Re: [libvirt] [PATCH 1/3] conf: Add rom.enabled attribute for PCI devices
On Mon, 2018-04-23 at 08:53 +0200, Peter Krempa wrote:
> + The optional <code>enabled</code> attribute
can be set to
> + <code>no</code> to disable PCI ROM loading completely for the
device.
> + <span class="since">Since 4.3.0 (QEMU and KVM
only)</span>.
Maybe you should mention that any other configration may not be
supported in that case.
Good idea.
> @@ -6798,6 +6813,14 @@
virDomainDeviceInfoParseXML(virDomainXMLOptionPtr xmlopt ATTRIBUTE_UNUSED,
> goto cleanup;
> }
> info->romfile = virXMLPropString(rom, "file");
> +
> + if (info->romenabled == VIR_TRISTATE_BOOL_NO &&
> + (info->rombar != VIR_TRISTATE_SWITCH_ABSENT || info->romfile)) {
I'd explicitly allow empty string in info->romfile, but that would mean
that this needs to be moved to the qemu post-parse callback, since that
is a qemu quirk.
Justification is that, mgmt tools will be able to use enabled='no'
together with the empty file string without having to do any probing
whether that is a valid configuration.
But enabled='no' would be rejected by earlier libvirt releases,
which makes the point about avoiding feature detection moot, no?
I would expect management applications that already use (invalid,
according to the schema, but working fine by all other counts)
file='' to keep using that until they bump their required libvirt
version to 4.3.0, and management applications that didn't already
use the existing kludge to just go straight for enabled='no'.
--
Andrea Bolognani / Red Hat / Virtualization