Date:   Mon, 21 Feb 2022 13:24:48 +0200
From:   Eli Cohen <elic@...dia.com>
To:     Jason Wang <jasowang@...hat.com>
CC:     <stephen@...workplumber.org>, <netdev@...r.kernel.org>,
        <lulu@...hat.com>, <si-wei.liu@...cle.com>
Subject: Re: [PATCH v2 2/4] vdpa: Allow for printing negotiated features of a
 device

On Mon, Feb 21, 2022 at 11:57:02AM +0800, Jason Wang wrote:
> 
> 在 2022/2/17 下午8:30, Eli Cohen 写道:
> > When reading the configuration of a vdpa device, check if the
> > VDPA_ATTR_DEV_NEGOTIATED_FEATURES is available. If it is, parse the
> > feature bits and print a string representation of each of the feature
> > bits.
> > 
> > We keep the strings in two different arrays. One for net device related
> > devices and one for generic feature bits.
> > 
> > In this patch we parse only net device specific features. Support for
> > other devices can be added later. If the device queried is not a net
> > device, we print its bit number only.
> > 
> > Examples:
> > 1. Standard presentation
> > $ vdpa dev config show vdpa-a
> > vdpa-a: mac 00:00:00:00:88:88 link up link_announce false max_vq_pairs 2 mtu 9000
> >    negotiated_features CSUM GUEST_CSUM MTU MAC HOST_TSO4 HOST_TSO6 STATUS \
> > CTRL_VQ MQ CTRL_MAC_ADDR VERSION_1 ACCESS_PLATFORM
> > 
> > 2. json output
> > $ vdpa -j dev config show vdpa-a
> > {"config":{"vdpa-a":{"mac":"00:00:00:00:88:88","link":"up","link_announce":false,\
> > "max_vq_pairs":2,"mtu":9000,"negotiated_features":["CSUM","GUEST_CSUM",\
> > "MTU","MAC","HOST_TSO4","HOST_TSO6","STATUS","CTRL_VQ","MQ","CTRL_MAC_ADDR",\
> > "VERSION_1","ACCESS_PLATFORM"]}}}
> > 
> > 3. Pretty json
> > $ vdpa -jp dev config show vdpa-a
> > {
> >      "config": {
> >          "vdpa-a": {
> >              "mac": "00:00:00:00:88:88",
> >              "link ": "up",
> >              "link_announce ": false,
> >              "max_vq_pairs": 2,
> >              "mtu": 9000,
> >              "negotiated_features": [
> > "CSUM","GUEST_CSUM","MTU","MAC","HOST_TSO4","HOST_TSO6","STATUS","CTRL_VQ",\
> > "MQ","CTRL_MAC_ADDR","VERSION_1","ACCESS_PLATFORM" ]
> >          }
> >      }
> > }
> > 
> > Signed-off-by: Eli Cohen <elic@...dia.com>
> > ---
> >   vdpa/include/uapi/linux/vdpa.h |   2 +
> >   vdpa/vdpa.c                    | 108 ++++++++++++++++++++++++++++++++-
> >   2 files changed, 107 insertions(+), 3 deletions(-)
> > 
> > diff --git a/vdpa/include/uapi/linux/vdpa.h b/vdpa/include/uapi/linux/vdpa.h
> > index b7eab069988a..748c350450b2 100644
> > --- a/vdpa/include/uapi/linux/vdpa.h
> > +++ b/vdpa/include/uapi/linux/vdpa.h
> > @@ -40,6 +40,8 @@ enum vdpa_attr {
> >   	VDPA_ATTR_DEV_NET_CFG_MAX_VQP,		/* u16 */
> >   	VDPA_ATTR_DEV_NET_CFG_MTU,		/* u16 */
> > +	VDPA_ATTR_DEV_NEGOTIATED_FEATURES,	/* u64 */
> > +
> >   	/* new attributes must be added above here */
> >   	VDPA_ATTR_MAX,
> >   };
> > diff --git a/vdpa/vdpa.c b/vdpa/vdpa.c
> > index 4ccb564872a0..f60e647b8cf8 100644
> > --- a/vdpa/vdpa.c
> > +++ b/vdpa/vdpa.c
> > @@ -10,6 +10,8 @@
> >   #include <linux/virtio_net.h>
> >   #include <linux/netlink.h>
> >   #include <libmnl/libmnl.h>
> > +#include <linux/virtio_ring.h>
> > +#include <linux/virtio_config.h>
> >   #include "mnl_utils.h"
> >   #include <rt_names.h>
> > @@ -78,6 +80,7 @@ static const enum mnl_attr_data_type vdpa_policy[VDPA_ATTR_MAX + 1] = {
> >   	[VDPA_ATTR_DEV_VENDOR_ID] = MNL_TYPE_U32,
> >   	[VDPA_ATTR_DEV_MAX_VQS] = MNL_TYPE_U32,
> >   	[VDPA_ATTR_DEV_MAX_VQ_SIZE] = MNL_TYPE_U16,
> > +	[VDPA_ATTR_DEV_NEGOTIATED_FEATURES] = MNL_TYPE_U64,
> >   };
> >   static int attr_cb(const struct nlattr *attr, void *data)
> > @@ -385,6 +388,96 @@ static const char *parse_class(int num)
> >   	return class ? class : "< unknown class >";
> >   }
> > +static const char * const net_feature_strs[64] = {
> > +	[VIRTIO_NET_F_CSUM] = "CSUM",
> > +	[VIRTIO_NET_F_GUEST_CSUM] = "GUEST_CSUM",
> > +	[VIRTIO_NET_F_CTRL_GUEST_OFFLOADS] = "CTRL_GUEST_OFFLOADS",
> > +	[VIRTIO_NET_F_MTU] = "MTU",
> > +	[VIRTIO_NET_F_MAC] = "MAC",
> > +	[VIRTIO_NET_F_GUEST_TSO4] = "GUEST_TSO4",
> > +	[VIRTIO_NET_F_GUEST_TSO6] = "GUEST_TSO6",
> > +	[VIRTIO_NET_F_GUEST_ECN] = "GUEST_ECN",
> > +	[VIRTIO_NET_F_GUEST_UFO] = "GUEST_UFO",
> > +	[VIRTIO_NET_F_HOST_TSO4] = "HOST_TSO4",
> > +	[VIRTIO_NET_F_HOST_TSO6] = "HOST_TSO6",
> > +	[VIRTIO_NET_F_HOST_ECN] = "HOST_ECN",
> > +	[VIRTIO_NET_F_HOST_UFO] = "HOST_UFO",
> > +	[VIRTIO_NET_F_MRG_RXBUF] = "MRG_RXBUF",
> > +	[VIRTIO_NET_F_STATUS] = "STATUS",
> > +	[VIRTIO_NET_F_CTRL_VQ] = "CTRL_VQ",
> > +	[VIRTIO_NET_F_CTRL_RX] = "CTRL_RX",
> > +	[VIRTIO_NET_F_CTRL_VLAN] = "CTRL_VLAN",
> > +	[VIRTIO_NET_F_CTRL_RX_EXTRA] = "CTRL_RX_EXTRA",
> > +	[VIRTIO_NET_F_GUEST_ANNOUNCE] = "GUEST_ANNOUNCE",
> > +	[VIRTIO_NET_F_MQ] = "MQ",
> > +	[VIRTIO_F_NOTIFY_ON_EMPTY] = "NOTIFY_ON_EMPTY",
> > +	[VIRTIO_NET_F_CTRL_MAC_ADDR] = "CTRL_MAC_ADDR",
> > +	[VIRTIO_F_ANY_LAYOUT] = "ANY_LAYOUT",
> > +	[VIRTIO_NET_F_RSC_EXT] = "RSC_EXT",
> > +	[VIRTIO_NET_F_HASH_REPORT] = "HASH_REPORT",
> > +	[VIRTIO_NET_F_RSS] = "RSS",
> > +	[VIRTIO_NET_F_STANDBY] = "STANDBY",
> > +	[VIRTIO_NET_F_SPEED_DUPLEX] = "SPEED_DUPLEX",
> > +};
> > +
> > +#define VIRTIO_F_IN_ORDER 35
> > +#define VIRTIO_F_NOTIFICATION_DATA 38
> > +#define VDPA_EXT_FEATURES_SZ (VIRTIO_TRANSPORT_F_END - \
> > +			      VIRTIO_TRANSPORT_F_START + 1)
> > +
> > +static const char * const ext_feature_strs[VDPA_EXT_FEATURES_SZ] = {
> > +	[VIRTIO_RING_F_INDIRECT_DESC - VIRTIO_TRANSPORT_F_START] = "RING_INDIRECT_DESC",
> > +	[VIRTIO_RING_F_EVENT_IDX - VIRTIO_TRANSPORT_F_START] = "RING_EVENT_IDX",
> > +	[VIRTIO_F_VERSION_1 - VIRTIO_TRANSPORT_F_START] = "VERSION_1",
> > +	[VIRTIO_F_ACCESS_PLATFORM - VIRTIO_TRANSPORT_F_START] = "ACCESS_PLATFORM",
> > +	[VIRTIO_F_RING_PACKED - VIRTIO_TRANSPORT_F_START] = "RING_PACKED",
> > +	[VIRTIO_F_IN_ORDER - VIRTIO_TRANSPORT_F_START] = "IN_ORDER",
> > +	[VIRTIO_F_ORDER_PLATFORM - VIRTIO_TRANSPORT_F_START] = "ORDER_PLATFORM",
> > +	[VIRTIO_F_SR_IOV - VIRTIO_TRANSPORT_F_START] = "SR_IOV",
> > +	[VIRTIO_F_NOTIFICATION_DATA - VIRTIO_TRANSPORT_F_START] = "NOTIFICATION_DATA",
> > +};
> > +
> > +static const char * const *dev_to_feature_str[] = {
> > +	[VIRTIO_ID_NET] = net_feature_strs,
> > +};
> > +
> > +static void print_features(struct vdpa *vdpa, uint64_t features, bool mgmtdevf,
> > +			   uint16_t dev_id)
> > +{
> > +	const char * const *feature_strs = NULL;
> > +	const char *s;
> > +	int i;
> > +
> > +	if (dev_id < ARRAY_SIZE(dev_to_feature_str))
> > +		feature_strs = dev_to_feature_str[dev_id];
> > +
> > +	if (mgmtdevf)
> > +		pr_out_array_start(vdpa, "dev_features");
> > +	else
> > +		pr_out_array_start(vdpa, "negotiated_features");
> > +
> > +	for (i = 0; i < 64; i++) {
> > +		if (!(features & (1ULL << i)))
> > +			continue;
> > +
> > +		if (i < VIRTIO_TRANSPORT_F_START || i > VIRTIO_TRANSPORT_F_END) {
> > +			if (feature_strs) {
> > +				s = feature_strs[i];
> > +			} else {
> > +				s = NULL;
> > +			}
> > +		} else {
> > +			s = ext_feature_strs[i - VIRTIO_TRANSPORT_F_START];
> > +		}
> > +		if (!s)
> > +			print_uint(PRINT_ANY, NULL, " bit_%d", i);
> > +		else
> > +			print_string(PRINT_ANY, NULL, " %s", s);
> > +	}
> > +
> > +	pr_out_array_end(vdpa);
> > +}
> > +
> >   static void pr_out_mgmtdev_show(struct vdpa *vdpa, const struct nlmsghdr *nlh,
> >   				struct nlattr **tb)
> >   {
> > @@ -395,7 +488,6 @@ static void pr_out_mgmtdev_show(struct vdpa *vdpa, const struct nlmsghdr *nlh,
> >   	if (tb[VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES]) {
> >   		uint64_t classes = mnl_attr_get_u64(tb[VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES]);
> > -
> 
> 
> Unnecessary changes.

Will fix.

> 
> 
> >   		pr_out_array_start(vdpa, "supported_classes");
> >   		for (i = 1; i < 64; i++) {
> > @@ -579,9 +671,10 @@ static int cmd_dev_del(struct vdpa *vdpa,  int argc, char **argv)
> >   	return mnlu_gen_socket_sndrcv(&vdpa->nlg, nlh, NULL, NULL);
> >   }
> > -static void pr_out_dev_net_config(struct nlattr **tb)
> > +static void pr_out_dev_net_config(struct vdpa *vdpa, struct nlattr **tb)
> >   {
> >   	SPRINT_BUF(macaddr);
> > +	uint64_t val_u64;
> >   	uint16_t val_u16;
> >   	if (tb[VDPA_ATTR_DEV_NET_CFG_MACADDR]) {
> > @@ -610,6 +703,15 @@ static void pr_out_dev_net_config(struct nlattr **tb)
> >   		val_u16 = mnl_attr_get_u16(tb[VDPA_ATTR_DEV_NET_CFG_MTU]);
> >   		print_uint(PRINT_ANY, "mtu", "mtu %d ", val_u16);
> >   	}
> > +	if (tb[VDPA_ATTR_DEV_NEGOTIATED_FEATURES]) {
> > +		uint16_t dev_id = 0;
> > +
> > +		if (tb[VDPA_ATTR_DEV_ID])
> > +			dev_id = mnl_attr_get_u32(tb[VDPA_ATTR_DEV_ID]);
> > +
> > +		val_u64 = mnl_attr_get_u64(tb[VDPA_ATTR_DEV_NEGOTIATED_FEATURES]);
> > +		print_features(vdpa, val_u64, false, dev_id);
> > +	}
> >   }
> >   static void pr_out_dev_config(struct vdpa *vdpa, struct nlattr **tb)
> > @@ -619,7 +721,7 @@ static void pr_out_dev_config(struct vdpa *vdpa, struct nlattr **tb)
> >   	pr_out_vdev_handle_start(vdpa, tb);
> >   	switch (device_id) {
> >   	case VIRTIO_ID_NET:
> > -		pr_out_dev_net_config(tb);
> > +		pr_out_dev_net_config(vdpa, tb);
> >   		break;
> >   	default:
> 
> 
> I wonder if we need a warning here.

I don't think. You will see the bit_xx printed instead of getting string
representation of the feature.

> 
> Otherwise looks good to me.
> 
> Thanks
> 
> 
> >   		break;
> 

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