On 6/12/20 2:37 PM, Gaëtan Rivet wrote:
> On 11/06/20 23:37 +0200, Maxime Coquelin wrote:
>> This patch introduces vDPA device class. It will enable
>> application to iterate over the vDPA devices.
>>
>> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
>> ---
>> lib/librte_vhost/vdpa.c | 116 +++++++++++++++++++++++++++++++++-------
>> 1 file changed, 98 insertions(+), 18 deletions(-)
>>
>> diff --git a/lib/librte_vhost/vdpa.c b/lib/librte_vhost/vdpa.c
>> index b2b2a105f1..61ab9aadb4 100644
>> --- a/lib/librte_vhost/vdpa.c
>> +++ b/lib/librte_vhost/vdpa.c
>> @@ -10,11 +10,12 @@
>>
>> #include <stdbool.h>
>>
>> +#include <rte_class.h>
>> #include <rte_malloc.h>
>> #include "rte_vdpa.h"
>> #include "vhost.h"
>>
>> -static struct rte_vdpa_device *vdpa_devices[MAX_VHOST_DEVICE];
>> +static struct rte_vdpa_device vdpa_devices[MAX_VHOST_DEVICE];
>> static uint32_t vdpa_device_num;
>>
>> static bool
>> @@ -46,35 +47,28 @@ rte_vdpa_register_device(struct rte_vdpa_dev_addr *addr,
>> struct rte_vdpa_dev_ops *ops)
>> {
>> struct rte_vdpa_device *dev;
>> - char device_name[MAX_VDPA_NAME_LEN];
>> int i;
>>
>> if (vdpa_device_num >= MAX_VHOST_DEVICE || addr == NULL || ops == NULL)
>> return -1;
>>
>> for (i = 0; i < MAX_VHOST_DEVICE; i++) {
>> - dev = vdpa_devices[i];
>> - if (dev && is_same_vdpa_device(&dev->addr, addr))
>> + dev = &vdpa_devices[i];
>> + if (dev->ops && is_same_vdpa_device(&dev->addr, addr))
>> return -1;
>> }
>>
>> for (i = 0; i < MAX_VHOST_DEVICE; i++) {
>> - if (vdpa_devices[i] == NULL)
>> + if (vdpa_devices[i].ops == NULL)
>> break;
>> }
>>
>> if (i == MAX_VHOST_DEVICE)
>> return -1;
>>
>> - snprintf(device_name, sizeof(device_name), "vdpa-dev-%d", i);
>> - dev = rte_zmalloc(device_name, sizeof(struct rte_vdpa_device),
>> - RTE_CACHE_LINE_SIZE);
>> - if (!dev)
>> - return -1;
>> -
>> + dev = &vdpa_devices[i];
>> memcpy(&dev->addr, addr, sizeof(struct rte_vdpa_dev_addr));
>> dev->ops = ops;
>> - vdpa_devices[i] = dev;
>> vdpa_device_num++;
>>
>> return i;
>> @@ -83,11 +77,10 @@ rte_vdpa_register_device(struct rte_vdpa_dev_addr *addr,
>> int
>> rte_vdpa_unregister_device(int did)
>> {
>> - if (did < 0 || did >= MAX_VHOST_DEVICE || vdpa_devices[did] == NULL)
>> + if (did < 0 || did >= MAX_VHOST_DEVICE || vdpa_devices[did].ops == NULL)
>> return -1;
>>
>> - rte_free(vdpa_devices[did]);
>> - vdpa_devices[did] = NULL;
>> + memset(&vdpa_devices[did], 0, sizeof(struct rte_vdpa_device));
>> vdpa_device_num--;
>>
>> return did;
>> @@ -103,8 +96,11 @@ rte_vdpa_find_device_id(struct rte_vdpa_dev_addr *addr)
>> return -1;
>>
>> for (i = 0; i < MAX_VHOST_DEVICE; ++i) {
>> - dev = vdpa_devices[i];
>> - if (dev && is_same_vdpa_device(&dev->addr, addr))
>> + dev = &vdpa_devices[i];
>> + if (dev->ops == NULL)
>> + continue;
>> +
>> + if (is_same_vdpa_device(&dev->addr, addr))
>> return i;
>> }
>>
>> @@ -117,7 +113,7 @@ rte_vdpa_get_device(int did)
>> if (did < 0 || did >= MAX_VHOST_DEVICE)
>> return NULL;
>>
>> - return vdpa_devices[did];
>> + return &vdpa_devices[did];
>> }
>>
>> int
>> @@ -227,3 +223,87 @@ rte_vdpa_relay_vring_used(int vid, uint16_t qid, void
>> *vring_m)
>> free_ind_table(idesc);
>> return -1;
>> }
>> +
>> +static uint16_t
>> +vdpa_dev_to_id(const struct rte_vdpa_device *dev)
>> +{
>> + if (dev == NULL)
>> + return MAX_VHOST_DEVICE;
>
> I know it comes from ethdev, this helper was introduced by 214ed1acd12
> and changed the comparison type from ptrdiff_t to uin16_t.
>
> This is incorrect, ideally it should instead be a ptrdiff_t, then
> if within acceptable range it should be casted to uin16_t to be used as
> an index.
>
>> + return dev - vdpa_devices;
>> +}
>> +
>> +static int
>> +vdpa_dev_match(struct rte_vdpa_device *dev,
>> + const struct rte_device *rte_dev)
>> +{
>> + struct rte_vdpa_dev_addr addr;
>> +
>> + /* Only PCI bus supported for now */
>> + if (strcmp(rte_dev->bus->name, "pci") != 0)
>> + return -1;
>> +
>> + addr.type = VDPA_ADDR_PCI;
>> +
>> + if (rte_pci_addr_parse(rte_dev->name, &addr.pci_addr) != 0)
>> + return -1;
>> +
>> + if (!is_same_vdpa_device(&dev->addr, &addr))
>> + return -1;
>> +
>> + return 0;
>> +}
>> +
>> +/* Generic rte_vdpa_dev comparison function. */
>> +typedef int (*rte_vdpa_cmp_t)(struct rte_vdpa_device *,
>> + const struct rte_device *rte_dev);
>> +
>> +static struct rte_vdpa_device *
>> +vdpa_find_device(const struct rte_vdpa_device *start, rte_vdpa_cmp_t cmp,
>> + struct rte_device *rte_dev)
>> +{
>> + struct rte_vdpa_device *dev;
>> + ptrdiff_t idx;
>
> The ptrdiff_t was used in ethdev due to the original
>
> start - &rte_eth_devices[0] + 1;
>
> The diff was removed by commit 214ed1acd12 . 'idx' should be
> the proper type to hold a device id, here probably uint16_t.
Ok, makes sense.
> Ethdev class should be cleaned up as well.
>
>> +
>> + /* Avoid Undefined Behaviour */
>> + if (start != NULL &&
>> + (start < &vdpa_devices[0] ||
>> + start >= &vdpa_devices[MAX_VHOST_DEVICE]))
>> + return NULL;
>
> Same as before, this guard made sense mostly for the diff following.
> It is coupled to the "random ptr to static array" comparison happening,
> it would be better in vpda_dev_to_id() I think.
OK, I will clean that in next version, but but this part moves away
later in the series, when switching to linked-list.
Thanks,
Maxime
>> +
>> + if (start != NULL)
>> + idx = vdpa_dev_to_id(start) + 1;
>> + else
>> + idx = 0;
>> + for (; idx < MAX_VHOST_DEVICE; idx++) {
>> + dev = &vdpa_devices[idx];
>> + /*
>> + * ToDo: Certainly better to introduce a state field,
>> + * but rely on ops being set for now.
>> + */
>> + if (dev->ops == NULL)
>> + continue;
>> + if (cmp(dev, rte_dev) == 0)
>> + return dev;
>> + }
>> + return NULL;
>> +}
>> +
>> +static void *
>> +vdpa_dev_iterate(const void *start,
>> + const char *str,
>> + const struct rte_dev_iterator *it)
>> +{
>> + struct rte_vdpa_device *vdpa_dev = NULL;
>> +
>> + RTE_SET_USED(str);
>> +
>> + vdpa_dev = vdpa_find_device(start, vdpa_dev_match, it->device);
>> +
>> + return vdpa_dev;
>> +}
>> +
>> +static struct rte_class rte_class_vdpa = {
>> + .dev_iterate = vdpa_dev_iterate,
>> +};
>> +
>> +RTE_REGISTER_CLASS(vdpa, rte_class_vdpa);
>> --
>> 2.26.2
>>
>
