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Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset |
Date: |
Thu, 12 Mar 2015 08:22:04 +0100 |
On Thu, Mar 12, 2015 at 02:40:55PM +0800, Fam Zheng wrote:
> Currently we could leave PCI IRQ asserted even after reset, it is safer
> to clear it.
>
> In the case that a buggy driver has disabled MSI-X unintentially, we may
> have already injected IRQ in previous virtio_pci_notify, which will not
> be cleared by guest because it doesn't expect it (i.e. no irq handler).
> However the driver may eventually notice the unresponsiveness and reset
> the device, at that point, clearing the irq is meaningful.
>
> Signed-off-by: Fam Zheng <address@hidden>
I don't get it. interrupts are de-asserted
in pci core:
static void pci_do_device_reset(PCIDevice *dev)
{
int r;
pci_device_deassert_intx(dev);
...
}
why isn't this sufficient?
> ---
> hw/virtio/virtio-pci.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index e7baf7b..2600f1e 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -988,6 +988,7 @@ static void virtio_pci_reset(DeviceState *qdev)
> virtio_pci_stop_ioeventfd(proxy);
> virtio_bus_reset(bus);
> msix_unuse_all_vectors(&proxy->pci_dev);
> + pci_irq_deassert(&proxy->pci_dev);
> }
>
> static Property virtio_pci_properties[] = {
> --
> 1.9.3
- [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Fam Zheng, 2015/03/12
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset,
Michael S. Tsirkin <=
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Michael S. Tsirkin, 2015/03/12
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Fam Zheng, 2015/03/12
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Michael S. Tsirkin, 2015/03/12
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Michael S. Tsirkin, 2015/03/12
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Peter Maydell, 2015/03/12
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Michael S. Tsirkin, 2015/03/12
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Peter Maydell, 2015/03/12
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Michael S. Tsirkin, 2015/03/12
- Re: [Qemu-devel] [PATCH] virtio-pci: Clear IRQ at reset, Fam Zheng, 2015/03/13