From: Matt Fleming <matt@codeblueprint.co.uk>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>,
Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Toshi Kani <toshi.kani@hp.com>, Brian Gerst <brgerst@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Luis Rodriguez <mcgrof@suse.com>,
Andrew Morton <akpm@linux-foundation.org>,
Denys Vlasenko <dvlasenk@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
ricardo.neri@intel.com, Hugh Dickins <hughd@google.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>
Subject: Re: [tip:efi/core] x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings
Date: Wed, 24 Feb 2016 19:33:15 +0000 [thread overview]
Message-ID: <20160224193315.GD2603@codeblueprint.co.uk> (raw)
In-Reply-To: <CALCETrVDy2hB_eww8rB0FSWNJMiU0ZZOmWNxpcXsfmupiO8YLw@mail.gmail.com>
On Wed, 24 Feb, at 08:36:33AM, Andy Lutomirski wrote:
> On Wed, Feb 24, 2016 at 8:20 AM, Borislav Petkov <bp@alien8.de> wrote:
> > On Wed, Feb 24, 2016 at 02:10:46PM +0000, Matt Fleming wrote:
> >> > Normally, the only pages with are _PAGE_GLOBAL are those that are in
> >> > the normal kernel mappings (swapper_pg_dir and normal mm_struct pgds).
> >> > By allowing _PAGE_GLOBAL to be set in EFI mappings, you're breaking
> >> > that convention, which forces you to use extra-expensive
> >> > __flush_tlb_all calls in efi_call_virt.
> >
> > Hold on, do you mean the __flush_tlb_all() in the CONFIG_EFI_MIXED code?
> >
> > That's mixed mode. I think you mean the FLUSH_TLB_ALL in efi_call.
> > That's EFI on 64-bit but that is mandated by the spec, AFAIR.
>
> I mean the one in efi_call_virt. Why would the spec mandate a TLB
> flush at all? EFI runtime services have no business touching the
> paging structures directly. Heck, the 32-bit ones don't even know the
> *format* of the paging structures.
Right, and it would necessitate copying out arguments because the
firmware won't understand where/how the kernel has mapped things.
No firmware is going to be doing that.
next prev parent reply other threads:[~2016-02-24 19:33 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-17 12:35 [GIT PULL 00/13] EFI changes for v4.6 part 2 Matt Fleming
2016-02-17 12:35 ` [PATCH 01/13] efi: Reformat GUID tables to follow the format in UEFI spec Matt Fleming
2016-02-22 12:12 ` [tip:efi/core] " =?UTF-8?B?dGlwLWJvdCBmb3IgUGV0ZXIgSm9uZXMgPHRpcGJvdEB6eXRvci5jb20+?=
2016-02-17 12:35 ` [PATCH 02/13] efi/runtime-wrappers: Run UEFI Runtime Services with interrupts enabled Matt Fleming
2016-02-22 12:13 ` [tip:efi/core] " =?UTF-8?B?dGlwLWJvdCBmb3IgQXJkIEJpZXNoZXV2ZWwgPHRpcGJvdEB6eXRvci5jb20+?=
2016-02-17 12:35 ` [PATCH 03/13] x86/mm/pageattr: Use _PAGE_GLOBAL bit for EFI page table mappings Matt Fleming
2016-02-22 12:13 ` [tip:efi/core] x86/mm/pat: " =?UTF-8?B?dGlwLWJvdCBmb3IgU2FpIFByYW5lZXRoIDx0aXBib3RAenl0b3IuY29tPg==?=
2016-02-23 17:47 ` Andy Lutomirski
2016-02-23 18:08 ` Linus Torvalds
2016-02-23 18:12 ` Borislav Petkov
2016-02-24 2:09 ` H. Peter Anvin
2016-02-24 2:13 ` H. Peter Anvin
2016-02-25 8:59 ` Ingo Molnar
2016-02-24 0:50 ` Sai Praneeth Prakhya
2016-02-24 2:43 ` Andy Lutomirski
2016-02-24 14:10 ` Matt Fleming
2016-02-24 16:20 ` Borislav Petkov
2016-02-24 16:36 ` Andy Lutomirski
2016-02-24 18:56 ` Linus Torvalds
2016-02-24 19:45 ` Matt Fleming
2016-02-24 19:50 ` Andy Lutomirski
2016-02-29 10:56 ` Sylvain Chouleur
2016-03-02 11:20 ` Matt Fleming
2016-02-24 19:33 ` Matt Fleming [this message]
2016-02-24 19:49 ` Andy Lutomirski
2016-02-25 9:06 ` Ingo Molnar
2016-02-25 15:27 ` Matt Fleming
2016-02-24 16:41 ` Borislav Petkov
2016-02-24 16:47 ` Andy Lutomirski
2016-02-24 16:39 ` Andy Lutomirski
2016-02-25 16:00 ` Matt Fleming
2016-02-17 12:35 ` [PATCH 04/13] efi/arm64: Drop __init annotation from handle_kernel_image() Matt Fleming
2016-02-22 12:14 ` [tip:efi/core] " =?UTF-8?B?dGlwLWJvdCBmb3IgQXJkIEJpZXNoZXV2ZWwgPHRpcGJvdEB6eXRvci5jb20+?=
2016-02-17 12:35 ` [PATCH 05/13] arm64: vmlinux.lds.S: Handle .init.rodata.xxx and .init.bss sections Matt Fleming
2016-02-22 12:14 ` [tip:efi/core] arm64/vmlinux.lds.S: " =?UTF-8?B?dGlwLWJvdCBmb3IgQXJkIEJpZXNoZXV2ZWwgPHRpcGJvdEB6eXRvci5jb20+?=
2016-02-17 12:35 ` [PATCH 06/13] efi/efistub: Prevent __init annotations from being used Matt Fleming
2016-02-22 12:14 ` [tip:efi/core] " =?UTF-8?B?dGlwLWJvdCBmb3IgQXJkIEJpZXNoZXV2ZWwgPHRpcGJvdEB6eXRvci5jb20+?=
2016-02-17 12:36 ` [PATCH 07/13] efi/arm-init: Use read-only early mappings Matt Fleming
2016-02-22 12:15 ` [tip:efi/core] " =?UTF-8?B?dGlwLWJvdCBmb3IgQXJkIEJpZXNoZXV2ZWwgPHRpcGJvdEB6eXRvci5jb20+?=
2016-02-17 12:36 ` [PATCH 08/13] efi/arm: Check for LPAE support before booting a LPAE kernel Matt Fleming
2016-02-22 12:15 ` [tip:efi/core] " =?UTF-8?B?dGlwLWJvdCBmb3IgQXJkIEJpZXNoZXV2ZWwgPHRpcGJvdEB6eXRvci5jb20+?=
2016-02-17 12:36 ` [PATCH 09/13] efi/arm64: Check for h/w support before booting a >4 KB granule kernel Matt Fleming
2016-02-22 12:16 ` [tip:efi/core] efi/arm64: Check for h/w support before booting a >4 KB granular kernel =?UTF-8?B?dGlwLWJvdCBmb3IgQXJkIEJpZXNoZXV2ZWwgPHRpcGJvdEB6eXRvci5jb20+?=
2016-03-06 3:35 ` [PATCH 09/13] efi/arm64: Check for h/w support before booting a >4 KB granule kernel Ard Biesheuvel
2016-03-07 11:02 ` Matt Fleming
2016-03-07 11:05 ` Ard Biesheuvel
2016-02-17 12:36 ` [PATCH 10/13] efi/arm*: Perform hardware compatibility check Matt Fleming
2016-02-22 12:16 ` [tip:efi/core] " =?UTF-8?B?dGlwLWJvdCBmb3IgQXJkIEJpZXNoZXV2ZWwgPHRpcGJvdEB6eXRvci5jb20+?=
2016-02-17 12:36 ` [PATCH 11/13] x86/mm/pageattr: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd() Matt Fleming
2016-02-22 12:16 ` [tip:efi/core] x86/mm/pat: " =?UTF-8?B?dGlwLWJvdCBmb3IgU2FpIFByYW5lZXRoIDx0aXBib3RAenl0b3IuY29tPg==?=
2016-02-17 12:36 ` [PATCH 12/13] x86/efi: Map EFI_MEMORY_{XP,RO} memory region bits to EFI page tables Matt Fleming
2016-02-22 12:17 ` [tip:efi/core] " =?UTF-8?B?dGlwLWJvdCBmb3IgU2FpIFByYW5lZXRoIDx0aXBib3RAenl0b3IuY29tPg==?=
2016-02-17 12:36 ` [PATCH 13/13] x86/efi: Only map kernel text for EFI mixed mode Matt Fleming
2016-02-22 12:17 ` [tip:efi/core] " =?UTF-8?B?dGlwLWJvdCBmb3IgU2FpIFByYW5lZXRoIDx0aXBib3RAenl0b3IuY29tPg==?=
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