On Thu, Feb 09, 2023 at 01:45:33PM +0000, Richard W.M. Jones wrote:
> This machine type is more modern than the older 'pc' type and as most
> qemu development is now focused there we expect it will perform and
> behave better.  In almost all respects this change should make no
> difference.

The key differences with q35 that have caused problems for
apps in the past

 - CDROMs must use 'sata' bus not 'ide'
 - PCI topology is completely different, so if you're
   trying to associate between the host side view of
   the config and the guest side view, your logic may
   need adapting
 - Hotplug of devices is limited to 1 device unless you
   pre-create a bunch of pcie-root-port devices

If you're already using 'virt' machine for aarch64 successfully
though, you should have already known about the last 2 points,
if they did indeed affect libguestfs.

The first point could conceivably affect the way to detect
devices, depending on what approach is used, but could equally
be a non issue.

I presume the libguestfs test suite would have complained if
there was any genuine problem with the change, since it is
pretty comphrensive.

> 
> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2168578
> ---
>  lib/guestfs-internal.h | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/lib/guestfs-internal.h b/lib/guestfs-internal.h
> index 07a2b9f617..4e9a103d78 100644
> --- a/lib/guestfs-internal.h
> +++ b/lib/guestfs-internal.h
> @@ -128,6 +128,9 @@ cleanup_mutex_unlock (pthread_mutex_t **ptr)
>  #define MAX_WINDOWS_EXPLORER_SIZE (4 * 1000 * 1000)
>  
>  /* Machine types. */
> +#if defined(__x86_64__)
> +#define MACHINE_TYPE "q35"
> +#endif
>  #ifdef __arm__
>  #define MACHINE_TYPE "virt"
>  #endif
> -- 
> 2.39.0
> 
> _______________________________________________
> Libguestfs mailing list
> Libguestfs@redhat.com
> https://listman.redhat.com/mailman/listinfo/libguestfs
> 

With regards,
Daniel
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