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From: Ingo Molnar <mingo@kernel.org>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	moritz.lipp@iaik.tugraz.at, daniel.gruss@iaik.tugraz.at,
	michael.schwarz@iaik.tugraz.at,
	richard.fellner@student.tugraz.at, luto@kernel.org,
	torvalds@linux-foundation.org, keescook@google.com,
	hughd@google.com, x86@kernel.org, jgross@suse.com
Subject: Re: [PATCH 00/23] [v4] KAISER: unmap most of the kernel from userspace page tables
Date: Fri, 24 Nov 2017 08:33:38 +0100	[thread overview]
Message-ID: <20171124073338.4petx4rxiwwb5bxu@gmail.com> (raw)
In-Reply-To: <132d8ad8-a85f-5184-2dee-39a47e22e1ff@linux.intel.com>


* Dave Hansen <dave.hansen@linux.intel.com> wrote:

> On 11/23/2017 10:35 PM, Ingo Molnar wrote:
> > So the pteval_t changes break the build on most non-x86 architectures (alpha, arm, 
> > arm64, etc.), because most of them don't have an asm/pgtable_types.h file.
> > 
> > pteval_t is an x86-ism.
> > 
> > So I left out the changes below.
> 
> There was a warning on the non-PAE 32-bit builds saying that there was a
> shift larger than the type.  I assumed this was because of a reference
> to _PAGE_NX, and thus we needed a change to pteval_t.
> 
> But, now that I think about it more, that doesn't make sense since
> _PAGE_NX should be #defined down to a 0 on those configs unless
> something is wrong.

If pte flags need to be passed around then the canonical way to do it is to pass 
around a pte_t, and use pte_val() on it and such.

But please investigate the warning.

One other detail: I see you fixed some of the commit titles to use standard x86 
tags - could you please also capitalize sentences? I.e.:

  - x86/mm/kaiser: allow flushing for future ASID switches
  + x86/mm/kaiser: Allow flushing for future ASID switches

Could you please also double-check whether the merges I did in the latest 
WIP.x86/mm branch are OK? Andy changed the entry stack code a bit under Kaiser, 
which created about 3 new conflicts.

The key resolutions that I did were:

        .macro interrupt func
        cld

        testb   $3, CS-ORIG_RAX(%rsp)
        jz      1f
        SWAPGS
        SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
        call    switch_to_thread_stack
1:

Plus I also dropped the extra switch_to_thread_stack call done in:

  x86/mm/kaiser: Prepare assembly for entry/exit CR3 switching

Because Andy's latest preparatory patch does it now:

  x86/entry/64: Use a percpu trampoline stack for IDT entries

Thanks,

	Ingo

      reply	other threads:[~2017-11-24  7:33 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-23  0:34 [PATCH 00/23] [v4] KAISER: unmap most of the kernel from userspace page tables Dave Hansen
2017-11-23  0:34 ` [PATCH 01/23] x86, kaiser: disable global pages by default with KAISER Dave Hansen
2017-11-23  0:34 ` [PATCH 02/23] x86, kaiser: prepare assembly for entry/exit CR3 switching Dave Hansen
2017-11-23  0:34 ` [PATCH 03/23] x86, kaiser: introduce user-mapped per-cpu areas Dave Hansen
2017-11-23  0:34 ` [PATCH 04/23] x86, kaiser: mark per-cpu data structures required for entry/exit Dave Hansen
2017-11-23  0:34 ` [PATCH 05/23] x86, kaiser: unmap kernel from userspace page tables (core patch) Dave Hansen
2017-11-23  4:07   ` Andy Lutomirski
2017-11-26 16:10     ` Andy Lutomirski
2017-11-26 16:24       ` Dave Hansen
2017-11-26 16:29         ` Andy Lutomirski
2018-01-05  4:16   ` Yisheng Xie
2018-01-05  5:18     ` Dave Hansen
2018-01-05  6:16       ` Yisheng Xie
2018-01-05  6:29         ` Dave Hansen
2018-01-05 11:49           ` Andrea Arcangeli
2018-01-05 18:19           ` Jiri Kosina
2018-01-05 19:00             ` Jiri Kosina
2018-01-05 19:03             ` Dave Hansen
2018-01-05 19:17               ` Jiri Kosina
2018-01-05 19:18                 ` Jiri Kosina
2018-01-05 19:55                 ` Andrea Arcangeli
2018-01-05 21:07                 ` Dave Hansen
2018-01-05 21:14                   ` Jiri Kosina
2018-01-05 21:29                     ` Andy Lutomirski
2018-01-05 22:48                     ` Hugh Dickins
2018-01-06  4:54             ` Hanjun Guo
2018-01-06  6:06               ` Dave Hansen
2018-01-06  6:28                 ` Hanjun Guo
2018-01-06  6:53                   ` Hanjun Guo
2018-01-06  7:55                     ` Dave Hansen
2018-01-06  8:42                       ` Hanjun Guo
2018-01-06  7:51                   ` Dave Hansen
2018-01-06 17:22                     ` Andrea Arcangeli
2017-11-23  0:34 ` [PATCH 06/23] x86, kaiser: allow NX poison to be set in p4d/pgd Dave Hansen
2017-11-23  0:34 ` [PATCH 07/23] x86, kaiser: make sure static PGDs are 8k in size Dave Hansen
2017-11-23  0:34 ` [PATCH 08/23] x86, kaiser: map cpu entry area Dave Hansen
2017-11-23  0:34 ` [PATCH 09/23] x86, kaiser: map dynamically-allocated LDTs Dave Hansen
2017-11-23 19:42   ` Eric Biggers
2017-11-23 20:12     ` Andy Lutomirski
2017-11-23  0:34 ` [PATCH 10/23] x86, kaiser: map espfix structures Dave Hansen
2017-11-23  0:34 ` [PATCH 11/23] x86, kaiser: map entry stack variables Dave Hansen
2017-11-23  3:31   ` Andy Lutomirski
2017-11-23 15:37     ` Dave Hansen
2017-11-23 15:55       ` Andy Lutomirski
2017-11-23  0:35 ` [PATCH 12/23] x86, kaiser: map virtually-addressed performance monitoring buffers Dave Hansen
2017-11-23  0:35 ` [PATCH 13/23] x86, mm: Move CR3 construction functions Dave Hansen
2017-11-23  0:35 ` [PATCH 14/23] x86, mm: remove hard-coded ASID limit checks Dave Hansen
2017-11-23  0:35 ` [PATCH 15/23] x86, mm: put mmu-to-h/w ASID translation in one place Dave Hansen
2017-11-23  0:35 ` [PATCH 16/23] x86, pcid, kaiser: allow flushing for future ASID switches Dave Hansen
2017-11-23  0:35 ` [PATCH 17/23] x86, kaiser: use PCID feature to make user and kernel switches faster Dave Hansen
2017-11-23  0:35 ` [PATCH 18/23] x86, kaiser: disable native VSYSCALL Dave Hansen
2017-11-23  0:35 ` [PATCH 19/23] x86, kaiser: add debugfs file to turn KAISER on/off at runtime Dave Hansen
2017-11-23  0:35 ` [PATCH 20/23] x86, kaiser: add a function to check for KAISER being enabled Dave Hansen
2017-11-25  1:23   ` Eduardo Valentin
2017-11-23  0:35 ` [PATCH 21/23] x86, kaiser: un-poison PGDs at runtime Dave Hansen
2017-11-25  1:17   ` Eduardo Valentin
2017-11-23  0:35 ` [PATCH 22/23] x86, kaiser: allow KAISER to be enabled/disabled " Dave Hansen
2017-11-23  0:35 ` [PATCH 23/23] x86, kaiser: add Kconfig Dave Hansen
2017-11-23  7:23 ` [PATCH 00/23] [v4] KAISER: unmap most of the kernel from userspace page tables Ingo Molnar
2017-11-23  7:27 ` Ingo Molnar
2017-11-23  7:32   ` Ingo Molnar
2017-11-23 15:02     ` Dave Hansen
2017-11-23 16:20 ` Dave Hansen
2017-11-24  6:35   ` Ingo Molnar
2017-11-24  6:41     ` Dave Hansen
2017-11-24  7:33       ` Ingo Molnar [this message]

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