From: Bin Meng <bmeng.cn@gmail.com>
To: Richard Henderson <richard.henderson@linaro.org>
Cc: QEMU riscv <qemu-riscv@nongnu.org>,
Sagar Karandikar <sagark@eecs.berkeley.edu>,
Bastian Koppelmann <kbastian@mail.uni-paderborn.de>,
Palmer Dabbelt <palmer@sifive.com>,
QEMU devel <qemu-devel@nongnu.org>,
Alistair Francis <Alistair.Francis@wdc.com>
Subject: Re: [Qemu-devel] [PATCH] riscv: rv32: Root page table address can be larger than 32-bit
Date: Thu, 1 Aug 2019 22:57:52 +0800 [thread overview]
Message-ID: <CAEUhbmX2C_FbW_m=Mri19hpz0c74SQTt3ogsatGgveH09t3_4g@mail.gmail.com> (raw)
In-Reply-To: <ac4453de-81cd-c32a-17f8-283fa3569ed0@linaro.org>
On Thu, Aug 1, 2019 at 10:16 PM Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> On 7/31/19 6:53 PM, Bin Meng wrote:
> > I am not sure how (idx * ptesize) could overflow. It represents the
> > offset by a page table which is [0, 4096).
>
> You're right, I mis-read what was going on there.
>
> However, lower down, "target_ulong ppn" needs to be promoted to hwaddr, so that
>
> ppn = pte >> PTE_PPN_SHIFT;
> ...
> base = ppn << PGSHIFT;
>
> does not overflow. (Which is the part of the page table walk that I thought I
> had gleaned from the patch without actually reading the entire function.)
Ah, yes. ppn should be promoted. Thanks for the review!
Regards,
Bin
next prev parent reply other threads:[~2019-08-01 15:01 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-31 12:45 [Qemu-devel] [PATCH] riscv: rv32: Root page table address can be larger than 32-bit Bin Meng
2019-07-31 17:35 ` Richard Henderson
2019-08-01 1:53 ` Bin Meng
2019-08-01 14:16 ` Richard Henderson
2019-08-01 14:57 ` Bin Meng [this message]
2019-08-07 20:55 ` Palmer Dabbelt
2019-08-08 1:49 ` Bin Meng
2019-08-08 2:49 ` [Qemu-devel] [PATCH v2] " Bin Meng
2019-08-10 1:49 ` Alistair Francis
2019-08-14 9:46 ` Bin Meng
2019-08-19 6:00 ` Bin Meng
2019-08-27 23:37 ` Palmer Dabbelt
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='CAEUhbmX2C_FbW_m=Mri19hpz0c74SQTt3ogsatGgveH09t3_4g@mail.gmail.com' \
--to=bmeng.cn@gmail.com \
--cc=Alistair.Francis@wdc.com \
--cc=kbastian@mail.uni-paderborn.de \
--cc=palmer@sifive.com \
--cc=qemu-devel@nongnu.org \
--cc=qemu-riscv@nongnu.org \
--cc=richard.henderson@linaro.org \
--cc=sagark@eecs.berkeley.edu \
/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).