
> -    return *s->status != VIRTIO_NET_OK;
> +    return 0;
>  }

I think EIO would be better, we have too many EINVAL cases,
making things hard to debug.


>  
>  static int vhost_vdpa_net_load(NetClientState *nc)
> -- 
> 2.25.1

Re: [PATCH RFC 1/1] vdpa: Return -EINVAL if device's ack is VIRTIO_NET_ERR

[Hawkins Jiawei]

On 2023/7/4 0:38, Eugenio Perez Martin wrote:
> On Wed, Jun 14, 2023 at 3:02 PM Hawkins Jiawei <yin31149@gmail.com> wrote:
>>
>> According to VirtIO standard, "The class, command and
>> command-specific-data are set by the driver,
>> and the device sets the ack byte.
>> There is little it can do except issue a diagnostic
>> if ack is not VIRTIO_NET_OK."
>>
>> Therefore, QEMU should stop sending the queued SVQ commands and
>> cancel the device startup if the device's ack is not VIRTIO_NET_OK.
>>
>> Yet the problem is that, vhost_vdpa_net_load_x() returns 1 based on
>> `*s->status != VIRTIO_NET_OK` when the device's ack is VIRTIO_NET_ERR.
>> As a result, net->nc->info->load() also returns 1, this makes
>> vhost_net_start_one() incorrectly assume the device state is
>> successfully loaded by vhost_vdpa_net_load() and return 0, instead of
>> goto `fail` label to cancel the device startup, as vhost_net_start_one()
>> only cancels the device startup when net->nc->info->load() returns a
>> negative value.
>>
>> This patch fixes this problem by returning -EINVAL when the device's
>> ack is not VIRTIO_NET_OK.
>>
>> Fixes: f73c0c43ac ("vdpa: extract vhost_vdpa_net_load_mac from vhost_vdpa_net_load")
>> Fixes: f64c7cda69 ("vdpa: Add vhost_vdpa_net_load_mq")
>> Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
>
> Maybe we could split the fixes? Either way:

OK, I will split these fixes according to your suggestion.

Thanks!


>
> Acked-by: Eugenio Pérez <eperezma@redhat.com>
>
> Thanks!
>
>> ---
>>   net/vhost-vdpa.c | 10 +++++++---
>>   1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
>> index 37cdc84562..630c9bf71e 100644
>> --- a/net/vhost-vdpa.c
>> +++ b/net/vhost-vdpa.c
>> @@ -651,8 +651,9 @@ static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n)
>>           if (unlikely(dev_written < 0)) {
>>               return dev_written;
>>           }
>> -
>> -        return *s->status != VIRTIO_NET_OK;
>> +        if (*s->status != VIRTIO_NET_OK) {
>> +            return -EINVAL;
>> +        }
>>       }
>>
>>       return 0;
>> @@ -676,8 +677,11 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
>>       if (unlikely(dev_written < 0)) {
>>           return dev_written;
>>       }
>> +    if (*s->status != VIRTIO_NET_OK) {
>> +        return -EINVAL;
>> +    }
>>
>> -    return *s->status != VIRTIO_NET_OK;
>> +    return 0;
>>   }
>>
>>   static int vhost_vdpa_net_load(NetClientState *nc)
>> --
>> 2.25.1
>>
>

Re: [PATCH RFC 1/1] vdpa: Return -EINVAL if device's ack is VIRTIO_NET_ERR

[Hawkins Jiawei]

On 2023/7/4 0:52, Michael S. Tsirkin wrote:
> On Wed, Jun 14, 2023 at 09:01:47PM +0800, Hawkins Jiawei wrote:
>> According to VirtIO standard, "The class, command and
>> command-specific-data are set by the driver,
>> and the device sets the ack byte.
>> There is little it can do except issue a diagnostic
>> if ack is not VIRTIO_NET_OK."
>>
>> Therefore, QEMU should stop sending the queued SVQ commands and
>> cancel the device startup if the device's ack is not VIRTIO_NET_OK.
>>
>> Yet the problem is that, vhost_vdpa_net_load_x() returns 1 based on
>> `*s->status != VIRTIO_NET_OK` when the device's ack is VIRTIO_NET_ERR.
>> As a result, net->nc->info->load() also returns 1, this makes
>> vhost_net_start_one() incorrectly assume the device state is
>> successfully loaded by vhost_vdpa_net_load() and return 0, instead of
>> goto `fail` label to cancel the device startup, as vhost_net_start_one()
>> only cancels the device startup when net->nc->info->load() returns a
>> negative value.
>>
>> This patch fixes this problem by returning -EINVAL when the device's
>> ack is not VIRTIO_NET_OK.
>>
>> Fixes: f73c0c43ac ("vdpa: extract vhost_vdpa_net_load_mac from vhost_vdpa_net_load")
>> Fixes: f64c7cda69 ("vdpa: Add vhost_vdpa_net_load_mq")
>> Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
>> ---
>>   net/vhost-vdpa.c | 10 +++++++---
>>   1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
>> index 37cdc84562..630c9bf71e 100644
>> --- a/net/vhost-vdpa.c
>> +++ b/net/vhost-vdpa.c
>> @@ -651,8 +651,9 @@ static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n)
>>           if (unlikely(dev_written < 0)) {
>>               return dev_written;
>>           }
>> -
>> -        return *s->status != VIRTIO_NET_OK;
>> +        if (*s->status != VIRTIO_NET_OK) {
>> +            return -EINVAL;
>> +        }
>>       }
>>
>>       return 0;
>> @@ -676,8 +677,11 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s,
>>       if (unlikely(dev_written < 0)) {
>>           return dev_written;
>>       }
>> +    if (*s->status != VIRTIO_NET_OK) {
>> +        return -EINVAL;
>> +    }
>>
>> -    return *s->status != VIRTIO_NET_OK;
>> +    return 0;
>>   }
>
> I think EIO would be better, we have too many EINVAL cases,
> making things hard to debug.

I will refactor this patch to return -EIO according to your suggestion.

Thanks!

>
>
>>

>>   static int vhost_vdpa_net_load(NetClientState *nc)
>> --
>> 2.25.1
>