On 27/07/2020 21:56, Jason Gunthorpe wrote:
> On Wed, Jul 22, 2020 at 05:03:11PM +0300, Gal Pressman wrote:
>> Introduce a mechanism that performs an handshake between the userspace
>> provider and kernel driver which verifies that the user supports all
>> required features in order to operate correctly.
>>
>> The handshake verifies the needed functionality by comparing the
>> reported device caps and the provider caps. If the device reports a
>> non-zero capability the appropriate comp mask is required from the
>> userspace provider in order to allocate the context.
>>
>> Reviewed-by: Shadi Ammouri <sammouri@xxxxxxxxxx>
>> Reviewed-by: Yossi Leybovich <sleybo@xxxxxxxxxx>
>> Signed-off-by: Gal Pressman <galpress@xxxxxxxxxx>
>> drivers/infiniband/hw/efa/efa_verbs.c | 40 +++++++++++++++++++++++++++
>> include/uapi/rdma/efa-abi.h | 10 +++++++
>> 2 files changed, 50 insertions(+)
>>
>> diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
>> index 26102ab333b2..fda175836fb6 100644
>> +++ b/drivers/infiniband/hw/efa/efa_verbs.c
>> @@ -1501,11 +1501,39 @@ static int efa_dealloc_uar(struct efa_dev *dev, u16 uarn)
>> return efa_com_dealloc_uar(&dev->edev, ¶ms);
>> }
>>
>> +#define EFA_CHECK_USER_COMP(_dev, _comp_mask, _attr, _mask, _attr_str) \
>> + (_attr_str = (!(_dev)->dev_attr._attr || ((_comp_mask) & (_mask))) ? \
>> + NULL : #_attr)
>> +
>> +static int efa_user_comp_handshake(const struct ib_ucontext *ibucontext,
>> + const struct efa_ibv_alloc_ucontext_cmd *cmd)
>> +{
>> + struct efa_dev *dev = to_edev(ibucontext->device);
>> + char *attr_str;
>> +
>> + if (EFA_CHECK_USER_COMP(dev, cmd->comp_mask, max_tx_batch,
>> + EFA_ALLOC_UCONTEXT_CMD_COMP_TX_BATCH, attr_str))
>> + goto err;
>> +
>> + if (EFA_CHECK_USER_COMP(dev, cmd->comp_mask, min_sq_depth,
>> + EFA_ALLOC_UCONTEXT_CMD_COMP_MIN_SQ_WR,
>> + attr_str))
>> + goto err;
>
> But this patch should be first, the kernel should never return a
> non-zero value unless these input bits are set
But that's exactly what this patch does, it can only fail in case
max_tx_batch/min_sq_depth is turned on by the device.
Anyway, the order doesn't matter as long as the pciid patch is last.
