[PATCH 5.16 0952/1017] virtio: use virtio_device_ready() in virtio_device_restore()

Greg Kroah-Hartman
2022-04-05T13:48:38Z

From: Stefano Garzarella <sgarzare@redhat.com>

commit 8d65bc9a5be3f23c5e2ab36b6b8ef40095165b18 upstream.

After waking up a suspended VM, the kernel prints the following trace
for virtio drivers which do not directly call virtio_device_ready() in
the .restore:

PM: suspend exit
irq 22: nobody cared (try booting with the "irqpoll" option)
Call Trace:
<IRQ>
dump_stack_lvl+0x38/0x49
dump_stack+0x10/0x12
__report_bad_irq+0x3a/0xaf
note_interrupt.cold+0xb/0x60
handle_irq_event+0x71/0x80
handle_fasteoi_irq+0x95/0x1e0
__common_interrupt+0x6b/0x110
common_interrupt+0x63/0xe0
asm_common_interrupt+0x1e/0x40
? __do_softirq+0x75/0x2f3
irq_exit_rcu+0x93/0xe0
sysvec_apic_timer_interrupt+0xac/0xd0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x12/0x20
arch_cpu_idle+0x12/0x20
default_idle_call+0x39/0xf0
do_idle+0x1b5/0x210
cpu_startup_entry+0x20/0x30
start_secondary+0xf3/0x100
secondary_startup_64_no_verify+0xc3/0xcb
</TASK>
handlers:
[<000000008f9bac49>] vp_interrupt
[<000000008f9bac49>] vp_interrupt
Disabling IRQ #22

This happens because we don't invoke .enable_cbs callback in
virtio_device_restore(). That callback is used by some transports
(e.g. virtio-pci) to enable interrupts.

Let's fix it, by calling virtio_device_ready() as we do in
virtio_dev_probe(). This function calls .enable_cts callback and sets
DRIVER_OK status bit.

This fix also avoids setting DRIVER_OK twice for those drivers that
call virtio_device_ready() in the .restore.

Fixes: d50497eb4e55 ("virtio_config: introduce a new .enable_cbs method")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20220322114313.116516-1-sgarzare@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/virtio/virtio.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -504,8 +504,9 @@ int virtio_device_restore(struct virtio_
goto err;
}

- /* Finally, tell the device we're all set */
- virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
+ /* If restore didn't do it, mark device DRIVER_OK ourselves. */
+ if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIVER_OK))
+ virtio_device_ready(dev);

virtio_config_enable(dev);