qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: wuxi <wu.andrew.xi@gmail.com>
To: Qemu Development List <qemu-devel@nongnu.org>
Subject: [Qemu-devel] [Qemu devel] Question: Qemu support up to 4GB physical memory?
Date: Sun, 26 Apr 2009 20:32:45 +0800	[thread overview]
Message-ID: <49F4546D.60300@gmail.com> (raw)

Hi, all:
I am hacking QEMU (for a course project) based on the 0.10.1 version on 
x86-64 architecture. My question arises when I was checking the code of 
PageDesc in QEMU. I found it uses a two level mapping (l1_map), and it 
seems that QEMU can support physical memory up to   210 * 210 * (4KB) = 
4GB.

the related code is:

(L1_BITS = 10, L2_BITS=10, TARGET_PAGE_BITS=12)

#define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS)
#define L1_SIZE (1 << L1_BITS)
#define L2_SIZE (1 << L2_BITS)

static PageDesc *l1_map[L1_SIZE];

p = qemu_mallocz(sizeof(PageDesc) * L2_SIZE); (for each l1_map entry)

Is this true for QEMU x86-64 emulation? or I made some silly mistakes...

Thanks !

yours sincerely

Andrew

             reply	other threads:[~2009-04-26 12:33 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-26 12:32 wuxi [this message]
2009-04-26 12:41 ` [Qemu-devel] Question: Qemu support up to 4GB physical memory? 吴曦

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=49F4546D.60300@gmail.com \
    --to=wu.andrew.xi@gmail.com \
    --cc=qemu-devel@nongnu.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;
as well as URLs for NNTP newsgroup(s).