linux.git/drivers/virtio/virtio.c, branch v5.19

virtio: disable notification hardening by default

2022-06-24T06:49:48+00:00

We try to harden virtio device notifications in 8b4ec69d7e09 ("virtio:
harden vring IRQ"). It works with the assumption that the driver or
core can properly call virtio_device_ready() at the right
place. Unfortunately, this seems to be not true and uncover various
bugs of the existing drivers, mainly the issue of using
virtio_device_ready() incorrectly.

So let's add a Kconfig option and disable it by default. It gives
us time to fix the drivers and then we can consider re-enabling it.

Signed-off-by: Jason Wang 
Message-Id: <20220622012940.21441-1-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Cornelia Huck

virtio: replace arch_has_restricted_virtio_memory_access()

2022-06-06T06:22:01+00:00

Instead of using arch_has_restricted_virtio_memory_access() together
with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those
with platform_has() and a new platform feature
PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS.

Signed-off-by: Juergen Gross 
Reviewed-by: Oleksandr Tyshchenko 
Tested-by: Oleksandr Tyshchenko  # Arm64 only
Reviewed-by: Christoph Hellwig 
Acked-by: Borislav Petkov

virtio: Directly use ida_alloc()/free()

2022-05-31T16:45:10+00:00

Use ida_alloc()/ida_free() instead of deprecated
ida_simple_get()/ida_simple_remove() .

Signed-off-by: keliu 
Message-Id: <20220527073302.2474073-1-liuke94@huawei.com>
Signed-off-by: Michael S. Tsirkin

virtio: harden vring IRQ

2022-05-31T16:45:10+00:00

This is a rework on the previous IRQ hardening that is done for
virtio-pci where several drawbacks were found and were reverted:

1) try to use IRQF_NO_AUTOEN which is not friendly to affinity managed IRQ
   that is used by some device such as virtio-blk
2) done only for PCI transport

The vq->broken is re-used in this patch for implementing the IRQ
hardening. The vq->broken is set to true during both initialization
and reset. And the vq->broken is set to false in
virtio_device_ready(). Then vring_interrupt() can check and return
when vq->broken is true. And in this case, switch to return IRQ_NONE
to let the interrupt core aware of such invalid interrupt to prevent
IRQ storm.

The reason of using a per queue variable instead of a per device one
is that we may need it for per queue reset hardening in the future.

Note that the hardening is only done for vring interrupt since the
config interrupt hardening is already done in commit 22b7050a024d7
("virtio: defer config changed notifications"). But the method that is
used by config interrupt can't be reused by the vring interrupt
handler because it uses spinlock to do the synchronization which is
expensive.

Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: "Paul E. McKenney" 
Cc: Marc Zyngier 
Cc: Halil Pasic 
Cc: Cornelia Huck 
Cc: Vineeth Vijayan 
Cc: Peter Oberparleiter 
Cc: linux-s390@vger.kernel.org
Signed-off-by: Jason Wang 
Message-Id: <20220527060120.20964-9-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Xuan Zhuo

virtio: use virtio_reset_device() when possible

2022-05-31T16:45:09+00:00

This allows us to do common extension without duplicating code.

Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: "Paul E. McKenney" 
Cc: Marc Zyngier 
Cc: Halil Pasic 
Cc: Cornelia Huck 
Cc: Vineeth Vijayan 
Cc: Peter Oberparleiter 
Cc: linux-s390@vger.kernel.org
Reviewed-by: Cornelia Huck 
Signed-off-by: Jason Wang 
Message-Id: <20220527060120.20964-3-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Xuan Zhuo 
Reviewed-by: Eugenio Pérez

virtio: use virtio_device_ready() in virtio_device_restore()

2022-05-31T16:45:09+00:00

It will allow us to do extension on virtio_device_ready() without
duplicating code.

Cc: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: "Paul E. McKenney" 
Cc: Marc Zyngier 
Cc: Halil Pasic 
Cc: Cornelia Huck 
Cc: Vineeth Vijayan 
Cc: Peter Oberparleiter 
Cc: linux-s390@vger.kernel.org
Reviewed-by: Cornelia Huck 
Signed-off-by: Stefano Garzarella 
Signed-off-by: Jason Wang 
Message-Id: <20220527060120.20964-2-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Xuan Zhuo

virtio: Replace unsigned with unsigned int

2022-05-31T16:45:09+00:00

This patch addresses the checkpatch.pl warning where unsigned int is
preferred over unsigned.

Signed-off-by: Solomon Tan 
Message-Id: 
Signed-off-by: Michael S. Tsirkin

Revert "virtio: use virtio_device_ready() in virtio_device_restore()"

2022-03-30T08:18:14+00:00

This reverts commit 8d65bc9a5be3f23c5e2ab36b6b8ef40095165b18.

We reverted the problematic changes, no more need for work
arounds on restore.

Signed-off-by: Michael S. Tsirkin 
Acked-by: Jason Wang

virtio: use virtio_device_ready() in virtio_device_restore()

2022-03-28T20:52:59+00:00

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:
     
     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
     
     
     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
     
    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 
Link: https://lore.kernel.org/r/20220322114313.116516-1-sgarzare@redhat.com
Signed-off-by: Michael S. Tsirkin

virtio: document virtio_reset_device

2022-03-04T13:33:22+00:00

Looks like most callers get driver/device removal wrong.
Document what's expected of callers.

Signed-off-by: Michael S. Tsirkin