From: Andrew Jones <drjones@redhat.com>
To: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <Peter.Maydell@arm.com>,
Juan Quintela <quintela@redhat.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, qemu-devel@nongnu.org,
"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
Marc Zyngier <maz@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Steven Price <steven.price@arm.com>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
Dave Martin <Dave.Martin@arm.com>
Subject: Re: [PATCH v2 0/2] MTE support for KVM guest
Date: Thu, 10 Sep 2020 07:44:40 +0200 [thread overview]
Message-ID: <20200910054440.pvnzk7p7riiy45e2@kamzik.brq.redhat.com> (raw)
In-Reply-To: <5cb1d7ed-54a5-4337-6c3d-2e3e7df89f17@linaro.org>
On Wed, Sep 09, 2020 at 06:45:33PM -0700, Richard Henderson wrote:
> On 9/9/20 8:25 AM, Andrew Jones wrote:
> >> * Provide a KVM-specific method to extract the tags from guest memory.
> >> This might also have benefits in terms of providing an easy way to
> >> read bulk tag data from guest memory (since the LDGM instruction
> >> isn't available at EL0).
> >
> > Maybe we need a new version of KVM_GET_DIRTY_LOG that also provides
> > the tags for all addresses of each dirty page.
>
> KVM_GET_DIRTY_LOG just provides one bit per dirty page, no? Then VMM copies
> the data out from its local address to guest memory.
>
> There'd be no difference with or without tags, afaik. It's just about how VMM
> copies the data, with or without tags.
Right, as long as it's fast enough to do
for_each_dirty_page(page, dirty_log)
for (i = 0; i < host-page-size/16; i += 16)
append_tag(LDG(page + i))
to get all the tags for each dirty page. I understood it would be faster
to use LDGM, but we'd need a new ioctl for that. So I was proposing we
just piggyback on a new dirty-log ioctl instead.
Thanks,
drew
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-09-10 5:46 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-04 16:00 [PATCH v2 0/2] MTE support for KVM guest Steven Price
2020-09-04 16:00 ` [PATCH v2 1/2] arm64: kvm: Save/restore MTE registers Steven Price
2020-09-04 16:00 ` [PATCH v2 2/2] arm64: kvm: Introduce MTE VCPU feature Steven Price
2020-09-09 15:48 ` Andrew Jones
2020-09-09 15:53 ` Peter Maydell
2020-09-10 6:38 ` Andrew Jones
2020-09-10 10:01 ` Andrew Jones
2020-09-10 9:21 ` Steven Price
2020-09-10 11:49 ` Andrew Jones
2020-09-07 15:28 ` [PATCH v2 0/2] MTE support for KVM guest Dr. David Alan Gilbert
2020-09-09 9:15 ` Steven Price
2020-09-09 15:25 ` Andrew Jones
2020-09-09 16:04 ` Steven Price
2020-09-10 6:29 ` Andrew Jones
2020-09-10 9:21 ` Steven Price
2020-09-10 13:56 ` Andrew Jones
2020-09-10 14:14 ` Steven Price
2020-09-10 1:45 ` Richard Henderson
2020-09-10 5:44 ` Andrew Jones [this message]
2020-09-10 13:27 ` Dr. David Alan Gilbert
2020-09-10 13:39 ` Andrew Jones
2020-09-10 0:33 ` Richard Henderson
2020-09-10 10:24 ` Steven Price
2020-09-10 15:36 ` Richard Henderson
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=20200910054440.pvnzk7p7riiy45e2@kamzik.brq.redhat.com \
--to=drjones@redhat.com \
--cc=Dave.Martin@arm.com \
--cc=Peter.Maydell@arm.com \
--cc=catalin.marinas@arm.com \
--cc=dgilbert@redhat.com \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=qemu-devel@nongnu.org \
--cc=quintela@redhat.com \
--cc=richard.henderson@linaro.org \
--cc=steven.price@arm.com \
--cc=tglx@linutronix.de \
--cc=will@kernel.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).