On Aug 10, 2020, 20:30 +0530, Michael S. Tsirkin <mst@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 <mst@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 <ani@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