All the mail mirrored from lore.kernel.org
 help / color / mirror / Atom feed
From: Laszlo Ersek <lersek@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel@redhat.com>,
	Kevin O'Connor <kevin@koconnor.net>,
	qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH v6 7/7] hw/pci-bridge: format SeaBIOS-compliant OFW device node for PXB
Date: Wed, 17 Jun 2015 21:35:20 +0200	[thread overview]
Message-ID: <5581CBF8.2000702@redhat.com> (raw)
In-Reply-To: <20150617211235-mutt-send-email-mst@redhat.com>

On 06/17/15 21:21, Michael S. Tsirkin wrote:
> On Wed, Jun 17, 2015 at 02:45:05PM +0200, Laszlo Ersek wrote:
>> SeaBIOS expects OpenFirmware device paths in the "bootorder" fw_cfg file
>> to follow the pattern
>>
>>   /pci-root@N/pci@i0cf8/...
>>
>> for devices that live behind an extra root bus. The extra root bus in
>> question is the N'th among the extra root bridges. (In other words, N
>> gives the position of the affected extra root bus relative to the other
>> extra root buses, in bus_nr order.) N starts at 1, and is formatted in
>> hex.
>>
>> The "pci@i0cf8" node text is hardcoded in SeaBIOS (see the macro
>> FW_PCI_DOMAIN).
>>
>> Cc: Kevin O'Connor <kevin@koconnor.net>
>> Cc: Marcel Apfelbaum <marcel@redhat.com>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
>> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
>> Tested-by: Marcel Apfelbaum <marcel@redhat.com>
>> Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
>> ---
>>
>> Notes:
>>     v6:
>>     - no changes
>>     
>>     v5:
>>     - constify parameter and local variables of pxb_host_ofw_unit_address(),
>>       in accord with the previous patch
>>     
>>     v4:
>>     - new in v4
>>
>>  hw/pci-bridge/pci_expander_bridge.c | 39 ++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 38 insertions(+), 1 deletion(-)
>>
>> diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
>> index 4398d98..37574ec 100644
>> --- a/hw/pci-bridge/pci_expander_bridge.c
>> +++ b/hw/pci-bridge/pci_expander_bridge.c
>> @@ -42,6 +42,8 @@ typedef struct PXBDev {
>>      uint16_t numa_node;
>>  } PXBDev;
>>  
>> +static GList *pxb_dev_list;
>> +
>>  #define TYPE_PXB_HOST "pxb-host"
>>  
>>  static int pxb_bus_num(PCIBus *bus)
> 
> 
> So this trick breaks if we ever do have multiple roots, with expanders
> under each.

Assuming I understand what you mean by "multiple roots", I guess the
trick could be extended to maintain a separate list of expanders for
each root.

> I guess you could go to parent bus, scan child devices of parent and
> count TYPE_PXB_DEVICE devices there.
> 
> 
> BTW does this work if we have pci bridges under the default root in
> addition to PXBs?

I have no clue how to configure that on the QEMU command line, sorry.

> Does seabios know to skip regular bridges when it's
> counting roots?

Something for Kevin to answer :)

The initial scan in OVMF doesn't look for regular bridges specifically.
When a device in 0x00..0x1f, function 0, responds from a bus in
0x01..0xff, that bus is considered a live extra root bus. The bridges
that hang off the expanders come to life much later, when the generic
edk2 PCI bus driver enumerates devices (on the root buses that the OVMF
PCI host bridge / root bridge driver produced). No clue about regular
bridges.

Thanks
Laszlo

>> @@ -88,12 +90,29 @@ static const char *pxb_host_root_bus_path(PCIHostState *host_bridge,
>>      return bus->bus_path;
>>  }
>>  
>> +static char *pxb_host_ofw_unit_address(const SysBusDevice *dev)
>> +{
>> +    const PCIHostState *host = PCI_HOST_BRIDGE(dev);
>> +    const PCIBus *bus;
>> +    const PXBDev *pxb;
>> +    int position;
>> +
>> +    bus = host->bus;
>> +    pxb = PXB_DEV(bus->parent_dev);
>> +    position = g_list_index(pxb_dev_list, pxb);
>> +    assert(position >= 0);
>> +
>> +    return g_strdup_printf("%x/pci@i0cf8", position + 1);
>> +}
>> +
>>  static void pxb_host_class_init(ObjectClass *class, void *data)
>>  {
>>      DeviceClass *dc = DEVICE_CLASS(class);
>> +    SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(class);
>>      PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
>>  
>> -    dc->fw_name = "pci";
>> +    dc->fw_name = "pci-root";
>> +    sbc->explicit_ofw_unit_address = pxb_host_ofw_unit_address;
>>      hc->root_bus_path = pxb_host_root_bus_path;
>>  }
>>  
>> @@ -148,6 +167,15 @@ static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
>>      return pin - PCI_SLOT(pxb->devfn);
>>  }
>>  
>> +static gint pxb_compare(gconstpointer a, gconstpointer b)
>> +{
>> +    const PXBDev *pxb_a = a, *pxb_b = b;
>> +
>> +    return pxb_a->bus_nr < pxb_b->bus_nr ? -1 :
>> +           pxb_a->bus_nr > pxb_b->bus_nr ?  1 :
>> +           0;
>> +}
>> +
>>  static int pxb_dev_initfn(PCIDevice *dev)
>>  {
>>      PXBDev *pxb = PXB_DEV(dev);
>> @@ -191,9 +219,17 @@ static int pxb_dev_initfn(PCIDevice *dev)
>>                                 PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
>>      pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_HOST);
>>  
>> +    pxb_dev_list = g_list_insert_sorted(pxb_dev_list, pxb, pxb_compare);
>>      return 0;
>>  }
>>  
>> +static void pxb_dev_exitfn(PCIDevice *pci_dev)
>> +{
>> +    PXBDev *pxb = PXB_DEV(pci_dev);
>> +
>> +    pxb_dev_list = g_list_remove(pxb_dev_list, pxb);
>> +}
>> +
>>  static Property pxb_dev_properties[] = {
>>      /* Note: 0 is not a legal a PXB bus number. */
>>      DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
>> @@ -207,6 +243,7 @@ static void pxb_dev_class_init(ObjectClass *klass, void *data)
>>      PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>>  
>>      k->init = pxb_dev_initfn;
>> +    k->exit = pxb_dev_exitfn;
>>      k->vendor_id = PCI_VENDOR_ID_REDHAT;
>>      k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
>>      k->class_id = PCI_CLASS_BRIDGE_HOST;
>> -- 
>> 1.8.3.1

  reply	other threads:[~2015-06-17 19:41 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-17 12:44 [Qemu-devel] [PATCH v6 0/7] PXB changes Laszlo Ersek
2015-06-17 12:44 ` [Qemu-devel] [PATCH v6 1/7] migration: introduce VMSTATE_BUFFER_UNSAFE_INFO_TEST() Laszlo Ersek
2015-06-17 12:45 ` [Qemu-devel] [PATCH v6 2/7] hw/pci-bridge: expose _test parameter in SHPC_VMSTATE() Laszlo Ersek
2015-06-17 12:45 ` [Qemu-devel] [PATCH v6 3/7] hw/pci-bridge: introduce "hotplug" property Laszlo Ersek
2015-06-17 13:42   ` Michael S. Tsirkin
2015-06-17 13:55     ` Laszlo Ersek
2015-06-17 14:02       ` Michael S. Tsirkin
2015-06-17 14:15         ` Laszlo Ersek
2015-06-17 19:54           ` Marcel Apfelbaum
2015-06-18 13:47         ` Paolo Bonzini
2015-06-18 14:44           ` Michael S. Tsirkin
2015-06-17 12:45 ` [Qemu-devel] [PATCH v6 4/7] hw/pci-bridge: disable hotplug in PXB Laszlo Ersek
2015-06-17 13:45   ` Michael S. Tsirkin
2015-06-17 19:52     ` Marcel Apfelbaum
2015-06-17 12:45 ` [Qemu-devel] [PATCH v6 5/7] hw/core: rebase sysbus_get_fw_dev_path() to g_strdup_printf() Laszlo Ersek
2015-06-17 13:46   ` Michael S. Tsirkin
2015-06-17 13:56     ` Laszlo Ersek
2015-06-17 12:45 ` [Qemu-devel] [PATCH v6 6/7] hw/core: explicit OFW unit address callback for SysBusDeviceClass Laszlo Ersek
2015-06-17 12:45 ` [Qemu-devel] [PATCH v6 7/7] hw/pci-bridge: format SeaBIOS-compliant OFW device node for PXB Laszlo Ersek
2015-06-17 13:57   ` Michael S. Tsirkin
2015-06-17 14:00     ` Laszlo Ersek
2015-06-17 14:03       ` Michael S. Tsirkin
2015-06-17 14:18     ` Kevin O'Connor
2015-06-17 14:45       ` Laszlo Ersek
2015-06-17 15:05         ` Michael S. Tsirkin
2015-06-17 18:16           ` Laszlo Ersek
2015-06-17 18:54             ` Michael S. Tsirkin
2015-06-17 19:15               ` Laszlo Ersek
2015-06-17 19:28                 ` Kevin O'Connor
2015-06-17 19:32                   ` Michael S. Tsirkin
2015-06-17 19:44                     ` Laszlo Ersek
2015-06-17 21:50                       ` Michael S. Tsirkin
2015-06-18 13:22                         ` Laszlo Ersek
2015-06-18 13:40                           ` Michael S. Tsirkin
2015-06-18 15:42                             ` Laszlo Ersek
2015-06-17 19:09             ` Kevin O'Connor
2015-06-17 19:21   ` Michael S. Tsirkin
2015-06-17 19:35     ` Laszlo Ersek [this message]
2015-06-17 21:49       ` Michael S. Tsirkin
2015-06-18 13:18         ` Laszlo Ersek
2015-06-17 19:38     ` Kevin O'Connor

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5581CBF8.2000702@redhat.com \
    --to=lersek@redhat.com \
    --cc=kevin@koconnor.net \
    --cc=marcel@redhat.com \
    --cc=mst@redhat.com \
    --cc=qemu-devel@nongnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.