From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Ferruh Yigit <ferruh.yigit@intel.com>,
dev@dpdk.org, thomas@monjalon.net, tiwei.bie@intel.com,
zhihong.wang@intel.com, jfreiman@redhat.com
Cc: stable@dpdk.org
Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH] vhost: fix packed ring defines declaration
Date: Thu, 22 Nov 2018 19:51:08 +0100 [thread overview]
Message-ID: <5437708e-d8cf-fe17-6fd6-fad67b3a0eb7@redhat.com> (raw)
In-Reply-To: <be131e16-1fe8-a02b-8299-76f3a17a07d1@intel.com>
On 11/22/18 7:23 PM, Ferruh Yigit wrote:
> On 11/22/2018 5:09 PM, Maxime Coquelin wrote:
>> The packed ring defines were declared only if kernel
>> header does not declare them.
>> The problem is that they are not applied in upstream kernel,
>> and some changes in the names have been required.
>>
>> This patch declares the defines unconditionally, which
>> fixes potential build issues.
>
> +1 to address possible build issues.
>
>>
>> Fixes: 297b1e7350f6 ("vhost: add virtio packed virtqueue defines")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> ---
>> lib/librte_vhost/vhost.h | 22 +++++++++++-----------
>> 1 file changed, 11 insertions(+), 11 deletions(-)
>>
>> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
>> index 760f42192..5218f1b12 100644
>> --- a/lib/librte_vhost/vhost.h
>> +++ b/lib/librte_vhost/vhost.h
>> @@ -219,13 +219,6 @@ struct vhost_msg {
>>
>> #define VIRTIO_F_RING_PACKED 34
>>
>> -#define VRING_DESC_F_NEXT 1
>> -#define VRING_DESC_F_WRITE 2
>> -#define VRING_DESC_F_INDIRECT 4
>
> Why these are not re-defined below? Not used?
These defines are in kernel headers since the beginning of virtio
support, so there are no reasons to keep them (and they aren't packed-
ring specific).
I can let them if you prefer, it does not hurt but shouldn't be here.
>> -
>> -#define VRING_DESC_F_AVAIL (1ULL << 7)
>> -#define VRING_DESC_F_USED (1ULL << 15)
>> -
>> struct vring_packed_desc {
>> uint64_t addr;
>> uint32_t len;
>> @@ -233,16 +226,23 @@ struct vring_packed_desc {
>> uint16_t flags;
>> };
>>
>> -#define VRING_EVENT_F_ENABLE 0x0
>> -#define VRING_EVENT_F_DISABLE 0x1
>> -#define VRING_EVENT_F_DESC 0x2
>> -
>> struct vring_packed_desc_event {
>> uint16_t off_wrap;
>> uint16_t flags;
>> };
>> #endif
>>
>> +/*
>> + * Declare below packed ring defines unconditionally
>> + * as Kernel header might use different names.
>> + */
>> +#define VRING_DESC_F_AVAIL (1ULL << 7)
>> +#define VRING_DESC_F_USED (1ULL << 15)
>> +
>> +#define VRING_EVENT_F_ENABLE 0x0
>> +#define VRING_EVENT_F_DISABLE 0x1
>> +#define VRING_EVENT_F_DESC 0x2
>
> What if Linux changes mind and uses old names again, build will fail again. If
> related part in Linux is not released yet, what do you think being on safe side
> and adding these defines with "#ifndef" wrap?
There are the "old" ones.
In any case it will work (I tested it).
In a future release, I plan to get rid of this dependency with Kernel
which only causes problems.
There was a benefit at the beginning when all needed declarations where
in the Kernel headers. But now, every time we add a new virtio feature,
we have to check kernel supports it and if not define it.
Thanks,
Maxime
>> +
>> /*
>> * Available and used descs are in same order
>> */
>>
>
next prev parent reply other threads:[~2018-11-22 18:51 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-22 17:09 [dpdk-stable] " Maxime Coquelin
2018-11-22 18:23 ` [dpdk-stable] [dpdk-dev] " Ferruh Yigit
2018-11-22 18:51 ` Maxime Coquelin [this message]
2018-11-22 19:20 ` Ferruh Yigit
2018-11-22 19:50 ` Maxime Coquelin
2018-11-22 22:04 ` Ferruh Yigit
2018-11-22 22:14 ` Ferruh Yigit
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