From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Jan Beulich" <JBeulich@suse.com>
Subject: Re: [PATCH 6/7] xen: Allow hardare domain != dom0
Date: Fri, 11 Apr 2014 10:13:25 +0100
Message-ID: <5347CE550200007800007E5E@nat28.tlf.novell.com>
References: <1395921128-7086-1-git-send-email-dgdegra@tycho.nsa.gov>
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Cc: Keir Fraser <keir@xen.org>, xen-devel@lists.xen.org
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>>> On 27.03.14 at 12:52, <dgdegra@tycho.nsa.gov> wrote:

I was about to commit this, but further changes are needed (along
with fixing the typo in the title):

> --- a/xen/arch/x86/setup.c
> +++ b/xen/arch/x86/setup.c
> @@ -84,6 +84,8 @@ unsigned long __initdata highmem_start;
>  size_param("highmem-start", highmem_start);
>  #endif
>  
> +integer_param("hardware_dom", hardware_domid);

This should be moved alongside the definition of the symbol in
common code, and be enclosed in "#ifdef CONFIG_LATE_HWDOM".

And docs/misc/xen-command-line.markdown wants an entry for it.

> --- a/xen/include/xen/sched.h
> +++ b/xen/include/xen/sched.h
> @@ -45,6 +45,7 @@ DEFINE_XEN_GUEST_HANDLE(vcpu_runstate_info_compat_t);
>  
>  /* A global pointer to the hardware domain (usually DOM0). */
>  extern struct domain *hardware_domain;
> +extern domid_t hardware_domid;
>  
>  #ifndef CONFIG_COMPAT
>  #define BITS_PER_EVTCHN_WORD(d) BITS_PER_XEN_ULONG
> @@ -794,7 +795,7 @@ void watchdog_domain_destroy(struct domain *d);
>   *    (that is, this would not be suitable for a driver domain)
>   *  - There is never a reason to deny dom0 access to this
>   */
> -#define is_hardware_domain(_d) ((_d)->domain_id == 0)
> +#define is_hardware_domain(d)  ((d)->domain_id == hardware_domid)

This macro should imo evaluate to true for Dom0 until the hardware
domain go created, i.e. you should compare _d with hardware_domain
rather than their IDs. With that the definition of hardware_domid can
then also be moved inside the #ifdef requested above.

Jan