Most of QEMU's PCI display device models, such as:
libvirt video/model/@type QEMU -device
------------------------- ------------
cirrus cirrus-vga
vga VGA
qxl qxl-vga
virtio virtio-vga
come with a linear framebuffer (sometimes called "VGA compatibility
framebuffer"). This linear framebuffer lives in one of the PCI device's
MMIO BARs, and allows guest code (primarily: firmware drivers, and
non-accelerated OS drivers) to display graphics with direct memory access.
Due to architectural reasons on aarch64/KVM hosts, this kind of
framebuffer doesn't / can't work in
qemu-system-(arm|aarch64) -M virt
machines. Cache coherency issues guarantee a corrupted / unusable display.
The problem has been researched by several people, including kvm-arm
maintainers, and it's been decided that the best way (practically the only
way) to have boot time graphics for such guests is to consolidate on
QEMU's "virtio-gpu-pci" device.
supports
<devices>
<video>
<model type='virtio'/>
</video>
</devices>
but libvirt unconditionally maps @type='virtio' to QEMU's
"virtio-vga"
device model. (See the qemuBuildDeviceVideoStr() function and the
"qemuDeviceVideo" enum impl.)
According to the above, this is not right for the "virt" machine type; the
qemu-system-(arm|aarch64) binaries don't even recognize the "virtio-vga"
device model (justifiedly). Whereas "virtio-gpu-pci", which is a pure
virtio device without a compatibility framebuffer, is available, and works
fine.
(The ArmVirtQemu ("AAVMF") platform of edk2 -- that is, the UEFI firmware
for "virt" -- supports "virtio-gpu-pci", as of upstream commit
3ef3209d3028. See
<
https://tianocore.acgmultimedia.com/show_bug.cgi?id=66>.)
Override the default mapping of "virtio", from "virtio-vga" to
"virtio-gpu-pci", if qemuDomainMachineIsVirt() evaluates to true.
Cc: Andrea Bolognani <abologna(a)redhat.com>
Cc: Drew Jones <drjones(a)redhat.com>
Cc: Marc-André Lureau <marcandre.lureau(a)redhat.com>
Suggested-by: Marc-André Lureau <marcandre.lureau(a)redhat.com>
Resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=1372901
Signed-off-by: Laszlo Ersek <lersek(a)redhat.com>
---
src/qemu/qemu_command.c | 4 ++
tests/qemuxml2argvtest.c | 5 +++
tests/qemuxml2xmltest.c | 5 +++
tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.args | 26
+++++++++++
tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.xml | 36
++++++++++++++++
tests/qemuxml2xmloutdata/qemuxml2xmlout-aarch64-video-virtio-gpu-pci.xml | 45
++++++++++++++++++++
6 files changed, 121 insertions(+)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 3a61863b9abb..038c38f2217c 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4325,6 +4325,10 @@ qemuBuildDeviceVideoStr(const virDomainDef *def,
virDomainVideoTypeToString(video->type));
goto error;
}
+ if (video->type == VIR_DOMAIN_VIDEO_TYPE_VIRTIO &&
+ qemuDomainMachineIsVirt(def)) {
+ model = "virtio-gpu-pci";
+ }
} else {
if (video->type != VIR_DOMAIN_VIDEO_TYPE_QXL) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index dbb0e4d56142..e8540779a4b5 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1872,6 +1872,11 @@ mymain(void)
QEMU_CAPS_DEVICE_VIRTIO_RNG, QEMU_CAPS_OBJECT_RNG_RANDOM,
QEMU_CAPS_OBJECT_GPEX, QEMU_CAPS_DEVICE_PCI_BRIDGE,
QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE, QEMU_CAPS_VIRTIO_SCSI);
+ DO_TEST("aarch64-video-virtio-gpu-pci",
+ QEMU_CAPS_NODEFCONFIG, QEMU_CAPS_OBJECT_GPEX,
+ QEMU_CAPS_DEVICE_PCI_BRIDGE, QEMU_CAPS_DEVICE_IOH3420,
+ QEMU_CAPS_PCI_MULTIFUNCTION, QEMU_CAPS_DEVICE_VIDEO_PRIMARY,
+ QEMU_CAPS_DEVICE_VIRTIO_GPU, QEMU_CAPS_BOOTINDEX);
DO_TEST("aarch64-aavmf-virtio-mmio",
QEMU_CAPS_NODEFCONFIG, QEMU_CAPS_DTB,
QEMU_CAPS_DEVICE_VIRTIO_MMIO,
diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index 14c2b0ccf2ce..fb05c8571411 100644
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -831,6 +831,11 @@ mymain(void)
QEMU_CAPS_DEVICE_VIRTIO_RNG, QEMU_CAPS_OBJECT_RNG_RANDOM,
QEMU_CAPS_OBJECT_GPEX, QEMU_CAPS_DEVICE_PCI_BRIDGE,
QEMU_CAPS_DEVICE_DMI_TO_PCI_BRIDGE, QEMU_CAPS_VIRTIO_SCSI);
+ DO_TEST("aarch64-video-virtio-gpu-pci",
+ QEMU_CAPS_NODEFCONFIG, QEMU_CAPS_OBJECT_GPEX,
+ QEMU_CAPS_DEVICE_PCI_BRIDGE, QEMU_CAPS_DEVICE_IOH3420,
+ QEMU_CAPS_PCI_MULTIFUNCTION, QEMU_CAPS_DEVICE_VIDEO_PRIMARY,
+ QEMU_CAPS_DEVICE_VIRTIO_GPU, QEMU_CAPS_BOOTINDEX);
DO_TEST_FULL("aarch64-gic-none", WHEN_BOTH, GIC_NONE, NONE);
DO_TEST_FULL("aarch64-gic-none-v2", WHEN_BOTH, GIC_V2, NONE);
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.args
b/tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.args
new file mode 100644
index 000000000000..56dbdfb66fa2
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.args
@@ -0,0 +1,26 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/opt/qemu-installed/bin/qemu-system-aarch64 \
+-name aarch64-vgpu \
+-S \
+-M virt \
+-cpu cortex-a57 \
+-m 1024 \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid f3197c89-6457-44fe-b26d-897090ba6541 \
+-nographic \
+-nodefconfig \
+-nodefaults \
+-monitor unix:/tmp/lib/domain--1-aarch64-vgpu/monitor.sock,server,nowait \
+-device ioh3420,port=0x8,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,\
+addr=0x1 \
+-device ioh3420,port=0x9,chassis=2,id=pci.2,bus=pcie.0,multifunction=on,\
+addr=0x1.0x1 \
+-device virtio-net-pci,vlan=0,id=net0,mac=52:54:00:73:34:53,bus=pci.1,\
+addr=0x0,bootindex=1 \
+-net user,vlan=0,name=hostnet0 \
+-device virtio-gpu-pci,id=video0,bus=pci.2,addr=0x0
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.xml
b/tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.xml
new file mode 100644
index 000000000000..4b52a731b043
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.xml
@@ -0,0 +1,36 @@
+<domain type='qemu'>
+ <name>aarch64-vgpu</name>
+ <uuid>f3197c89-6457-44fe-b26d-897090ba6541</uuid>
+ <memory unit='KiB'>1048576</memory>
+ <currentMemory unit='KiB'>1048576</currentMemory>
+ <vcpu placement='static'>1</vcpu>
+ <os>
+ <type arch='aarch64' machine='virt'>hvm</type>
+ </os>
+ <features>
+ <acpi/>
+ </features>
+ <cpu mode='custom' match='exact'>
+ <model fallback='allow'>cortex-a57</model>
+ </cpu>
+ <devices>
+ <emulator>/opt/qemu-installed/bin/qemu-system-aarch64</emulator>
+ <controller type='pci' index='0' model='pcie-root'/>
+ <controller type='pci' index='1'
model='pcie-root-port'>
+ <address type='pci' domain='0x0000' bus='0x00'
slot='0x01' function='0x0' multifunction='on'/>
+ </controller>
+ <controller type='pci' index='2'
model='pcie-root-port'>
+ <address type='pci' domain='0x0000' bus='0x00'
slot='0x01' function='0x1' multifunction='on'/>
+ </controller>
+ <interface type='user'>
+ <mac address='52:54:00:73:34:53'/>
+ <model type='virtio'/>
+ <boot order='1'/>
+ <address type='pci' domain='0x0000' bus='0x01'
slot='0x00' function='0x0'/>
+ </interface>
+ <video>
+ <model type='virtio'/>
+ <address type='pci' domain='0x0000' bus='0x02'
slot='0x00' function='0x0'/>
+ </video>
+ </devices>
+</domain>
diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-aarch64-video-virtio-gpu-pci.xml
b/tests/qemuxml2xmloutdata/qemuxml2xmlout-aarch64-video-virtio-gpu-pci.xml
new file mode 100644
index 000000000000..26f6a51622ef
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-aarch64-video-virtio-gpu-pci.xml
@@ -0,0 +1,45 @@
+<domain type='qemu'>
+ <name>aarch64-vgpu</name>
+ <uuid>f3197c89-6457-44fe-b26d-897090ba6541</uuid>
+ <memory unit='KiB'>1048576</memory>
+ <currentMemory unit='KiB'>1048576</currentMemory>
+ <vcpu placement='static'>1</vcpu>
+ <os>
+ <type arch='aarch64' machine='virt'>hvm</type>
+ </os>
+ <features>
+ <acpi/>
+ <gic version='2'/>
+ </features>
+ <cpu mode='custom' match='exact'>
+ <model fallback='allow'>cortex-a57</model>
+ </cpu>
+ <clock offset='utc'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ <emulator>/opt/qemu-installed/bin/qemu-system-aarch64</emulator>
+ <controller type='pci' index='0' model='pcie-root'/>
+ <controller type='pci' index='1'
model='pcie-root-port'>
+ <model name='ioh3420'/>
+ <target chassis='1' port='0x8'/>
+ <address type='pci' domain='0x0000' bus='0x00'
slot='0x01' function='0x0' multifunction='on'/>
+ </controller>
+ <controller type='pci' index='2'
model='pcie-root-port'>
+ <model name='ioh3420'/>
+ <target chassis='2' port='0x9'/>
+ <address type='pci' domain='0x0000' bus='0x00'
slot='0x01' function='0x1' multifunction='on'/>
+ </controller>
+ <interface type='user'>
+ <mac address='52:54:00:73:34:53'/>
+ <model type='virtio'/>
+ <boot order='1'/>
+ <address type='pci' domain='0x0000' bus='0x01'
slot='0x00' function='0x0'/>
+ </interface>
+ <video>
+ <model type='virtio' heads='1' primary='yes'/>
+ <address type='pci' domain='0x0000' bus='0x02'
slot='0x00' function='0x0'/>
+ </video>
+ </devices>
+</domain>
--
2.9.2