[pve-devel] [PATCH qemu-server] fix #4553: nvidia vgpu: reuse smbios uuid for '-uuid' parameter

[pve-devel] [PATCH qemu-server] fix #4553: nvidia vgpu: reuse smbios uuid for '-uuid' parameter

[Dominik Csapak]

instead of using the mdev uuid. The nvidia driver does not actually care
that it's the same as the mdev, and in qemu the uuid parameter
overwrites the smbios1 uuid internally, so we should have been reusing
that in the first place.

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
when i was writing the uuid appending in the first place, i was sure
that the nvidia driver needed the mdev uuid, but i was wrong

also i wrongly assumed the '-uuid' parameter does not do anything to the
guest, but it overwrites the smbios uuid. seems i misread the qemu source
code then.. (the man/help pages are not very helpful in that regard)

 PVE/QemuServer.pm | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 096e7f0d..b5836f7a 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -5851,9 +5851,14 @@ sub vm_start_nolock {
 	    for my $dev ($d->{pciid}->@*) {
 		my $info = PVE::QemuServer::PCI::prepare_pci_device($vmid, $dev->{id}, $id, $d->{mdev});
 
-		# nvidia grid needs the uuid of the mdev as qemu parameter
+		# nvidia grid needs the qemu parameter '-uuid' set
+		# use smbios uuid or mdev uuid as fallback for that
 		if ($d->{mdev} && !defined($uuid) && $info->{vendor} eq '10de') {
-		    $uuid = PVE::QemuServer::PCI::generate_mdev_uuid($vmid, $id);
+		    if (defined($conf->{smbios1})) {
+			my $smbios_conf = parse_smbios1($conf->{smbios1});
+			$uuid = $smbios_conf->{uuid} if defined($smbios_conf->{uuid});
+		    }
+		    $uuid = PVE::QemuServer::PCI::generate_mdev_uuid($vmid, $id) if !defined($uuid);
 		}
 	    }
 	}
-- 
2.30.2

[pve-devel] applied: [PATCH qemu-server] fix #4553: nvidia vgpu: reuse smbios uuid for '-uuid' parameter

[Wolfgang Bumiller]

applied, thanks

On Mon, Feb 27, 2023 at 04:34:27PM +0100, Dominik Csapak wrote:
> instead of using the mdev uuid. The nvidia driver does not actually care
> that it's the same as the mdev, and in qemu the uuid parameter
> overwrites the smbios1 uuid internally, so we should have been reusing
> that in the first place.
> 
> Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
> ---
> when i was writing the uuid appending in the first place, i was sure
> that the nvidia driver needed the mdev uuid, but i was wrong
> 
> also i wrongly assumed the '-uuid' parameter does not do anything to the
> guest, but it overwrites the smbios uuid. seems i misread the qemu source
> code then.. (the man/help pages are not very helpful in that regard)
> 
>  PVE/QemuServer.pm | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
> index 096e7f0d..b5836f7a 100644
> --- a/PVE/QemuServer.pm
> +++ b/PVE/QemuServer.pm
> @@ -5851,9 +5851,14 @@ sub vm_start_nolock {
>  	    for my $dev ($d->{pciid}->@*) {
>  		my $info = PVE::QemuServer::PCI::prepare_pci_device($vmid, $dev->{id}, $id, $d->{mdev});
>  
> -		# nvidia grid needs the uuid of the mdev as qemu parameter
> +		# nvidia grid needs the qemu parameter '-uuid' set
> +		# use smbios uuid or mdev uuid as fallback for that
>  		if ($d->{mdev} && !defined($uuid) && $info->{vendor} eq '10de') {
> -		    $uuid = PVE::QemuServer::PCI::generate_mdev_uuid($vmid, $id);
> +		    if (defined($conf->{smbios1})) {
> +			my $smbios_conf = parse_smbios1($conf->{smbios1});
> +			$uuid = $smbios_conf->{uuid} if defined($smbios_conf->{uuid});
> +		    }
> +		    $uuid = PVE::QemuServer::PCI::generate_mdev_uuid($vmid, $id) if !defined($uuid);
>  		}
>  	    }
>  	}
> -- 
> 2.30.2