Linux-Fsdevel Archive on lore.kernel.org
help / color / mirror / Atom feed
From: David Laight <David.Laight@ACULAB.COM>
To: 'James Bottomley' <James.Bottomley@HansenPartnership.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Steven Sistare <steven.sistare@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>,
	Anthony Yznaga <anthony.yznaga@oracle.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
	"mhocko@kernel.org" <mhocko@kernel.org>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"bp@alien8.de" <bp@alien8.de>, "x86@kernel.org" <x86@kernel.org>,
	"hpa@zytor.com" <hpa@zytor.com>,
	"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"arnd@arndb.de" <arnd@arndb.de>,
	"keescook@chromium.org" <keescook@chromium.org>,
	"gerg@linux-m68k.org" <gerg@linux-m68k.org>,
	"ktkhai@virtuozzo.com" <ktkhai@virtuozzo.com>,
	"christian.brauner@ubuntu.com" <christian.brauner@ubuntu.com>,
	"peterz@infradead.org" <peterz@infradead.org>,
	"esyr@redhat.com" <esyr@redhat.com>,
	"jgg@ziepe.ca" <jgg@ziepe.ca>,
	"christian@kellner.me" <christian@kellner.me>,
	"areber@redhat.com" <areber@redhat.com>,
	"cyphar@cyphar.com" <cyphar@cyphar.com>
Subject: RE: [RFC PATCH 0/5] madvise MADV_DOEXEC
Date: Tue, 4 Aug 2020 08:44:42 +0000	[thread overview]
Message-ID: <9371b8272fd84280ae40b409b260bab3@AcuMS.aculab.com> (raw)
In-Reply-To: <1596469370.29091.13.camel@HansenPartnership.com>

From: James Bottomley
> Sent: 03 August 2020 16:43
> 
> On Mon, 2020-08-03 at 10:28 -0500, Eric W. Biederman wrote:
> [...]
> > What is wrong with live migration between one qemu process and
> > another qemu process on the same machine not work for this use case?
> >
> > Just reusing live migration would seem to be the simplest path of
> > all, as the code is already implemented.  Further if something goes
> > wrong with the live migration you can fallback to the existing
> > process.  With exec there is no fallback if the new version does not
> > properly support the handoff protocol of the old version.
> 
> Actually, could I ask this another way: the other patch set you sent to
> the KVM list was to snapshot the VM to a PKRAM capsule preserved across
> kexec using zero copy for extremely fast save/restore.  The original
> idea was to use this as part of a CRIU based snapshot, kexec to new
> system, restore.  However, why can't you do a local snapshot, restart
> qemu, restore using the PKRAM capsule to achieve exactly the same as
> MADV_DOEXEC does but using a system that's easy to reason about?  It
> may be slightly slower, but I think we're still talking milliseconds.


I've had another idea (that is probably impossible...).
What about a 'reverse mmap' operation.
Something that creates an fd whose contents are a chunk of the
processes address space.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

  parent reply	other threads:[~2020-08-04  8:44 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-27 17:11 Anthony Yznaga
2020-07-27 17:07 ` Eric W. Biederman
2020-07-27 18:00   ` Steven Sistare
2020-07-28 13:40     ` Christian Brauner
2020-07-27 17:11 ` [RFC PATCH 1/5] elf: reintroduce using MAP_FIXED_NOREPLACE for elf executable mappings Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 2/5] mm: do not assume only the stack vma exists in setup_arg_pages() Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 3/5] mm: introduce VM_EXEC_KEEP Anthony Yznaga
2020-07-28 13:38   ` Eric W. Biederman
2020-07-28 17:44     ` Anthony Yznaga
2020-07-29 13:52   ` Kirill A. Shutemov
2020-07-29 23:20     ` Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 4/5] exec, elf: require opt-in for accepting preserved mem Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 5/5] mm: introduce MADV_DOEXEC Anthony Yznaga
2020-07-28 13:22   ` Kirill Tkhai
2020-07-28 14:06     ` Steven Sistare
2020-07-28 11:34 ` [RFC PATCH 0/5] madvise MADV_DOEXEC Kirill Tkhai
2020-07-28 17:28   ` Anthony Yznaga
2020-07-28 14:23 ` Andy Lutomirski
2020-07-28 14:30   ` Steven Sistare
2020-07-30 15:22 ` Matthew Wilcox
2020-07-30 15:27   ` Christian Brauner
2020-07-30 15:34     ` Matthew Wilcox
2020-07-30 15:54       ` Christian Brauner
2020-07-31  9:12     ` Stefan Hajnoczi
2020-07-30 15:59   ` Steven Sistare
2020-07-30 17:12     ` Matthew Wilcox
2020-07-30 17:35       ` Steven Sistare
2020-07-30 17:49         ` Matthew Wilcox
2020-07-30 18:27           ` Steven Sistare
2020-07-30 21:58             ` Eric W. Biederman
2020-07-31 14:57               ` Steven Sistare
2020-07-31 15:27                 ` Matthew Wilcox
2020-07-31 16:11                   ` Steven Sistare
2020-07-31 16:56                     ` Jason Gunthorpe
2020-07-31 17:15                       ` Steven Sistare
2020-07-31 17:48                         ` Jason Gunthorpe
2020-07-31 17:55                           ` Steven Sistare
2020-08-03  8:32                             ` David Laight
2020-07-31 17:23                     ` Matthew Wilcox
2020-08-03 15:28                 ` Eric W. Biederman
2020-08-03 15:42                   ` James Bottomley
2020-08-03 20:03                     ` Steven Sistare
2020-08-04  8:44                     ` David Laight [this message]
2020-08-04 11:13                       ` Matthew Wilcox
2020-08-03 19:29                   ` Steven Sistare
2020-07-31 19:41 ` Steven Sistare
2021-07-08  9:52 ` Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
2021-07-08 12:48   ` Steven Sistare

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=9371b8272fd84280ae40b409b260bab3@AcuMS.aculab.com \
    --to=david.laight@aculab.com \
    --cc=James.Bottomley@HansenPartnership.com \
    --cc=akpm@linux-foundation.org \
    --cc=anthony.yznaga@oracle.com \
    --cc=areber@redhat.com \
    --cc=arnd@arndb.de \
    --cc=bp@alien8.de \
    --cc=christian.brauner@ubuntu.com \
    --cc=christian@kellner.me \
    --cc=cyphar@cyphar.com \
    --cc=ebiederm@xmission.com \
    --cc=esyr@redhat.com \
    --cc=gerg@linux-m68k.org \
    --cc=hpa@zytor.com \
    --cc=jgg@ziepe.ca \
    --cc=keescook@chromium.org \
    --cc=ktkhai@virtuozzo.com \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=steven.sistare@oracle.com \
    --cc=tglx@linutronix.de \
    --cc=viro@zeniv.linux.org.uk \
    --cc=willy@infradead.org \
    --cc=x86@kernel.org \
    --subject='RE: [RFC PATCH 0/5] madvise MADV_DOEXEC' \
    /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

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).