Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1233638
| From | Borislav Petkov <bp@alien8.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions |
| Date | 2015-09-27 12:20 +0200 |
| Message-ID | <qdhdL-4an-3@gated-at.bofh.it> (permalink) |
| References | <qcJlL-5Zx-9@gated-at.bofh.it> <qcJlL-5Zx-11@gated-at.bofh.it> <qcQQh-8hB-7@gated-at.bofh.it> <qcRMm-1bF-5@gated-at.bofh.it> <qdefT-8pw-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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..."
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Matt Fleming <matt@codeblueprint.co.uk> - 2015-09-26 00:10 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Ingo Molnar <mingo@kernel.org> - 2015-09-26 08:10 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2015-09-26 09:10 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Ingo Molnar <mingo@kernel.org> - 2015-09-27 09:10 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Borislav Petkov <bp@alien8.de> - 2015-09-27 12:20 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Ingo Molnar <mingo@kernel.org> - 2015-09-28 08:30 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Dave Young <dyoung@redhat.com> - 2015-09-29 11:40 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Borislav Petkov <bp@alien8.de> - 2015-09-29 12:30 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Matt Fleming <matt@codeblueprint.co.uk> - 2015-09-29 16:40 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions "H. Peter Anvin" <hpa@zytor.com> - 2015-09-30 03:00 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Borislav Petkov <bp@alien8.de> - 2015-09-30 10:40 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions "H. Peter Anvin" <hpa@zytor.com> - 2015-09-30 03:10 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Andy Lutomirski <luto@amacapital.net> - 2015-09-30 03:20 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions "H. Peter Anvin" <hpa@zytor.com> - 2015-09-30 03:20 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2015-09-30 06:30 +0200
Re: [PATCH 2/2] arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions Ingo Molnar <mingo@kernel.org> - 2015-10-01 12:50 +0200
[tip:core/urgent] arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions tip-bot for Ard Biesheuvel <tipbot@zytor.com> - 2015-10-01 15:00 +0200
csiph-web