All of lore.kernel.org
 help / color / mirror / Atom feed
From: Bob Pearson <rpearsonhpe@gmail.com>
To: jgg@nvidia.com, zyjzyj2000@gmail.com, linux-rdma@vger.kernel.org
Cc: Bob Pearson <rpearsonhpe@gmail.com>
Subject: [PATCH for-next v11 02/13] RDMA/rxe: Replace mr by rkey in responder resources
Date: Thu,  3 Mar 2022 18:07:58 -0600	[thread overview]
Message-ID: <20220304000808.225811-3-rpearsonhpe@gmail.com> (raw)
In-Reply-To: <20220304000808.225811-1-rpearsonhpe@gmail.com>

Currently rxe saves a copy of MR in responder resources for RDMA reads.
Since the responder resources are never freed just over written if
more are needed this MR may not have a reference freed until the QP
is destroyed. This patch uses the rkey instead of the MR and on
subsequent packets of a multipacket read reply message it looks up the
MR from the rkey for each packet. This makes it possible for a user
to deregister an MR or unbind a MW on the fly and get correct behaviour.

Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe_qp.c    |  10 +--
 drivers/infiniband/sw/rxe/rxe_resp.c  | 123 ++++++++++++++++++--------
 drivers/infiniband/sw/rxe/rxe_verbs.h |   1 -
 3 files changed, 87 insertions(+), 47 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c
index 5f270cbf18c6..26d461a8d71c 100644
--- a/drivers/infiniband/sw/rxe/rxe_qp.c
+++ b/drivers/infiniband/sw/rxe/rxe_qp.c
@@ -135,12 +135,8 @@ static void free_rd_atomic_resources(struct rxe_qp *qp)
 
 void free_rd_atomic_resource(struct rxe_qp *qp, struct resp_res *res)
 {
-	if (res->type == RXE_ATOMIC_MASK) {
+	if (res->type == RXE_ATOMIC_MASK)
 		kfree_skb(res->atomic.skb);
-	} else if (res->type == RXE_READ_MASK) {
-		if (res->read.mr)
-			rxe_drop_ref(res->read.mr);
-	}
 	res->type = 0;
 }
 
@@ -825,10 +821,8 @@ static void rxe_qp_do_cleanup(struct work_struct *work)
 	if (qp->pd)
 		rxe_drop_ref(qp->pd);
 
-	if (qp->resp.mr) {
+	if (qp->resp.mr)
 		rxe_drop_ref(qp->resp.mr);
-		qp->resp.mr = NULL;
-	}
 
 	if (qp_type(qp) == IB_QPT_RC)
 		sk_dst_reset(qp->sk->sk);
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index b5ebe853748a..b1ec003f0bb8 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -642,6 +642,78 @@ static struct sk_buff *prepare_ack_packet(struct rxe_qp *qp,
 	return skb;
 }
 
+static struct resp_res *rxe_prepare_read_res(struct rxe_qp *qp,
+					struct rxe_pkt_info *pkt)
+{
+	struct resp_res *res;
+	u32 pkts;
+
+	res = &qp->resp.resources[qp->resp.res_head];
+	rxe_advance_resp_resource(qp);
+	free_rd_atomic_resource(qp, res);
+
+	res->type = RXE_READ_MASK;
+	res->replay = 0;
+	res->read.va = qp->resp.va + qp->resp.offset;
+	res->read.va_org = qp->resp.va + qp->resp.offset;
+	res->read.resid = qp->resp.resid;
+	res->read.length = qp->resp.resid;
+	res->read.rkey = qp->resp.rkey;
+
+	pkts = max_t(u32, (reth_len(pkt) + qp->mtu - 1)/qp->mtu, 1);
+	res->first_psn = pkt->psn;
+	res->cur_psn = pkt->psn;
+	res->last_psn = (pkt->psn + pkts - 1) & BTH_PSN_MASK;
+
+	res->state = rdatm_res_state_new;
+
+	return res;
+}
+
+/**
+ * rxe_recheck_mr - revalidate MR from rkey and get a reference
+ * @qp: the qp
+ * @rkey: the rkey
+ *
+ * This code allows the MR to be invalidated or deregistered or
+ * the MW if one was used to be invalidated or deallocated.
+ * It is assumed that the access permissions if originally good
+ * are OK and the mappings to be unchanged.
+ *
+ * Return: mr on success else NULL
+ */
+static struct rxe_mr *rxe_recheck_mr(struct rxe_qp *qp, u32 rkey)
+{
+	struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
+	struct rxe_mr *mr;
+	struct rxe_mw *mw;
+
+	if (rkey_is_mw(rkey)) {
+		mw = rxe_pool_get_index(&rxe->mw_pool, rkey >> 8);
+		if (!mw || mw->rkey != rkey)
+			return NULL;
+
+		if (mw->state != RXE_MW_STATE_VALID) {
+			rxe_drop_ref(mw);
+			return NULL;
+		}
+
+		mr = mw->mr;
+		rxe_drop_ref(mw);
+	} else {
+		mr = rxe_pool_get_index(&rxe->mr_pool, rkey >> 8);
+		if (!mr || mr->rkey != rkey)
+			return NULL;
+	}
+
+	if (mr->state != RXE_MR_STATE_VALID) {
+		rxe_drop_ref(mr);
+		return NULL;
+	}
+
+	return mr;
+}
+
 /* RDMA read response. If res is not NULL, then we have a current RDMA request
  * being processed or replayed.
  */
@@ -656,53 +728,26 @@ static enum resp_states read_reply(struct rxe_qp *qp,
 	int opcode;
 	int err;
 	struct resp_res *res = qp->resp.res;
+	struct rxe_mr *mr;
 
 	if (!res) {
-		/* This is the first time we process that request. Get a
-		 * resource
-		 */
-		res = &qp->resp.resources[qp->resp.res_head];
-
-		free_rd_atomic_resource(qp, res);
-		rxe_advance_resp_resource(qp);
-
-		res->type		= RXE_READ_MASK;
-		res->replay		= 0;
-
-		res->read.va		= qp->resp.va +
-					  qp->resp.offset;
-		res->read.va_org	= qp->resp.va +
-					  qp->resp.offset;
-
-		res->first_psn		= req_pkt->psn;
-
-		if (reth_len(req_pkt)) {
-			res->last_psn	= (req_pkt->psn +
-					   (reth_len(req_pkt) + mtu - 1) /
-					   mtu - 1) & BTH_PSN_MASK;
-		} else {
-			res->last_psn	= res->first_psn;
-		}
-		res->cur_psn		= req_pkt->psn;
-
-		res->read.resid		= qp->resp.resid;
-		res->read.length	= qp->resp.resid;
-		res->read.rkey		= qp->resp.rkey;
-
-		/* note res inherits the reference to mr from qp */
-		res->read.mr		= qp->resp.mr;
-		qp->resp.mr		= NULL;
-
-		qp->resp.res		= res;
-		res->state		= rdatm_res_state_new;
+		res = rxe_prepare_read_res(qp, req_pkt);
+		qp->resp.res = res;
 	}
 
 	if (res->state == rdatm_res_state_new) {
+		mr = qp->resp.mr;
+		qp->resp.mr = NULL;
+
 		if (res->read.resid <= mtu)
 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_ONLY;
 		else
 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST;
 	} else {
+		mr = rxe_recheck_mr(qp, res->read.rkey);
+		if (!mr)
+			return RESPST_ERR_RKEY_VIOLATION;
+
 		if (res->read.resid > mtu)
 			opcode = IB_OPCODE_RC_RDMA_READ_RESPONSE_MIDDLE;
 		else
@@ -718,10 +763,12 @@ static enum resp_states read_reply(struct rxe_qp *qp,
 	if (!skb)
 		return RESPST_ERR_RNR;
 
-	err = rxe_mr_copy(res->read.mr, res->read.va, payload_addr(&ack_pkt),
+	err = rxe_mr_copy(mr, res->read.va, payload_addr(&ack_pkt),
 			  payload, RXE_FROM_MR_OBJ);
 	if (err)
 		pr_err("Failed copying memory\n");
+	if (mr)
+		rxe_drop_ref(mr);
 
 	if (bth_pad(&ack_pkt)) {
 		u8 *pad = payload_addr(&ack_pkt) + payload;
diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h b/drivers/infiniband/sw/rxe/rxe_verbs.h
index 6b15251ff67a..e7eff1ca75e9 100644
--- a/drivers/infiniband/sw/rxe/rxe_verbs.h
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
@@ -157,7 +157,6 @@ struct resp_res {
 			struct sk_buff	*skb;
 		} atomic;
 		struct {
-			struct rxe_mr	*mr;
 			u64		va_org;
 			u32		rkey;
 			u32		length;
-- 
2.32.0


  parent reply	other threads:[~2022-03-04  0:08 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-04  0:07 [PATCH for-next v11 00/13] Fix race conditions in rxe_pool Bob Pearson
2022-03-04  0:07 ` [PATCH for-next v11 01/13] RDMA/rxe: Fix ref error in rxe_av.c Bob Pearson
2022-03-04  0:07 ` Bob Pearson [this message]
2022-03-04  0:07 ` [PATCH for-next v11 03/13] RDMA/rxe: Reverse the sense of RXE_POOL_NO_ALLOC Bob Pearson
2022-03-04  0:08 ` [PATCH for-next v11 04/13] RDMA/rxe: Delete _locked() APIs for pool objects Bob Pearson
2022-03-04  0:08 ` [PATCH for-next v11 05/13] RDMA/rxe: Replace obj by elem in declaration Bob Pearson
2022-03-04  0:08 ` [PATCH for-next v11 06/13] RDMA/rxe: Move max_elem into rxe_type_info Bob Pearson
2022-03-04  0:08 ` [PATCH for-next v11 07/13] RDMA/rxe: Shorten pool names in rxe_pool.c Bob Pearson
2022-03-04  0:08 ` [PATCH for-next v11 08/13] RDMA/rxe: Replace red-black trees by xarrays Bob Pearson
2022-03-15 23:45   ` Jason Gunthorpe
2022-03-16  3:05     ` Bob Pearson
2022-03-04  0:08 ` [PATCH for-next v11 09/13] RDMA/rxe: Use standard names for ref counting Bob Pearson
2022-03-04  0:08 ` [PATCH for-next v11 10/13] RDMA/rxe: Stop lookup of partially built objects Bob Pearson
2022-03-16  0:16   ` Jason Gunthorpe
2022-03-16  3:55     ` Bob Pearson
2022-03-16 13:42       ` Jason Gunthorpe
2022-03-04  0:08 ` [PATCH for-next v11 11/13] RDMA/rxe: Add wait_for_completion to pool objects Bob Pearson
2022-03-16  0:17   ` Jason Gunthorpe
2022-03-16  3:57     ` Bob Pearson
2022-03-16 13:43       ` Jason Gunthorpe
2022-03-04  0:08 ` [PATCH for-next v11 12/13] RDMA/rxe: Convert read side locking to rcu Bob Pearson
2022-03-16  0:18   ` Jason Gunthorpe
2022-03-16  4:05     ` Bob Pearson
2022-03-04  0:08 ` [PATCH for-next v11 13/13] RDMA/rxe: Cleanup rxe_pool.c Bob Pearson
2022-03-16  0:25 ` [PATCH for-next v11 00/13] Fix race conditions in rxe_pool Jason Gunthorpe
2022-03-16  4:05   ` Bob Pearson
2022-03-16 16:08     ` Jason Gunthorpe
2022-03-16 16:09       ` Pearson, Robert B

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220304000808.225811-3-rpearsonhpe@gmail.com \
    --to=rpearsonhpe@gmail.com \
    --cc=jgg@nvidia.com \
    --cc=linux-rdma@vger.kernel.org \
    --cc=zyjzyj2000@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.