[Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Gerd Hoffmann]

This sets a default PCI subsystem ID for all emulated PCI devices.  PCI
specs require this, so do it.  The defaults are global variables so
they can easily be changed (before device creation) as Xen probably
wants to use the XenSource vendor ID instead of the qemu default.

The defaults are pre-filled by pci_register_device().  Individual
drivers can overwrite it of course when setting up the config space
for the emulated device.

TODO: get an official vendor ID assigned, or borrow one (maybe
      Qumranet which already sponsors the virtio IDs ???).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/pci.c |   11 +++++++++++
 hw/pci.h |    2 ++
 2 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index bc55989..15e8173 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -50,6 +50,8 @@ static void pci_update_mappings(PCIDevice *d);
 static void pci_set_irq(void *opaque, int irq_num, int level);
 
 target_phys_addr_t pci_mem_base;
+uint16_t pci_default_sub_vendor_id = 0xfffa; /* FIXME: get one assigned */
+uint16_t pci_default_sub_device_id = 0x0001;
 static int pci_irq_index;
 static PCIBus *first_bus;
 
@@ -145,6 +147,14 @@ int pci_device_load(PCIDevice *s, QEMUFile *f)
     return 0;
 }
 
+static int pci_set_default_subsystem_id(PCIDevice *pci_dev)
+{
+    struct pci_config_header *conf = (void*)pci_dev->config;
+
+    conf->sub_vendor_id = write_le16(pci_default_sub_vendor_id);
+    conf->sub_device_id = write_le16(pci_default_sub_device_id);
+}
+
 /* -1 for devfn means auto assign */
 PCIDevice *pci_register_device(PCIBus *bus, const char *name,
                                int instance_size, int devfn,
@@ -171,6 +181,7 @@ PCIDevice *pci_register_device(PCIBus *bus, const char *name,
     pci_dev->devfn = devfn;
     pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
     memset(pci_dev->irq_state, 0, sizeof(pci_dev->irq_state));
+    pci_set_default_subsystem_id(pci_dev);
 
     if (!config_read)
         config_read = pci_default_read_config;
diff --git a/hw/pci.h b/hw/pci.h
index f518e5e..28e8fb5 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -33,6 +33,8 @@ struct pci_config_header {
 };
 
 extern target_phys_addr_t pci_mem_base;
+extern uint16_t pci_default_sub_vendor_id;
+extern uint16_t pci_default_sub_device_id;
 
 typedef void PCIConfigWriteFunc(PCIDevice *pci_dev,
                                 uint32_t address, uint32_t data, int len);
-- 
1.5.5.1

[Qemu-devel] [PATCH 1/4] add byteordered types to qemu.

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 bswap.h      |    7 +++++++
 hw/usb-net.c |    2 --
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/bswap.h b/bswap.h
index 523d805..b294d96 100644
--- a/bswap.h
+++ b/bswap.h
@@ -206,4 +206,11 @@ static inline void cpu_to_be32wu(uint32_t *p, uint32_t v)
 #undef le_bswaps
 #undef be_bswaps
 
+typedef uint16_t le16;
+typedef uint32_t le32;
+typedef uint64_t le64;
+typedef uint16_t be16;
+typedef uint32_t be32;
+typedef uint64_t be64;
+
 #endif /* BSWAP_H */
diff --git a/hw/usb-net.c b/hw/usb-net.c
index 27dea10..447c0ce 100644
--- a/hw/usb-net.c
+++ b/hw/usb-net.c
@@ -326,8 +326,6 @@ enum {
 #define OID_PNP_REMOVE_WAKE_UP_PATTERN	0xfd010104
 #define OID_PNP_ENABLE_WAKE_UP		0xfd010106
 
-typedef uint32_t le32;
-
 typedef struct rndis_init_msg_type {
     le32 MessageType;
     le32 MessageLength;
-- 
1.5.5.1

[Qemu-devel] [PATCH 2/4] pci: add config space struct (from qemu-xen).

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/pci.h |   26 ++++++++++++++++++++++++++
 1 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/hw/pci.h b/hw/pci.h
index e870987..f518e5e 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -6,6 +6,32 @@
 
 /* PCI bus */
 
+struct pci_config_header {
+    le16    vendor_id;
+    le16    device_id;
+    le16    command;
+    le16    status;
+    uint8_t revision;
+    uint8_t api;
+    uint8_t subclass;
+    uint8_t class;
+    uint8_t cache_line_size; /* Units of 32 bit words */
+    uint8_t latency_timer;   /* In units of bus cycles */
+    uint8_t header_type;     /* Should be 0 */
+    uint8_t bist;            /* Built in self test */
+    le32    base_address_regs[6];
+    le32    reserved1;
+    le16    sub_vendor_id;
+    le16    sub_device_id;
+    le32    rom_addr;
+    le32    reserved3;
+    le32    reserved4;
+    uint8_t interrupt_line;
+    uint8_t interrupt_pin;
+    uint8_t min_gnt;
+    uint8_t max_lat;
+};
+
 extern target_phys_addr_t pci_mem_base;
 
 typedef void PCIConfigWriteFunc(PCIDevice *pci_dev,
-- 
1.5.5.1

[Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Gerd Hoffmann]

This sets a default PCI subsystem ID for all emulated PCI devices.  PCI
specs require this, so do it.  The defaults are global variables so
they can easily be changed (before device creation) as Xen probably
wants to use the XenSource vendor ID instead of the qemu default.

The defaults are pre-filled by pci_register_device().  Individual
drivers can overwrite it of course when setting up the config space
for the emulated device.

TODO: get an official vendor ID assigned, or borrow one (maybe
      Qumranet which already sponsors the virtio IDs ???).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/pci.c |   11 +++++++++++
 hw/pci.h |    2 ++
 2 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index bc55989..ffc90d7 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -50,6 +50,8 @@ static void pci_update_mappings(PCIDevice *d);
 static void pci_set_irq(void *opaque, int irq_num, int level);
 
 target_phys_addr_t pci_mem_base;
+uint16_t pci_default_sub_vendor_id = 0xfffa; /* FIXME: get one assigned */
+uint16_t pci_default_sub_device_id = 0x0001;
 static int pci_irq_index;
 static PCIBus *first_bus;
 
@@ -145,6 +147,14 @@ int pci_device_load(PCIDevice *s, QEMUFile *f)
     return 0;
 }
 
+static int pci_set_default_subsystem_id(PCIDevice *pci_dev)
+{
+    struct pci_config_header *conf = (void*)pci_dev->config;
+
+    conf->sub_vendor_id = cpu_to_le16(pci_default_sub_vendor_id);
+    conf->sub_device_id = cpu_to_le16(pci_default_sub_device_id);
+}
+
 /* -1 for devfn means auto assign */
 PCIDevice *pci_register_device(PCIBus *bus, const char *name,
                                int instance_size, int devfn,
@@ -171,6 +181,7 @@ PCIDevice *pci_register_device(PCIBus *bus, const char *name,
     pci_dev->devfn = devfn;
     pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
     memset(pci_dev->irq_state, 0, sizeof(pci_dev->irq_state));
+    pci_set_default_subsystem_id(pci_dev);
 
     if (!config_read)
         config_read = pci_default_read_config;
diff --git a/hw/pci.h b/hw/pci.h
index f518e5e..28e8fb5 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -33,6 +33,8 @@ struct pci_config_header {
 };
 
 extern target_phys_addr_t pci_mem_base;
+extern uint16_t pci_default_sub_vendor_id;
+extern uint16_t pci_default_sub_device_id;
 
 typedef void PCIConfigWriteFunc(PCIDevice *pci_dev,
                                 uint32_t address, uint32_t data, int len);
-- 
1.5.5.1

[Qemu-devel] [PATCH 4/4] pci: use pci_config_header in pci.c

[Gerd Hoffmann]

This makes use of the new pci_config_header struct in pci.c,
squashing a bunch of casts and hard-coded magic numbers.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/pci.c |   64 +++++++++++++++++++++++++++++++-------------------------------
 1 files changed, 32 insertions(+), 32 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index ffc90d7..4212e1f 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -199,8 +199,9 @@ void pci_register_io_region(PCIDevice *pci_dev, int region_num,
                             uint32_t size, int type,
                             PCIMapIORegionFunc *map_func)
 {
+    struct pci_config_header *conf = (void*)pci_dev->config;
     PCIIORegion *r;
-    uint32_t addr;
+    le32 *addr;
 
     if ((unsigned int)region_num >= PCI_NUM_REGIONS)
         return;
@@ -210,11 +211,11 @@ void pci_register_io_region(PCIDevice *pci_dev, int region_num,
     r->type = type;
     r->map_func = map_func;
     if (region_num == PCI_ROM_SLOT) {
-        addr = 0x30;
+        addr = &conf->rom_addr;
     } else {
-        addr = 0x10 + region_num * 4;
+        addr = conf->base_address_regs + region_num;
     }
-    *(uint32_t *)(pci_dev->config + addr) = cpu_to_le32(type);
+    *addr = cpu_to_le32(type);
 }
 
 static target_phys_addr_t pci_to_cpu_addr(target_phys_addr_t addr)
@@ -224,23 +225,24 @@ static target_phys_addr_t pci_to_cpu_addr(target_phys_addr_t addr)
 
 static void pci_update_mappings(PCIDevice *d)
 {
+    struct pci_config_header *conf = (void*)d->config;
     PCIIORegion *r;
     int cmd, i;
-    uint32_t last_addr, new_addr, config_ofs;
+    uint32_t last_addr, new_addr;
+    le32 *config_addr;
 
-    cmd = le16_to_cpu(*(uint16_t *)(d->config + PCI_COMMAND));
+    cmd = le16_to_cpu(conf->command);
     for(i = 0; i < PCI_NUM_REGIONS; i++) {
         r = &d->io_regions[i];
         if (i == PCI_ROM_SLOT) {
-            config_ofs = 0x30;
+            config_addr = &conf->rom_addr;
         } else {
-            config_ofs = 0x10 + i * 4;
+            config_addr = conf->base_address_regs + i;
         }
         if (r->size != 0) {
             if (r->type & PCI_ADDRESS_SPACE_IO) {
                 if (cmd & PCI_COMMAND_IO) {
-                    new_addr = le32_to_cpu(*(uint32_t *)(d->config +
-                                                         config_ofs));
+                    new_addr = le32_to_cpu(*config_addr);
                     new_addr = new_addr & ~(r->size - 1);
                     last_addr = new_addr + r->size - 1;
                     /* NOTE: we have only 64K ioports on PC */
@@ -253,8 +255,7 @@ static void pci_update_mappings(PCIDevice *d)
                 }
             } else {
                 if (cmd & PCI_COMMAND_MEMORY) {
-                    new_addr = le32_to_cpu(*(uint32_t *)(d->config +
-                                                         config_ofs));
+                    new_addr = le32_to_cpu(*config_addr);
                     /* the ROM slot has a specific enable bit */
                     if (i == PCI_ROM_SLOT && !(new_addr & 1))
                         goto no_mem_map;
@@ -568,13 +569,14 @@ static pci_class_desc pci_class_descriptions[] =
 
 static void pci_info_device(PCIDevice *d)
 {
+    struct pci_config_header *conf = (void*)d->config;
     int i, class;
     PCIIORegion *r;
     pci_class_desc *desc;
 
     term_printf("  Bus %2d, device %3d, function %d:\n",
            d->bus->bus_num, d->devfn >> 3, d->devfn & 7);
-    class = le16_to_cpu(*((uint16_t *)(d->config + PCI_CLASS_DEVICE)));
+    class = conf->class << 8 | conf->subclass;
     term_printf("    ");
     desc = pci_class_descriptions;
     while (desc->desc && class != desc->class)
@@ -585,11 +587,11 @@ static void pci_info_device(PCIDevice *d)
         term_printf("Class %04x", class);
     }
     term_printf(": PCI device %04x:%04x\n",
-           le16_to_cpu(*((uint16_t *)(d->config + PCI_VENDOR_ID))),
-           le16_to_cpu(*((uint16_t *)(d->config + PCI_DEVICE_ID))));
+                le16_to_cpu(conf->vendor_id),
+                le16_to_cpu(conf->device_id));
 
-    if (d->config[PCI_INTERRUPT_PIN] != 0) {
-        term_printf("      IRQ %d.\n", d->config[PCI_INTERRUPT_LINE]);
+    if (conf->interrupt_line != 0) {
+        term_printf("      IRQ %d.\n", conf->interrupt_line);
     }
     if (class == 0x0604) {
         term_printf("      BUS %d.\n", d->config[0x19]);
@@ -686,25 +688,23 @@ static void pci_bridge_write_config(PCIDevice *d,
 PCIBus *pci_bridge_init(PCIBus *bus, int devfn, uint32_t id,
                         pci_map_irq_fn map_irq, const char *name)
 {
+    struct pci_config_header *conf;
     PCIBridge *s;
     s = (PCIBridge *)pci_register_device(bus, name, sizeof(PCIBridge),
                                          devfn, NULL, pci_bridge_write_config);
-    s->dev.config[0x00] = id >> 16;
-    s->dev.config[0x01] = id >> 24;
-    s->dev.config[0x02] = id; // device_id
-    s->dev.config[0x03] = id >> 8;
-    s->dev.config[0x04] = 0x06; // command = bus master, pci mem
-    s->dev.config[0x05] = 0x00;
-    s->dev.config[0x06] = 0xa0; // status = fast back-to-back, 66MHz, no error
-    s->dev.config[0x07] = 0x00; // status = fast devsel
-    s->dev.config[0x08] = 0x00; // revision
-    s->dev.config[0x09] = 0x00; // programming i/f
-    s->dev.config[0x0A] = 0x04; // class_sub = PCI to PCI bridge
-    s->dev.config[0x0B] = 0x06; // class_base = PCI_bridge
-    s->dev.config[0x0D] = 0x10; // latency_timer
-    s->dev.config[0x0E] = 0x81; // header_type
-    s->dev.config[0x1E] = 0xa0; // secondary status
+    conf = (void*)s->dev.config;
+    conf->vendor_id = cpu_to_le16(id >> 16);
+    conf->device_id = cpu_to_le16(id & 0xffff);
+    conf->command   = cpu_to_le16(0x0006); // bus master, pci mem
+    conf->status    = cpu_to_le16(0x00a0); // fast back-to-back, 66MHz, no error, fast devsel
+    conf->revision      = 0x00;
+    conf->api           = 0x00;
+    conf->subclass      = 0x04; // PCI to PCI bridge
+    conf->class         = 0x06; // PCI_bridge
+    conf->latency_timer = 0x10;
+    conf->header_type   = 0x81;
 
+    s->dev.config[0x1E] = 0xa0; // secondary status
     s->bus = pci_register_secondary_bus(&s->dev, map_irq);
     return s->bus;
 }
-- 
1.5.5.1

Re: [Qemu-devel] [PATCH 1/4] add byteordered types to qemu.

[Anthony Liguori]

Is there a 4/4 in the series?

Regards,

Anthony Liguori

Gerd Hoffmann wrote:
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  bswap.h      |    7 +++++++
>  hw/usb-net.c |    2 --
>  2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/bswap.h b/bswap.h
> index 523d805..b294d96 100644
> --- a/bswap.h
> +++ b/bswap.h
> @@ -206,4 +206,11 @@ static inline void cpu_to_be32wu(uint32_t *p, uint32_t v)
>  #undef le_bswaps
>  #undef be_bswaps
>  
> +typedef uint16_t le16;
> +typedef uint32_t le32;
> +typedef uint64_t le64;
> +typedef uint16_t be16;
> +typedef uint32_t be32;
> +typedef uint64_t be64;
> +
>  #endif /* BSWAP_H */
> diff --git a/hw/usb-net.c b/hw/usb-net.c
> index 27dea10..447c0ce 100644
> --- a/hw/usb-net.c
> +++ b/hw/usb-net.c
> @@ -326,8 +326,6 @@ enum {
>  #define OID_PNP_REMOVE_WAKE_UP_PATTERN	0xfd010104
>  #define OID_PNP_ENABLE_WAKE_UP		0xfd010106
>  
> -typedef uint32_t le32;
> -
>  typedef struct rndis_init_msg_type {
>      le32 MessageType;
>      le32 MessageLength;
>   

Re: [Qemu-devel] [PATCH 1/4] add byteordered types to qemu.

[Anthony Liguori]

Anthony Liguori wrote:
> Is there a 4/4 in the series?

Apparently so.  Sorry, my mail delivery is quite lagged today.

Regards,

Anthony Liguori

Re: [Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Anthony Liguori]

Gerd Hoffmann wrote:
> This sets a default PCI subsystem ID for all emulated PCI devices.  PCI
> specs require this, so do it.  The defaults are global variables so
> they can easily be changed (before device creation) as Xen probably
> wants to use the XenSource vendor ID instead of the qemu default.
>
> The defaults are pre-filled by pci_register_device().  Individual
> drivers can overwrite it of course when setting up the config space
> for the emulated device.
>
> TODO: get an official vendor ID assigned, or borrow one (maybe
>       Qumranet which already sponsors the virtio IDs ???).
>   

Does the subvendor ID have to be an official vendor ID?  I thought that 
the subvendor ID could be defined by the vendor as whatever it wants..

> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  hw/pci.c |   11 +++++++++++
>  hw/pci.h |    2 ++
>  2 files changed, 13 insertions(+), 0 deletions(-)
>
> diff --git a/hw/pci.c b/hw/pci.c
> index bc55989..ffc90d7 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -50,6 +50,8 @@ static void pci_update_mappings(PCIDevice *d);
>  static void pci_set_irq(void *opaque, int irq_num, int level);
>  
>  target_phys_addr_t pci_mem_base;
> +uint16_t pci_default_sub_vendor_id = 0xfffa; /* FIXME: get one assigned */
> +uint16_t pci_default_sub_device_id = 0x0001;
>   

Probably should just be a define.

Regards,

Anthony Liguori

Re: [Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Gerd Hoffmann]

Anthony Liguori wrote:
>> TODO: get an official vendor ID assigned, or borrow one (maybe
>>       Qumranet which already sponsors the virtio IDs ???).
> 
> Does the subvendor ID have to be an official vendor ID?

I think so, as far I know there is no difference between vendor and
subvendor ID in that respect.

> I thought that
> the subvendor ID could be defined by the vendor as whatever it wants..

Each vendor can assign the device (and subdevice) IDs freely.

cheers,
  Gerd

Re: [Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Anthony Liguori]

Gerd Hoffmann wrote:
> Anthony Liguori wrote:
>   
>>> TODO: get an official vendor ID assigned, or borrow one (maybe
>>>       Qumranet which already sponsors the virtio IDs ???).
>>>       
>> Does the subvendor ID have to be an official vendor ID?
>>     
>
> I think so, as far I know there is no difference between vendor and
> subvendor ID in that respect.
>
>   
>> I thought that
>> the subvendor ID could be defined by the vendor as whatever it wants..
>>     
>
> Each vendor can assign the device (and subdevice) IDs freely.
>   

It's worth looking into because in virtio, we currently define the 
subvendor ID to be not the PCI vendor ID space.  I'll try to dig up a 
copy of the PCI spec and confirm.  If it's not required to be the PCI 
vendor ID space, then this patch is unnecessary.  We can just set it to 
a non-0 value of our choosing.

Regards,

Anthony Liguori

> cheers,
>   Gerd
>
>
>   

Re: [Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Gerd Hoffmann]

  Hi,

>> Each vendor can assign the device (and subdevice) IDs freely.
> 
> It's worth looking into because in virtio, we currently define the
> subvendor ID to be not the PCI vendor ID space.  I'll try to dig up a
> copy of the PCI spec and confirm.  If it's not required to be the PCI
> vendor ID space, then this patch is unnecessary.  We can just set it to
> a non-0 value of our choosing.

Ehrm, no.  I'll try a bit more verbose ...

Each PCI device has a PCI ID.  It should also have a PCI Subsystem ID.
The PCI subsystem ID wasn't mandatory in early PCI spec revisions, IIRC
2.0 added that requirement.  Thats why you usually get away without a
PCI subsystem ID, although it isn't correct.

Both IDs have a 16bit vendor and a 16bit device part.  The vendor IDs
are handed out by the PCI SIG.  The device IDs are assigned by the
vendor owning the vendor ID.

The PCI ID tells you which PCI chip is used, whereas the the PCI
Subsystem ID identifies the actual device (created using the PCI chip).

Example #1:  TV cards.  All TV cards using the bt878 chipset (first and
only one on the market for a few years in the 90-ies) have the same PCI
ID, the one of the bt878 chip.  But each TV card has different PCI
Subsystem IDs, which can be used to figure what the actual TV card is.

Example #2:  Laptops.  It is quite common to find the PCI Subsytem ID
pointing to the laptop vendor and model.  So the PCI ID says
'this is a intel ich7 ide controller', whereas the the PCI Subsystem ID
says 'this ich7 sits in a lenovo thinkpad', like this:

--------- cut here ----------
[root@zweiblum ~]# lspci -vs1f.1
00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE
Controller (rev 02) (prog-if 8a [Master SecP PriP])
        Subsystem: Lenovo ThinkPad T60/R60 series
        [ ... more stuff snipped ... ]
--------- cut here ----------

In many cases it is enougth to know the PCI ID to handle a device
correctly.  Sometimes a device driver must identify the exact piece of
hardware (via PCI Subsystem ID) though.


Ok, now to qemu.  Right now the emulated PCI devices have no PCI
subsystem ID, only the PCI ID.  The discussed patch sets a default PCI
subsystem ID for all emulated devices.  Which will make the qemu devices
look pretty much like in the laptop case: all PCI subsystem IDs will
point to qemu by default.

If a driver emulates a very specific piece of hardware where it has to
emulate more than just the PCI chip, it can overwrite the PCI subsystem
ID without problems.  The es1370 driver does that for example.


Right now the patch uses the vendor ID 0xfffa.  XenSource grabbed a
temporary ID (before they got one official assigned) from the 0xfffx
space too.  We'll better get something official though, to avoid
clashes.  We could try to get a vendor ID assigned (no idea how
difficuilt and/or expensive that would be).  Or we could try get get a
device ID range from a vendor (like the qumranet-sponsored IDs for
virtio ...).

cheers,
  Gerd

[Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Gerd Hoffmann]

This sets a default PCI subsystem ID for all emulated PCI devices.  PCI
specs require this, so do it.  The defaults are global variables so
they can easily be changed (before device creation) as Xen probably
wants to use the XenSource vendor ID instead of the qemu default.

The defaults are pre-filled by pci_register_device().  Individual
drivers can overwrite it of course when setting up the config space
for the emulated device.

TODO: get an official vendor ID assigned, or borrow one (maybe
      Qumranet which already sponsors the virtio IDs ???).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/pci.c |   11 +++++++++++
 hw/pci.h |    5 +++++
 2 files changed, 16 insertions(+), 0 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index bc55989..1304dae 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -50,6 +50,8 @@ static void pci_update_mappings(PCIDevice *d);
 static void pci_set_irq(void *opaque, int irq_num, int level);
 
 target_phys_addr_t pci_mem_base;
+uint16_t pci_default_sub_vendor_id = PCI_VENDOR_ID_QEMU;
+uint16_t pci_default_sub_device_id = PCI_SUBDEVICE_ID_QEMU_DEFAULT;
 static int pci_irq_index;
 static PCIBus *first_bus;
 
@@ -145,6 +147,14 @@ int pci_device_load(PCIDevice *s, QEMUFile *f)
     return 0;
 }
 
+static int pci_set_default_subsystem_id(PCIDevice *pci_dev)
+{
+    struct pci_config_header *conf = (void*)pci_dev->config;
+
+    conf->sub_vendor_id = cpu_to_le16(pci_default_sub_vendor_id);
+    conf->sub_device_id = cpu_to_le16(pci_default_sub_device_id);
+}
+
 /* -1 for devfn means auto assign */
 PCIDevice *pci_register_device(PCIBus *bus, const char *name,
                                int instance_size, int devfn,
@@ -171,6 +181,7 @@ PCIDevice *pci_register_device(PCIBus *bus, const char *name,
     pci_dev->devfn = devfn;
     pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
     memset(pci_dev->irq_state, 0, sizeof(pci_dev->irq_state));
+    pci_set_default_subsystem_id(pci_dev);
 
     if (!config_read)
         config_read = pci_default_read_config;
diff --git a/hw/pci.h b/hw/pci.h
index f518e5e..3c6976a 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -33,6 +33,11 @@ struct pci_config_header {
 };
 
 extern target_phys_addr_t pci_mem_base;
+extern uint16_t pci_default_sub_vendor_id;
+extern uint16_t pci_default_sub_device_id;
+
+#define PCI_VENDOR_ID_QEMU               0xfffa  /* FIXME: get one assigned */
+#define PCI_SUBDEVICE_ID_QEMU_DEFAULT    0x0001
 
 typedef void PCIConfigWriteFunc(PCIDevice *pci_dev,
                                 uint32_t address, uint32_t data, int len);
-- 
1.5.5.1

Re: [Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Paul Brook]

On Wednesday 10 September 2008, Gerd Hoffmann wrote:
> +extern uint16_t pci_default_sub_vendor_id;
> +extern uint16_t pci_default_sub_device_id;

Why are these being exported?

Paul

Re: [Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Gerd Hoffmann]

Paul Brook wrote:
> On Wednesday 10 September 2008, Gerd Hoffmann wrote:
>> +extern uint16_t pci_default_sub_vendor_id;
>> +extern uint16_t pci_default_sub_device_id;
> 
> Why are these being exported?

So you can change the defaults.  Main user for that I have in mind is
Xen.  They have added a subsystem id (5853:0001, XenSource vendor ID) to
some of the devices (by patching the indiviudual drivers, not by adding
a global default like this patch does).

I expect they probably want to keep the XenSource subsystem ID instead
of going with the qemu default.  So the idea is that we can have "if
(using_xen) { make 5853:0001 the default }" in the initialization path
some day.

cheers,
  Gerd

Re: [Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Gerd Hoffmann]

Gerd Hoffmann wrote:
>   Hi,
> 
>>> Each vendor can assign the device (and subdevice) IDs freely.
>> It's worth looking into because in virtio, we currently define the
>> subvendor ID to be not the PCI vendor ID space.  I'll try to dig up a
>> copy of the PCI spec and confirm.  If it's not required to be the PCI
>> vendor ID space, then this patch is unnecessary.  We can just set it to
>> a non-0 value of our choosing.

Ping.  What is the status of this?  Did you find time to check the PCI
specs?  Did the explanation I've tried below the trick?  Any other
outstanding issues with the patches?  I'm not aware of any ...

cheers,
  Gerd

> Ehrm, no.  I'll try a bit more verbose ...
> 
> Each PCI device has a PCI ID.  It should also have a PCI Subsystem ID.
> The PCI subsystem ID wasn't mandatory in early PCI spec revisions, IIRC
> 2.0 added that requirement.  Thats why you usually get away without a
> PCI subsystem ID, although it isn't correct.
> 
> Both IDs have a 16bit vendor and a 16bit device part.  The vendor IDs
> are handed out by the PCI SIG.  The device IDs are assigned by the
> vendor owning the vendor ID.
> 
> The PCI ID tells you which PCI chip is used, whereas the the PCI
> Subsystem ID identifies the actual device (created using the PCI chip).
> 
> Example #1:  TV cards.  All TV cards using the bt878 chipset (first and
> only one on the market for a few years in the 90-ies) have the same PCI
> ID, the one of the bt878 chip.  But each TV card has different PCI
> Subsystem IDs, which can be used to figure what the actual TV card is.
> 
> Example #2:  Laptops.  It is quite common to find the PCI Subsytem ID
> pointing to the laptop vendor and model.  So the PCI ID says
> 'this is a intel ich7 ide controller', whereas the the PCI Subsystem ID
> says 'this ich7 sits in a lenovo thinkpad', like this:
> 
> --------- cut here ----------
> [root@zweiblum ~]# lspci -vs1f.1
> 00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE
> Controller (rev 02) (prog-if 8a [Master SecP PriP])
>         Subsystem: Lenovo ThinkPad T60/R60 series
>         [ ... more stuff snipped ... ]
> --------- cut here ----------
> 
> In many cases it is enougth to know the PCI ID to handle a device
> correctly.  Sometimes a device driver must identify the exact piece of
> hardware (via PCI Subsystem ID) though.
> 
> 
> Ok, now to qemu.  Right now the emulated PCI devices have no PCI
> subsystem ID, only the PCI ID.  The discussed patch sets a default PCI
> subsystem ID for all emulated devices.  Which will make the qemu devices
> look pretty much like in the laptop case: all PCI subsystem IDs will
> point to qemu by default.
> 
> If a driver emulates a very specific piece of hardware where it has to
> emulate more than just the PCI chip, it can overwrite the PCI subsystem
> ID without problems.  The es1370 driver does that for example.
> 
> 
> Right now the patch uses the vendor ID 0xfffa.  XenSource grabbed a
> temporary ID (before they got one official assigned) from the 0xfffx
> space too.  We'll better get something official though, to avoid
> clashes.  We could try to get a vendor ID assigned (no idea how
> difficuilt and/or expensive that would be).  Or we could try get get a
> device ID range from a vendor (like the qumranet-sponsored IDs for
> virtio ...).
> 
> cheers,
>   Gerd
> 

[Qemu-devel] [PATCH 3/4] pci: add default pci subsystem id for all devices.

[Gerd Hoffmann]

This sets a default PCI subsystem ID for all emulated PCI devices.  PCI
specs require this, so do it.

Some background info:

Each PCI device has a PCI ID.  It should also have a PCI Subsystem ID.
The PCI subsystem ID wasn't mandatory in early PCI spec revisions, IIRC
2.0 added that requirement.  Thats why you usually get away without a
PCI subsystem ID, although it isn't correct.

Both IDs have a 16bit vendor and a 16bit device part.  The vendor IDs
are handed out by the PCI SIG.  The device IDs are assigned by the
vendor owning the vendor ID.

The PCI ID tells you which PCI chip is used, whereas the the PCI
Subsystem ID identifies the actual device (created using the PCI chip).

Example #1:  TV cards.  All TV cards using the bt878 chipset (first and
only one on the market for a few years in the 90-ies) have the same PCI
ID, the one of the bt878 chip.  But each TV card has different PCI
Subsystem IDs, which can be used to figure what the actual TV card is.

Example #2:  Laptops.  It is quite common to find the PCI Subsytem ID
pointing to the laptop vendor and model.  So the PCI ID says
'this is a intel ich7 ide controller', whereas the the PCI Subsystem ID
says 'this ich7 sits in a lenovo thinkpad', like this:

--------- cut here ----------
[root@zweiblum ~]# lspci -vs1f.1
00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE
Controller (rev 02) (prog-if 8a [Master SecP PriP])
        Subsystem: Lenovo ThinkPad T60/R60 series
        [ ... more stuff snipped ... ]
--------- cut here ----------

In many cases it is enougth to know the PCI ID to handle a device
correctly.  Sometimes a device driver must identify the exact piece of
hardware (via PCI Subsystem ID) though.

What does this patch to qemu devices:

Right now the emulated PCI devices have no PCI subsystem ID, only the
PCI ID.  The discussed patch sets a default PCI subsystem ID for all
emulated devices.  Which will make the qemu devices look pretty much
like in the laptop case: all PCI subsystem IDs will point to qemu by
default.

If a driver emulates a very specific piece of hardware where it has to
emulate more than just the PCI chip, it can overwrite the PCI subsystem
ID without problems.  The es1370 driver does that for example.

Right now the patch uses the vendor ID 0xfffa.  XenSource grabbed a
temporary ID (before they got one official assigned) from the 0xfffx
space too.  We'll better get something official though, to avoid
clashes.  We could try to get a vendor ID assigned (no idea how
difficuilt and/or expensive that would be).  Or we could try get get a
device ID range from a vendor (like the qumranet-sponsored IDs for
virtio ...).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/pci.c |   11 +++++++++++
 hw/pci.h |    3 +++
 2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index bc55989..f2d0c4b 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -50,6 +50,8 @@ static void pci_update_mappings(PCIDevice *d);
 static void pci_set_irq(void *opaque, int irq_num, int level);
 
 target_phys_addr_t pci_mem_base;
+static uint16_t pci_default_sub_vendor_id = PCI_VENDOR_ID_QEMU;
+static uint16_t pci_default_sub_device_id = PCI_SUBDEVICE_ID_QEMU_DEFAULT;
 static int pci_irq_index;
 static PCIBus *first_bus;
 
@@ -145,6 +147,14 @@ int pci_device_load(PCIDevice *s, QEMUFile *f)
     return 0;
 }
 
+static int pci_set_default_subsystem_id(PCIDevice *pci_dev)
+{
+    struct pci_config_header *conf = (void*)pci_dev->config;
+
+    conf->sub_vendor_id = cpu_to_le16(pci_default_sub_vendor_id);
+    conf->sub_device_id = cpu_to_le16(pci_default_sub_device_id);
+}
+
 /* -1 for devfn means auto assign */
 PCIDevice *pci_register_device(PCIBus *bus, const char *name,
                                int instance_size, int devfn,
@@ -171,6 +181,7 @@ PCIDevice *pci_register_device(PCIBus *bus, const char *name,
     pci_dev->devfn = devfn;
     pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
     memset(pci_dev->irq_state, 0, sizeof(pci_dev->irq_state));
+    pci_set_default_subsystem_id(pci_dev);
 
     if (!config_read)
         config_read = pci_default_read_config;
diff --git a/hw/pci.h b/hw/pci.h
index f518e5e..d0b8a3e 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -34,6 +34,9 @@ struct pci_config_header {
 
 extern target_phys_addr_t pci_mem_base;
 
+#define PCI_VENDOR_ID_QEMU               0xfffa  /* FIXME: get one assigned */
+#define PCI_SUBDEVICE_ID_QEMU_DEFAULT    0x0001
+
 typedef void PCIConfigWriteFunc(PCIDevice *pci_dev,
                                 uint32_t address, uint32_t data, int len);
 typedef uint32_t PCIConfigReadFunc(PCIDevice *pci_dev,
-- 
1.5.5.1