Re: [PATCH v2 04/12] x86/altp2m: basic data structures and support routines.

From: Ed White <edmund.h.white@intel.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>, xen-devel@lists.xen.org
Cc: Ravi Sahita <ravi.sahita@intel.com>,
	Wei Liu <wei.liu2@citrix.com>,
	Ian Jackson <ian.jackson@eu.citrix.com>, Tim Deegan <tim@xen.org>,
	Jan Beulich <jbeulich@suse.com>,
	tlengyel@novetta.com, Daniel De Graaf <dgdegra@tycho.nsa.gov>
Subject: Re: [PATCH v2 04/12] x86/altp2m: basic data structures and support routines.
Date: Wed, 24 Jun 2015 10:20:28 -0700	[thread overview]
Message-ID: <558AE6DC.9060905@intel.com> (raw)
In-Reply-To: <558A813F.4050402@citrix.com>

On 06/24/2015 03:06 AM, Andrew Cooper wrote:
>> diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
>> index d0d3f1e..202aa42 100644
>> --- a/xen/arch/x86/mm/hap/hap.c
>> +++ b/xen/arch/x86/mm/hap/hap.c
>> @@ -459,7 +459,7 @@ void hap_domain_init(struct domain *d)
>>  int hap_enable(struct domain *d, u32 mode)
>>  {
>>      unsigned int old_pages;
>> -    uint8_t i;
>> +    uint16_t i;
>>      int rv = 0;
>>  
>>      domain_pause(d);
>> @@ -498,6 +498,24 @@ int hap_enable(struct domain *d, u32 mode)
>>             goto out;
>>      }
>>  
>> +    /* Init alternate p2m data */
>> +    if ( (d->arch.altp2m_eptp = alloc_xenheap_page()) == NULL )
> 
> Please use alloc_domheap_page() and map_domain_page_global() so the
> allocation is accounted against the domain.

You raised this back in January too, and I did try it. Unfortunately,
allocating that way caused repeated Xen panics, and when I reported that
to you and Tim on the list 2 or 3 months ago Tim said that he thought
the existing code was acceptable in this instance, since this is only 1
page per-domain.

Ed