Re: [Qemu-stable] [Qemu-devel] [PULL 11/26] pci-bridge/i82801b11: clear bridge registers on platform reset

[Laszlo Ersek]

Michael, Peter,

On 02/08/18 20:09, Michael S. Tsirkin wrote:
> From: Laszlo Ersek <address@hidden>
> 
> The "i82801b11-bridge" device model is a descendant of "base-pci-bridge"
> (TYPE_PCI_BRIDGE). However, unlike other similar devices, such as
> 
> - pci-bridge,
> - pcie-pci-bridge,
> - PCIE Root Port,
> - xio3130 switch upstream and downstream ports,
> - dec-21154-p2p-bridge,
> - pbm-bridge,
> - xilinx-pcie-root,
> 
> "i82801b11-bridge" does not clear the bridge specific registers at
> platform reset.
> 
> This is a problem because devices on "i82801b11-bridge" continue to
> respond to config space cycles after platform reset, when addressed with
> the bus number that was previously programmed into the secondary bus
> number register of "i82801b11-bridge". This error breaks OVMF's search for
> extra (PXB) root buses, for example.
> 
> The device class reset method for "i82801b11-bridge" is currently NULL;
> set it directly to pci_bridge_reset(), like the last three bridge models
> in the above listing do.
> 
> Cc: "Michael S. Tsirkin" <address@hidden>
> Cc: Marcel Apfelbaum <address@hidden>
> Cc: address@hidden
> Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1541839
> Signed-off-by: Laszlo Ersek <address@hidden>
> Reviewed-by: Marcel Apfelbaum <address@hidden>
> Reviewed-by: Michael S. Tsirkin <address@hidden>
> Signed-off-by: Michael S. Tsirkin <address@hidden>
> ---
>  hw/pci-bridge/i82801b11.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/pci-bridge/i82801b11.c b/hw/pci-bridge/i82801b11.c
> index cb522bf..ebf7f5f 100644
> --- a/hw/pci-bridge/i82801b11.c
> +++ b/hw/pci-bridge/i82801b11.c
> @@ -98,6 +98,7 @@ static void i82801b11_bridge_class_init(ObjectClass *klass, 
> void *data)
>      k->realize = i82801b11_bridge_realize;
>      k->config_write = pci_bridge_write_config;
>      dc->vmsd = &i82801b11_bridge_dev_vmstate;
> +    dc->reset = pci_bridge_reset;
>      set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
>  }
>  
> 

this patch didn't get included in the 2.11.1 round-up:

http://mid.mail-archive.com/address@hidden

(The patch was posted, CC stable, between Mike's round-up set and the
actual 2.11.1 release.)

Can we please make sure that the commit doesn't miss the 2.11.2 bus?
2.12 is still a month out, and without this patch, rebooting an UEFI
guest OS (with OVMF) hangs, on certain VM configs (see the commit message).

(Apologies if there is a "queue" or "next" branch for stable releases --
in that case I should have probably checked that branch before sending
this email.)

The commit hash on the master branch is
ed247f40db84c8bd4bb7d10948702cd47cc4d5ae; it's part of v2.12.0-rc0.

Thanks!
Laszlo