git: f8fa2d77bc30 - main - iflib: Add restart transactions for IOV reconfiguration

The branch main has been updated by kbowling:

URL: https://cgit.FreeBSD.org/src/commit/?id=f8fa2d77bc305bec519f9f02afe211e903c57573

commit f8fa2d77bc305bec519f9f02afe211e903c57573
Author:     Kevin Bowling <kbowling@FreeBSD.org>
AuthorDate: 2026-07-28 21:53:18 +0000
Commit:     Kevin Bowling <kbowling@FreeBSD.org>
CommitDate: 2026-07-30 00:08:41 +0000

    iflib: Add restart transactions for IOV reconfiguration
    
    Some devices remap the PF queues when entering or leaving SR-IOV. Add
    opt-in PCI IOV helpers that hold the iflib context lock across the
    complete stop, driver callback, and restart transaction.
    
    Existing drivers continue to use the non-restarting helpers.
    
    Sponsored by:   BBOX.io
---
 sys/net/iflib.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 sys/net/iflib.h |  2 ++
 2 files changed, 55 insertions(+)

diff --git a/sys/net/iflib.c b/sys/net/iflib.c
index 87626ae59815..b6a8ec1eb6ce 100644
--- a/sys/net/iflib.c
+++ b/sys/net/iflib.c
@@ -5545,6 +5545,37 @@ iflib_device_iov_init(device_t dev, uint16_t num_vfs, const nvlist_t *params)
 	return (error);
 }
 
+int
+iflib_device_iov_init_restart(device_t dev, uint16_t num_vfs,
+    const nvlist_t *params)
+{
+	if_ctx_t ctx;
+	if_t ifp;
+	int error;
+
+	ctx = device_get_softc(dev);
+	ifp = ctx->ifc_ifp;
+
+	CTX_LOCK(ctx);
+	/*
+	 * Drivers which change the PF queue layout need the complete iflib
+	 * stop/init sequence around their IOV callback.  Keep that transition
+	 * within one context-lock critical section.
+	 */
+	if ((if_getflags(ifp) & IFF_UP) == 0 ||
+	    (if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0) {
+		error = ENETDOWN;
+		goto out;
+	}
+
+	iflib_stop(ctx);
+	error = IFDI_IOV_INIT(ctx, num_vfs, params);
+	iflib_init_locked(ctx);
+out:
+	CTX_UNLOCK(ctx);
+	return (error);
+}
+
 void
 iflib_device_iov_uninit(device_t dev)
 {
@@ -5555,6 +5586,28 @@ iflib_device_iov_uninit(device_t dev)
 	CTX_UNLOCK(ctx);
 }
 
+void
+iflib_device_iov_uninit_restart(device_t dev)
+{
+	if_ctx_t ctx;
+	bool restart;
+
+	ctx = device_get_softc(dev);
+
+	CTX_LOCK(ctx);
+	/*
+	 * RUNNING can be clear while a watchdog reset is pending but the
+	 * hardware is still live.  Always stop before the driver changes its
+	 * queue layout, and use IFF_UP only to preserve administrative state.
+	 */
+	restart = (if_getflags(ctx->ifc_ifp) & IFF_UP) != 0;
+	iflib_stop(ctx);
+	IFDI_IOV_UNINIT(ctx);
+	if (restart)
+		iflib_init_locked(ctx);
+	CTX_UNLOCK(ctx);
+}
+
 int
 iflib_device_iov_add_vf(device_t dev, uint16_t vfnum, const nvlist_t *params)
 {
diff --git a/sys/net/iflib.h b/sys/net/iflib.h
index c73c50e5a3b3..6e9c6e10cc5d 100644
--- a/sys/net/iflib.h
+++ b/sys/net/iflib.h
@@ -450,7 +450,9 @@ int iflib_device_shutdown(device_t);
 int iflib_device_probe_vendor(device_t);
 
 int iflib_device_iov_init(device_t, uint16_t, const nvlist_t *);
+int iflib_device_iov_init_restart(device_t, uint16_t, const nvlist_t *);
 void iflib_device_iov_uninit(device_t);
+void iflib_device_iov_uninit_restart(device_t);
 int iflib_device_iov_add_vf(device_t, uint16_t, const nvlist_t *);
 
 /*