git: d75b0870e542 - main - cxgbei: Restrict received PDUs to 4 DDP pages in length.

[John Baldwin]

The branch main has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=d75b0870e542613e63d9f4ac8ec9fb22817e34fa

commit d75b0870e542613e63d9f4ac8ec9fb22817e34fa
Author:     John Baldwin <jhb at FreeBSD.org>
AuthorDate: 2021-08-17 18:14:37 +0000
Commit:     John Baldwin <jhb at FreeBSD.org>
CommitDate: 2021-08-17 18:14:37 +0000

    cxgbei: Restrict received PDUs to 4 DDP pages in length.
    
    Reviewed by:    np
    Sponsored by:   Chelsio Communications
    Differential Revision:  https://reviews.freebsd.org/D31576
---
 sys/dev/cxgbe/cxgbei/cxgbei.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/sys/dev/cxgbe/cxgbei/cxgbei.c b/sys/dev/cxgbe/cxgbei/cxgbei.c
index acf6ee74c94f..8dc580d65770 100644
--- a/sys/dev/cxgbe/cxgbei/cxgbei.c
+++ b/sys/dev/cxgbe/cxgbei/cxgbei.c
@@ -98,7 +98,7 @@ static struct proc *cxgbei_proc;
 
 static void
 read_pdu_limits(struct adapter *sc, uint32_t *max_tx_data_len,
-    uint32_t *max_rx_data_len)
+    uint32_t *max_rx_data_len, struct ppod_region *pr)
 {
 	uint32_t tx_len, rx_len, r, v;
 
@@ -123,6 +123,14 @@ read_pdu_limits(struct adapter *sc, uint32_t *max_tx_data_len,
 	tx_len -= ISCSI_BHS_SIZE + ISCSI_HEADER_DIGEST_SIZE +
 	    ISCSI_DATA_DIGEST_SIZE;
 
+	/*
+	 * DDP can place only 4 pages for a single PDU.  A single
+	 * request might use larger pages than the smallest page size,
+	 * but that cannot be guaranteed.  Assume the smallest DDP
+	 * page size for this limit.
+	 */
+	rx_len = min(rx_len, 4 * (1U << pr->pr_page_shift[0]));
+
 	if (chip_id(sc) == CHELSIO_T5) {
 		rx_len = rounddown2(rx_len, 512);
 		tx_len = rounddown2(tx_len, 512);
@@ -149,8 +157,6 @@ cxgbei_init(struct adapter *sc, struct cxgbei_data *ci)
 	MPASS(sc->vres.iscsi.size > 0);
 	MPASS(ci != NULL);
 
-	read_pdu_limits(sc, &ci->max_tx_data_len, &ci->max_rx_data_len);
-
 	pr = &ci->pr;
 	r = t4_read_reg(sc, A_ULP_RX_ISCSI_PSZ);
 	rc = t4_init_ppod_region(pr, &sc->vres.iscsi, r, "iSCSI page pods");
@@ -176,6 +182,8 @@ cxgbei_init(struct adapter *sc, struct cxgbei_data *ci)
 		    V_ISCSITAGMASK(M_ISCSITAGMASK), pr->pr_tag_mask);
 	}
 
+	read_pdu_limits(sc, &ci->max_tx_data_len, &ci->max_rx_data_len, pr);
+
 	sysctl_ctx_init(&ci->ctx);
 	oid = device_get_sysctl_tree(sc->dev);	/* dev.t5nex.X */
 	children = SYSCTL_CHILDREN(oid);