Re: [Qemu-devel] [PATCH for-1.2] msix: make [un]use vectors on reset/load optional

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2012-08-29 18:40, Michael S. Tsirkin wrote:
> The facility to use/unuse vectors dynamically is helpful
> for virtio but little else: everyone just seems to use
> vectors in their init function.
> 
> Avoid clearing msix vector use info on reset and load.
> For virtio, clear it explicitly.
> This should fix regressions reported with ivshmem - though
> I didn't test this, I verified that virtio keeps
> working like it did.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/msix.c       | 13 +++++++++++--
>  hw/virtio-pci.c |  2 ++
>  2 files changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/msix.c b/hw/msix.c
> index 800fc32..d040cc2 100644
> --- a/hw/msix.c
> +++ b/hw/msix.c
> @@ -340,6 +340,15 @@ static void msix_free_irq_entries(PCIDevice *dev)
>      }
>  }
>  
> +static void msix_clear_all_vectors(PCIDevice *dev)
> +{
> +    int vector;
> +
> +    for (vector = 0; vector < dev->msix_entries_nr; ++vector) {
> +        msix_clr_pending(dev, vector);
> +    }
> +}
> +
>  /* Clean up resources for the device. */
>  void msix_uninit(PCIDevice *dev, MemoryRegion *table_bar, MemoryRegion *pba_bar)
>  {
> @@ -394,7 +403,7 @@ void msix_load(PCIDevice *dev, QEMUFile *f)
>          return;
>      }
>  
> -    msix_free_irq_entries(dev);
> +    msix_clear_all_vectors(dev);
>      qemu_get_buffer(f, dev->msix_table, n * PCI_MSIX_ENTRY_SIZE);
>      qemu_get_buffer(f, dev->msix_pba, (n + 7) / 8);
>      msix_update_function_masked(dev);
> @@ -440,7 +449,7 @@ void msix_reset(PCIDevice *dev)
>      if (!msix_present(dev)) {
>          return;
>      }
> -    msix_free_irq_entries(dev);
> +    msix_clear_all_vectors(dev);
>      dev->config[dev->msix_cap + MSIX_CONTROL_OFFSET] &=
>  	    ~dev->wmask[dev->msix_cap + MSIX_CONTROL_OFFSET];
>      memset(dev->msix_table, 0, dev->msix_entries_nr * PCI_MSIX_ENTRY_SIZE);
> diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> index 125eded..ca0b204 100644
> --- a/hw/virtio-pci.c
> +++ b/hw/virtio-pci.c
> @@ -131,6 +131,7 @@ static int virtio_pci_load_config(void * opaque, QEMUFile *f)
>      if (ret) {
>          return ret;
>      }
> +    msix_unuse_all_vectors(&proxy->pci_dev);
>      msix_load(&proxy->pci_dev, f);
>      if (msix_present(&proxy->pci_dev)) {
>          qemu_get_be16s(f, &proxy->vdev->config_vector);
> @@ -246,6 +247,7 @@ void virtio_pci_reset(DeviceState *d)
>      VirtIOPCIProxy *proxy = container_of(d, VirtIOPCIProxy, pci_dev.qdev);
>      virtio_pci_stop_ioeventfd(proxy);
>      virtio_reset(proxy->vdev);
> +    msix_unuse_all_vectors(&proxy->pci_dev);
>      proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
>  }
>  
> 

Fine with me, but let's ask Cam to test.

Jan

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