From: X <studyxen@gmail.com>
To: xen-devel@lists.xensource.com
Subject: question about syscall interception
Date: Thu, 16 Feb 2012 15:34:31 -0500 [thread overview]
Message-ID: <CAJEOSFvFV-zNXrmqkiu+aLHy0cG+qz2gOdVC7foOvm+TKrv31g@mail.gmail.com> (raw)
[-- Attachment #1.1: Type: text/plain, Size: 1000 bytes --]
Hello everyone,
I have a few questions about syscall interception in Xen. Thanks for any
advice/suggestion.
Setting: CPU, Xen and PV Linux guest are all 64-bit
(1) If a guest app uses "syscall" instruction to launch a system call to
the guest kernel, is that behavior intercepted by Xen by default? If yes,
could someone please point me to the related code in Xen for this
interception? (anything to do with "switch_to_kernel in
xen/arch/x86/x86_64/entry.S"?) If no, then how could I intercept that
instruction in this case?
(2) If a guest app uses "int 0x80" to launch a system call, then is it true
that after "init_int80_direct_trap," the int 0x80 is no longer intercepted
by Xen, and the app can trap directly into the guest kernel? My
understanding is that "init_int80_direct_trap" initializes vcpu's
arch_vpuc.int80_bounce. Could someone please briefly explain how things
work after this struct is properly setup? How could I intercept system
calls launched in this way in Xen?
Thanks.
X
[-- Attachment #1.2: Type: text/html, Size: 1207 bytes --]
[-- Attachment #2: Type: text/plain, Size: 138 bytes --]
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel
reply other threads:[~2012-02-16 20:34 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=CAJEOSFvFV-zNXrmqkiu+aLHy0cG+qz2gOdVC7foOvm+TKrv31g@mail.gmail.com \
--to=studyxen@gmail.com \
--cc=xen-devel@lists.xensource.com \
/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).