public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Glauber de Oliveira Costa <gcosta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: Akio Takebe <takebe_akio-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
	jeremy-TSDbQ3PG+2Y@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	hollisb-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org,
	avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org
Subject: Re: include files for kvmclock
Date: Wed, 07 Nov 2007 11:16:34 -0200	[thread overview]
Message-ID: <4731BAB2.9040004@redhat.com> (raw)
In-Reply-To: <1DC8211684B62Btakebe_akio-+CUm20s59erQFUHtdCDX3A@public.gmane.org>

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Akio Takebe escreveu:
> Hi, Glauber
> 
> This is interesting facility. :-)
> 
>> +#define KVM_HCALL_REGISTER_CLOCK	1
>> +
>> +union kvm_hv_clock {
>> +	struct {
>> +		u64 tsc_mult;
>> +		u64 now_ns;
>> +		/* That's the wall clock, not the water closet */
>> +		u64 wc_sec;
>> +		u64 wc_nsec;
>> +		u64 last_tsc;
>> +		/* At first, we could use the tsc value as a marker, but Jeremy
>> +		 * well noted that it will cause us locking problems in 32-bit
>> +		 * sys, so we have a special version field */
>> +		u32 version;
>> +	};
>> +	char page_align[PAGE_SIZE];
>> +};
>> +
> Why does kvm_hv_clock need page_align?
Each vcpu will register a page on its own. In the guest side, it will be
an array of pages. So, we make it page sized.

> And also the kvm_hv_clock is alloced with kvm_vcpu,
There's no requirements on the host part at all. So it doesn't really
matter. In the next version, I may make it even a simple pointer.

> so the align is not enough, isn't it?
> I thik __atribute__((__aligne__(PAGE_SIZE)))) is better than it.
It deals with the start of the structure, but not with its size. See the
guest part: Where it matters, I do use it.


Thanks

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (GNU/Linux)
Comment: Using GnuPG with Remi - http://enigmail.mozdev.org

iD8DBQFHMbqyjYI8LaFUWXMRAgfOAKCTeKF3cWbhILYSXY+MjtXo8B87EwCeNNhn
z9RDYaCWHIxsqlciMF0i27w=
=EIEM
-----END PGP SIGNATURE-----

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/

  parent reply	other threads:[~2007-11-07 13:16 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-06 22:18 KVM paravirt clocksource - Take 3 out of <put your number here> Glauber de Oliveira Costa
     [not found] ` <11943875362987-git-send-email-gcosta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2007-11-06 22:18   ` include files for kvmclock Glauber de Oliveira Costa
     [not found]     ` <11943875433821-git-send-email-gcosta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2007-11-06 21:35       ` Glauber de Oliveira Costa
     [not found]         ` <5d6222a80711061335q7ef03b42i335bb1e8c07eb7e4-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2007-11-07  5:55           ` Avi Kivity
     [not found]             ` <4731535E.5000808-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-11-07  5:58               ` Jeremy Fitzhardinge
     [not found]                 ` <47315421.7080706-TSDbQ3PG+2Y@public.gmane.org>
2007-11-07 12:49                   ` Glauber de Oliveira Costa
2007-11-06 22:18       ` kvmclock - the host part Glauber de Oliveira Costa
     [not found]         ` <11943875471622-git-send-email-gcosta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2007-11-06 22:18           ` kvmclock implementation, the guest part Glauber de Oliveira Costa
2007-11-07  5:50           ` kvmclock - the host part Avi Kivity
     [not found]             ` <47315229.1010502-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
2007-11-07 13:08               ` Glauber de Oliveira Costa
2007-11-07 13:59                 ` Avi Kivity
2007-11-06 22:50       ` include files for kvmclock Jeremy Fitzhardinge
     [not found]         ` <4730EF9F.3020803-TSDbQ3PG+2Y@public.gmane.org>
2007-11-06 22:58           ` Glauber de Oliveira Costa
2007-11-07  8:16       ` Akio Takebe
     [not found]         ` <1DC8211684B62Btakebe_akio-+CUm20s59erQFUHtdCDX3A@public.gmane.org>
2007-11-07 13:16           ` Glauber de Oliveira Costa [this message]
     [not found]             ` <4731BAB2.9040004-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2007-11-07 13:27               ` Akio Takebe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4731BAB2.9040004@redhat.com \
    --to=gcosta-h+wxahxf7alqt0dzr+alfa@public.gmane.org \
    --cc=avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org \
    --cc=hollisb-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org \
    --cc=jeremy-TSDbQ3PG+2Y@public.gmane.org \
    --cc=kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=takebe_akio-+CUm20s59erQFUHtdCDX3A@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox