Re: [RFC PATCH v3 6/7] hw/acpi/ich9: Set ACPI PCI hot-plug as default

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Sep 24, 2020 at 11:33:45AM +0200, Igor Mammedov wrote:
> On Thu, 24 Sep 2020 09:00:12 +0200
> Julia Suvorova <jusual@redhat.com> wrote:
> 
> > Signed-off-by: Julia Suvorova <jusual@redhat.com>
> 
> I'd drop this patch for now.
> mgmt can turn it on for Windows guests to workaround
> its native hotplug issues.

It's not just windows either, the hack we have in the hotplug code is an
example of a linux issue.  I'd rather not let management worry about
which type of hotplug is in use. Nothing here sets any policy, this is
strictly a mechanism thing.

> > ---
> >  hw/acpi/ich9.c | 2 +-
> >  hw/i386/pc.c   | 1 +
> >  2 files changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
> > index 987f23e388..c67c20de4e 100644
> > --- a/hw/acpi/ich9.c
> > +++ b/hw/acpi/ich9.c
> > @@ -425,7 +425,7 @@ void ich9_pm_add_properties(Object *obj, ICH9LPCPMRegs *pm)
> >      pm->disable_s3 = 0;
> >      pm->disable_s4 = 0;
> >      pm->s4_val = 2;
> > -    pm->use_acpi_hotplug_bridge = false;
> > +    pm->use_acpi_hotplug_bridge = true;
> >  
> >      object_property_add_uint32_ptr(obj, ACPI_PM_PROP_PM_IO_BASE,
> >                                     &pm->pm_io_base, OBJ_PROP_FLAG_READ);
> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > index b55369357e..5de4475570 100644
> > --- a/hw/i386/pc.c
> > +++ b/hw/i386/pc.c
> > @@ -101,6 +101,7 @@ GlobalProperty pc_compat_5_1[] = {};
> >  const size_t pc_compat_5_1_len = G_N_ELEMENTS(pc_compat_5_1);
> >  
> >  GlobalProperty pc_compat_5_0[] = {
> > +    { "ICH9-LPC", "acpi-pci-hotplug-with-bridge-support", "off" },
> >  };
> >  const size_t pc_compat_5_0_len = G_N_ELEMENTS(pc_compat_5_0);
> >