From c60d168605dffeb1ad17398328efd9456435def8 Mon Sep 17 00:00:00 2001
From: Andrea Bolognani <abologna@redhat.com>
Date: Mon, 22 Sep 2025 15:09:29 +0200
Subject: [PATCH] qemu: Don't add PCI, USB or memballoon to microvm
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The microvm machine type doesn't support PCI, so adding PCI
controllers to it doesn't make sense, nor does adding a
USB controller or a memballon since both are PCI devices.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
---
 src/qemu/qemu_postparse.c                     |  3 +-
 .../microvm-pci.x86_64-latest.args            |  2 --
 .../microvm-pci.x86_64-latest.xml             |  6 ----
 ...oller-automatic-microvm.x86_64-latest.args | 31 +++++++++++++++++++
 ...roller-automatic-microvm.x86_64-latest.err |  1 -
 ...roller-automatic-microvm.x86_64-latest.xml | 23 ++++++++++++++
 tests/qemuxmlconftest.c                       |  2 +-
 7 files changed, 57 insertions(+), 11 deletions(-)
 create mode 100644 tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.args
 delete mode 100644 tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.err
 create mode 100644 tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.xml

diff --git a/src/qemu/qemu_postparse.c b/src/qemu/qemu_postparse.c
index ab39dfe138..d5708fbff9 100644
--- a/src/qemu/qemu_postparse.c
+++ b/src/qemu/qemu_postparse.c
@@ -1252,7 +1252,8 @@ qemuDomainDefAddDefaultDevices(virQEMUDriver *driver,
     switch (def->os.arch) {
     case VIR_ARCH_I686:
     case VIR_ARCH_X86_64:
-        if (STREQ(def->os.machine, "isapc")) {
+        if (STREQ(def->os.machine, "isapc") ||
+            STREQ(def->os.machine, "microvm")) {
             break;
         }
 
diff --git a/tests/qemuxmlconfdata/microvm-pci.x86_64-latest.args b/tests/qemuxmlconfdata/microvm-pci.x86_64-latest.args
index 33bbaacd7c..06598ddcbc 100644
--- a/tests/qemuxmlconfdata/microvm-pci.x86_64-latest.args
+++ b/tests/qemuxmlconfdata/microvm-pci.x86_64-latest.args
@@ -26,8 +26,6 @@ XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-test/.config \
 -rtc base=utc \
 -no-shutdown \
 -boot strict=on \
--device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1"}' \
 -audiodev '{"id":"audio1","driver":"none"}' \
--device '{"driver":"virtio-balloon-pci","id":"balloon0","bus":"pci.0","addr":"0x2"}' \
 -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
 -msg timestamp=on
diff --git a/tests/qemuxmlconfdata/microvm-pci.x86_64-latest.xml b/tests/qemuxmlconfdata/microvm-pci.x86_64-latest.xml
index 1cac541367..06b5a8b789 100644
--- a/tests/qemuxmlconfdata/microvm-pci.x86_64-latest.xml
+++ b/tests/qemuxmlconfdata/microvm-pci.x86_64-latest.xml
@@ -18,12 +18,6 @@
   <devices>
     <emulator>/usr/bin/qemu-system-x86_64</emulator>
     <controller type='pci' index='0' model='pci-root'/>
-    <controller type='usb' index='0' model='piix3-uhci'>
-      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/>
-    </controller>
     <audio id='1' type='none'/>
-    <memballoon model='virtio'>
-      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
-    </memballoon>
   </devices>
 </domain>
diff --git a/tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.args b/tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.args
new file mode 100644
index 0000000000..4aaf685a38
--- /dev/null
+++ b/tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.args
@@ -0,0 +1,31 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1 \
+USER=test \
+LOGNAME=test \
+XDG_DATA_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.local/share \
+XDG_CACHE_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.cache \
+XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.config \
+/usr/bin/qemu-system-x86_64 \
+-name guest=QEMUGuest1,debug-threads=on \
+-S \
+-object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain--1-QEMUGuest1/master-key.aes"}' \
+-machine microvm,usb=off,dump-guest-core=off,memory-backend=microvm.ram,acpi=off \
+-accel tcg \
+-cpu qemu64 \
+-m size=219136k \
+-object '{"qom-type":"memory-backend-ram","id":"microvm.ram","size":224395264}' \
+-overcommit mem-lock=off \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-display none \
+-no-user-config \
+-nodefaults \
+-chardev socket,id=charmonitor,fd=1729,server=on,wait=off \
+-mon chardev=charmonitor,id=monitor,mode=control \
+-rtc base=utc \
+-no-shutdown \
+-boot strict=on \
+-audiodev '{"id":"audio1","driver":"none"}' \
+-sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny \
+-msg timestamp=on
diff --git a/tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.err b/tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.err
deleted file mode 100644
index a0ca4fba5d..0000000000
--- a/tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.err
+++ /dev/null
@@ -1 +0,0 @@
-XML error: No PCI buses available
diff --git a/tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.xml b/tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.xml
new file mode 100644
index 0000000000..09f26bb422
--- /dev/null
+++ b/tests/qemuxmlconfdata/usb-controller-automatic-microvm.x86_64-latest.xml
@@ -0,0 +1,23 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='microvm'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='custom' match='exact' check='none'>
+    <model fallback='forbid'>qemu64</model>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu-system-x86_64</emulator>
+    <audio id='1' type='none'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxmlconftest.c b/tests/qemuxmlconftest.c
index 87da7f8e05..c135faf33c 100644
--- a/tests/qemuxmlconftest.c
+++ b/tests/qemuxmlconftest.c
@@ -2078,7 +2078,7 @@ mymain(void)
     DO_TEST_CAPS_LATEST_PARSE_ERROR("chardev-reconnect-generated-path");
 
     DO_TEST_CAPS_LATEST("usb-controller-automatic-isapc");
-    DO_TEST_CAPS_LATEST_PARSE_ERROR("usb-controller-automatic-microvm");
+    DO_TEST_CAPS_LATEST("usb-controller-automatic-microvm");
     DO_TEST_CAPS_LATEST("usb-controller-automatic-i440fx");
     DO_TEST_CAPS_LATEST("usb-controller-automatic-q35");
     DO_TEST_CAPS_ARCH_LATEST("usb-controller-automatic-pseries", "ppc64");
-- 
2.47.3