From: Thomas Falcon <tlfalcon@linux.ibm.com>
To: Michal Kubecek <mkubecek@suse.cz>, netdev@vger.kernel.org
Cc: Cris Forno <cforno12@linux.vnet.ibm.com>,
mst@redhat.com, jasowang@redhat.com, haiyangz@microsoft.com,
sthemmin@microsoft.com, sashal@kernel.org,
David Miller <davem@davemloft.net>,
Jakub Kicinski <jakub.kicinski@netronome.com>
Subject: Re: [PATCH, net-next, v3, 1/2] Three virtual devices (ibmveth, virtio_net, and netvsc) all have similar code to set/get link settings and validate ethtool command. To eliminate duplication of code, it is factored out into core/ethtool.c.
Date: Thu, 19 Dec 2019 19:26:14 -0600 [thread overview]
Message-ID: <bac064bd-fba1-e453-7754-022ea6a191f2@linux.ibm.com> (raw)
In-Reply-To: <20191219223603.GC21614@unicorn.suse.cz>
On 12/19/19 4:36 PM, Michal Kubecek wrote:
> On Thu, Dec 19, 2019 at 01:40:56PM -0600, Cris Forno wrote:
>> Signed-off-by: Cris Forno <cforno12@linux.vnet.ibm.com>
Hi Michal, thanks for your comments. I have a question on your
suggestions for the ethtool_virtdev_validate_cmd below.
>> ---
>> include/linux/ethtool.h | 2 ++
>> net/core/ethtool.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 60 insertions(+)
>>
>> diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
>> index 95991e43..1b0417b 100644
>> --- a/include/linux/ethtool.h
>> +++ b/include/linux/ethtool.h
>> @@ -394,6 +394,8 @@ struct ethtool_ops {
>> struct ethtool_coalesce *);
>> int (*set_per_queue_coalesce)(struct net_device *, u32,
>> struct ethtool_coalesce *);
>> + bool (*virtdev_validate_link_ksettings)(const struct
>> + ethtool_link_ksettings *);
>> int (*get_link_ksettings)(struct net_device *,
>> struct ethtool_link_ksettings *);
>> int (*set_link_ksettings)(struct net_device *,
>> diff --git a/net/core/ethtool.c b/net/core/ethtool.c
>> index cd9bc67..4091a94 100644
>> --- a/net/core/ethtool.c
>> +++ b/net/core/ethtool.c
> You should probably rebase on top of current net-next; this file has
> been moved to net/ethtool/ioctl.c recently.
>
>> @@ -579,6 +579,32 @@ static int load_link_ksettings_from_user(struct ethtool_link_ksettings *to,
>> return 0;
>> }
>>
>> +/* Check if the user is trying to change anything besides speed/duplex */
>> +static bool
>> +ethtool_virtdev_validate_cmd(const struct ethtool_link_ksettings *cmd)
>> +{
>> + struct ethtool_link_ksettings diff1 = *cmd;
>> + struct ethtool_link_ksettings diff2 = {};
>> +
>> + /* cmd is always set so we need to clear it, validate the port type
>> + * and also without autonegotiation we can ignore advertising
>> + */
>> + diff1.base.speed = 0;
>> + diff2.base.port = PORT_OTHER;
>> + ethtool_link_ksettings_zero_link_mode(&diff1, advertising);
>> + diff1.base.duplex = 0;
>> + diff1.base.cmd = 0;
>> + diff1.base.link_mode_masks_nwords = 0;
>> +
>> + return !memcmp(&diff1.base, &diff2.base, sizeof(diff1.base)) &&
>> + bitmap_empty(diff1.link_modes.supported,
>> + __ETHTOOL_LINK_MODE_MASK_NBITS) &&
>> + bitmap_empty(diff1.link_modes.advertising,
>> + __ETHTOOL_LINK_MODE_MASK_NBITS) &&
> Isn't this condition always true? You zeroed the advertising bitmap
> above. Could you just omit this part and clearing of advertising above?
>
>> + bitmap_empty(diff1.link_modes.lp_advertising,
>> + __ETHTOOL_LINK_MODE_MASK_NBITS);
>> +}
> Another idea: instead of zeroing parts of diff1, you could copy these
> members from *cmd to diff2 and compare cmd->base with diff2.base. You
> could then drop diff1. And you wouldn't even need whole struct
> ethtool_link_ksettings for diff2 as you only compare embedded struct
> ethtool_link_settings (and check two bitmaps in cmd->link_modes).
If I understand your suggestion correctly, then the validate function
might look something like this?
/* Check if the user is trying to change anything besides speed/duplex */
static bool
ethtool_virtdev_validate_cmd(const struct ethtool_link_ksettings *cmd)
{
struct ethtool_link_settings base2 = {};
base2.speed = cmd->base.speed;
base2.port = PORT_OTHER;
base2.duplex = cmd->base.duplex;
base2.cmd = cmd->base.cmd;
base2.link_mode_masks_nwords = cmd->base.link_mode_masks_nwords;
return !memcmp(&base2, cmd->base, sizeof(base2)) &&
bitmap_empty(cmd->link_modes.supported,
__ETHTOOL_LINK_MODE_MASK_NBITS) &&
bitmap_empty(cmd->link_modes.lp_advertising,
__ETHTOOL_LINK_MODE_MASK_NBITS);
}
Thanks again,
Tom
>
>> +
>> /* convert a kernel internal ethtool_link_ksettings to
>> * ethtool_link_usettings in user space. return 0 on success, errno on
>> * error.
>> @@ -660,6 +686,17 @@ static int ethtool_get_link_ksettings(struct net_device *dev,
>> return store_link_ksettings_for_user(useraddr, &link_ksettings);
>> }
>>
>> +static int
>> +ethtool_virtdev_get_link_ksettings(struct net_device *dev,
>> + struct ethtool_link_ksettings *cmd,
>> + u32 *speed, u8 *duplex)
>> +{
>> + cmd->base.speed = *speed;
>> + cmd->base.duplex = *duplex;
>> + cmd->base.port = PORT_OTHER;
>> + return 0;
>> +}
> speed and duplex can be passed by value here; if you prefer pointers,
> please make them const.
>
> Michal Kubecek
next prev parent reply other threads:[~2019-12-20 1:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-19 19:40 [PATCH, net-next, v3, 0/2] net/ethtool: Introduce link_ksettings API for virtual network devices Cris Forno
2019-12-19 19:40 ` [PATCH, net-next, v3, 1/2] Three virtual devices (ibmveth, virtio_net, and netvsc) all have similar code to set/get link settings and validate ethtool command. To eliminate duplication of code, it is factored out into core/ethtool.c Cris Forno
2019-12-19 22:36 ` Michal Kubecek
2019-12-20 1:26 ` Thomas Falcon [this message]
2019-12-20 7:04 ` Michal Kubecek
2020-01-07 17:40 ` Cristobal Forno
2019-12-19 19:40 ` [PATCH, net-next, v3, 2/2] With get/set link settings functions in core/ethtool.c, ibmveth, netvsc, and virtio now use the core's helper function Cris Forno
2019-12-19 21:11 ` [PATCH, net-next, v3, 0/2] net/ethtool: Introduce link_ksettings API for virtual network devices Stephen Hemminger
2019-12-19 22:16 ` David Miller
2019-12-20 3:29 ` Stephen Hemminger
2019-12-20 22:53 ` David Miller
2019-12-20 3:58 ` Stephen Hemminger
2019-12-20 22:30 ` Stephen Hemminger
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