Re: [PATCH v5 4/7] hw/pci/pcie: Do not set HPC flag if acpihp is used

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

On Fri, Jun 18, 2021 at 01:54:40PM +0200, Igor Mammedov wrote:
> On Thu, 17 Jun 2021 21:07:36 +0200
> Julia Suvorova <jusual@redhat.com> wrote:
> 
> > Instead of changing the hot-plug type in _OSC register, do not
> > set the 'Hot-Plug Capable' flag. This way guest will choose ACPI
> > hot-plug if it is preferred and leave the option to use SHPC with
> > pcie-pci-bridge.
> > 
> > The ability to control hot-plug for each downstream port is retained,
> > while 'hotplug=off' on the port means all hot-plug types are disabled.
> > 
> > Signed-off-by: Julia Suvorova <jusual@redhat.com>
> > ---
> >  include/hw/pci/pcie_port.h |  5 ++++-
> >  hw/acpi/pcihp.c            |  8 ++++++++
> >  hw/core/machine.c          |  1 -
> >  hw/i386/pc_q35.c           | 11 +++++++++++
> >  hw/pci/pcie.c              |  8 +++++++-
> >  hw/pci/pcie_port.c         |  1 +
> >  6 files changed, 31 insertions(+), 3 deletions(-)
> > 
> > diff --git a/include/hw/pci/pcie_port.h b/include/hw/pci/pcie_port.h
> > index bea8ecad0f..e25b289ce8 100644
> > --- a/include/hw/pci/pcie_port.h
> > +++ b/include/hw/pci/pcie_port.h
> > @@ -57,8 +57,11 @@ struct PCIESlot {
> >      /* Disable ACS (really for a pcie_root_port) */
> >      bool        disable_acs;
> >  
> > -    /* Indicates whether hot-plug is enabled on the slot */
> > +    /* Indicates whether any type of hot-plug is allowed on the slot */
> >      bool        hotplug;
> > +
> > +    bool        native_hotplug;
> > +
> >      QLIST_ENTRY(PCIESlot) next;
> >  };
> >  
> > diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
> > index 5355618608..7a6bc1b31e 100644
> > --- a/hw/acpi/pcihp.c
> > +++ b/hw/acpi/pcihp.c
> > @@ -31,6 +31,7 @@
> >  #include "hw/pci/pci.h"
> >  #include "hw/pci/pci_bridge.h"
> >  #include "hw/pci/pci_host.h"
> > +#include "hw/pci/pcie_port.h"
> >  #include "hw/i386/acpi-build.h"
> >  #include "hw/acpi/acpi.h"
> >  #include "hw/pci/pci_bus.h"
> > @@ -332,6 +333,13 @@ void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
> >              object_dynamic_cast(OBJECT(dev), TYPE_PCI_BRIDGE)) {
> >              PCIBus *sec = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
> >  
> > +            /* Remove all hot-plug handlers if hot-plug is disabled on slot */
> > +            if (object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT) &&
> > +                !PCIE_SLOT(pdev)->hotplug) {
> > +                qbus_set_hotplug_handler(BUS(sec), NULL);
> > +                return;
> > +            }
> > +
> >              qbus_set_hotplug_handler(BUS(sec), OBJECT(hotplug_dev));
> >              /* We don't have to overwrite any other hotplug handler yet */
> >              assert(QLIST_EMPTY(&sec->child));
> > diff --git a/hw/core/machine.c b/hw/core/machine.c
> > index 55b9bc7817..6ed0575d81 100644
> > --- a/hw/core/machine.c
> > +++ b/hw/core/machine.c
> > @@ -582,7 +582,6 @@ static void machine_set_memdev(Object *obj, const char *value, Error **errp)
> >      ms->ram_memdev_id = g_strdup(value);
> >  }
> >  
> > -
> >  static void machine_init_notify(Notifier *notifier, void *data)
> >  {
> >      MachineState *machine = MACHINE(qdev_get_machine());
> > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> > index 46a0f196f4..a0ec7964cc 100644
> > --- a/hw/i386/pc_q35.c
> > +++ b/hw/i386/pc_q35.c
> > @@ -37,6 +37,7 @@
> >  #include "sysemu/kvm.h"
> >  #include "hw/kvm/clock.h"
> >  #include "hw/pci-host/q35.h"
> > +#include "hw/pci/pcie_port.h"
> >  #include "hw/qdev-properties.h"
> >  #include "hw/i386/x86.h"
> >  #include "hw/i386/pc.h"
> > @@ -136,6 +137,7 @@ static void pc_q35_init(MachineState *machine)
> >      ram_addr_t lowmem;
> >      DriveInfo *hd[MAX_SATA_PORTS];
> >      MachineClass *mc = MACHINE_GET_CLASS(machine);
> > +    bool acpi_pcihp;
> >  
> >      /* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory
> >       * and 256 Mbytes for PCI Express Enhanced Configuration Access Mapping
> > @@ -236,6 +238,15 @@ static void pc_q35_init(MachineState *machine)
> >      object_property_set_link(OBJECT(machine), PC_MACHINE_ACPI_DEVICE_PROP,
> >                               OBJECT(lpc), &error_abort);
> >  
> > +    acpi_pcihp = object_property_get_bool(OBJECT(lpc),
> > +                                          "acpi-pci-hotplug-with-bridge-support",
> > +                                          NULL);
> > +
> > +    if (acpi_pcihp) {
> > +        object_register_sugar_prop(TYPE_PCIE_SLOT, "enable-native-hotplug",
> I'd s/enable-native-hotplug/native-hotplug/
> which is more concise and consistent with other similar properties.
> Perhaps Michael can fix it up on merge.
> 
> [...]

Can be a patch on top - I don't like tweaking code on merge.


> > +    DEFINE_PROP_BOOL("enable-native-hotplug", PCIESlot, native_hotplug, true),
> >      DEFINE_PROP_END_OF_LIST()
> >  };
> >  
> 
> Otherwise looks good to me, so with this or without above nitpicking:
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>