Re: [Xen-devel] [PATCH 2/2] xen_platform: SUSE xenlinux unplug for emulated PCI

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 1 Sep 2016, Konrad Rzeszutek Wilk wrote:
> On Thu, Sep 01, 2016 at 02:11:31PM +0200, Olaf Hering wrote:
> > Implement SUSE specific unplug protocol for emulated PCI devices
> > in PVonHVM guests. Its a simple 'outl(1, (ioaddr + 4));'.
> > This protocol was implemented and used since Xen 3.0.4.
> > It is used in all SUSE/SLES/openSUSE releases up to SLES11SP3 and
> > openSUSE 12.3.
> 
> Should this be documented in the protocol?

Yes, please. The file is docs/misc/hvm-emulated-unplug.markdown in the
Xen repository. Please also document the behavior with SCSI disks, which
is currently missing.


> > 
> > Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>
> > ---
> >  hw/i386/xen/xen_platform.c | 31 ++++++++++++++++++++++++++++++-
> >  1 file changed, 30 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/i386/xen/xen_platform.c b/hw/i386/xen/xen_platform.c
> > index d94b53c..8802482 100644
> > --- a/hw/i386/xen/xen_platform.c
> > +++ b/hw/i386/xen/xen_platform.c
> > @@ -314,13 +314,42 @@ static void xen_platform_ioport_writeb(void *opaque, 
> > hwaddr addr,
> >                                         uint64_t val, unsigned int size)
> >  {
> >      PCIXenPlatformState *s = opaque;
> > +    PCIDevice *pci_dev = PCI_DEVICE(s);
> >  
> >      switch (addr) {
> >      case 0: /* Platform flags */
> >          platform_fixed_ioport_writeb(opaque, 0, (uint32_t)val);
> >          break;
> > +    case 4:
> > +        if (val == 1) {
> > +            /*
> > +             * SUSE unplug for Xenlinux
> > +             * xen-kmp used this since xen-3.0.4, instead the official 
> > protocol from xen-3.3+
> > +             * It did an unconditional "outl(1, (ioaddr + 4));"
> > +             * Pre VMDP 1.7 made use of 4 and 8 depending on how VMDP was 
> > configured.
> > +             * If VMDP was to control both disk and LAN it would use 4.
> > +             * If it controlled just disk or just LAN, it would use 8 
> > below.
> > +             */
> > +            blk_drain_all();
> > +            blk_flush_all();
> > +            pci_unplug_disks(pci_dev->bus);
> > +            pci_unplug_nics(pci_dev->bus);
> > +        }
> > +        break;
> >      case 8:
> > -        log_writeb(s, (uint32_t)val);
> > +        switch (val) {
> > +        case 1:
> > +            blk_drain_all();
> > +            blk_flush_all();
> > +            pci_unplug_disks(pci_dev->bus);
> > +            break;
> > +        case 2:
> > +            pci_unplug_nics(pci_dev->bus);
> > +            break;
> > +        default:
> > +            log_writeb(s, (uint32_t)val);
> > +            break;
> > +        }
> >          break;
> >      default:
> >          break;
> > 
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxx
> > https://lists.xen.org/xen-devel
> 

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