diff mbox series

[v2] hw/pcie-root-port: Fix hotplug for PCI devices requiring IO

Message ID 20210802090057.1709775-1-marcel@redhat.com (mailing list archive)
State New, archived
Headers show
Series [v2] hw/pcie-root-port: Fix hotplug for PCI devices requiring IO | expand

Commit Message

Marcel Apfelbaum Aug. 2, 2021, 9 a.m. UTC
Q35 has now ACPI hotplug enabled by default for PCI(e) devices.
As opposed to native PCIe hotplug, guests like Fedora 34
will not assign IO range to pcie-root-ports not supporting
native hotplug, resulting into a regression.

Reproduce by:
    qemu-bin -M q35 -device pcie-root-port,id=p1 -monitor stdio
    device_add e1000,bus=p1
In the Guest OS the respective pcie-root-port will have the IO range
disabled.

Fix it by setting the "reserve-io" hint capability of the
pcie-root-ports so the firmware will allocate the IO range instead.

Acked-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---
v2:
   - improve commit message (Igor)

 hw/pci-bridge/gen_pcie_root_port.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Daniel P. Berrangé Aug. 2, 2021, 9:05 a.m. UTC | #1
On Mon, Aug 02, 2021 at 12:00:57PM +0300, Marcel Apfelbaum wrote:
> Q35 has now ACPI hotplug enabled by default for PCI(e) devices.
> As opposed to native PCIe hotplug, guests like Fedora 34
> will not assign IO range to pcie-root-ports not supporting
> native hotplug, resulting into a regression.

Presumably this means this patch should have 'for 6.1' tagged
in subject, as we don't want 6.1 to regress ?

> 
> Reproduce by:
>     qemu-bin -M q35 -device pcie-root-port,id=p1 -monitor stdio
>     device_add e1000,bus=p1
> In the Guest OS the respective pcie-root-port will have the IO range
> disabled.
> 
> Fix it by setting the "reserve-io" hint capability of the
> pcie-root-ports so the firmware will allocate the IO range instead.
> 
> Acked-by: Igor Mammedov <imammedo@redhat.com>
> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
> ---
> v2:
>    - improve commit message (Igor)
> 
>  hw/pci-bridge/gen_pcie_root_port.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/hw/pci-bridge/gen_pcie_root_port.c b/hw/pci-bridge/gen_pcie_root_port.c
> index ec9907917e..20099a8ae3 100644
> --- a/hw/pci-bridge/gen_pcie_root_port.c
> +++ b/hw/pci-bridge/gen_pcie_root_port.c
> @@ -28,6 +28,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(GenPCIERootPort, GEN_PCIE_ROOT_PORT)
>          (GEN_PCIE_ROOT_PORT_AER_OFFSET + PCI_ERR_SIZEOF)
>  
>  #define GEN_PCIE_ROOT_PORT_MSIX_NR_VECTOR       1
> +#define GEN_PCIE_ROOT_DEFAULT_IO_RANGE          4096
>  
>  struct GenPCIERootPort {
>      /*< private >*/
> @@ -75,6 +76,7 @@ static bool gen_rp_test_migrate_msix(void *opaque, int version_id)
>  static void gen_rp_realize(DeviceState *dev, Error **errp)
>  {
>      PCIDevice *d = PCI_DEVICE(dev);
> +    PCIESlot *s = PCIE_SLOT(d);
>      GenPCIERootPort *grp = GEN_PCIE_ROOT_PORT(d);
>      PCIERootPortClass *rpc = PCIE_ROOT_PORT_GET_CLASS(d);
>      Error *local_err = NULL;
> @@ -85,6 +87,9 @@ static void gen_rp_realize(DeviceState *dev, Error **errp)
>          return;
>      }
>  
> +    if (grp->res_reserve.io == -1 && s->hotplug && !s->native_hotplug) {
> +        grp->res_reserve.io = GEN_PCIE_ROOT_DEFAULT_IO_RANGE;
> +    }
>      int rc = pci_bridge_qemu_reserve_cap_init(d, 0,
>                                                grp->res_reserve, errp);
>  
> -- 
> 2.31.1
> 
> 

Regards,
Daniel
Marcel Apfelbaum Aug. 2, 2021, 1:30 p.m. UTC | #2
Hi Daniel,

On Mon, Aug 2, 2021 at 12:05 PM Daniel P. Berrangé <berrange@redhat.com>
wrote:

> On Mon, Aug 02, 2021 at 12:00:57PM +0300, Marcel Apfelbaum wrote:
> > Q35 has now ACPI hotplug enabled by default for PCI(e) devices.
> > As opposed to native PCIe hotplug, guests like Fedora 34
> > will not assign IO range to pcie-root-ports not supporting
> > native hotplug, resulting into a regression.
>
> Presumably this means this patch should have 'for 6.1' tagged
> in subject, as we don't want 6.1 to regress ?
>

I agree I should have added the tag, however Michael is aware as
he proposed this patch.
I can re-spin if necessary.

Thanks,
Marcel


>
> >
> > Reproduce by:
> >     qemu-bin -M q35 -device pcie-root-port,id=p1 -monitor stdio
> >     device_add e1000,bus=p1
> > In the Guest OS the respective pcie-root-port will have the IO range
> > disabled.
> >
> > Fix it by setting the "reserve-io" hint capability of the
> > pcie-root-ports so the firmware will allocate the IO range instead.
> >
> > Acked-by: Igor Mammedov <imammedo@redhat.com>
> > Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
> > ---
> > v2:
> >    - improve commit message (Igor)
> >
> >  hw/pci-bridge/gen_pcie_root_port.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/hw/pci-bridge/gen_pcie_root_port.c
> b/hw/pci-bridge/gen_pcie_root_port.c
> > index ec9907917e..20099a8ae3 100644
> > --- a/hw/pci-bridge/gen_pcie_root_port.c
> > +++ b/hw/pci-bridge/gen_pcie_root_port.c
> > @@ -28,6 +28,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(GenPCIERootPort,
> GEN_PCIE_ROOT_PORT)
> >          (GEN_PCIE_ROOT_PORT_AER_OFFSET + PCI_ERR_SIZEOF)
> >
> >  #define GEN_PCIE_ROOT_PORT_MSIX_NR_VECTOR       1
> > +#define GEN_PCIE_ROOT_DEFAULT_IO_RANGE          4096
> >
> >  struct GenPCIERootPort {
> >      /*< private >*/
> > @@ -75,6 +76,7 @@ static bool gen_rp_test_migrate_msix(void *opaque, int
> version_id)
> >  static void gen_rp_realize(DeviceState *dev, Error **errp)
> >  {
> >      PCIDevice *d = PCI_DEVICE(dev);
> > +    PCIESlot *s = PCIE_SLOT(d);
> >      GenPCIERootPort *grp = GEN_PCIE_ROOT_PORT(d);
> >      PCIERootPortClass *rpc = PCIE_ROOT_PORT_GET_CLASS(d);
> >      Error *local_err = NULL;
> > @@ -85,6 +87,9 @@ static void gen_rp_realize(DeviceState *dev, Error
> **errp)
> >          return;
> >      }
> >
> > +    if (grp->res_reserve.io == -1 && s->hotplug && !s->native_hotplug)
> {
> > +        grp->res_reserve.io = GEN_PCIE_ROOT_DEFAULT_IO_RANGE;
> > +    }
> >      int rc = pci_bridge_qemu_reserve_cap_init(d, 0,
> >                                                grp->res_reserve, errp);
> >
> > --
> > 2.31.1
> >
> >
>
> Regards,
> Daniel
> --
> |: https://berrange.com      -o-
> https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org         -o-
> https://fstop138.berrange.com :|
> |: https://entangle-photo.org    -o-
> https://www.instagram.com/dberrange :|
>
>
diff mbox series

Patch

diff --git a/hw/pci-bridge/gen_pcie_root_port.c b/hw/pci-bridge/gen_pcie_root_port.c
index ec9907917e..20099a8ae3 100644
--- a/hw/pci-bridge/gen_pcie_root_port.c
+++ b/hw/pci-bridge/gen_pcie_root_port.c
@@ -28,6 +28,7 @@  OBJECT_DECLARE_SIMPLE_TYPE(GenPCIERootPort, GEN_PCIE_ROOT_PORT)
         (GEN_PCIE_ROOT_PORT_AER_OFFSET + PCI_ERR_SIZEOF)
 
 #define GEN_PCIE_ROOT_PORT_MSIX_NR_VECTOR       1
+#define GEN_PCIE_ROOT_DEFAULT_IO_RANGE          4096
 
 struct GenPCIERootPort {
     /*< private >*/
@@ -75,6 +76,7 @@  static bool gen_rp_test_migrate_msix(void *opaque, int version_id)
 static void gen_rp_realize(DeviceState *dev, Error **errp)
 {
     PCIDevice *d = PCI_DEVICE(dev);
+    PCIESlot *s = PCIE_SLOT(d);
     GenPCIERootPort *grp = GEN_PCIE_ROOT_PORT(d);
     PCIERootPortClass *rpc = PCIE_ROOT_PORT_GET_CLASS(d);
     Error *local_err = NULL;
@@ -85,6 +87,9 @@  static void gen_rp_realize(DeviceState *dev, Error **errp)
         return;
     }
 
+    if (grp->res_reserve.io == -1 && s->hotplug && !s->native_hotplug) {
+        grp->res_reserve.io = GEN_PCIE_ROOT_DEFAULT_IO_RANGE;
+    }
     int rc = pci_bridge_qemu_reserve_cap_init(d, 0,
                                               grp->res_reserve, errp);