Re: [libvirt] [PATCHv8 1/7] bhyve: Support /domain/bootloader configuration for non-FreeBSD guests.
On Tue, Nov 11, 2014 at 10:40 AM, Michal Privoznik <mprivozn(a)redhat.com> wrote:
On 11.11.2014 16:17, Conrad Meyer wrote:
>
> On Tue, Nov 11, 2014 at 9:52 AM, Michal Privoznik <mprivozn(a)redhat.com>
> wrote:
>> One of the things I'm worried about is, if the boot args are not
>> specified
>> we properly add memory configured in domain XML.
>>
>> However, IIUC the memory amount can be overridden with boot args. Is that
>> expected?
>
>
> Yes. If you use bootloader_args, you get exactly what you ask for and no
> more.
Well, if one is modifying XML to change booloader_args already he can change
the memory amount there too. What I'm trying to say is, we should add '-m
def->mem.max_balloon' unconditionally. Or do you intend to give users so
much freedom? I worried it can bite us later when libvirt fails to see the
real amount of memory that domain has.
I think also bhyve(8) itself will be unhappy. The man page specifies:
"""
-m size[K|k|M|m|G|g|T|t]
Guest physical memory size in bytes. This must be the same
size that was given to bhyveload(8).
"""
However, I think the messaging around bootloader_args for bhyve /
bhyveload is and should remain: "if you need this, you're on your own
and need to specify *everything* manually." We expect most users to
not need <bootloader> for bhyve at all, especially in the medium-term
future, and even fewer users to need <bootloader_args>.
IMO, as a user it is more surprising to get additional arguments
prepended to the arguments I have specified than to have them passed
through unmodified. And we would have to prepend or otherwise shove
the -m flag in the middle somewhere. I think it is probably too much
magic.
>
>>> +static virCommandPtr
>>> +virBhyveProcessBuildGrubbhyveCmd(virDomainDefPtr def,
>>> + virConnectPtr conn,
>>> + const char *devmap_file,
>>> + char **devicesmap_out)
>>> +{
>>> + virDomainDiskDefPtr disk, cd;
>>> + virBuffer devicemap;
>>> + virCommandPtr cmd;
>>> + size_t i;
>>> +
>>> + if (def->os.bootloaderArgs != NULL)
>>> + return virBhyveProcessBuildCustomLoaderCmd(def);
>>> +
>>> + devicemap = (virBuffer)VIR_BUFFER_INITIALIZER;
>>> +
>>> + /* Search disk list for CD or HDD device. */
>>> + cd = disk = NULL;
>>> + for (i = 0; i < def->ndisks; i++) {
>>> + if (!virBhyveUsableDisk(conn, def->disks[i]))
>>> + continue;
>>> +
>>> + if (cd == NULL &&
>>> + def->disks[i]->device == VIR_DOMAIN_DISK_DEVICE_CDROM) {
>>> + cd = def->disks[i];
>>> + VIR_INFO("Picking %s as boot CD",
>>> virDomainDiskGetSource(cd));
>>> + }
>>> +
>>> + if (disk == NULL &&
>>> + def->disks[i]->device == VIR_DOMAIN_DISK_DEVICE_DISK) {
>>> + disk = def->disks[i];
>>> + VIR_INFO("Picking %s as HDD",
>>> virDomainDiskGetSource(disk));
>>> + }
>>
>>
>>
>> Can we utilize <boot order='X'/> attribute here?
>
>
> This has come up before and the answer is yes, but I'd prefer to do so
> in a later patch series; this one is already growing unwieldy.
Agreed. This can be addressed later, when needed.
Michal
Thanks,
Conrad