From: Dave Young <dyoung@redhat.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@kernel.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Matt Fleming <matt@codeblueprint.co.uk>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
Leif Lindholm <leif.lindholm@linaro.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
Matt Fleming <matt.fleming@intel.com>,
Mark Rutland <mark.rutland@arm.com>,
Mark Salter <msalter@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>,
Denys Vlasenko <dvlasenk@redhat.com>,
Brian Gerst <brgerst@gmail.com>
Subject: Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions
Date: Tue, 29 Sep 2015 17:31:00 +0800 [thread overview]
Message-ID: <20150929093100.GF30623@dhcp-129-73.nay.redhat.com> (raw)
In-Reply-To: <20150927104014.GA7631@pd.tnic>
On 09/27/15 at 12:40pm, Borislav Petkov wrote:
> On Sun, Sep 27, 2015 at 09:06:44AM +0200, Ingo Molnar wrote:
> > Could we please re-list all the arguments pro and contra of 1:1 physical mappings,
> > in a post that also explains the background so that more people can chime in, not
> > just people versed in EFI internals? It's very much possible that a bad decision
> > was made.
>
> The main reason why we did the additional, top-down mapping was kexec
> kernel wanting to use UEFI runtime facilities too and the braindead
> design of SetVirtualAddressMap() being callable only once per system
> boot. So we had to have stable mappings which are valid in the kexec-ed
> kernel too.
>
> But this was long time ago and I most certainly have forgotten all the
> details.
>
> And now I'm wondering why didn't we do the 1:1 thing and rebuild the
> exact same EFI pagetable in the kexec-ed kernel? Because when we do
> an EFI call, we switch to the special pagetable so why didn't we make
> the kexec-ed kernel rebuild the 1:1 pagetable which it can use for EFI
> calls...
>
> Hmm, again, I've forgotten a lot of details so I'm sure Matt will come
> in and say "No, you can't do that because..."
>
http://permalink.gmane.org/gmane.linux.kernel.efi/822
And more replies here:
http://comments.gmane.org/gmane.linux.kernel.efi/820
Thanks
Dave
next prev parent reply other threads:[~2015-09-29 9:31 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-25 22:02 [GIT PULL 0/2] EFI urgent fixes Matt Fleming
2015-09-25 22:02 ` [PATCH 1/2] x86/efi: Map EFI memmap entries in-order at runtime Matt Fleming
[not found] ` <1443218539-7610-2-git-send-email-matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2015-09-26 5:56 ` Ingo Molnar
[not found] ` <20150926055643.GA25877-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-09-26 6:44 ` Ard Biesheuvel
2015-09-26 17:01 ` Andy Lutomirski
2015-09-26 17:20 ` H. Peter Anvin
[not found] ` <E40EBF14-FD9E-49C0-A7FB-951958F72F79-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2015-09-26 18:15 ` Ard Biesheuvel
2015-09-26 19:49 ` H. Peter Anvin
2015-09-26 19:57 ` Matt Fleming
[not found] ` <20150926195755.GC3144-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2015-09-26 20:09 ` Ard Biesheuvel
2015-09-26 20:19 ` H. Peter Anvin
2015-09-27 16:30 ` Andy Lutomirski
[not found] ` <CALCETrUA6k-oHzuWA54VzEA1v63b5--JPCCuBoOxLisOtjUn+g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-27 18:06 ` Matthew Garrett
[not found] ` <20150927180633.GA29466-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org>
2015-09-28 6:16 ` Ingo Molnar
2015-09-28 6:41 ` Matthew Garrett
[not found] ` <20150928064143.GA7380-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org>
2015-09-29 21:58 ` Laszlo Ersek
2015-09-30 9:30 ` Ard Biesheuvel
[not found] ` <CAKv+Gu-enULj-OMRufB3OPSUVueM1843bD1CdFybaAS7xMUKgw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-30 16:43 ` Andy Lutomirski
2015-09-30 17:24 ` James Bottomley
[not found] ` <20150928061646.GA21690-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-09-30 0:54 ` H. Peter Anvin
2015-09-26 19:55 ` Matt Fleming
2015-09-27 6:50 ` Ingo Molnar
2015-09-26 13:43 ` Matt Fleming
[not found] ` <20150926134329.GA3144-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2015-09-27 7:03 ` Ingo Molnar
2015-09-28 6:49 ` Ard Biesheuvel
[not found] ` <CAKv+Gu8M2pmzfeA=NT4c44E6-PQvRKHZjEJt78mryGcp6bBD8w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-28 8:22 ` Ingo Molnar
[not found] ` <20150928082245.GA28796-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-09-28 9:51 ` Ard Biesheuvel
2015-09-29 9:12 ` Ingo Molnar
2015-09-29 10:41 ` Ard Biesheuvel
[not found] ` <CAKv+Gu8GpaHRL8EZxJCs8dw8ngFVoYNP1Q=hqhZ=LOF+3vXPLw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-29 14:18 ` Matt Fleming
[not found] ` <20150929091230.GA2023-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-09-29 13:52 ` Matt Fleming
2015-09-25 22:02 ` [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Matt Fleming
[not found] ` <1443218539-7610-3-git-send-email-matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2015-09-26 6:01 ` Ingo Molnar
[not found] ` <20150926060159.GB25877-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-09-26 7:08 ` Ard Biesheuvel
[not found] ` <CAKv+Gu_JRCmx5qKq7SDDq73BegVs3LKZwe+OdvTKb4YD_CURyw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-27 7:06 ` Ingo Molnar
2015-09-27 10:40 ` Borislav Petkov
2015-09-28 6:20 ` Ingo Molnar
2015-09-29 9:31 ` Dave Young [this message]
2015-09-29 10:24 ` Borislav Petkov
[not found] ` <20150927104014.GA7631-fF5Pk5pvG8Y@public.gmane.org>
2015-09-29 14:36 ` Matt Fleming
[not found] ` <20150929143612.GC4401-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2015-09-30 0:56 ` H. Peter Anvin
[not found] ` <560B3327.9020801-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2015-09-30 8:33 ` Borislav Petkov
2015-09-30 1:03 ` H. Peter Anvin
2015-09-30 1:16 ` Andy Lutomirski
2015-09-30 1:19 ` H. Peter Anvin
[not found] ` <CALCETrVvwxZN95swaUDG2fkz9brWV3BQkfMDtLJXZkTRpe8nRg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-09-30 4:24 ` Ard Biesheuvel
2015-10-01 10:44 ` Ingo Molnar
-- strict thread matches above, loose matches on Subject: below --
2015-06-30 10:17 [PATCH 0/2] arm64/efi: adapt to UEFI 2.5 properties table changes Ard Biesheuvel
[not found] ` <1435659443-17625-1-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2015-06-30 10:17 ` [PATCH 2/2] arm64/efi: don't pad between EFI_MEMORY_RUNTIME regions Ard Biesheuvel
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