From: Fabian Ebner <f.ebner@proxmox.com>
To: Thomas Lamprecht <t.lamprecht@proxmox.com>,
Proxmox VE development discussion <pve-devel@lists.proxmox.com>
Subject: Re: [pve-devel] [PATCH qemu-server] cfg2cmd: turn smm off when SeaBIOS and serial display are used
Date: Fri, 5 Nov 2021 15:47:30 +0100 [thread overview]
Message-ID: <d7dce99e-d7cc-5529-c93c-978923e1fdef@proxmox.com> (raw)
In-Reply-To: <67a3068b-50f7-f0a3-f947-e2723081fa65@proxmox.com>
Am 05.11.21 um 14:12 schrieb Thomas Lamprecht:
> On 05.11.21 14:06, Fabian Ebner wrote:
>> Since commit 277d33454f77ec1d1e0bc04e37621e4dd2424b67 in pve-qemu,
>> smm=off is no longer the default, but with SeaBIOS and serial display,
>> this can lead to a boot loop.
>>
>> Reported in the community forum [0] and reproduced with a Debian 10
>> VM.
>>
>> [0]: https://forum.proxmox.com/threads/pve-7-0-all-vms-with-cloud-init-seabios-fail-during-boot-process-bootloop-disk-not-found.97310/post-427129
>>
>> Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
>> ---
>> PVE/QemuServer.pm | 12 ++++++++++
>> test/cfg2cmd/seabios_serial.conf | 16 ++++++++++++++
>> test/cfg2cmd/seabios_serial.conf.cmd | 33 ++++++++++++++++++++++++++++
>> 3 files changed, 61 insertions(+)
>> create mode 100644 test/cfg2cmd/seabios_serial.conf
>> create mode 100644 test/cfg2cmd/seabios_serial.conf.cmd
>>
>> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
>> index 763c412..9b76512 100644
>> --- a/PVE/QemuServer.pm
>> +++ b/PVE/QemuServer.pm
>> @@ -3403,6 +3403,16 @@ my sub get_cpuunits {
>> my ($conf) = @_;
>> return $conf->{cpuunits} // (PVE::CGroup::cgroup_mode() == 2 ? 100 : 1024);
>> }
>> +
>> +# Since commit 277d33454f77ec1d1e0bc04e37621e4dd2424b67 in pve-qemu, smm is not off by default
>> +# anymore. But smm=off seems to be required when using SeaBIOS and serial display.
>> +my sub should_disable_smm {
>> + my ($conf, $vga) = @_;
>> +
>> + return (!defined($conf->{bios}) || $conf->{bios} eq 'seabios') &&
>> + $vga->{type} && $vga->{type} =~ m/^serial\d+$/;
>> +}
>> +
>> sub config_to_command {
>> my ($storecfg, $vmid, $conf, $defaults, $forcemachine, $forcecpu,
>> $pbs_backing) = @_;
>> @@ -4002,6 +4012,8 @@ sub config_to_command {
>> push @$machineFlags, 'accel=tcg';
>> }
>>
>> + push @$machineFlags, 'smm=off' if should_disable_smm($conf, $vga);
>
> doesn't that breaks live migration or do we know that it could never work with smm=on
> under seabios + display=serial, so that there can no running VM that could be live
> migrated?
>
Stefan tested migration in both direction when the pve-qemu patch was
dropped [0], but he did sound more confident about the smm=off -> smm=on
direction. And now the scenario Wolfgang mentioned would actually be
relevant, because we can get into a situation where smm=off -> smm=on ->
smm=off by migrating from older -> old -> new. I'll test around some
more and see if I can break it.
[0]: https://lists.proxmox.com/pipermail/pve-devel/2021-August/049778.html
next prev parent reply other threads:[~2021-11-05 14:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-05 13:06 Fabian Ebner
2021-11-05 13:12 ` Thomas Lamprecht
2021-11-05 14:47 ` Fabian Ebner [this message]
2021-11-08 11:36 ` Fabian Ebner
2021-11-11 9:32 ` [pve-devel] applied: " Thomas Lamprecht
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