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

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

[Marcel Apfelbaum]

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 all 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.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---
 hw/pci-bridge/pci_bridge_dev.c | 2 +-
 include/hw/compat.h            | 4 ----
 2 files changed, 1 insertion(+), 5 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..eff021f 100644
--- a/include/hw/compat.h
+++ b/include/hw/compat.h
@@ -18,10 +18,6 @@
         .property = "old-multiple-chip-handling",\
         .value    = "on",\
     },{\
-        .driver   = "pci-bridge",\
-        .property = "shpc",\
-        .value    = "on",\
-    },{\
         .driver   = TYPE_PCI_DEVICE,\
         .property = "x-pcie-extcap-init",\
         .value    = "off",\
-- 
2.9.3

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

[Paolo Bonzini]

On 10/05/2017 11:29, Marcel Apfelbaum wrote:
> +++ 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..eff021f 100644
> --- a/include/hw/compat.h
> +++ b/include/hw/compat.h
> @@ -18,10 +18,6 @@
>          .property = "old-multiple-chip-handling",\
>          .value    = "on",\
>      },{\
> -        .driver   = "pci-bridge",\
> -        .property = "shpc",\
> -        .value    = "on",\
> -    },{\

Unless we make a conscious decision to break PCI bridge backwards
compatibility, you now have to disable it for 2.9 and leave this
HW_COMPAT_2_8 hunk intact.  Peter Xu has a patch to add the 2.10 machine
types.

Paolo

>          .driver   = TYPE_PCI_DEVICE,\
>          .property = "x-pcie-extcap-init",\
>          .value    = "off",\
> -- 2.9.3

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

[Marcel Apfelbaum]

----- Original Message -----
> From: "Paolo Bonzini" <pbonzini@redhat.com>
> To: "Marcel Apfelbaum" <marcel@redhat.com>, qemu-devel@nongnu.org
> Cc: qemu-stable@nongnu.org, mst@redhat.com
> Sent: Wednesday, May 10, 2017 6:38:45 PM
> Subject: Re: [Qemu-devel] [PATCH] Revert "hw/pci: disable pci-bridge's shpc by default"
> 
> 
> 
> On 10/05/2017 11:29, Marcel Apfelbaum wrote:
> > +++ 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..eff021f 100644
> > --- a/include/hw/compat.h
> > +++ b/include/hw/compat.h
> > @@ -18,10 +18,6 @@
> >          .property = "old-multiple-chip-handling",\
> >          .value    = "on",\
> >      },{\
> > -        .driver   = "pci-bridge",\
> > -        .property = "shpc",\
> > -        .value    = "on",\
> > -    },{\
> 

Hi Paolo,

> Unless we make a conscious decision to break PCI bridge backwards
> compatibility, you now have to disable it for 2.9 and leave this
> HW_COMPAT_2_8 hunk intact.  Peter Xu has a patch to add the 2.10 machine
> types.
> 

I thought is not an interesting enough scenario to keep it "broken" for 2.9,
but I'll do that, sure, I'll add it on top of Peter's patch.

Thanks,
Marcel

> Paolo
> 
> >          .driver   = TYPE_PCI_DEVICE,\
> >          .property = "x-pcie-extcap-init",\
> >          .value    = "off",\
> > -- 2.9.3
> 

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

[Michael S. Tsirkin]

On Wed, May 10, 2017 at 05:38:45PM +0200, Paolo Bonzini wrote:
> 
> 
> On 10/05/2017 11:29, Marcel Apfelbaum wrote:
> > +++ 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..eff021f 100644
> > --- a/include/hw/compat.h
> > +++ b/include/hw/compat.h
> > @@ -18,10 +18,6 @@
> >          .property = "old-multiple-chip-handling",\
> >          .value    = "on",\
> >      },{\
> > -        .driver   = "pci-bridge",\
> > -        .property = "shpc",\
> > -        .value    = "on",\
> > -    },{\
> 
> Unless we make a conscious decision to break PCI bridge backwards
> compatibility, you now have to disable it for 2.9 and leave this
> HW_COMPAT_2_8 hunk intact.  Peter Xu has a patch to add the 2.10 machine
> types.
> 
> Paolo
> 
> >          .driver   = TYPE_PCI_DEVICE,\
> >          .property = "x-pcie-extcap-init",\
> >          .value    = "off",\
> > -- 2.9.3


It's going upstream now, I just need to rebase.

-- 
MST