From: "Gerd Hoffmann" <kraxel@redhat.com>
To: Dun Tan <dun.tan@intel.com>
Cc: devel@edk2.groups.io, Ray Ni <ray.ni@intel.com>,
Laszlo Ersek <lersek@redhat.com>,
Rahul Kumar <rahul1.kumar@intel.com>
Subject: Re: [edk2-devel] [PATCH] UefiCpuPkg:Limit PhysicalAddressBits in speicial case
Date: Wed, 10 Jan 2024 11:54:30 +0100 [thread overview]
Message-ID: <c7ahft27s5rozrirr3mdlzfdc7gfid2qaaf4c3iwhcn6x4czsy@3hiex4wsjftd> (raw)
In-Reply-To: <20240110080544.1350-1-dun.tan@intel.com>
On Wed, Jan 10, 2024 at 04:05:44PM +0800, Dun Tan wrote:
> When creating smm page table, limit maximum
> supported physical address bits returned by
> CalculateMaximumSupportAddress() to 48 if
> 5-Level Paging is disabled.
> When 5-Level Paging is disabled and the
> PhysicalAddressBits retrived from CPU HOB or
> CpuId is bigger than 48, only [0, 2^48 -1]
> range in 52-bit physical address is mapped
> in page table.
I think this is wrong. Virtual addresses are sign-extended,
i.e. the virtual address space without 5-level paging is:
0x0000000000000000 -> 0x00007fffffffffff and
0xffff800000000000 -> 0xffffffffffffffff
Therefore identity-mapping works for [0, 2^47-1] only.
take care,
Gerd
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#113523): https://edk2.groups.io/g/devel/message/113523
Mute This Topic: https://groups.io/mt/103637402/7686176
Group Owner: devel+owner@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io]
-=-=-=-=-=-=-=-=-=-=-=-
next prev parent reply other threads:[~2024-01-10 10:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-10 8:05 [edk2-devel] [PATCH] UefiCpuPkg:Limit PhysicalAddressBits in speicial case duntan
2024-01-10 9:08 ` Ni, Ray
2024-01-10 10:54 ` Gerd Hoffmann [this message]
2024-01-10 12:19 ` Laszlo Ersek
2024-01-11 1:56 ` duntan
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-list 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=c7ahft27s5rozrirr3mdlzfdc7gfid2qaaf4c3iwhcn6x4czsy@3hiex4wsjftd \
--to=devel@edk2.groups.io \
/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