[pve-devel] [PATCH qemu-server 1/2] add support for nvme emulation

[Thomas Lamprecht]

please always include the bug/feature # somewhere as reference, e.g. a
"fix #2255: ..." ideally in the subject, or at least in the commit message
would be good.

On 5/13/20 5:36 PM, Oguz Bektas wrote:
> now we can add nvme drives;
> 
> nvme0: local-lvm:vm-103-disk-0,size=32G

An example I can use end to end is nicer for a reviewer, e.g., something like:
qm set 100 --nvme0 local-lvm:32


> max number is 8

The "hows" and especially the "whys" are missing a bit here, I know them as I
answered question to you directly during development of this, but in a month
most is forgot, git commit messages are eternal ;)

Nicer would be something like:
"allow maximal 8 drives, most real hardware provides normally 1 to 3 slots and
PCIe can host possibly a few more. For the default case 8 should be enough to
mirror common HW, and more can be added easily if a real usecase comes up.
 
Also, decreasing it later is impossible without breaking setups"


> 
> Signed-off-by: Oguz Bektas <o.bektas at proxmox.com>
> ---
>  PVE/QemuServer.pm       | 20 +++++++++++++++++---
>  PVE/QemuServer/Drive.pm | 21 +++++++++++++++++++++
>  2 files changed, 38 insertions(+), 3 deletions(-)
> 
> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
> index dcf05df..441d209 100644
> --- a/PVE/QemuServer.pm
> +++ b/PVE/QemuServer.pm
> @@ -406,7 +406,7 @@ EODESC
>  	optional => 1,
>  	type => 'string', format => 'pve-qm-bootdisk',
>  	description => "Enable booting from specified disk.",
> -	pattern => '(ide|sata|scsi|virtio)\d+',
> +	pattern => '(ide|sata|scsi|virtio|nvme)\d+',
>      },
>      smp => {
>  	optional => 1,
> @@ -1424,7 +1424,11 @@ sub print_drivedevice_full {
>  	    $device .= ",rotation_rate=1";
>  	}
>  	$device .= ",wwn=$drive->{wwn}" if $drive->{wwn};
> -
> +    } elsif ($drive->{interface} eq 'nvme') {
> +	my $maxdev = $PVE::QemuServer::Drive::MAX_NVME_DISKS;

not used here

> +	my $path = $drive->{file};
> +	$drive->{serial} = "$drive->{interface}$drive->{index}"; # serial is mandatory for nvme

hmm, but this doesn't allows for users setting there own serial...
Maybe:

$drive->{serial} //= "$drive->{interface}$drive->{index}";


> +	$device = "nvme,drive=drive-$drive->{interface}$drive->{index}";
>      } elsif ($drive->{interface} eq 'ide' || $drive->{interface} eq 'sata') {
>  	my $maxdev = ($drive->{interface} eq 'sata') ? $PVE::QemuServer::Drive::MAX_SATA_DISKS : 2;
>  	my $controller = int($drive->{index} / $maxdev);
> @@ -2157,7 +2161,7 @@ sub parse_vm_config {
>  	    } else {
>  		$key = 'ide2' if $key eq 'cdrom';
>  		my $fmt = $confdesc->{$key}->{format};
> -		if ($fmt && $fmt =~ /^pve-qm-(?:ide|scsi|virtio|sata)$/) {
> +		if ($fmt && $fmt =~ /^pve-qm-(?:ide|scsi|virtio|sata|nvme)$/) {
>  		    my $v = parse_drive($key, $value);
>  		    if (my $volid = filename_to_volume_id($vmid, $v->{file}, $v->{media})) {
>  			$v->{file} = $volid;
> @@ -3784,7 +3788,17 @@ sub vm_deviceplug {
>  	    warn $@ if $@;
>  	    die $err;
>          }
> +    } elsif ($deviceid =~ m/^(nvme)(\d+)$/) {
> +
> +        qemu_driveadd($storecfg, $vmid, $device);
>  
> +	my $devicefull = print_drivedevice_full($storecfg, $conf, $vmid, $device, $arch, $machine_type);
> +	eval { qemu_deviceadd($vmid, $devicefull); };
> +	if (my $err = $@) {
> +	    eval { qemu_drivedel($vmid, $deviceid); };
> +	    warn $@ if $@;
> +	    die $err;
> +        }
>      } elsif ($deviceid =~ m/^(net)(\d+)$/) {
>  
>  	return undef if !qemu_netdevadd($vmid, $conf, $arch, $device, $deviceid);
> diff --git a/PVE/QemuServer/Drive.pm b/PVE/QemuServer/Drive.pm
> index f84333f..b8a553a 100644
> --- a/PVE/QemuServer/Drive.pm
> +++ b/PVE/QemuServer/Drive.pm
> @@ -27,6 +27,7 @@ PVE::JSONSchema::register_standard_option('pve-qm-image-format', {
>  
>  my $MAX_IDE_DISKS = 4;
>  my $MAX_SCSI_DISKS = 31;
> +my $MAX_NVME_DISKS = 8;
>  my $MAX_VIRTIO_DISKS = 16;
>  our $MAX_SATA_DISKS = 6;
>  our $MAX_UNUSED_DISKS = 256;
> @@ -275,6 +276,20 @@ my $scsidesc = {
>  };
>  PVE::JSONSchema::register_standard_option("pve-qm-scsi", $scsidesc);
>  
> +my $nvme_fmt = {
> +    %drivedesc_base,
> +    %ssd_fmt,
> +    %wwn_fmt,
> +};
> +
> +my $nvmedesc = {
> +    optional => 1,
> +    type => 'string', format => $nvme_fmt,
> +    description => "Use volume as NVME disk (n is 0 to " . ($MAX_NVME_DISKS -1) . ").",
> +};
> +
> +PVE::JSONSchema::register_standard_option("pve-qm-nvme", $nvmedesc);

format is registered but not used in any of the code, or is there some
funky auto use or the like?

> +
>  my $sata_fmt = {
>      %drivedesc_base,
>      %ssd_fmt,
> @@ -364,6 +379,11 @@ for (my $i = 0; $i < $MAX_SCSI_DISKS; $i++)  {
>      $drivedesc_hash->{"scsi$i"} = $scsidesc;
>  }
>  
> +for (my $i = 0; $i < $MAX_NVME_DISKS; $i++)  {
> +    $drivedesc_hash->{"nvme$i"} = $nvmedesc;
> +}

OK, as all is like that, but we could transform it maybe to

$drivedesc_hash->{"nvme$_"} for (0..$MAX_SCSI_DISKS);

lines, made it compacter and more concise without losing readability.
But nothing for this series, just got to my mind now.

> +
> +
>  for (my $i = 0; $i < $MAX_VIRTIO_DISKS; $i++)  {
>      $drivedesc_hash->{"virtio$i"} = $virtiodesc;
>  }
> @@ -380,6 +400,7 @@ sub valid_drive_names {
>              (map { "scsi$_" } (0 .. ($MAX_SCSI_DISKS - 1))),
>              (map { "virtio$_" } (0 .. ($MAX_VIRTIO_DISKS - 1))),
>              (map { "sata$_" } (0 .. ($MAX_SATA_DISKS - 1))),
> +            (map { "nvme$_" } (0 .. ($MAX_NVME_DISKS - 1))),
>              'efidisk0');
>  }
>  
>