From a5d87b698547233321466b2dc91271f5855a4df6 Mon Sep 17 00:00:00 2001 From: Gal Pressman Date: Wed, 22 Jul 2020 17:03:11 +0300 Subject: RDMA/efa: User/kernel compatibility handshake mechanism 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. Link: https://lore.kernel.org/r/20200722140312.3651-4-galpress@amazon.com Reviewed-by: Shadi Ammouri Reviewed-by: Yossi Leybovich Signed-off-by: Gal Pressman Signed-off-by: Jason Gunthorpe --- drivers/infiniband/hw/efa/efa_verbs.c | 40 +++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) (limited to 'drivers/infiniband/hw') diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c index 26102ab333b2..fda175836fb6 100644 --- a/drivers/infiniband/hw/efa/efa_verbs.c +++ 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; + + return 0; + +err: + ibdev_dbg(&dev->ibdev, "Userspace handshake failed for %s attribute\n", + attr_str); + return -EOPNOTSUPP; +} + int efa_alloc_ucontext(struct ib_ucontext *ibucontext, struct ib_udata *udata) { struct efa_ucontext *ucontext = to_eucontext(ibucontext); struct efa_dev *dev = to_edev(ibucontext->device); struct efa_ibv_alloc_ucontext_resp resp = {}; + struct efa_ibv_alloc_ucontext_cmd cmd = {}; struct efa_com_alloc_uar_result result; int err; @@ -1514,6 +1542,18 @@ int efa_alloc_ucontext(struct ib_ucontext *ibucontext, struct ib_udata *udata) * we will ack input fields in our response. */ + err = ib_copy_from_udata(&cmd, udata, + min(sizeof(cmd), udata->inlen)); + if (err) { + ibdev_dbg(&dev->ibdev, + "Cannot copy udata for alloc_ucontext\n"); + goto err_out; + } + + err = efa_user_comp_handshake(ibucontext, &cmd); + if (err) + goto err_out; + err = efa_com_alloc_uar(&dev->edev, &result); if (err) goto err_out; -- cgit v1.2.3-59-g8ed1b