Re: [Qemu-devel] [Xen-devel] [PATCH 3/3] xen: implement unplug protocol in xen_platform

[Anthony PERARD]

On Thu, Jun 16, 2011 at 17:05,  <address@hidden> wrote:
> From: Stefano Stabellini <address@hidden>
>
> The unplug protocol is necessary to support PV drivers in the guest: the
> drivers expect to be able to "unplug" emulated disks and nics before
> initializing the Xen PV interfaces.
> It is responsibility of the guest to make sure that the unplug is done
> before the emulated devices or the PV interface start to be used.
>
> We use pci_for_each_device to walk the PCI bus, identify the devices and
> disks that we want to disable and dynamically unplug them.
>
> Signed-off-by: Stefano Stabellini <address@hidden>
> ---
>  hw/xen_platform.c |   63 
> ++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  1 files changed, 62 insertions(+), 1 deletions(-)
>
> diff --git a/hw/xen_platform.c b/hw/xen_platform.c
> index b167eee..9f8c843 100644
> --- a/hw/xen_platform.c
> +++ b/hw/xen_platform.c
> @@ -34,6 +34,9 @@
>  #include "xen_backend.h"
>  #include "rwhandler.h"
>  #include "trace.h"
> +#include "hw/ide/internal.h"
> +#include "hw/ide/pci.h"
> +#include "hw/pci_ids.h"
>
>  #include <xenguest.h>
>
> @@ -76,6 +79,54 @@ static void log_writeb(PCIXenPlatformState *s, char val)
>  }
>
>  /* Xen Platform, Fixed IOPort */
> +#define UNPLUG_ALL_IDE_DISKS 1
> +#define UNPLUG_ALL_NICS 2
> +#define UNPLUG_AUX_IDE_DISKS 4
> +
> +static int unplug_param;
> +
> +static void unplug_nic(PCIBus *b, PCIDevice *d)
> +{
> +    if (d->config[0xa] == 0 && d->config[0xb] == 2) {

You should use:
pci_get_word(d->config+PCI_CLASS_DEVICE) == PCI_CLASS_NETWORK_ETHERNET

It'll be clearer.

> +        pci_unplug_device(&(d->qdev));
> +    }
> +}
> +
> +static void pci_unplug_nics(PCIBus *bus)
> +{
> +    pci_for_each_device(bus, 0, unplug_nic);
> +}
> +
> +static void unplug_disks(PCIBus *b, PCIDevice *d)
> +{
> +    if (d->config[0xa] == 1 && d->config[0xb] == 1) {

Same here with PCI_CLASS_STORAGE_IDE.

Regards,

-- 
Anthony PERARD