Yes, xml editor is great. Here is my cmd for generating xml for
IGD.virt-install -n test --memory 3092 --vcpu
cpuset="2,3",threads=2,cores=1,sockets=1 --cpu host --hostdev pci_0000_00_02_0
--import --disk path=/home/ctos/win7.qcow2,format=qcow2 --network none
--graphics none --noautoconsole --print-xml --autostart | xmlstarlet
ed--omit-decl --append
domain/devices/hostdev/source/address[@domain=0][@bus=0][@slot=2]/.. -t elem -n
"address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'"
On Wednesday, September 27, 2017 10:31 AM, Daimon Wang
<daimon_sw...@yahoo.com> wrote:
Thanks Laszlo. Yes, the xml editor looks good to me. I'll try to insert the
address property for hostdev device.While the virt-xml can't do that, because
it use the same cmd options as virt-install.
On Tuesday, September 26, 2017 6:45 PM, Laszlo Ersek <ler...@redhat.com>
wrote:
On 09/26/17 11:55, Daimon Wang wrote:
> Hi, I'm planning to write a program that control an VM with IGD
> passthrough. Now the environment is ready: kernel param && driver
> blacklist ok and the VM start correctly with virt-install plus virsh
> edit the xml. So it's time to convert that process to a program.
> What stop me is the "virsh edit" part, which modify the "address"
> property of the hostdev to "slot=0x02" (required for IGD). I'm
> wondering if there's already some tool that deal with such an VM
> creation. The virt-manager can't modify the "address" property and
> virsh-install even doesn't create the it. I think libvirt can achieve
> that, but that would require a lot more code (to deal with other
> normal properties, e.g. network/usb/sound).
I can recommend two tools for scripting domain XML editing:
(1) The same package that gives you "virt-install" should give you
"virt-xml" too.
I don't have much personal experience with "virt-xml", but it is part of
the standard tools, so you might prefer it to option (2) below.
(2) I frequently use the following triplet (in scripts, in fact):
- virsh dumpxml # dump the current domain XML to a file
- xmlstarlet # modify the XML file
- virsh define # redefine the domain from the modified XML
xmlstarlet is a "command line XML/XSLT toolkit". With the "ed"
subcommand, you can update elements and attributes in the XML file,
using XPath expressions. You do need to learn a bit of XML and XPath,
but it's not hard.
For example, here's a raw script I frequently use to conveniently switch
a domain between OVMF builds:
------
#!/bin/bash
set -e -u -C
# This script flips the domain between the ad-hoc OVMF build and the
# system-wide OVMF package.
DOMAIN="$1"
FWBIN="$2"
TMPF=$(mktemp)
trap 'rm -f -- "$TMPF"' EXIT
# This is how "virsh edit" extracts the current domain info.
virsh dumpxml --inactive --security-info -- "$DOMAIN" >> "$TMPF"
# Flip the firmware binary.
case "$FWBIN" in
(installed)
NEW_FW=/usr/share/OVMF/OVMF_CODE.fd
;;
(installed-smm)
NEW_FW=/usr/share/OVMF/OVMF_CODE.secboot.fd
;;
(ad-hoc)
NEW_FW=/home/virt-images/OVMF_CODE.fd
;;
(ad-hoc-smm)
NEW_FW=/home/virt-images/OVMF_CODE.3264.fd
;;
(ad-hoc-4m)
NEW_FW=/home/virt-images/OVMF_CODE.4m.fd
;;
(ad-hoc-4m-smm)
NEW_FW=/home/virt-images/OVMF_CODE.4m.3264.fd
;;
(*)
echo "unknown firmware option" >&2
exit 1
esac
xmlstarlet ed --omit-decl --inplace \
--update /domain/os/loader --value "$NEW_FW" "$TMPF"
# This is how "virsh edit" verifies and makes the changes permanent.
# virt-xml validate doesn't work alas
# virt-xml-validate -- "$TMPF" domain
virsh define -- "$TMPF"
------
The above is convenient for modifying existing domains. If you start
from zero (i.e., create a new domain every time), you can pass
"--print-xml" to virt-install, and then insert (not update) the right
address element with xmlstarlet into the XML generated by virt-install.
Another option is to just take the final, complete XML (one that already
works for a guest), and save it as a template within your program.
Remove the uuid and mac address elements (libvirt will auto-generate
them), and customize the rest (as necessary) with xmlstarlet when the
program is invoked. Then run "virsh define" to create the domain.
HTH,
Laszlo
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