This is related to the discussion we had a few weeks ago:
https://www.mail-archive.com/qemu-devel@nongnu.org/msg705212.html
Igor, could you please comment if this will do. I have not tested it
since I do not have a setup handy. Sending this out for a quick
review.
thanks
ani
On Mon, Aug 10, 2020 at 4:59 PM Ani Sinha <a...@anisinha.ca> 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>
> ---
> 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
>
