Ani
On Aug 10, 2020, 20:30 +0530, Michael S. Tsirkin <m...@redhat.com>, wrote:
> On Mon, Aug 10, 2020 at 08:24:53PM +0530, Ani Sinha wrote:
> >
> >
> > On Mon, Aug 10, 2020 at 8:17 PM Michael S. Tsirkin <m...@redhat.com> wrote:
> >
> > On Mon, Aug 10, 2020 at 04:59:41PM +0530, Ani Sinha wrote:
> > > We introduce a new global flag for PIIX with which we can
> > > turn on or off PCI device hotplug. This flag can be used
> > > to prevent all PCI devices from getting hotplugged/unplugged
> > > on the PCI bus. The new options disables all hotpluh HW
> > > initialization code as well as the ACPI AMLs.
> > >
> > > Signed-off-by: Ani Sinha <a...@anisinha.ca>
> >
> > Well we have a flag like this for pci bridges, right?
> > So all that's left is an option to disable hotplug
> > for the pci root, right?
> > Wouldn't that be better than disabling it globally?
> >
> >
> > The idea is to have just one option to disable all hotplug globally. But if
> > you
> > want to have two flags one for the bridges and one for the pci root, we can
> > certainly look into it.
> >
>
> I can certainly see the attraction of a global flag.
>
> However, with the interface we have for bridges right now, how are we
> going to resolve the conflict if hotplug is disabled globally but
> enabled for a given bridge?
>
> A reasonable way would be to change the default value for bridges,
> have a user-specified value override it.
> This patch doesn't do it, though.
I think the global option should override the bridge option. So if the global
option disables hotplug, the bridge option should be a noop.
>
>
>
>
> >
> >
> > > ---
> > > hw/acpi/piix4.c | 8 ++++++--
> > > hw/i386/acpi-build.c | 20 ++++++++++++++------
> > > 2 files changed, 20 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> > > index 26bac4f..8b13e86 100644
> > > --- a/hw/acpi/piix4.c
> > > +++ b/hw/acpi/piix4.c
> > > @@ -78,6 +78,7 @@ typedef struct PIIX4PMState {
> > >
> > > AcpiPciHpState acpi_pci_hotplug;
> > > bool use_acpi_hotplug_bridge;
> > > + bool use_acpi_pci_hotplug;
> > >
> > > uint8_t disable_s3;
> > > uint8_t disable_s4;
> > > @@ -595,8 +596,9 @@ static void piix4_acpi_system_hot_add_init
> > (MemoryRegion *parent,
> > > "acpi-gpe0", GPE_LEN);
> > > memory_region_add_subregion(parent, GPE_BASE, &s->io_gpe);
> > >
> > > - acpi_pcihp_init(OBJECT(s), &s->acpi_pci_hotplug, bus, parent,
> > > - s->use_acpi_hotplug_bridge);
> > > + if (s->use_acpi_pci_hotplug)
> > > + acpi_pcihp_init(OBJECT(s), &s->acpi_pci_hotplug, bus, parent,
> > > + s->use_acpi_hotplug_bridge);
> > >
> > > s->cpu_hotplug_legacy = true;
> > > object_property_add_bool(OBJECT(s), "cpu-hotplug-legacy",
> > > @@ -635,6 +637,8 @@ static Property piix4_pm_properties[] = {
> > > DEFINE_PROP_UINT8(ACPI_PM_PROP_S4_VAL, PIIX4PMState, s4_val, 2),
> > > DEFINE_PROP_BOOL("acpi-pci-hotplug-with-bridge-support",
> > PIIX4PMState,
> > > use_acpi_hotplug_bridge, true),
> > > + DEFINE_PROP_BOOL("acpi-pci-hotplug", PIIX4PMState,
> > > + use_acpi_pci_hotplug, true),
> > > DEFINE_PROP_BOOL("memory-hotplug-support", PIIX4PMState,
> > > acpi_memory_hotplug.is_enabled, true),
> > > DEFINE_PROP_END_OF_LIST(),
> > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > > index b7bcbbb..343b9b6 100644
> > > --- a/hw/i386/acpi-build.c
> > > +++ b/hw/i386/acpi-build.c
> > > @@ -95,6 +95,7 @@ typedef struct AcpiPmInfo {
> > > bool s3_disabled;
> > > bool s4_disabled;
> > > bool pcihp_bridge_en;
> > > + bool pcihp_en;
> > > uint8_t s4_val;
> > > AcpiFadtData fadt;
> > > uint16_t cpu_hp_io_base;
> > > @@ -245,6 +246,9 @@ static void acpi_get_pm_info(MachineState *machine,
> > AcpiPmInfo *pm)
> > > pm->pcihp_bridge_en =
> > > object_property_get_bool(obj,
> > "acpi-pci-hotplug-with-bridge-support",
> > > NULL);
> > > + pm->pcihp_en =
> > > + object_property_get_bool(obj, "acpi-pci-hotplug", NULL);
> > > +
> > > }
> > >
> > > static void acpi_get_misc_info(AcpiMiscInfo *info)
> > > @@ -337,14 +341,16 @@ static void build_append_pcihp_notify_entry(Aml
> > *method, int slot)
> > > }
> > >
> > > static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
> > > - bool pcihp_bridge_en)
> > > + bool pcihp_bridge_en, bool
> > pcihp_en)
> > > {
> > > Aml *dev, *notify_method = NULL, *method;
> > > - QObject *bsel;
> > > + QObject *bsel = NULL;
> > > PCIBus *sec;
> > > int i;
> > >
> > > - bsel = object_property_get_qobject(OBJECT(bus),
> > ACPI_PCIHP_PROP_BSEL, NULL);
> > > + if (pcihp_en)
> > > + bsel = object_property_get_qobject(OBJECT(bus),
> > > + ACPI_PCIHP_PROP_BSEL, NULL);
> > > if (bsel) {
> > > uint64_t bsel_val = qnum_get_uint(qobject_to(QNum, bsel));
> > >
> > > @@ -439,7 +445,8 @@ static void build_append_pci_bus_devices(Aml
> > *parent_scope, PCIBus *bus,
> > > */
> > > PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
> > >
> > > - build_append_pci_bus_devices(dev, sec_bus, pcihp_bridge_en);
> > > + build_append_pci_bus_devices(dev, sec_bus, pcihp_bridge_en,
> > > + pcihp_en);
> > > }
> > > /* slot descriptor has been composed, add it into parent context
> > */
> > > aml_append(parent_scope, dev);
> > > @@ -468,7 +475,7 @@ static void build_append_pci_bus_devices(Aml
> > *parent_scope, PCIBus *bus,
> > > }
> > >
> > > /* Notify about child bus events in any case */
> > > - if (pcihp_bridge_en) {
> > > + if (pcihp_bridge_en && pcihp_en) {
> > > QLIST_FOREACH(sec, &bus->child, sibling) {
> > > int32_t devfn = sec->parent_dev->devfn;
> > >
> > > @@ -1818,7 +1825,8 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
> > > if (bus) {
> > > Aml *scope = aml_scope("PCI0");
> > > /* Scan all PCI buses. Generate tables to support hotplug. *
> > /
> > > - build_append_pci_bus_devices(scope, bus, pm->
> > pcihp_bridge_en);
> > > + build_append_pci_bus_devices(scope, bus, pm->
> > pcihp_bridge_en,
> > > + pm->pcihp_en);
> > >
> > > if (TPM_IS_TIS_ISA(tpm)) {
> > > if (misc->tpm_version == TPM_VERSION_2_0) {
> > > --
> > > 2.7.4
> >
> >
>
