From 706b5b627719e95a33606c463bc83c841c7b5b0e Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Fri, 16 Sep 2016 09:30:23 +0200 Subject: [PATCH] qemu: map "virtio" video model to "virt" machtype correctly (arm/aarch64) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. >From , libvirt supports 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 .) Override the default mapping of "virtio", from "virtio-vga" to "virtio-gpu-pci", if qemuDomainMachineIsVirt() evaluates to true. Cc: Andrea Bolognani Cc: Drew Jones Cc: Marc-André Lureau Cc: Martin Kletzander Suggested-by: Marc-André Lureau Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1372901 Signed-off-by: Laszlo Ersek Acked-by: Martin Kletzander --- src/qemu/qemu_command.c | 4 ++ ...xml2argv-aarch64-video-virtio-gpu-pci.args | 26 +++++++++++ ...uxml2argv-aarch64-video-virtio-gpu-pci.xml | 36 +++++++++++++++ tests/qemuxml2argvtest.c | 5 +++ ...ml2xmlout-aarch64-video-virtio-gpu-pci.xml | 45 +++++++++++++++++++ tests/qemuxml2xmltest.c | 5 +++ 6 files changed, 121 insertions(+) create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.args create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.xml create mode 100644 tests/qemuxml2xmloutdata/qemuxml2xmlout-aarch64-video-virtio-gpu-pci.xml diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 3a61863b9a..038c38f221 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/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.args b/tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.args new file mode 100644 index 0000000000..76ee977a3c --- /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 0000000000..4b52a731b0 --- /dev/null +++ b/tests/qemuxml2argvdata/qemuxml2argv-aarch64-video-virtio-gpu-pci.xml @@ -0,0 +1,36 @@ + + aarch64-vgpu + f3197c89-6457-44fe-b26d-897090ba6541 + 1048576 + 1048576 + 1 + + hvm + + + + + + cortex-a57 + + + /opt/qemu-installed/bin/qemu-system-aarch64 + + +
+ + +
+ + + + + +
+ +