Re: [Qemu-devel] [PATCH V2] Revert "hw/pci: disable pci-bridge's shpc by default"

[Marcel Apfelbaum <marcel@redhat.com>]

----- Original Message -----
> From: "Marcel Apfelbaum" <marcel@redhat.com>
> To: qemu-devel@nongnu.org
> Cc: marcel@redhat.com, mst@redhat.com, pbonzini@redhat.com, lersek@redhat.com, dgilbert@redhat.com
> Sent: Thursday, May 11, 2017 1:25:29 PM
> Subject: [Qemu-devel] [PATCH V2] Revert "hw/pci: disable pci-bridge's shpc by default"
> 
> This reverts commit dc0ae767700c156894e36fab89a745a2dc4173de.
> 
> Disabling the shpc controller has an undesired side effect.
> The PCI bridge remains with no attached devices at boot time,
> and the guest operating systems do not allocate any resources
> for it, leaving the bridge unusable. Note that the behaviour
> is dictated by the pci bridge specification.
> 
> Revert the commit and leave the shpc controller even if is not
> actually used by any architecture. Slot 0 remains unusable at boot time.
> 
> Keep shpc off for QEMU 2.9 machines.
> 
> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
> ---
> 
> V1 -> V2:
>  - Keep shpc off for QEMU 2.9 machines

Forgot to mentioned the above was Paolo's review, thanks Palo!
Marcel

>  - Rebased on Michael's tree to get QEMU 2.10 machine types
> 
> Thanks,
> Marcel
> 
>  hw/pci-bridge/pci_bridge_dev.c | 2 +-
>  include/hw/compat.h            | 6 +++++-
>  2 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/pci-bridge/pci_bridge_dev.c b/hw/pci-bridge/pci_bridge_dev.c
> index 647ad80..5dbd933 100644
> --- a/hw/pci-bridge/pci_bridge_dev.c
> +++ b/hw/pci-bridge/pci_bridge_dev.c
> @@ -163,7 +163,7 @@ static Property pci_bridge_dev_properties[] = {
>      DEFINE_PROP_ON_OFF_AUTO(PCI_BRIDGE_DEV_PROP_MSI, PCIBridgeDev, msi,
>                              ON_OFF_AUTO_AUTO),
>      DEFINE_PROP_BIT(PCI_BRIDGE_DEV_PROP_SHPC, PCIBridgeDev, flags,
> -                    PCI_BRIDGE_DEV_F_SHPC_REQ, false),
> +                    PCI_BRIDGE_DEV_F_SHPC_REQ, true),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> diff --git a/include/hw/compat.h b/include/hw/compat.h
> index 846b90e..55b1765 100644
> --- a/include/hw/compat.h
> +++ b/include/hw/compat.h
> @@ -2,7 +2,11 @@
>  #define HW_COMPAT_H
>  
>  #define HW_COMPAT_2_9 \
> -    /* empty */
> +    {\
> +        .driver   = "pci-bridge",\
> +        .property = "shpc",\
> +        .value    = "off",\
> +    },
>  
>  #define HW_COMPAT_2_8 \
>      {\
> --
> 2.9.3
> 
>