On Sun, Jan 13, 2019 at 06:12:06PM -0500, Cole Robinson wrote:
Add new <disk> model values for virtio transitional devices. When combined with bus='virtio':
* "virtio-transitional" maps to qemu "virtio-blk-pci-transitional" * "virtio-non-transitional" maps to qemu "virtio-blk-pci-non-transitional"
Signed-off-by: Cole Robinson <crobinso@redhat.com> --- src/qemu/qemu_command.c | 31 ++++++++++++++++++- src/qemu/qemu_domain_address.c | 2 ++ ...virtio-non-transitional.x86_64-latest.args | 7 +++-- .../virtio-transitional.x86_64-latest.args | 4 +-- .../virtio-non-transitional.xml | 10 ++++-- 5 files changed, 45 insertions(+), 9 deletions(-)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 822d5f8669..ca6abea227 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -443,6 +443,33 @@ qemuBuildVirtioDevStr(virBufferPtr buf, return 0; }
+static int +qemuBuildVirtioTransitional(virBufferPtr buf, + const char *baseName, + virDomainDeviceAddressType type, + bool transitional, + bool nontransitional) +{ + if (qemuBuildVirtioDevStr(buf, baseName, type) < 0) + return -1; + + if (type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI && + (transitional || nontransitional)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("virtio transitional models are not supported " + "for address type=%s"), + virDomainDeviceAddressTypeToString(type)); + return -1; + } + + if (transitional) { + virBufferAddLit(buf, "-transitional"); + } else if (nontransitional) { + virBufferAddLit(buf, "-non-transitional"); + } + return 0;
So this only works on QEMU >= 4.0.0 - earlier versions will fail to start. We can, however, make it work correctly with old QEMU. A transitional device is 100% identical to the existing device types, so we can simply not add the "-transitional" suffix for old QEMU. The only difference is the way libvirt does PCI bus placement of the transitional device - we'd never use PCIe. A non-transitional device is identical to the existing device types, but with disable-legacy=true set. QEMU guarantees this compatibility of the different devices, but only for machine types < pc-i440fx-4.0.0 / pc-q35-4.0.0. So we should none the less make sure we use the modern device names for any QEMU which genuinely supports them. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|