Re: [Qemu-devel] [PATCH v2] pci-assign: sync MSI/MSI-X cap and table with PCIDevice

[Michael S. Tsirkin]

On Fri, Nov 25, 2016 at 10:55:22AM +0800, Peter Xu wrote:
> Since commit e1d4fb2d ("kvm-irqchip: x86: add msi route notify fn"),
> kvm_irqchip_add_msi_route() starts to use pci_get_msi_message() to fetch
> MSI info. This requires that we setup MSI related fields in PCIDevice.
> For most devices, that won't be a problem, as long as we are using
> general interfaces like msi_init()/msix_init().
> 
> However, for pci-assign devices, MSI/MSI-X is treated differently - PCI
> assign devices are maintaining its own MSI table and cap information in
> AssignedDevice struct. however that's not synced up with PCIDevice's
> fields. That will leads to pci_get_msi_message() failed to find correct
> MSI capability, even with an NULL msix_table.
> 
> A quick fix is to sync up the two places: both the capability bits and
> table address for MSI/MSI-X.
> 
> Reported-by: Changlimin <address@hidden>
> Tested-by: Changlimin <address@hidden>
> Cc: address@hidden
> Fixes: e1d4fb2d ("kvm-irqchip: x86: add msi route notify fn")
> Signed-off-by: Peter Xu <address@hidden>


Reviewed-by: Michael S. Tsirkin <address@hidden>

Paolo, want to pick this up?

> ---
> Do we still support pci-assign?
> 
> v2:
> - add (uint8_t *) for msix_table assignment [Limin]
> ---
>  hw/i386/kvm/pci-assign.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/hw/i386/kvm/pci-assign.c b/hw/i386/kvm/pci-assign.c
> index 8238fbc..87dcbdd 100644
> --- a/hw/i386/kvm/pci-assign.c
> +++ b/hw/i386/kvm/pci-assign.c
> @@ -1251,6 +1251,7 @@ static int assigned_device_pci_cap_init(PCIDevice 
> *pci_dev, Error **errp)
>              error_propagate(errp, local_err);
>              return -ENOTSUP;
>          }
> +        dev->dev.cap_present |= QEMU_PCI_CAP_MSI;
>          dev->cap.available |= ASSIGNED_DEVICE_CAP_MSI;
>          /* Only 32-bit/no-mask currently supported */
>          ret = pci_add_capability2(pci_dev, PCI_CAP_ID_MSI, pos, 10,
> @@ -1285,6 +1286,7 @@ static int assigned_device_pci_cap_init(PCIDevice 
> *pci_dev, Error **errp)
>              error_propagate(errp, local_err);
>              return -ENOTSUP;
>          }
> +        dev->dev.cap_present |= QEMU_PCI_CAP_MSIX;
>          dev->cap.available |= ASSIGNED_DEVICE_CAP_MSIX;
>          ret = pci_add_capability2(pci_dev, PCI_CAP_ID_MSIX, pos, 12,
>                                    &local_err);
> @@ -1648,6 +1650,7 @@ static void 
> assigned_dev_register_msix_mmio(AssignedDevice *dev, Error **errp)
>          dev->msix_table = NULL;
>          return;
>      }
> +    dev->dev.msix_table = (uint8_t *)dev->msix_table;
>  
>      assigned_dev_msix_reset(dev);
>  
> @@ -1665,6 +1668,7 @@ static void 
> assigned_dev_unregister_msix_mmio(AssignedDevice *dev)
>          error_report("error unmapping msix_table! %s", strerror(errno));
>      }
>      dev->msix_table = NULL;
> +    dev->dev.msix_table = NULL;
>  }
>  
>  static const VMStateDescription vmstate_assigned_device = {
> -- 
> 2.7.4
>