On Tue, Jul 13, 2021 at 02:42:04AM +0200, Julia Suvorova wrote: > Q35 has three different types of PCI devices hot-plug: PCIe Native, > SHPC Native and ACPI hot-plug. This patch changes the default choice > for cold-plugged bridges from PCIe Native to ACPI Hot-plug with > ability to use SHPC and PCIe Native for hot-plugged bridges. > > This is a list of the PCIe Native hot-plug issues that led to this > change: > * no racy behavior during boot (see 110c477c2ed) > * no delay during deleting - after the actual power off software > must wait at least 1 second before indicating about it. This case > is quite important for users, it even has its own bug: > https://bugzilla.redhat.com/show_bug.cgi?id=1594168 > * no timer-based behavior - in addition to the previous example, > the attention button has a 5-second waiting period, during which > the operation can be canceled with a second press. While this > looks fine for manual button control, automation will result in > the need to queue or drop events, and the software receiving > events in all sort of unspecified combinations of attention/power > indicator states, which is racy and uppredictable. > * fixes: > * https://bugzilla.redhat.com/show_bug.cgi?id=1752465 > * https://bugzilla.redhat.com/show_bug.cgi?id=1690256 > > To return to PCIe Native hot-plug: > -global ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off > > Signed-off-by: Julia Suvorova <jus...@redhat.com> > Reviewed-by: Igor Mammedov <imamm...@redhat.com>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> hw/acpi/ich9.c | 2 +-
> hw/i386/pc.c | 1 +
> 2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
> index 2f4eb453ac..778e27b659 100644
> --- a/hw/acpi/ich9.c
> +++ b/hw/acpi/ich9.c
> @@ -427,7 +427,7 @@ void ich9_pm_add_properties(Object *obj, ICH9LPCPMRegs
> *pm)
> pm->disable_s3 = 0;
> pm->disable_s4 = 0;
> pm->s4_val = 2;
> - pm->use_acpi_hotplug_bridge = false;
> + pm->use_acpi_hotplug_bridge = true;
>
> object_property_add_uint32_ptr(obj, ACPI_PM_PROP_PM_IO_BASE,
> &pm->pm_io_base, OBJ_PROP_FLAG_READ);
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 8e1220db72..7e03848792 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -98,6 +98,7 @@ GlobalProperty pc_compat_6_0[] = {
> { "qemu64" "-" TYPE_X86_CPU, "family", "6" },
> { "qemu64" "-" TYPE_X86_CPU, "model", "6" },
> { "qemu64" "-" TYPE_X86_CPU, "stepping", "3" },
> + { "ICH9-LPC", "acpi-pci-hotplug-with-bridge-support", "off" },
> };
> const size_t pc_compat_6_0_len = G_N_ELEMENTS(pc_compat_6_0);
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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