Re: [PATCH v4 07/10] x86/mm: add vmtrace_buf resource type

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

On Tue, Jun 30, 2020 at 02:33:50PM +0200, Michał Leszczyński wrote:
> From: Michal Leszczynski <michal.leszczynski@xxxxxxx>
> 
> Allow to map processor trace buffer using
> acquire_resource().
> 
> Signed-off-by: Michal Leszczynski <michal.leszczynski@xxxxxxx>
> ---
>  xen/arch/x86/mm.c           | 25 +++++++++++++++++++++++++
>  xen/include/public/memory.h |  1 +
>  2 files changed, 26 insertions(+)
> 
> diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
> index e376fc7e8f..bb781bd90c 100644
> --- a/xen/arch/x86/mm.c
> +++ b/xen/arch/x86/mm.c
> @@ -4624,6 +4624,31 @@ int arch_acquire_resource(struct domain *d, unsigned 
> int type,
>          }
>          break;
>      }
> +
> +    case XENMEM_resource_vmtrace_buf:
> +    {
> +        mfn_t mfn;
> +        unsigned int i;
> +        struct vcpu *v = domain_vcpu(d, id);

Missing blank newline between variable definitions and code.

> +        rc = -EINVAL;
> +
> +        if ( !v )
> +            break;
> +
> +        if ( !v->arch.vmtrace.pt_buf )
> +            break;
> +
> +        mfn = page_to_mfn(v->arch.vmtrace.pt_buf);
> +
> +        if ( frame + nr_frames > (v->domain->vmtrace_pt_size >> PAGE_SHIFT) )
> +            break;

You can place all the checks done above in a single if.

Thanks, Roger.