From: Wei Liu <wl@xen.org>
To: Hongyan Xia <hx242@xen.org>
Cc: "Stefano Stabellini" <sstabellini@kernel.org>,
julien@xen.org, "Wei Liu" <wl@xen.org>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Ian Jackson" <ian.jackson@eu.citrix.com>,
"George Dunlap" <george.dunlap@citrix.com>,
"Jan Beulich" <jbeulich@suse.com>,
xen-devel@lists.xenproject.org,
"Volodymyr Babchuk" <Volodymyr_Babchuk@epam.com>,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [PATCH 11/16] x86: add a boot option to enable and disable the direct map
Date: Fri, 1 May 2020 13:11:58 +0000 [thread overview]
Message-ID: <20200501131158.utexymcn3lnt65qp@liuwe-devbox-debian-v2.j3c5onc20sse1dnehy4noqpfcg.zx.internal.cloudapp.net> (raw)
In-Reply-To: <2235f884b65c9f20cf55637f91ddab6924f53ca1.camel@xen.org>
On Fri, May 01, 2020 at 01:59:24PM +0100, Hongyan Xia wrote:
> On Fri, 2020-05-01 at 12:11 +0000, Wei Liu wrote:
> > On Thu, Apr 30, 2020 at 09:44:20PM +0100, Hongyan Xia wrote:
> > > From: Hongyan Xia <hongyxia@amazon.com>
> > >
> > > Also add a helper function to retrieve it. Change
> > > arch_mfn_in_direct_map
> > > to check this option before returning.
> > >
> > > This is added as a boot command line option, not a Kconfig. We do
> > > not
> > > produce different builds for EC2 so this is not introduced as a
> > > compile-time configuration.
> >
> > Having a Kconfig will probably allow the compiler to eliminate dead
> > code.
> >
> > This is not asking you to do the work, someone can come along and
> > adjust
> > arch_has_directmap easily.
>
> My original code added this as a CONFIG option, but I converted it into
> a boot-time switch, so I can just dig out history and convert it back.
> I wonder if we should get more opinions on this to make a decision.
Form my perspective, you as a contributor has done the work to scratch
your own itch, hence I said "not asking you to do the work". I don't
want to turn every comment into a formal ask and eventually lead to
feature creep.
>
> I would love Xen to have static key support though so that a boot-time
> switch costs no run-time performance.
>
Yes that would be great.
Wei.
> Hongyan
>
next prev parent reply other threads:[~2020-05-01 13:12 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-30 20:44 [PATCH 00/16] Remove the direct map Hongyan Xia
2020-04-30 20:44 ` [PATCH 01/16] x86/setup: move vm_init() before acpi calls Hongyan Xia
2020-04-30 20:44 ` [PATCH 02/16] acpi: vmap pages in acpi_os_alloc_memory Hongyan Xia
2020-05-01 12:02 ` Wei Liu
2020-05-01 12:46 ` Hongyan Xia
2020-05-01 21:35 ` Julien Grall
2020-05-04 8:27 ` Hongyan Xia
2020-04-30 20:44 ` [PATCH 03/16] x86/numa: vmap the pages for memnodemap Hongyan Xia
2020-04-30 20:44 ` [PATCH 04/16] x86/srat: vmap the pages for acpi_slit Hongyan Xia
2020-11-30 10:16 ` Jan Beulich
2020-11-30 18:11 ` Hongyan Xia
2020-12-01 7:37 ` Jan Beulich
2020-04-30 20:44 ` [PATCH 05/16] x86: map/unmap pages in restore_all_guests Hongyan Xia
2020-04-30 20:44 ` [PATCH 06/16] x86/pv: domheap pages should be mapped while relocating initrd Hongyan Xia
2020-04-30 20:44 ` [PATCH 07/16] x86/pv: rewrite how building PV dom0 handles domheap mappings Hongyan Xia
2020-04-30 20:44 ` [PATCH 08/16] x86: add Persistent Map (PMAP) infrastructure Hongyan Xia
2020-04-30 20:44 ` [PATCH 09/16] x86: lift mapcache variable to the arch level Hongyan Xia
2020-04-30 20:44 ` [PATCH 10/16] x86/mapcache: initialise the mapcache for the idle domain Hongyan Xia
2020-04-30 20:44 ` [PATCH 11/16] x86: add a boot option to enable and disable the direct map Hongyan Xia
2020-05-01 8:43 ` Julien Grall
2020-05-01 12:11 ` Wei Liu
2020-05-01 12:59 ` Hongyan Xia
2020-05-01 13:11 ` Wei Liu [this message]
2020-05-01 15:59 ` Julien Grall
2020-04-30 20:44 ` [PATCH 12/16] x86/domain_page: remove the fast paths when mfn is not in the directmap Hongyan Xia
2020-04-30 20:44 ` [PATCH 13/16] xen/page_alloc: add a path for xenheap when there is no direct map Hongyan Xia
2020-05-01 8:50 ` Julien Grall
2021-04-22 12:31 ` Jan Beulich
2021-04-28 11:04 ` Hongyan Xia
2021-04-28 11:51 ` Jan Beulich
2021-04-28 13:22 ` Hongyan Xia
2021-04-28 13:55 ` Jan Beulich
2020-04-30 20:44 ` [PATCH 14/16] x86/setup: leave early boot slightly earlier Hongyan Xia
2020-04-30 20:44 ` [PATCH 15/16] x86/setup: vmap heap nodes when they are outside the direct map Hongyan Xia
2020-04-30 20:44 ` [PATCH 16/16] x86/setup: do not create valid mappings when directmap=no Hongyan Xia
2020-05-01 12:07 ` [PATCH 00/16] Remove the direct map Wei Liu
2020-05-01 13:53 ` Hongyan Xia
2020-06-02 9:08 ` Wei Liu
2021-04-28 10:14 ` Hongyan Xia
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=20200501131158.utexymcn3lnt65qp@liuwe-devbox-debian-v2.j3c5onc20sse1dnehy4noqpfcg.zx.internal.cloudapp.net \
--to=wl@xen.org \
--cc=Volodymyr_Babchuk@epam.com \
--cc=andrew.cooper3@citrix.com \
--cc=george.dunlap@citrix.com \
--cc=hx242@xen.org \
--cc=ian.jackson@eu.citrix.com \
--cc=jbeulich@suse.com \
--cc=julien@xen.org \
--cc=roger.pau@citrix.com \
--cc=sstabellini@kernel.org \
--cc=xen-devel@lists.xenproject.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).