[Qemu-devel] Re: [PATCH] pci: disable migration of p2p bridge

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

On Wed, Dec 22, 2010 at 12:13:43PM +0900, Isaku Yamahata wrote:
> Right now pcibus_get_dev_path() isn't migration save because
> bus number/secondary bus number are set by guest OS.
> So it can't be used reliably for qemu internal id.
> 
> For 0.14 release, disable p2p bridge migration at the moment.
> Once pcibus_get_dev_path() is fixed, this patch should be reverted.
> It will be addressed for 0.15 release.
> 
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Alex Williamson <alex.williamson@redhat.com>
> Cc: Blue Swirl <blauwirbel@gmail.com>
> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>


Hmm, haven't looked into this deeply - can we do this in one place
when the bridge is created?

> ---
>  hw/apb_pci.c            |    9 +++++++++
>  hw/dec_pci.c            |    6 ++++++
>  hw/ioh3420.c            |    4 ++++
>  hw/xio3130_downstream.c |    4 ++++
>  hw/xio3130_upstream.c   |    4 ++++
>  5 files changed, 27 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/apb_pci.c b/hw/apb_pci.c
> index 84e9af7..c456d8d 100644
> --- a/hw/apb_pci.c
> +++ b/hw/apb_pci.c
> @@ -368,6 +368,11 @@ PCIBus *pci_apb_init(target_phys_addr_t special_base,
>      qdev_init_nofail(&pci_dev->qdev);
>      *bus2 = pci_bridge_get_sec_bus(br);
>  
> +    /* TODO: p2p bridge migration. pcibus_get_dev_path() isn't migration-safe.
> +       remove this once p2p bridge migration is supported */
> +    register_device_unmigratable(&pci_dev->qdev, "pbm-bridge", &pci_dev->qdev);
> +
> +
>      pci_dev = pci_create_multifunction(d->bus, PCI_DEVFN(1, 1), true,
>                                     "pbm-bridge");
>      br = DO_UPCAST(PCIBridge, dev, pci_dev);
> @@ -376,6 +381,10 @@ PCIBus *pci_apb_init(target_phys_addr_t special_base,
>      qdev_init_nofail(&pci_dev->qdev);
>      *bus3 = pci_bridge_get_sec_bus(br);
>  
> +    /* TODO: p2p bridge migration. pcibus_get_dev_path() isn't migration-safe.
> +       remove this once p2p bridge migration is supported */
> +    register_device_unmigratable(&pci_dev->qdev, "pbm-bridge", &pci_dev->qdev);
> +
>      return d->bus;
>  }
>  
> diff --git a/hw/dec_pci.c b/hw/dec_pci.c
> index bf88f2a..3710984 100644
> --- a/hw/dec_pci.c
> +++ b/hw/dec_pci.c
> @@ -86,6 +86,12 @@ PCIBus *pci_dec_21154_init(PCIBus *parent_bus, int devfn)
>      br = DO_UPCAST(PCIBridge, dev, dev);
>      pci_bridge_map_irq(br, "DEC 21154 PCI-PCI bridge", dec_map_irq);
>      qdev_init_nofail(&dev->qdev);
> +
> +    /* TODO: p2p bridge migration. pcibus_get_dev_path() isn't migration-safe.
> +       remove this once p2p bridge migration is supported */
> +    register_device_unmigratable(&dev->qdev, "dec-21154-p2p-bridge",
> +                                 &dev->qdev);
> +
>      return pci_bridge_get_sec_bus(br);
>  }
>  
> diff --git a/hw/ioh3420.c b/hw/ioh3420.c
> index 95adf09..b1a5c96 100644
> --- a/hw/ioh3420.c
> +++ b/hw/ioh3420.c
> @@ -188,6 +188,10 @@ PCIESlot *ioh3420_init(PCIBus *bus, int devfn, bool multifunction,
>      qdev_prop_set_uint16(qdev, "slot", slot);
>      qdev_init_nofail(qdev);
>  
> +    /* TODO: p2p bridge migration. pcibus_get_dev_path() isn't migration-safe.
> +       remove this once p2p bridge migration is supported */
> +    register_device_unmigratable(qdev, "ioh3420", qdev);
> +
>      return DO_UPCAST(PCIESlot, port, DO_UPCAST(PCIEPort, br, br));
>  }
>  
> diff --git a/hw/xio3130_downstream.c b/hw/xio3130_downstream.c
> index 1a2d258..83394ab 100644
> --- a/hw/xio3130_downstream.c
> +++ b/hw/xio3130_downstream.c
> @@ -153,6 +153,10 @@ PCIESlot *xio3130_downstream_init(PCIBus *bus, int devfn, bool multifunction,
>      qdev_prop_set_uint16(qdev, "slot", slot);
>      qdev_init_nofail(qdev);
>  
> +    /* TODO: p2p bridge migration. pcibus_get_dev_path() isn't migration-safe.
> +       remove this once p2p bridge migration is supported */
> +    register_device_unmigratable(qdev, "x3130-downstream", qdev);
> +
>      return DO_UPCAST(PCIESlot, port, DO_UPCAST(PCIEPort, br, br));
>  }
>  
> diff --git a/hw/xio3130_upstream.c b/hw/xio3130_upstream.c
> index 387bf6c..cbd126a 100644
> --- a/hw/xio3130_upstream.c
> +++ b/hw/xio3130_upstream.c
> @@ -134,6 +134,10 @@ PCIEPort *xio3130_upstream_init(PCIBus *bus, int devfn, bool multifunction,
>      qdev_prop_set_uint8(qdev, "port", port);
>      qdev_init_nofail(qdev);
>  
> +    /* TODO: p2p bridge migration. pcibus_get_dev_path() isn't migration-safe.
> +       remove this once p2p bridge migration is supported */
> +    register_device_unmigratable(qdev, "x3130-upstream", qdev);
> +
>      return DO_UPCAST(PCIEPort, br, br);
>  }
>  
> -- 
> 1.7.1.1