hw/acpi/ich9: Add compat prop to keep HPC bit set for 6.1 machine type

To solve issues [1-2] the Hot Plug Capable bit in PCIe Slots will be
turned on, while the switch to ACPI Hot-plug will be done in the
DSDT table.

Introducing 'x-keep-native-hpc' property disables the HPC bit only
in 6.1 and as a result keeps the forced 'reserve-io' on
pcie-root-ports in 6.1 too.

[1] https://gitlab.com/qemu-project/qemu/-/issues/641
[2] https://bugzilla.redhat.com/show_bug.cgi?id=2006409

Signed-off-by: Julia Suvorova <jusual@redhat.com>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20211112110857.3116853-3-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/acpi/ich9.c

@@ -419,6 +419,20 @@ static void ich9_pm_set_acpi_pci_hotplug(Object *obj, bool value, Error **errp)
     s->pm.use_acpi_hotplug_bridge = value;
 }
 
+static bool ich9_pm_get_keep_pci_slot_hpc(Object *obj, Error **errp)
+{
+    ICH9LPCState *s = ICH9_LPC_DEVICE(obj);
+
+    return s->pm.keep_pci_slot_hpc;
+}
+
+static void ich9_pm_set_keep_pci_slot_hpc(Object *obj, bool value, Error **errp)
+{
+    ICH9LPCState *s = ICH9_LPC_DEVICE(obj);
+
+    s->pm.keep_pci_slot_hpc = value;
+}
+
 void ich9_pm_add_properties(Object *obj, ICH9LPCPMRegs *pm)
 {
     static const uint32_t gpe0_len = ICH9_PMIO_GPE0_LEN;
@@ -428,6 +442,7 @@ void ich9_pm_add_properties(Object *obj, ICH9LPCPMRegs *pm)
     pm->disable_s4 = 0;
     pm->s4_val = 2;
     pm->use_acpi_hotplug_bridge = true;
+    pm->keep_pci_slot_hpc = true;
 
     object_property_add_uint32_ptr(obj, ACPI_PM_PROP_PM_IO_BASE,
                                    &pm->pm_io_base, OBJ_PROP_FLAG_READ);
@@ -454,6 +469,9 @@ void ich9_pm_add_properties(Object *obj, ICH9LPCPMRegs *pm)
     object_property_add_bool(obj, ACPI_PM_PROP_ACPI_PCIHP_BRIDGE,
                              ich9_pm_get_acpi_pci_hotplug,
                              ich9_pm_set_acpi_pci_hotplug);
+    object_property_add_bool(obj, "x-keep-pci-slot-hpc",
+                             ich9_pm_get_keep_pci_slot_hpc,
+                             ich9_pm_set_keep_pci_slot_hpc);
 }
 
 void ich9_pm_device_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,

hw/i386/pc.c

@@ -98,6 +98,7 @@ GlobalProperty pc_compat_6_1[] = {
     { TYPE_X86_CPU, "hv-version-id-build", "0x1bbc" },
     { TYPE_X86_CPU, "hv-version-id-major", "0x0006" },
     { TYPE_X86_CPU, "hv-version-id-minor", "0x0001" },
+    { "ICH9-LPC", "x-keep-pci-slot-hpc", "false" },
 };
 const size_t pc_compat_6_1_len = G_N_ELEMENTS(pc_compat_6_1);
 
@@ -107,6 +108,7 @@ GlobalProperty pc_compat_6_0[] = {
     { "qemu64" "-" TYPE_X86_CPU, "stepping", "3" },
     { TYPE_X86_CPU, "x-vendor-cpuid-only", "off" },
     { "ICH9-LPC", ACPI_PM_PROP_ACPI_PCIHP_BRIDGE, "off" },
+    { "ICH9-LPC", "x-keep-pci-slot-hpc", "true" },
 };
 const size_t pc_compat_6_0_len = G_N_ELEMENTS(pc_compat_6_0);
 

hw/i386/pc_q35.c

@@ -137,6 +137,7 @@ static void pc_q35_init(MachineState *machine)
     DriveInfo *hd[MAX_SATA_PORTS];
     MachineClass *mc = MACHINE_GET_CLASS(machine);
     bool acpi_pcihp;
+    bool keep_pci_slot_hpc;
 
     /* Check whether RAM fits below 4G (leaving 1/2 GByte for IO memory
      * and 256 Mbytes for PCI Express Enhanced Configuration Access Mapping
@@ -242,7 +243,11 @@ static void pc_q35_init(MachineState *machine)
                                           ACPI_PM_PROP_ACPI_PCIHP_BRIDGE,
                                           NULL);
 
-    if (acpi_pcihp) {
+    keep_pci_slot_hpc = object_property_get_bool(OBJECT(lpc),
+                                                 "x-keep-pci-slot-hpc",
+                                                 NULL);
+
+    if (!keep_pci_slot_hpc && acpi_pcihp) {
         object_register_sugar_prop(TYPE_PCIE_SLOT, "x-native-hotplug",
                                    "false", true);
     }

include/hw/acpi/ich9.h

@@ -56,6 +56,7 @@ typedef struct ICH9LPCPMRegs {
     AcpiCpuHotplug gpe_cpu;
     CPUHotplugState cpuhp_state;
 
+    bool keep_pci_slot_hpc;
     bool use_acpi_hotplug_bridge;
     AcpiPciHpState acpi_pci_hotplug;
     MemHotplugState acpi_memory_hotplug;