From: Peter Xu <peterx@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>,
Yan Zhao <yan.y.zhao@intel.com>,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] memory: do not do out of bound notification
Date: Fri, 21 Jun 2019 10:36:13 +0800 [thread overview]
Message-ID: <20190621023613.GB9371@xz-x1> (raw)
In-Reply-To: <df223a1f-bb87-0914-6216-8a4a70aae3ab@redhat.com>
On Thu, Jun 20, 2019 at 03:14:04PM +0200, Paolo Bonzini wrote:
> On 20/06/19 14:59, Peter Xu wrote:
> > I feel like this can be problematic. I'm imaging:
> >
> > start=0x1000_0000, size=0x1000_1000
> >
> > This will get size=0x1000 but actually we can do size=0x1000_0000 as
> > the first.
>
> Right, we can do:
>
> /*
> * If a naturally aligned region starting at "start" ends before "end",
> * use it. Otherwise, keep the lowest bit of size.
> */
> if (size > (start & -start))
> size = start & -start;
May need to consider start==0, otherwise size will be zero here?
> else
> size = size & -size;
Should use MSB rather than LSB of size?
>
> >>
> >> + trace_vtd_as_unmap_whole(pci_bus_num(as->bus),
> >> + VTD_PCI_SLOT(as->devfn),
> >> + VTD_PCI_FUNC(as->devfn),
> >> + entry.iova, size);
> >
> > Can move this out because this is a trace only so we don't have
> > restriction on mask?
> >
> >>
> >> - map.iova = entry.iova;
> >> - map.size = entry.addr_mask;
> >> - iova_tree_remove(as->iova_tree, &map);
> >> + map.iova = entry.iova;
> >> + map.size = entry.addr_mask;
> >> + iova_tree_remove(as->iova_tree, &map);
> >
> > Same here?
> >
>
> Yes, I would move these and the iova_tree_remove outside the loop, while
> keeping entry's initialization inside looks cleaner.
Yeah that's ok to me too.
Thanks,
--
Peter Xu
next prev parent reply other threads:[~2019-06-21 2:48 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-19 8:49 [Qemu-devel] [PATCH] memory: do not do out of bound notification Yan Zhao
2019-06-19 13:17 ` Auger Eric
2019-06-20 1:46 ` Yan Zhao
2019-06-20 4:02 ` Peter Xu
2019-06-20 4:14 ` Yan Zhao
2019-06-20 8:14 ` Peter Xu
2019-06-20 8:13 ` Yan Zhao
2019-06-20 8:35 ` Paolo Bonzini
2019-06-20 10:57 ` Yan Zhao
2019-06-20 12:04 ` Paolo Bonzini
2019-06-20 12:59 ` Peter Xu
2019-06-20 13:04 ` Peter Xu
2019-06-24 5:22 ` Yan Zhao
2019-06-24 6:14 ` Peter Xu
2019-06-20 13:14 ` Paolo Bonzini
2019-06-21 2:36 ` Peter Xu [this message]
2019-06-21 7:57 ` Yan Zhao
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=20190621023613.GB9371@xz-x1 \
--to=peterx@redhat.com \
--cc=eric.auger@redhat.com \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=yan.y.zhao@intel.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).