qemu/i386-acpi-restore-device-paths-for-pre-5.patch

From: Vitaly Cheptsov <cheptsov@ispras.ru>
Date: Mon, 1 Mar 2021 22:59:18 +0300
Subject: i386/acpi: restore device paths for pre-5.1 vms

Git-commit: 0a343a5add75f9f90c65e932863d57ddbcb28f5c

After fixing the _UID value for the primary PCI root bridge in
af1b80ae it was discovered that this change updates Windows
configuration in an incompatible way causing network configuration
failure unless DHCP is used. More details provided on the list:

https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg08484.html

This change reverts the _UID update from 1 to 0 for q35 and i440fx
VMs before version 5.2 to maintain the original behaviour when
upgrading.

Cc: qemu-stable@nongnu.org
Cc: qemu-devel@nongnu.org
Reported-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Vitaly Cheptsov <cheptsov@ispras.ru>
Message-Id: <20210301195919.9333-1-cheptsov@ispras.ru>
Tested-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Fixes: af1b80ae56c9 ("i386/acpi: fix inconsistent QEMU/OVMF device paths")
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 hw/i386/acpi-build.c | 4 ++--
 hw/i386/pc_piix.c    | 2 ++
 hw/i386/pc_q35.c     | 2 ++
 include/hw/i386/pc.h | 1 +
 4 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 1f5c2112452a74bc19cb3a129fa9..b5616582a5d8395ab38080567356 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1513,7 +1513,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
         dev = aml_device("PCI0");
         aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
         aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
-        aml_append(dev, aml_name_decl("_UID", aml_int(0)));
+        aml_append(dev, aml_name_decl("_UID", aml_int(pcmc->pci_root_uid)));
         aml_append(sb_scope, dev);
         aml_append(dsdt, sb_scope);
 
@@ -1530,7 +1530,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
         aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A08")));
         aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
         aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
-        aml_append(dev, aml_name_decl("_UID", aml_int(0)));
+        aml_append(dev, aml_name_decl("_UID", aml_int(pcmc->pci_root_uid)));
         aml_append(dev, build_q35_osc_method());
         aml_append(sb_scope, dev);
 
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 13d1628f13bfc537cbefaec47e27..2524c962161115d026cc810b8dc8 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -417,6 +417,7 @@ static void pc_i440fx_machine_options(MachineClass *m)
 {
     PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
     pcmc->default_nic_model = "e1000";
+    pcmc->pci_root_uid = 0;
 
     m->family = "pc_piix";
     m->desc = "Standard PC (i440FX + PIIX, 1996)";
@@ -448,6 +449,7 @@ static void pc_i440fx_5_1_machine_options(MachineClass *m)
     compat_props_add(m->compat_props, hw_compat_5_1, hw_compat_5_1_len);
     compat_props_add(m->compat_props, pc_compat_5_1, pc_compat_5_1_len);
     pcmc->kvmclock_create_always = false;
+    pcmc->pci_root_uid = 1;
 }
 
 DEFINE_I440FX_MACHINE(v5_1, "pc-i440fx-5.1", NULL,
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index a3f4959c43575ad9809a0ac8b7a5..c58dad5ae37f7190f308c512c339 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -329,6 +329,7 @@ static void pc_q35_machine_options(MachineClass *m)
 {
     PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
     pcmc->default_nic_model = "e1000e";
+    pcmc->pci_root_uid = 0;
 
     m->family = "pc_q35";
     m->desc = "Standard PC (Q35 + ICH9, 2009)";
@@ -364,6 +365,7 @@ static void pc_q35_5_1_machine_options(MachineClass *m)
     compat_props_add(m->compat_props, hw_compat_5_1, hw_compat_5_1_len);
     compat_props_add(m->compat_props, pc_compat_5_1, pc_compat_5_1_len);
     pcmc->kvmclock_create_always = false;
+    pcmc->pci_root_uid = 1;
 }
 
 DEFINE_Q35_MACHINE(v5_1, "pc-q35-5.1", NULL,
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 911e4600970c36de9371a46601c6..7f8e1a791f88ead6cd5cb2a91e8b 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -99,6 +99,7 @@ struct PCMachineClass {
     int legacy_acpi_table_size;
     unsigned acpi_data_size;
     bool do_not_add_smb_acpi;
+    int pci_root_uid;
 
     /* SMBIOS compat: */
     bool smbios_defaults;