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authorJulia Suvorova <jusual@redhat.com>2021-07-13 02:42:04 +0200
committerMichael S. Tsirkin <mst@redhat.com>2021-07-16 04:34:22 -0400
commit17858a169508609ca9063c544833e5a1adeb7b52 (patch)
treef0e51beb4d3da89fb162379549b0214f904c984d /hw
parent383d11f217feca0f9947f790f2deafc09fe69ec5 (diff)
hw/acpi/ich9: Set ACPI PCI hot-plug as default on Q35
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 Known issue: older linux guests need the following flag to allow hotplugged pci express devices to use io: -device pcie-root-port,io-reserve=4096. io is unusual for pci express so this seems minor. We'll fix this by a follow up patch. Signed-off-by: Julia Suvorova <jusual@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Message-Id: <20210713004205.775386-6-jusual@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'hw')
-rw-r--r--hw/acpi/ich9.c2
-rw-r--r--hw/i386/pc.c1
2 files changed, 2 insertions, 1 deletions
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 aa79c5e0e6..f4c7a78362 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -99,6 +99,7 @@ GlobalProperty pc_compat_6_0[] = {
{ "qemu64" "-" TYPE_X86_CPU, "model", "6" },
{ "qemu64" "-" TYPE_X86_CPU, "stepping", "3" },
{ TYPE_X86_CPU, "x-vendor-cpuid-only", "off" },
+ { "ICH9-LPC", "acpi-pci-hotplug-with-bridge-support", "off" },
};
const size_t pc_compat_6_0_len = G_N_ELEMENTS(pc_compat_6_0);