Re: Hot unplug disabling on pci-pci bridge

[Ani Sinha]

On Mar 24, 2020, at 4:47 PM, Igor Mammedov <address@hidden> wrote:

you probably have APCI hotplug for bridges enabled (which applies to
all  cold-plugged bridges).
You can disable it by setting following property
-global PIIX4_PM.acpi-pci-hotplug-with-bridge-support=off
then it should fall back to SHPC which are are tying to disable

Ok I patched to change the default :

---
hw/acpi/piix4.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index d706360..db888cb 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -675,7 +675,7 @@ static Property piix4_pm_properties[] = {
    DEFINE_PROP_UINT8(ACPI_PM_PROP_S4_DISABLED, PIIX4PMState, disable_s4, 1),
    DEFINE_PROP_UINT8(ACPI_PM_PROP_S4_VAL, PIIX4PMState, s4_val, 2),
    DEFINE_PROP_BOOL("acpi-pci-hotplug-with-bridge-support", PIIX4PMState,
-                     use_acpi_pci_hotplug, true),
+                     use_acpi_pci_hotplug, false),
    DEFINE_PROP_BOOL("memory-hotplug-support", PIIX4PMState,
                     acpi_memory_hotplug.is_enabled, true),
    DEFINE_PROP_END_OF_LIST(),
-- 
1.9.4

This seems to work but now Windows is giving an option to eject pci bridges. Clicking it does not do anything. I wonder if we can disable that as well. AFAIK hot unplugging bridges would not take effect until ACPI tables are updated and the OS kernel re-reads the updated tables. See https://bugzilla.redhat.com/show_bug.cgi?id=1339875

Ani