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Citrix PV Bus device [V3]

Message ID 1372779366-25446-1-git-send-email-paul.durrant@citrix.com
State New
Headers show

Commit Message

Paul Durrant July 2, 2013, 3:36 p.m. UTC
This patch introduces a new PCI device which will act as the binding point
for Citrix branded PV drivers for Xen.
The intention is that Citrix Windows PV drivers will be available on Windows
Update and thus using the existing Xen platform PCI device as an anchor
point is not desirable as that device has been ubiquitous in HVM guests for
a long time and thus existing HVM guests running Windows would start
automatically downloading drivers from Windows Update when this may not be
desired by either the host or guest admin. This device therefore acts as
an opt-in for those wishing to deploy Citrix PV drivers.

V3:
- Addresses comments from Anthony Liguori and Peter Maydell

V2:
- Addresses comments from Andreas Farber and Paolo Bonzini

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
---
 hw/misc/Makefile.objs    |    2 +
 hw/misc/citrix_pv_bus.c  |  127 ++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/pci/pci_ids.h |    7 ++-
 trace-events             |    4 ++
 4 files changed, 138 insertions(+), 2 deletions(-)
 create mode 100644 hw/misc/citrix_pv_bus.c

Comments

Stefano Stabellini July 2, 2013, 4:42 p.m. UTC | #1
On Tue, 2 Jul 2013, Paul Durrant wrote:
> This patch introduces a new PCI device which will act as the binding point
> for Citrix branded PV drivers for Xen.
> The intention is that Citrix Windows PV drivers will be available on Windows
> Update and thus using the existing Xen platform PCI device as an anchor
> point is not desirable as that device has been ubiquitous in HVM guests for
> a long time and thus existing HVM guests running Windows would start
> automatically downloading drivers from Windows Update when this may not be
> desired by either the host or guest admin. This device therefore acts as
> an opt-in for those wishing to deploy Citrix PV drivers.
> 
> V3:
> - Addresses comments from Anthony Liguori and Peter Maydell
> 
> V2:
> - Addresses comments from Andreas Farber and Paolo Bonzini
> 
> Signed-off-by: Paul Durrant <paul.durrant@citrix.com>

I do realize that this is v3 and I didn't step in the discussion
before, sorry for the delay in my response. I admit I didn't read the
entire thread, so excuse me if I repeat things already said before.


>  hw/misc/Makefile.objs    |    2 +
>  hw/misc/citrix_pv_bus.c  |  127 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/pci/pci_ids.h |    7 ++-
>  trace-events             |    4 ++
>  4 files changed, 138 insertions(+), 2 deletions(-)
>  create mode 100644 hw/misc/citrix_pv_bus.c
> 
> diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
> index 2578e29..ffd29ea 100644
> --- a/hw/misc/Makefile.objs
> +++ b/hw/misc/Makefile.objs
> @@ -41,3 +41,5 @@ obj-$(CONFIG_SLAVIO) += slavio_misc.o
>  obj-$(CONFIG_ZYNQ) += zynq_slcr.o
>  
>  obj-$(CONFIG_PVPANIC) += pvpanic.o
> +
> +obj-$(CONFIG_XEN) += citrix-pv-bus.o
> diff --git a/hw/misc/citrix_pv_bus.c b/hw/misc/citrix_pv_bus.c
> new file mode 100644
> index 0000000..76e5e13
> --- /dev/null
> +++ b/hw/misc/citrix_pv_bus.c
> @@ -0,0 +1,127 @@
> +
> +/* Copyright (c) Citrix Systems Inc.
> + * All rights reserved.
> + * 
> + * Redistribution and use in source and binary forms, 
> + * with or without modification, are permitted provided 
> + * that the following conditions are met:
> + * 
> + * *   Redistributions of source code must retain the above 
> + *     copyright notice, this list of conditions and the 
> + *     following disclaimer.
> + * *   Redistributions in binary form must reproduce the above 
> + *     copyright notice, this list of conditions and the 
> + *     following disclaimer in the documentation and/or other 
> + *     materials provided with the distribution.
> + * 
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
> + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
> + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
> + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
> + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
> + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
> + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
> + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
> + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
> + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
> + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
> + * SUCH DAMAGE.
> + */
> +
> +#include "hw/hw.h"
> +#include "hw/pci/pci.h"
> +#include "trace.h"
> +
> +#define TYPE_CITRIX_PV_BUS_DEVICE  "citrix-pv"
> +
> +#define CITRIX_PV_BUS_DEVICE(obj) \
> +     OBJECT_CHECK(CitrixPVBusDevice, (obj), TYPE_CITRIX_PV_BUS_DEVICE)
> +
> +typedef struct CitrixPVBusDevice {
> +    /*< private >*/
> +    PCIDevice       parent_obj;
> +    /*< public >*/
> +    uint8_t         revision;
> +    uint32_t        size;
> +    MemoryRegion    mmio;
> +} CitrixPVBusDevice;
> +
> +static uint64_t citrix_pv_bus_mmio_read(void *opaque, hwaddr addr,
> +                                        unsigned size)
> +{
> +    trace_citrix_pv_bus_mmio_read(addr);
> +
> +    return ~(uint64_t)0;
> +}
> +
> +static void citrix_pv_bus_mmio_write(void *opaque, hwaddr addr,
> +                                     uint64_t val, unsigned size)
> +{
> +    trace_citrix_pv_bus_mmio_write(addr);
> +}
> +
> +static const MemoryRegionOps citrix_pv_bus_mmio_ops = {
> +    .read = &citrix_pv_bus_mmio_read,
> +    .write = &citrix_pv_bus_mmio_write,
> +    .endianness = DEVICE_LITTLE_ENDIAN,
> +};
> +
> +static int citrix_pv_bus_init(PCIDevice *pci_dev)
> +{
> +    CitrixPVBusDevice *d = CITRIX_PV_BUS_DEVICE(pci_dev);
> +    uint8_t *pci_conf;
> +
> +    pci_conf = pci_dev->config;
> +
> +    pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_MEMORY);
> +    pci_set_byte(pci_conf + PCI_REVISION_ID, d->revision);
> +
> +    pci_config_set_prog_interface(pci_conf, 0);
> +
> +    pci_conf[PCI_INTERRUPT_PIN] = 1;
> +
> +    memory_region_init_io(&d->mmio, &citrix_pv_bus_mmio_ops, d,
> +                          "citrix-bus-mmio", d->size);
> +
> +    pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_MEM_PREFETCH,
> +                     &d->mmio);
> +
> +    return 0;
> +}
> +
> +static Property citrix_pv_bus_props[] = {
> +    DEFINE_PROP_UINT8("revision", CitrixPVBusDevice, revision, 0x01),
> +    DEFINE_PROP_UINT32("size", CitrixPVBusDevice, size, 0x400000),
> +    DEFINE_PROP_END_OF_LIST()
> +};
> +
> +static void citrix_pv_bus_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> +
> +    k->init = citrix_pv_bus_init;
> +    k->vendor_id = PCI_VENDOR_ID_CITRIX;
> +    k->device_id = PCI_DEVICE_ID_CITRIX_PV_BUS;
> +    k->class_id = PCI_CLASS_SYSTEM_OTHER;
> +    k->subsystem_vendor_id = PCI_VENDOR_ID_CITRIX;
> +    k->subsystem_id = PCI_DEVICE_ID_CITRIX_PV_BUS;
> +    dc->desc = "Citrix PV Bus";
> +    dc->props = citrix_pv_bus_props;
> +}
> +
> +static const TypeInfo citrix_pv_bus_type_info = {
> +    .name          = TYPE_CITRIX_PV_BUS_DEVICE,
> +    .parent        = TYPE_PCI_DEVICE,
> +    .instance_size = sizeof(CitrixPVBusDevice),
> +    .class_init    = citrix_pv_bus_class_init,
> +};

I get that we need a new device because Windows drivers from Windows
Update need to bind to it and we can't simply "force" an update to all
the Windows HVM instances out there.
For example one might have installed another vendor's Windows PV drivers
and might not want to switch to the ones provided by Citrix.

However we simply can't add a new device in QEMU for each vendor that
decides to implement Windows Xen PV drivers. We have to make this
configurable.

Finally if possible we shouldn't assume that the admin knows beforehand
what operating system is installed in the VM.

As a result I think that:

- it's a good idea to add a new device but at the same time we should
also leave the old one there, so that existing installations (Linux,
BSD, Solaris, etc.) will keep working without troubles and people that
wants to manually install the Windows PV drivers from the installer
can keep doing so;

- the new device should have configurable vendor and device ids, so that
host admins can select which vendor's PV drivers are going to be
automatically installed on all your Windows guests. This should probably
be a VM config option (pvdevice=<gplpv|citrix|suse|oracle|etc>, libxl would
then pass a vendor and device id pair to QEMU via command line.
We can come up with a config syntax that would support both numeric
pairs as well as simple labels.

- the Citrix [vendor id|device id] pair has to be different from the
xenproject one (0x5853|0x0001). I am sure we can arrange the
xenproject device id space so that Windows PV drivers vendors don't have
to acquire their own PCI vendor ids.

- Windows PV drivers vendors might want to consider continuing on
providing a Windows PV drivers installer that binds to the current PCI
vendor and device ids so that people can continue consuming them the
same way they have been doing so far without requiring host admin
intervention.



> diff --git a/include/hw/pci/pci_ids.h b/include/hw/pci/pci_ids.h
> index d8dc2f1..95b236f 100644
> --- a/include/hw/pci/pci_ids.h
> +++ b/include/hw/pci/pci_ids.h
> @@ -142,8 +142,11 @@
>  
>  #define PCI_DEVICE_ID_INTEL_Q35_MCH      0x29c0
>  
> -#define PCI_VENDOR_ID_XEN               0x5853
> -#define PCI_DEVICE_ID_XEN_PLATFORM      0x0001
> +#define PCI_VENDOR_ID_CITRIX             0x5853
> +#define PCI_DEVICE_ID_CITRIX_PV_BUS      0x0002
> +
> +#define PCI_VENDOR_ID_XEN                (PCI_VENDOR_ID_CITRIX)
> +#define PCI_DEVICE_ID_XEN_PLATFORM       0x0001
>  
>  #define PCI_VENDOR_ID_NEC                0x1033
>  #define PCI_DEVICE_ID_NEC_UPD720200      0x0194

This is unacceptable. Since when the xenproject pci vendor ID has become
the Citrix vendor ID?
Stefano Stabellini July 2, 2013, 6:05 p.m. UTC | #2
On Tue, 2 Jul 2013, Stefano Stabellini wrote:
> - the new device should have configurable vendor and device ids, so that
> host admins can select which vendor's PV drivers are going to be
> automatically installed on all your Windows guests. This should probably
> be a VM config option (pvdevice=<gplpv|citrix|suse|oracle|etc>, libxl would
> then pass a vendor and device id pair to QEMU via command line.
> We can come up with a config syntax that would support both numeric
> pairs as well as simple labels.

Anthony,
would you be happy to have a PCI device in QEMU with configurable vendor
and device IDs?
If not, would you be OK with a PCI device with the Xen vendor ID but a
configurable device ID?
Anthony Liguori July 2, 2013, 6:31 p.m. UTC | #3
Stefano Stabellini <stefano.stabellini@eu.citrix.com> writes:

> On Tue, 2 Jul 2013, Stefano Stabellini wrote:
>> - the new device should have configurable vendor and device ids, so that
>> host admins can select which vendor's PV drivers are going to be
>> automatically installed on all your Windows guests. This should probably
>> be a VM config option (pvdevice=<gplpv|citrix|suse|oracle|etc>, libxl would
>> then pass a vendor and device id pair to QEMU via command line.
>> We can come up with a config syntax that would support both numeric
>> pairs as well as simple labels.
>
> Anthony,
> would you be happy to have a PCI device in QEMU with configurable vendor
> and device IDs?

We already have this in other places (USB devices, for instance), so
yeah, no problem there.

I will say that having to force a user to choose which "vendor" drivers
they use sucks.  It's ashame that both Xen and KVM suffer this problem
of everyone introducing their own variants of pv drivers.

Regards,

Anthony Liguori

> If not, would you be OK with a PCI device with the Xen vendor ID but a
> configurable device ID?
Paul Durrant July 3, 2013, 7:58 a.m. UTC | #4
> -----Original Message-----
> From: Stefano Stabellini [mailto:stefano.stabellini@eu.citrix.com]
> Sent: 02 July 2013 17:42
> To: Paul Durrant
> Cc: qemu-devel@nongnu.org; xen-devel@lists.xen.org
> Subject: Re: [Xen-devel] [PATCH] Citrix PV Bus device [V3]
> 
> On Tue, 2 Jul 2013, Paul Durrant wrote:
> > This patch introduces a new PCI device which will act as the binding point
> > for Citrix branded PV drivers for Xen.
> > The intention is that Citrix Windows PV drivers will be available on Windows
> > Update and thus using the existing Xen platform PCI device as an anchor
> > point is not desirable as that device has been ubiquitous in HVM guests for
> > a long time and thus existing HVM guests running Windows would start
> > automatically downloading drivers from Windows Update when this may
> not be
> > desired by either the host or guest admin. This device therefore acts as
> > an opt-in for those wishing to deploy Citrix PV drivers.
> >
> > V3:
> > - Addresses comments from Anthony Liguori and Peter Maydell
> >
> > V2:
> > - Addresses comments from Andreas Farber and Paolo Bonzini
> >
> > Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
> 
> I do realize that this is v3 and I didn't step in the discussion
> before, sorry for the delay in my response. I admit I didn't read the
> entire thread, so excuse me if I repeat things already said before.
> 
> 
> >  hw/misc/Makefile.objs    |    2 +
> >  hw/misc/citrix_pv_bus.c  |  127
> ++++++++++++++++++++++++++++++++++++++++++++++
> >  include/hw/pci/pci_ids.h |    7 ++-
> >  trace-events             |    4 ++
> >  4 files changed, 138 insertions(+), 2 deletions(-)
> >  create mode 100644 hw/misc/citrix_pv_bus.c
> >
> > diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
> > index 2578e29..ffd29ea 100644
> > --- a/hw/misc/Makefile.objs
> > +++ b/hw/misc/Makefile.objs
> > @@ -41,3 +41,5 @@ obj-$(CONFIG_SLAVIO) += slavio_misc.o
> >  obj-$(CONFIG_ZYNQ) += zynq_slcr.o
> >
> >  obj-$(CONFIG_PVPANIC) += pvpanic.o
> > +
> > +obj-$(CONFIG_XEN) += citrix-pv-bus.o
> > diff --git a/hw/misc/citrix_pv_bus.c b/hw/misc/citrix_pv_bus.c
> > new file mode 100644
> > index 0000000..76e5e13
> > --- /dev/null
> > +++ b/hw/misc/citrix_pv_bus.c
> > @@ -0,0 +1,127 @@
> > +
> > +/* Copyright (c) Citrix Systems Inc.
> > + * All rights reserved.
> > + *
> > + * Redistribution and use in source and binary forms,
> > + * with or without modification, are permitted provided
> > + * that the following conditions are met:
> > + *
> > + * *   Redistributions of source code must retain the above
> > + *     copyright notice, this list of conditions and the
> > + *     following disclaimer.
> > + * *   Redistributions in binary form must reproduce the above
> > + *     copyright notice, this list of conditions and the
> > + *     following disclaimer in the documentation and/or other
> > + *     materials provided with the distribution.
> > + *
> > + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
> > + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
> > + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
> > + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
> > + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
> > + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
> > + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
> > + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
> > + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
> > + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
> > + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
> > + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
> > + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> > + * SUCH DAMAGE.
> > + */
> > +
> > +#include "hw/hw.h"
> > +#include "hw/pci/pci.h"
> > +#include "trace.h"
> > +
> > +#define TYPE_CITRIX_PV_BUS_DEVICE  "citrix-pv"
> > +
> > +#define CITRIX_PV_BUS_DEVICE(obj) \
> > +     OBJECT_CHECK(CitrixPVBusDevice, (obj),
> TYPE_CITRIX_PV_BUS_DEVICE)
> > +
> > +typedef struct CitrixPVBusDevice {
> > +    /*< private >*/
> > +    PCIDevice       parent_obj;
> > +    /*< public >*/
> > +    uint8_t         revision;
> > +    uint32_t        size;
> > +    MemoryRegion    mmio;
> > +} CitrixPVBusDevice;
> > +
> > +static uint64_t citrix_pv_bus_mmio_read(void *opaque, hwaddr addr,
> > +                                        unsigned size)
> > +{
> > +    trace_citrix_pv_bus_mmio_read(addr);
> > +
> > +    return ~(uint64_t)0;
> > +}
> > +
> > +static void citrix_pv_bus_mmio_write(void *opaque, hwaddr addr,
> > +                                     uint64_t val, unsigned size)
> > +{
> > +    trace_citrix_pv_bus_mmio_write(addr);
> > +}
> > +
> > +static const MemoryRegionOps citrix_pv_bus_mmio_ops = {
> > +    .read = &citrix_pv_bus_mmio_read,
> > +    .write = &citrix_pv_bus_mmio_write,
> > +    .endianness = DEVICE_LITTLE_ENDIAN,
> > +};
> > +
> > +static int citrix_pv_bus_init(PCIDevice *pci_dev)
> > +{
> > +    CitrixPVBusDevice *d = CITRIX_PV_BUS_DEVICE(pci_dev);
> > +    uint8_t *pci_conf;
> > +
> > +    pci_conf = pci_dev->config;
> > +
> > +    pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_MEMORY);
> > +    pci_set_byte(pci_conf + PCI_REVISION_ID, d->revision);
> > +
> > +    pci_config_set_prog_interface(pci_conf, 0);
> > +
> > +    pci_conf[PCI_INTERRUPT_PIN] = 1;
> > +
> > +    memory_region_init_io(&d->mmio, &citrix_pv_bus_mmio_ops, d,
> > +                          "citrix-bus-mmio", d->size);
> > +
> > +    pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_MEM_PREFETCH,
> > +                     &d->mmio);
> > +
> > +    return 0;
> > +}
> > +
> > +static Property citrix_pv_bus_props[] = {
> > +    DEFINE_PROP_UINT8("revision", CitrixPVBusDevice, revision, 0x01),
> > +    DEFINE_PROP_UINT32("size", CitrixPVBusDevice, size, 0x400000),
> > +    DEFINE_PROP_END_OF_LIST()
> > +};
> > +
> > +static void citrix_pv_bus_class_init(ObjectClass *klass, void *data)
> > +{
> > +    DeviceClass *dc = DEVICE_CLASS(klass);
> > +    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> > +
> > +    k->init = citrix_pv_bus_init;
> > +    k->vendor_id = PCI_VENDOR_ID_CITRIX;
> > +    k->device_id = PCI_DEVICE_ID_CITRIX_PV_BUS;
> > +    k->class_id = PCI_CLASS_SYSTEM_OTHER;
> > +    k->subsystem_vendor_id = PCI_VENDOR_ID_CITRIX;
> > +    k->subsystem_id = PCI_DEVICE_ID_CITRIX_PV_BUS;
> > +    dc->desc = "Citrix PV Bus";
> > +    dc->props = citrix_pv_bus_props;
> > +}
> > +
> > +static const TypeInfo citrix_pv_bus_type_info = {
> > +    .name          = TYPE_CITRIX_PV_BUS_DEVICE,
> > +    .parent        = TYPE_PCI_DEVICE,
> > +    .instance_size = sizeof(CitrixPVBusDevice),
> > +    .class_init    = citrix_pv_bus_class_init,
> > +};
> 
> I get that we need a new device because Windows drivers from Windows
> Update need to bind to it and we can't simply "force" an update to all
> the Windows HVM instances out there.
> For example one might have installed another vendor's Windows PV drivers
> and might not want to switch to the ones provided by Citrix.
> 
> However we simply can't add a new device in QEMU for each vendor that
> decides to implement Windows Xen PV drivers. We have to make this
> configurable.
> 
> Finally if possible we shouldn't assume that the admin knows beforehand
> what operating system is installed in the VM.
> 
> As a result I think that:
> 
> - it's a good idea to add a new device but at the same time we should
> also leave the old one there, so that existing installations (Linux,
> BSD, Solaris, etc.) will keep working without troubles and people that
> wants to manually install the Windows PV drivers from the installer
> can keep doing so;
> 

Absolutely, and since Alex Bligh's comment on my original xen-platform-2 patch I realise this had to be the case; hence the idea of the secondary device.

> - the new device should have configurable vendor and device ids, so that
> host admins can select which vendor's PV drivers are going to be
> automatically installed on all your Windows guests. This should probably
> be a VM config option (pvdevice=<gplpv|citrix|suse|oracle|etc>, libxl would
> then pass a vendor and device id pair to QEMU via command line.
> We can come up with a config syntax that would support both numeric
> pairs as well as simple labels.
> 
> - the Citrix [vendor id|device id] pair has to be different from the
> xenproject one (0x5853|0x0001). I am sure we can arrange the
> xenproject device id space so that Windows PV drivers vendors don't have
> to acquire their own PCI vendor ids.
> 

This all sounds fine; it's a generalization of what I've already coded up so I'm happy to refactor it. Any suggestions on a name? "xen-pvdevice", perhaps, to link it to your proposed VM config option?

> - Windows PV drivers vendors might want to consider continuing on
> providing a Windows PV drivers installer that binds to the current PCI
> vendor and device ids so that people can continue consuming them the
> same way they have been doing so far without requiring host admin
> intervention.
> 

We (Citrix) may well do that too. The build script for the win-xenbus driver takes the binding information as an argument so it's trivial for anyone to build that driver to bind to any PCI device.

  Paul
Ian Campbell July 3, 2013, 8:28 a.m. UTC | #5
On Tue, 2013-07-02 at 19:05 +0100, Stefano Stabellini wrote:
> On Tue, 2 Jul 2013, Stefano Stabellini wrote:
> > - the new device should have configurable vendor and device ids, so that
> > host admins can select which vendor's PV drivers are going to be
> > automatically installed on all your Windows guests. This should probably
> > be a VM config option (pvdevice=<gplpv|citrix|suse|oracle|etc>, libxl would
> > then pass a vendor and device id pair to QEMU via command line.
> > We can come up with a config syntax that would support both numeric
> > pairs as well as simple labels.
> 
> Anthony,
> would you be happy to have a PCI device in QEMU with configurable vendor
> and device IDs?

IIRC there is also a revision field in the PCI config space. Might as
well make that configurable too.

There are also sub-vendor and sub-device IDs but I don't think they are
so useful for us (AFAIK they are intended to allow the board
manufacturer to "subclass" the IDs baked into the ASIC).

> If not, would you be OK with a PCI device with the Xen vendor ID but a
> configurable device ID?
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
Paul Durrant July 3, 2013, 8:34 a.m. UTC | #6
> -----Original Message-----

> From: Ian Campbell

> Sent: 03 July 2013 09:29

> To: Stefano Stabellini

> Cc: Paolo Bonzini; Paul Durrant; qemu-devel@nongnu.org; Anthony Liguori;

> xen-devel@lists.xen.org

> Subject: Re: [Xen-devel] [Qemu-devel] [PATCH] Citrix PV Bus device [V3]

> 

> On Tue, 2013-07-02 at 19:05 +0100, Stefano Stabellini wrote:

> > On Tue, 2 Jul 2013, Stefano Stabellini wrote:

> > > - the new device should have configurable vendor and device ids, so that

> > > host admins can select which vendor's PV drivers are going to be

> > > automatically installed on all your Windows guests. This should probably

> > > be a VM config option (pvdevice=<gplpv|citrix|suse|oracle|etc>, libxl

> would

> > > then pass a vendor and device id pair to QEMU via command line.

> > > We can come up with a config syntax that would support both numeric

> > > pairs as well as simple labels.

> >

> > Anthony,

> > would you be happy to have a PCI device in QEMU with configurable

> vendor

> > and device IDs?

> 

> IIRC there is also a revision field in the PCI config space. Might as

> well make that configurable too.

> 


Already did that  :-)

> There are also sub-vendor and sub-device IDs but I don't think they are

> so useful for us (AFAIK they are intended to allow the board

> manufacturer to "subclass" the IDs baked into the ASIC).

> 


I'm always hazy about what those mean. I thought the idea was that a vendor may collect together many devices, potentially from different vendors, into a single chip/board and they should use common subsystem vendor/device info for all those devices to indicate that they were all part of that larger unit - but maybe I'm completely wrong.

  Paul
Ian Campbell July 3, 2013, 8:40 a.m. UTC | #7
On Wed, 2013-07-03 at 09:34 +0100, Paul Durrant wrote:
> > -----Original Message-----
> > From: Ian Campbell
> > Sent: 03 July 2013 09:29
> > To: Stefano Stabellini
> > Cc: Paolo Bonzini; Paul Durrant; qemu-devel@nongnu.org; Anthony Liguori;
> > xen-devel@lists.xen.org
> > Subject: Re: [Xen-devel] [Qemu-devel] [PATCH] Citrix PV Bus device [V3]
> > 
> > On Tue, 2013-07-02 at 19:05 +0100, Stefano Stabellini wrote:
> > > On Tue, 2 Jul 2013, Stefano Stabellini wrote:
> > > > - the new device should have configurable vendor and device ids, so that
> > > > host admins can select which vendor's PV drivers are going to be
> > > > automatically installed on all your Windows guests. This should probably
> > > > be a VM config option (pvdevice=<gplpv|citrix|suse|oracle|etc>, libxl
> > would
> > > > then pass a vendor and device id pair to QEMU via command line.
> > > > We can come up with a config syntax that would support both numeric
> > > > pairs as well as simple labels.
> > >
> > > Anthony,
> > > would you be happy to have a PCI device in QEMU with configurable
> > vendor
> > > and device IDs?
> > 
> > IIRC there is also a revision field in the PCI config space. Might as
> > well make that configurable too.
> > 
> 
> Already did that  :-)
> 
> > There are also sub-vendor and sub-device IDs but I don't think they are
> > so useful for us (AFAIK they are intended to allow the board
> > manufacturer to "subclass" the IDs baked into the ASIC).
> > 
> 
> I'm always hazy about what those mean. I thought the idea was that a
> vendor may collect together many devices, potentially from different
> vendors, into a single chip/board and they should use common subsystem
> vendor/device info for all those devices to indicate that they were
> all part of that larger unit - but maybe I'm completely wrong.

I figured it was so the board vendor could add "value" in their drivers
by taking advantage of the higher precedence given to the binding to the
sub-ids by OSs.
Stefano Stabellini July 3, 2013, 10:49 a.m. UTC | #8
On Wed, 3 Jul 2013, Paul Durrant wrote:
> > - the Citrix [vendor id|device id] pair has to be different from the
> > xenproject one (0x5853|0x0001). I am sure we can arrange the
> > xenproject device id space so that Windows PV drivers vendors don't have
> > to acquire their own PCI vendor ids.
> > 
> 
> This all sounds fine; it's a generalization of what I've already coded up so I'm happy to refactor it. Any suggestions on a name? "xen-pvdevice", perhaps, to link it to your proposed VM config option?

xen-pvdevice is good for me
Paul Durrant July 3, 2013, 10:57 a.m. UTC | #9
> -----Original Message-----
> From: Stefano Stabellini [mailto:stefano.stabellini@eu.citrix.com]
> Sent: 03 July 2013 11:50
> To: Paul Durrant
> Cc: Stefano Stabellini; qemu-devel@nongnu.org; xen-devel@lists.xen.org
> Subject: RE: [Xen-devel] [PATCH] Citrix PV Bus device [V3]
> 
> On Wed, 3 Jul 2013, Paul Durrant wrote:
> > > - the Citrix [vendor id|device id] pair has to be different from the
> > > xenproject one (0x5853|0x0001). I am sure we can arrange the
> > > xenproject device id space so that Windows PV drivers vendors don't
> have
> > > to acquire their own PCI vendor ids.
> > >
> >
> > This all sounds fine; it's a generalization of what I've already coded up so I'm
> happy to refactor it. Any suggestions on a name? "xen-pvdevice", perhaps,
> to link it to your proposed VM config option?
> 
> xen-pvdevice is good for me

Cool, new patch coming up.
Anthony Liguori July 3, 2013, 1:45 p.m. UTC | #10
Ian Campbell <Ian.Campbell@citrix.com> writes:

> On Wed, 2013-07-03 at 09:34 +0100, Paul Durrant wrote:
>> Already did that  :-)
>> 
>> > There are also sub-vendor and sub-device IDs but I don't think they are
>> > so useful for us (AFAIK they are intended to allow the board
>> > manufacturer to "subclass" the IDs baked into the ASIC).
>> > 
>> 
>> I'm always hazy about what those mean. I thought the idea was that a
>> vendor may collect together many devices, potentially from different
>> vendors, into a single chip/board and they should use common subsystem
>> vendor/device info for all those devices to indicate that they were
>> all part of that larger unit - but maybe I'm completely wrong.
>
> I figured it was so the board vendor could add "value" in their drivers
> by taking advantage of the higher precedence given to the binding to the
> sub-ids by OSs.

It's essentially an OEM id.  Often times it's an EEPROM setting on real
hardware.  A different subsystem vendor/device does not indicate a
different programming interface.

We set it to a vendor/device ID reserved for QEMU by default.  It's best
to keep it the QEMU ID to identify it as a device implemented by QEMU.

It's mighty handy as it lets software figure out that it's a Cirrus VGA
card emulated by QEMU (not real hardware).  In fact, I believe the
kernel KMS driver for Cirrus only binds to the QEMU vendor/device ID
since that's the only thing reasonably testable these days.

Regards,

Anthony Liguori
Ian Campbell July 3, 2013, 1:49 p.m. UTC | #11
On Wed, 2013-07-03 at 08:45 -0500, Anthony Liguori wrote:
> Ian Campbell <Ian.Campbell@citrix.com> writes:
> 
> > On Wed, 2013-07-03 at 09:34 +0100, Paul Durrant wrote:
> >> Already did that  :-)
> >> 
> >> > There are also sub-vendor and sub-device IDs but I don't think they are
> >> > so useful for us (AFAIK they are intended to allow the board
> >> > manufacturer to "subclass" the IDs baked into the ASIC).
> >> > 
> >> 
> >> I'm always hazy about what those mean. I thought the idea was that a
> >> vendor may collect together many devices, potentially from different
> >> vendors, into a single chip/board and they should use common subsystem
> >> vendor/device info for all those devices to indicate that they were
> >> all part of that larger unit - but maybe I'm completely wrong.
> >
> > I figured it was so the board vendor could add "value" in their drivers
> > by taking advantage of the higher precedence given to the binding to the
> > sub-ids by OSs.
> 
> It's essentially an OEM id.  Often times it's an EEPROM setting on real
> hardware.  A different subsystem vendor/device does not indicate a
> different programming interface.
> 
> We set it to a vendor/device ID reserved for QEMU by default.  It's best
> to keep it the QEMU ID to identify it as a device implemented by QEMU.
> 
> It's mighty handy as it lets software figure out that it's a Cirrus VGA
> card emulated by QEMU (not real hardware).  In fact, I believe the
> kernel KMS driver for Cirrus only binds to the QEMU vendor/device ID
> since that's the only thing reasonably testable these days.

That makes sense.

> 
> Regards,
> 
> Anthony Liguori
>
diff mbox

Patch

diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index 2578e29..ffd29ea 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -41,3 +41,5 @@  obj-$(CONFIG_SLAVIO) += slavio_misc.o
 obj-$(CONFIG_ZYNQ) += zynq_slcr.o
 
 obj-$(CONFIG_PVPANIC) += pvpanic.o
+
+obj-$(CONFIG_XEN) += citrix-pv-bus.o
diff --git a/hw/misc/citrix_pv_bus.c b/hw/misc/citrix_pv_bus.c
new file mode 100644
index 0000000..76e5e13
--- /dev/null
+++ b/hw/misc/citrix_pv_bus.c
@@ -0,0 +1,127 @@ 
+
+/* Copyright (c) Citrix Systems Inc.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, 
+ * with or without modification, are permitted provided 
+ * that the following conditions are met:
+ * 
+ * *   Redistributions of source code must retain the above 
+ *     copyright notice, this list of conditions and the 
+ *     following disclaimer.
+ * *   Redistributions in binary form must reproduce the above 
+ *     copyright notice, this list of conditions and the 
+ *     following disclaimer in the documentation and/or other 
+ *     materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
+ * SUCH DAMAGE.
+ */
+
+#include "hw/hw.h"
+#include "hw/pci/pci.h"
+#include "trace.h"
+
+#define TYPE_CITRIX_PV_BUS_DEVICE  "citrix-pv"
+
+#define CITRIX_PV_BUS_DEVICE(obj) \
+     OBJECT_CHECK(CitrixPVBusDevice, (obj), TYPE_CITRIX_PV_BUS_DEVICE)
+
+typedef struct CitrixPVBusDevice {
+    /*< private >*/
+    PCIDevice       parent_obj;
+    /*< public >*/
+    uint8_t         revision;
+    uint32_t        size;
+    MemoryRegion    mmio;
+} CitrixPVBusDevice;
+
+static uint64_t citrix_pv_bus_mmio_read(void *opaque, hwaddr addr,
+                                        unsigned size)
+{
+    trace_citrix_pv_bus_mmio_read(addr);
+
+    return ~(uint64_t)0;
+}
+
+static void citrix_pv_bus_mmio_write(void *opaque, hwaddr addr,
+                                     uint64_t val, unsigned size)
+{
+    trace_citrix_pv_bus_mmio_write(addr);
+}
+
+static const MemoryRegionOps citrix_pv_bus_mmio_ops = {
+    .read = &citrix_pv_bus_mmio_read,
+    .write = &citrix_pv_bus_mmio_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static int citrix_pv_bus_init(PCIDevice *pci_dev)
+{
+    CitrixPVBusDevice *d = CITRIX_PV_BUS_DEVICE(pci_dev);
+    uint8_t *pci_conf;
+
+    pci_conf = pci_dev->config;
+
+    pci_set_word(pci_conf + PCI_COMMAND, PCI_COMMAND_MEMORY);
+    pci_set_byte(pci_conf + PCI_REVISION_ID, d->revision);
+
+    pci_config_set_prog_interface(pci_conf, 0);
+
+    pci_conf[PCI_INTERRUPT_PIN] = 1;
+
+    memory_region_init_io(&d->mmio, &citrix_pv_bus_mmio_ops, d,
+                          "citrix-bus-mmio", d->size);
+
+    pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_MEM_PREFETCH,
+                     &d->mmio);
+
+    return 0;
+}
+
+static Property citrix_pv_bus_props[] = {
+    DEFINE_PROP_UINT8("revision", CitrixPVBusDevice, revision, 0x01),
+    DEFINE_PROP_UINT32("size", CitrixPVBusDevice, size, 0x400000),
+    DEFINE_PROP_END_OF_LIST()
+};
+
+static void citrix_pv_bus_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    k->init = citrix_pv_bus_init;
+    k->vendor_id = PCI_VENDOR_ID_CITRIX;
+    k->device_id = PCI_DEVICE_ID_CITRIX_PV_BUS;
+    k->class_id = PCI_CLASS_SYSTEM_OTHER;
+    k->subsystem_vendor_id = PCI_VENDOR_ID_CITRIX;
+    k->subsystem_id = PCI_DEVICE_ID_CITRIX_PV_BUS;
+    dc->desc = "Citrix PV Bus";
+    dc->props = citrix_pv_bus_props;
+}
+
+static const TypeInfo citrix_pv_bus_type_info = {
+    .name          = TYPE_CITRIX_PV_BUS_DEVICE,
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(CitrixPVBusDevice),
+    .class_init    = citrix_pv_bus_class_init,
+};
+
+static void citrix_pv_bus_register_types(void)
+{
+    type_register_static(&citrix_pv_bus_type_info);
+}
+
+type_init(citrix_pv_bus_register_types)
diff --git a/include/hw/pci/pci_ids.h b/include/hw/pci/pci_ids.h
index d8dc2f1..95b236f 100644
--- a/include/hw/pci/pci_ids.h
+++ b/include/hw/pci/pci_ids.h
@@ -142,8 +142,11 @@ 
 
 #define PCI_DEVICE_ID_INTEL_Q35_MCH      0x29c0
 
-#define PCI_VENDOR_ID_XEN               0x5853
-#define PCI_DEVICE_ID_XEN_PLATFORM      0x0001
+#define PCI_VENDOR_ID_CITRIX             0x5853
+#define PCI_DEVICE_ID_CITRIX_PV_BUS      0x0002
+
+#define PCI_VENDOR_ID_XEN                (PCI_VENDOR_ID_CITRIX)
+#define PCI_DEVICE_ID_XEN_PLATFORM       0x0001
 
 #define PCI_VENDOR_ID_NEC                0x1033
 #define PCI_DEVICE_ID_NEC_UPD720200      0x0194
diff --git a/trace-events b/trace-events
index c5f1ccb..63052b9 100644
--- a/trace-events
+++ b/trace-events
@@ -1161,3 +1161,7 @@  kvm_run_exit(int cpu_index, uint32_t reason) "cpu_index %d, reason %d"
 # qom/object.c
 object_dynamic_cast_assert(const char *type, const char *target, const char *file, int line, const char *func) "%s->%s (%s:%d:%s)"
 object_class_dynamic_cast_assert(const char *type, const char *target, const char *file, int line, const char *func) "%s->%s (%s:%d:%s)"
+
+# hw/i386/citrix_pv_bus.c
+citrix_pv_bus_mmio_read(uint64_t addr) "WARNING: read from Citrix PV MMIO space (address %"PRIx64")"
+citrix_pv_bus_mmio_write(uint64_t addr) "WARNING: write to Citrix PV MMIO space (address %"PRIx64")"