From: Wanlong Gao <gaowanlong@xxxxxxxxxxxxxx>
Add hot cpu notifier to reset the request virtqueue affinity
when doing cpu hotplug.
Cc: linux-scsi@xxxxxxxxxxxxxxx
Signed-off-by: Wanlong Gao <gaowanlong@xxxxxxxxxxxxxx>
[ The version that doesn't get/put_online_cpus is now called
__virtscsi_set_affinity - Paolo ]
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
drivers/scsi/virtio_scsi.c | 31 +++++++++++++++++++++++++++++++
1 files changed, 31 insertions(+), 0 deletions(-)
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index a2bdae1..733307a 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -20,6 +20,7 @@
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>
#include <linux/virtio_scsi.h>
+#include <linux/cpu.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
@@ -109,6 +110,9 @@ struct virtio_scsi {
/* Does the affinity hint is set for virtqueues? */
bool affinity_hint_set;
+ /* CPU hotplug notifier */
+ struct notifier_block nb;
+
struct virtio_scsi_vq ctrl_vq;
struct virtio_scsi_vq event_vq;
struct virtio_scsi_vq req_vqs[];
@@ -734,6 +738,7 @@ static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
}
}
+
static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
{
get_online_cpus();
@@ -741,6 +746,23 @@ static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
put_online_cpus();
}
+static int virtscsi_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb);
+ switch(action) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ __virtscsi_set_affinity(vscsi, true);
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
struct virtqueue *vq)
{
@@ -885,6 +907,13 @@ static int virtscsi_probe(struct virtio_device *vdev)
if (err)
goto virtscsi_init_failed;
+ vscsi->nb.notifier_call = &virtscsi_cpu_callback;
+ err = register_hotcpu_notifier(&vscsi->nb);
+ if (err) {
+ pr_err("virtio_scsi: registering cpu notifier failed\n");
+ goto scsi_add_host_failed;
+ }
+
cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
@@ -922,6 +951,8 @@ static void virtscsi_remove(struct virtio_device *vdev)
scsi_remove_host(shost);
+ unregister_hotcpu_notifier(&vscsi->nb);
+
virtscsi_remove_vqs(vdev);
scsi_host_put(shost);
}
--
1.7.1
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