Re: [PATCH 4/7] runqemu: do not rely on grepping images

[Patrick Ohly <patrick.ohly@intel.com>]

On Tue, 2017-04-11 at 02:21 -0700, Robert Yang wrote:
> Fixed when the image is large and not enough memory:
>   grep: memory exhausted
>   Aborted
> 
> [YOCTO #11073]
> 
> Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
> ---
>  meta/classes/qemuboot.bbclass |  3 +++
>  scripts/runqemu               | 19 +++++++++++--------
>  2 files changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/meta/classes/qemuboot.bbclass b/meta/classes/qemuboot.bbclass
> index 3ca97cad4c..2870388dfb 100644
> --- a/meta/classes/qemuboot.bbclass
> +++ b/meta/classes/qemuboot.bbclass
> @@ -64,6 +64,9 @@ QB_DEFAULT_FSTYPE ?= "ext4"
>  QB_OPT_APPEND ?= "-show-cursor"
>  QB_NETWORK_DEVICE ?= "-device virtio-net-pci,netdev=net0,mac=@MAC@"
>  
> +# This should be kept align with ROOT_VM
> +QB_DRIVE_TYPE ?= "/dev/sd"

Now that I am faced with the problem of selecting virtio I'm starting to
wonder how to do that.

Our refkit image doesn't expect the image on a particular drive, using
PARTUUID instead to find it. But when running under qemu, it would be
nice to use virtio for performance reasons... if the kernel supports it.
But that's not something that the image recipe or even the distro should
make assumptions about.

It seems safer to let the machine configuration which chooses the kernel
also set QB_DRIVE_TYPE, but with ?= so that it can still be changed
elsewhere. In that case, we would need:

qemuboot.bbclass: QB_DRIVE_TYPE ??= "/dev/sd"
qemuboot-intel.inc (from meta-intel): QB_DRIVE_TYPE ?= "/dev/vd"
distro, local or image (optional): QB_DRIVE_TYPE = "/dev/..."

> +                elif self.get('QB_DRIVE_TYPE'):
> +                    drive_type = self.get('QB_DRIVE_TYPE')
> +                    if drive_type.startswith("/dev/sd"):
>                          logger.info('Using scsi drive')
>                          vm_drive = '-drive if=none,id=hd,file=%s,format=%s -device virtio-scsi-pci,id=scsi -device scsi-hd,drive=hd' \
>                                         % (self.rootfs, rootfs_format)
> -                    elif subprocess.call(cmd2, shell=True) == 0:
> +                    elif drive_type.startswith("/dev/hd"):
>                          logger.info('Using ide drive')
>                          vm_drive = "%s,format=%s" % (self.rootfs, rootfs_format)
>                      else:
> -                        logger.warn("Can't detect drive type %s" % self.rootfs)
> -                        logger.warn('Trying to use virtio block drive')
> -                        vm_drive = '-drive if=virtio,file=%s,format=%s' % (self.rootfs, rootfs_format)
> +                        logger.warn("Unknown QB_DRIVE_TYPE: %s" % drive_type)
> +
> +                if not vm_drive:
> +                    logger.warn("Failed to figure out drive type, consider define or fix QB_DRIVE_TYPE")
> +                    logger.warn('Trying to use virtio block drive')
> +                    vm_drive = '-drive if=virtio,file=%s,format=%s' % (self.rootfs, rootfs_format)

Here "/dev/sd" should be treated as an explicit selection of virtio,
without triggering warnings.

I'll send a patch for both if there are no objections.

-- 
Best Regards, Patrick Ohly

The content of this message is my personal opinion only and although
I am an employee of Intel, the statements I make here in no way
represent Intel's position on the issue, nor am I authorized to speak
on behalf of Intel on this matter.