From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Egger, Christoph" <chegger@amazon.de>
Subject: Re: [PATCH] x86/p2m: also clear defer_nested_flush on
 error
Date: Tue, 15 Apr 2014 16:50:22 +0200
Message-ID: <534D472E.3060407@amazon.de>
References: <534D59DF02000078000090A1@nat28.tlf.novell.com>
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To: Jan Beulich <JBeulich@suse.com>, xen-devel <xen-devel@lists.xenproject.org>
Cc: Tim Deegan <tim@xen.org>
List-Id: xen-devel@lists.xenproject.org

On 15.04.14 16:10, Jan Beulich wrote:
> While presumably benign (domain creation ought to fail when P2M setup
> fails) let's be on the safe side and clear the flag as intended. And
> actually, the code can be streamlined quite a bit by recognizing that
> the only difference between the success and error cases is the message
> printed in each case. With that, a stray spin_unlock() also goes away.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Nice cleanup!

Reviewed-by: Christoph Egger <chegger@amazon.de>

> 
> --- a/xen/arch/x86/mm/p2m.c
> +++ b/xen/arch/x86/mm/p2m.c
> @@ -435,18 +435,12 @@ int p2m_alloc_table(struct p2m_domain *p
>      p2m->defer_nested_flush = 1;
>      rc = p2m_set_entry(p2m, 0, _mfn(INVALID_MFN), PAGE_ORDER_4K,
>                         p2m_invalid, p2m->default_access);
> -    if ( rc )
> -        goto error;
>      p2m->defer_nested_flush = 0;
> -
> -    P2M_PRINTK("p2m table initialised for slot zero\n");
> -    p2m_unlock(p2m);
> -    return 0;
> -
> -    spin_unlock(&p2m->domain->page_alloc_lock);
> - error:
> -    P2M_PRINTK("failed to initialise p2m table for slot zero. rc:%d\n", rc);
>      p2m_unlock(p2m);
> +    if ( !rc )
> +        P2M_PRINTK("p2m table initialised for slot zero\n");
> +    else
> +        P2M_PRINTK("failed to initialise p2m table for slot zero (%d)\n", rc);
>      return rc;
>  }