Re: [PATCH v2 09/35] x86/domain: print emulation_flags

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Thu, Dec 05, 2024 at 08:41:39PM -0800, Denis Mukhin via B4 Relay wrote:
> From: Denis Mukhin <dmukhin@xxxxxxxx>
> 
> Print d->arch.emulation_flags on the console for better traceability while
> debugging in-hypervisor hardware emulators.
> 
> Signed-off-by: Denis Mukhin <dmukhin@xxxxxxxx>
> ---
>  xen/arch/x86/domain.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
> index 
> 78a13e6812c9120901d0a70fb3bc1bd6a8b6917d..c88d422a64544531c1e1058fa484364bb4277d1e
>  100644
> --- a/xen/arch/x86/domain.c
> +++ b/xen/arch/x86/domain.c
> @@ -818,11 +818,15 @@ int arch_domain_create(struct domain *d,
>  
>      if ( !emulation_flags_ok(d, emflags) )
>      {
> -        printk(XENLOG_G_ERR "d%d: Xen does not allow %s domain creation "
> +        printk(XENLOG_G_ERR "d%d: Xen does not allow %s %sdomain creation "

gprintk(XENLOG_ERR, "...

Might be more natural now that we have the macro (together with Jan's
suggestion to use %pd (same below).

>                 "with the current selection of emulators: %#x\n",
> -               d->domain_id, is_hvm_domain(d) ? "HVM" : "PV", emflags);
> +               d->domain_id,
> +               is_hvm_domain(d) ? "HVM" : "PV",
> +               is_hardware_domain(d) ? "(hardware) " : "",
> +               emflags);
>          return -EOPNOTSUPP;
>      }
> +    printk(XENLOG_G_INFO "d%d: emulation_flags %#x\n", d->domain_id, 
> emflags);

This would need to be a dprintk at least, and the log level should be
XENLOG_DEBUG.

Maybe it would be better if you could print this information as part
of some debug key, for not having to print it for every guest
creation.  Maybe as part of the 'q' debug key?

Thanks, Roger.