Re: [Qemu-devel] [PATCH v2] pci-assign: Add MSI affinity support

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, May 13, 2013 at 02:20:02PM -0600, Alex Williamson wrote:
> To support guest MSI affinity changes update the MSI message any time
> the guest writes to the address or data fields.
> 
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

Seems the only way we can fix this for 1.5.

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
> 
> v2: Don't cache MSIMessage
> 
>  hw/i386/kvm/pci-assign.c |   18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/hw/i386/kvm/pci-assign.c b/hw/i386/kvm/pci-assign.c
> index c1e08ec..ff85590 100644
> --- a/hw/i386/kvm/pci-assign.c
> +++ b/hw/i386/kvm/pci-assign.c
> @@ -1026,6 +1026,21 @@ static void assigned_dev_update_msi(PCIDevice *pci_dev)
>      }
>  }
>  
> +static void assigned_dev_update_msi_msg(PCIDevice *pci_dev)
> +{
> +    AssignedDevice *assigned_dev = DO_UPCAST(AssignedDevice, dev, pci_dev);
> +    uint8_t ctrl_byte = pci_get_byte(pci_dev->config + pci_dev->msi_cap +
> +                                     PCI_MSI_FLAGS);
> +
> +    if (assigned_dev->assigned_irq_type != ASSIGNED_IRQ_MSI ||
> +        !(ctrl_byte & PCI_MSI_FLAGS_ENABLE)) {
> +        return;
> +    }
> +
> +    kvm_irqchip_update_msi_route(kvm_state, assigned_dev->msi_virq[0],
> +                                 msi_get_message(pci_dev, 0));
> +}
> +
>  static bool assigned_dev_msix_masked(MSIXTableEntry *entry)
>  {
>      return (entry->ctrl & cpu_to_le32(0x1)) != 0;
> @@ -1201,6 +1216,9 @@ static void assigned_dev_pci_write_config(PCIDevice *pci_dev, uint32_t address,
>          if (range_covers_byte(address, len,
>                                pci_dev->msi_cap + PCI_MSI_FLAGS)) {
>              assigned_dev_update_msi(pci_dev);
> +        } else if (ranges_overlap(address, len, /* 32bit MSI only */
> +                                  pci_dev->msi_cap + PCI_MSI_ADDRESS_LO, 6)) {
> +            assigned_dev_update_msi_msg(pci_dev);
>          }
>      }
>      if (assigned_dev->cap.available & ASSIGNED_DEVICE_CAP_MSIX) {