pc,virtio,pci: bug fixes

Fixes all over the place. Specifically this fixes
 a bug which made windows guests lose device config
 (such as the configured fixed IP) after upgrading
 to the new QEMU.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

pc,virtio,pci: bug fixes

Fixes all over the place. Specifically this fixes
a bug which made windows guests lose device config
(such as the configured fixed IP) after upgrading
to the new QEMU.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Tue 02 Mar 2021 14:19:51 GMT
# gpg:                using RSA key 5D09FD0871C8F85B94CA8A0D281F0DB8D28D5469
# gpg:                issuer "mst@redhat.com"
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>" [full]
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>" [full]
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream:
  vhost: simplify vhost_dev_init() fail_busyloop label
  hw/pci: Have safer pcie_bus_realize() by checking error path
  virtio-net: handle zero mac for a vdpa peer
  i386/acpi: restore device paths for pre-5.1 vms

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/i386/acpi-build.c

@@ -1277,7 +1277,7 @@ 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);
 
@@ -1296,7 +1296,7 @@ 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);
         if (mcfg_valid) {

hw/i386/pc_piix.c

@@ -405,6 +405,7 @@ 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,

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)";
@@ -375,6 +376,7 @@ 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,

hw/net/virtio-net.c

@@ -126,6 +126,7 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
     VirtIONet *n = VIRTIO_NET(vdev);
     struct virtio_net_config netcfg;
     NetClientState *nc = qemu_get_queue(n->nic);
+    static const MACAddr zero = { .a = { 0, 0, 0, 0, 0, 0 } };
 
     int ret = 0;
     memset(&netcfg, 0 , sizeof(struct virtio_net_config));
@@ -151,6 +152,17 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
         ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
                                    n->config_size);
         if (ret != -1) {
+            /*
+             * Some NIC/kernel combinations present 0 as the mac address.  As
+             * that is not a legal address, try to proceed with the
+             * address from the QEMU command line in the hope that the
+             * address has been configured correctly elsewhere - just not
+             * reported by the device.
+             */
+            if (memcmp(&netcfg.mac, &zero, sizeof(zero)) == 0) {
+                info_report("Zero hardware mac address detected. Ignoring.");
+                memcpy(netcfg.mac, n->mac, ETH_ALEN);
+            }
             memcpy(config, &netcfg, n->config_size);
         }
     }

hw/pci/pci.c

@@ -132,8 +132,13 @@ static void pci_bus_realize(BusState *qbus, Error **errp)
 static void pcie_bus_realize(BusState *qbus, Error **errp)
 {
     PCIBus *bus = PCI_BUS(qbus);
+    Error *local_err = NULL;
 
-    pci_bus_realize(qbus, errp);
+    pci_bus_realize(qbus, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
 
     /*
      * A PCI-E bus can support extended config space if it's the root

hw/virtio/vhost.c

@@ -1388,18 +1388,16 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
         error_report("vhost backend memory slots limit is less"
                 " than current number of present memory slots");
         r = -1;
-        if (busyloop_timeout) {
+        goto fail_busyloop;
-            goto fail_busyloop;
-        } else {
-            goto fail;
-        }
     }
 
     return 0;
 
 fail_busyloop:
-    while (--i >= 0) {
+    if (busyloop_timeout) {
-        vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0);
+        while (--i >= 0) {
+            vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0);
+        }
     }
 fail:
     hdev->nvqs = n_initialized_vqs;

include/hw/i386/pc.h

@@ -105,6 +105,7 @@ 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;