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* hap_2mb and hap_1gb options
@ 2012-03-08  0:36 AP
  2012-03-08  6:11 ` Keir Fraser
  0 siblings, 1 reply; 6+ messages in thread
From: AP @ 2012-03-08  0:36 UTC (permalink / raw)
  To: xen-devel

I wanted to run without 2MB and 1GB EPT pages, so I added "hap_2mb=0
hap_1gb=0" to the Xen grub command line. However I see the following
on Xen boot:

(XEN) EPT supports 2MB super page.

When I bring up a guest I see a non-zero number of 2MB pages in the
"xl create" output:

xc: info: VIRTUAL MEMORY ARRANGEMENT:
  Loader:        0000000000100000->000000000017af10
  TOTAL:         0000000000000000->000000001f000000
  ENTRY ADDRESS: 00000000001015a0
xc: info: PHYSICAL MEMORY ALLOCATION:
  4KB PAGES: 0x0000000000000200
  2MB PAGES: 0x00000000000000f7
  1GB PAGES: 0x0000000000000000
Daemon running with PID 2867

Have I added the options in the right place? Do I need to do anything
else to disable super pages?

Thanks,
AP

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: hap_2mb and hap_1gb options
  2012-03-08  0:36 hap_2mb and hap_1gb options AP
@ 2012-03-08  6:11 ` Keir Fraser
  2012-03-08  9:47   ` Keir Fraser
  0 siblings, 1 reply; 6+ messages in thread
From: Keir Fraser @ 2012-03-08  6:11 UTC (permalink / raw)
  To: AP, xen-devel

On 08/03/2012 00:36, "AP" <apxeng@gmail.com> wrote:

> I wanted to run without 2MB and 1GB EPT pages, so I added "hap_2mb=0
> hap_1gb=0" to the Xen grub command line. However I see the following
> on Xen boot:
> 
> (XEN) EPT supports 2MB super page.

This simply indicates the CPU supports this feature, regardless of whether
Xen is configured to use it.

> When I bring up a guest I see a non-zero number of 2MB pages in the
> "xl create" output:
> 
> xc: info: VIRTUAL MEMORY ARRANGEMENT:
>   Loader:        0000000000100000->000000000017af10
>   TOTAL:         0000000000000000->000000001f000000
>   ENTRY ADDRESS: 00000000001015a0
> xc: info: PHYSICAL MEMORY ALLOCATION:
>   4KB PAGES: 0x0000000000000200
>   2MB PAGES: 0x00000000000000f7
>   1GB PAGES: 0x0000000000000000
> Daemon running with PID 2867

This simply indicates that the HVM domain builder managed to allocate that
number of 2MB extents of memory. It does not necessarily mean that those 2MB
extents will be mapped into guest address space with 2MB superpage mappings.

> Have I added the options in the right place? Do I need to do anything
> else to disable super pages?

Unfortunately there is no logging output that indicates that the
hap_2mb/hap_1gb=0 options are working. You have set the options correctly.

I will sort out a small patch for this.

 -- Keir

> Thanks,
> AP
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: hap_2mb and hap_1gb options
  2012-03-08  6:11 ` Keir Fraser
@ 2012-03-08  9:47   ` Keir Fraser
  2012-03-08 19:38     ` AP
  0 siblings, 1 reply; 6+ messages in thread
From: Keir Fraser @ 2012-03-08  9:47 UTC (permalink / raw)
  To: AP, xen-devel

On 08/03/2012 06:11, "Keir Fraser" <keir.xen@gmail.com> wrote:

>> Have I added the options in the right place? Do I need to do anything
>> else to disable super pages?
> 
> Unfortunately there is no logging output that indicates that the
> hap_2mb/hap_1gb=0 options are working. You have set the options correctly.
> 
> I will sort out a small patch for this.

Done as xen_unstable:24992. I removed the VMX-specific "EPT supports XX
super page" lines, and replaced with a single line of the form (for
example):
HVM: HAP page sizes: 4kB, 2MB [disabled], 1GB [disabled]

The '[disabled]' bit corresponds to setting hap_2mb/1gb=0.

 -- Keir

>  -- Keir
> 
>> Thanks,
>> AP
>> 
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xen.org
>> http://lists.xen.org/xen-devel
> 
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: hap_2mb and hap_1gb options
  2012-03-08  9:47   ` Keir Fraser
@ 2012-03-08 19:38     ` AP
  2012-03-08 21:44       ` Keir Fraser
  2012-03-09 10:03       ` Keir Fraser
  0 siblings, 2 replies; 6+ messages in thread
From: AP @ 2012-03-08 19:38 UTC (permalink / raw)
  To: Keir Fraser; +Cc: xen-devel

On Thu, Mar 8, 2012 at 1:47 AM, Keir Fraser <keir@xen.org> wrote:
> On 08/03/2012 06:11, "Keir Fraser" <keir.xen@gmail.com> wrote:
>
>>> Have I added the options in the right place? Do I need to do anything
>>> else to disable super pages?
>>
>> Unfortunately there is no logging output that indicates that the
>> hap_2mb/hap_1gb=0 options are working. You have set the options correctly.
>>
>> I will sort out a small patch for this.
>
> Done as xen_unstable:24992. I removed the VMX-specific "EPT supports XX
> super page" lines, and replaced with a single line of the form (for
> example):
> HVM: HAP page sizes: 4kB, 2MB [disabled], 1GB [disabled]
>
> The '[disabled]' bit corresponds to setting hap_2mb/1gb=0.

Thank you. This is very helpful. I realize that this is just an info
output patch albeit a useful one. So any chance of having this
considered for a backport to Xen 4.1.x?

AP

>  -- Keir
>
>>  -- Keir
>>
>>> Thanks,
>>> AP
>>>
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@lists.xen.org
>>> http://lists.xen.org/xen-devel
>>
>>
>
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: hap_2mb and hap_1gb options
  2012-03-08 19:38     ` AP
@ 2012-03-08 21:44       ` Keir Fraser
  2012-03-09 10:03       ` Keir Fraser
  1 sibling, 0 replies; 6+ messages in thread
From: Keir Fraser @ 2012-03-08 21:44 UTC (permalink / raw)
  To: AP; +Cc: xen-devel

On 08/03/2012 19:38, "AP" <apxeng@gmail.com> wrote:

> On Thu, Mar 8, 2012 at 1:47 AM, Keir Fraser <keir@xen.org> wrote:
>> On 08/03/2012 06:11, "Keir Fraser" <keir.xen@gmail.com> wrote:
>> 
>>>> Have I added the options in the right place? Do I need to do anything
>>>> else to disable super pages?
>>> 
>>> Unfortunately there is no logging output that indicates that the
>>> hap_2mb/hap_1gb=0 options are working. You have set the options correctly.
>>> 
>>> I will sort out a small patch for this.
>> 
>> Done as xen_unstable:24992. I removed the VMX-specific "EPT supports XX
>> super page" lines, and replaced with a single line of the form (for
>> example):
>> HVM: HAP page sizes: 4kB, 2MB [disabled], 1GB [disabled]
>> 
>> The '[disabled]' bit corresponds to setting hap_2mb/1gb=0.
> 
> Thank you. This is very helpful. I realize that this is just an info
> output patch albeit a useful one. So any chance of having this
> considered for a backport to Xen 4.1.x?

Yes, should be easy to do.

 -- Keir

> AP
> 
>>  -- Keir
>> 
>>>  -- Keir
>>> 
>>>> Thanks,
>>>> AP
>>>> 
>>>> _______________________________________________
>>>> Xen-devel mailing list
>>>> Xen-devel@lists.xen.org
>>>> http://lists.xen.org/xen-devel
>>> 
>>> 
>> 
>> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: hap_2mb and hap_1gb options
  2012-03-08 19:38     ` AP
  2012-03-08 21:44       ` Keir Fraser
@ 2012-03-09 10:03       ` Keir Fraser
  1 sibling, 0 replies; 6+ messages in thread
From: Keir Fraser @ 2012-03-09 10:03 UTC (permalink / raw)
  To: AP; +Cc: xen-devel

On 08/03/2012 19:38, "AP" <apxeng@gmail.com> wrote:

> On Thu, Mar 8, 2012 at 1:47 AM, Keir Fraser <keir@xen.org> wrote:
>> On 08/03/2012 06:11, "Keir Fraser" <keir.xen@gmail.com> wrote:
>> 
>>>> Have I added the options in the right place? Do I need to do anything
>>>> else to disable super pages?
>>> 
>>> Unfortunately there is no logging output that indicates that the
>>> hap_2mb/hap_1gb=0 options are working. You have set the options correctly.
>>> 
>>> I will sort out a small patch for this.
>> 
>> Done as xen_unstable:24992. I removed the VMX-specific "EPT supports XX
>> super page" lines, and replaced with a single line of the form (for
>> example):
>> HVM: HAP page sizes: 4kB, 2MB [disabled], 1GB [disabled]
>> 
>> The '[disabled]' bit corresponds to setting hap_2mb/1gb=0.
> 
> Thank you. This is very helpful. I realize that this is just an info
> output patch albeit a useful one. So any chance of having this
> considered for a backport to Xen 4.1.x?

Done, xen-4.1-testing:23264.

 -- Keir

> AP
> 
>>  -- Keir
>> 
>>>  -- Keir
>>> 
>>>> Thanks,
>>>> AP
>>>> 
>>>> _______________________________________________
>>>> Xen-devel mailing list
>>>> Xen-devel@lists.xen.org
>>>> http://lists.xen.org/xen-devel
>>> 
>>> 
>> 
>> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2012-03-09 10:03 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-03-08  0:36 hap_2mb and hap_1gb options AP
2012-03-08  6:11 ` Keir Fraser
2012-03-08  9:47   ` Keir Fraser
2012-03-08 19:38     ` AP
2012-03-08 21:44       ` Keir Fraser
2012-03-09 10:03       ` Keir Fraser

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