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From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Andy Lutomirski <luto@amacapital.net>, Mark D Rustad <mrustad@gmail.com>
Cc: Adam Borowski <kilobyte@angband.pl>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Joerg Roedel <jroedel@suse.de>, Andy Lutomirski <luto@kernel.org>,
	Joerg Roedel <joro@8bytes.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	 Ingo Molnar <mingo@kernel.org>,
	"H . Peter Anvin" <hpa@zytor.com>, X86 ML <x86@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Juergen Gross <jgross@suse.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Brian Gerst <brgerst@gmail.com>,
	David Laight <David.Laight@aculab.com>,
	Denys Vlasenko <dvlasenk@redhat.com>,
	Eduardo Valentin <eduval@amazon.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	Will Deacon <will.deacon@arm.com>,
	 "Liguori, Anthony" <aliguori@amazon.com>,
	Daniel Gruss <daniel.gruss@iaik.tugraz.at>,
	Hugh Dickins <hughd@google.com>, Kees Cook <keescook@google.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Waiman Long <llong@redhat.com>, Pavel Machek <pavel@ucw.cz>
Subject: Re: [PATCH 00/31 v2] PTI support for x86_32
Date: Sun, 11 Feb 2018 14:12:40 -0800	[thread overview]
Message-ID: <1518387160.3979.10.camel@HansenPartnership.com> (raw)
In-Reply-To: <0C6EFF56-F135-480C-867C-B117F114A99F@amacapital.net>

On Sun, 2018-02-11 at 11:42 -0800, Andy Lutomirski wrote:
> 
> On Feb 11, 2018, at 9:40 AM, Mark D Rustad <mrustad@gmail.com> wrote:
> 
> > 
> > > 
> > > On Feb 11, 2018, at 2:59 AM, Adam Borowski <kilobyte@angband.pl>
> > > wrote:
> > > 
> > > > 
> > > > Does Debian make it easy to upgrade to a 64-bit kernel if you
> > > > have a
> > > > 32-bit install?
> > > 
> > > Quite easy, yeah.  Crossgrading userspace is not for the faint of
> > > the heart,
> > > but changing just the kernel is fine.
> > 
> > ISTR that iscsi doesn't work when running a 64-bit kernel with a
> > 32-bit userspace. I remember someone offered kernel patches to fix
> > it, but I think they were rejected. I haven't messed with that
> > stuff in many years, so perhaps the userspace side now has
> > accommodation for it. It might be something to check on.
> > 
> 
> At the risk of suggesting heresy, should we consider removing x86_32
> support at some point?

Hey, my cloud server is 32 bit:

bedivere:~# cat /proc/cpuinfo 
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 15
model		: 2
model name	: Intel(R) Pentium(R) 4 CPU 2.80GHz
stepping	: 9
microcode	: 0x2e
cpu MHz		: 2813.464
[...]

I suspect a lot of people are in the same position: grandfathered in on
an old hosting plan, but not really willing to switch to a new 64 bit
box because the monthly cost about doubles and nothing it does is
currently anywhere up to (let alone over) the capacity of the single
686 processor.

The thing which is making me consider it is actually getting a TPM to
protect the private keys, but doubling the monthly cost is still a huge
disincentive.

James

WARNING: multiple messages have this Message-ID (diff)
From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Andy Lutomirski <luto@amacapital.net>, Mark D Rustad <mrustad@gmail.com>
Cc: Adam Borowski <kilobyte@angband.pl>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Joerg Roedel <jroedel@suse.de>, Andy Lutomirski <luto@kernel.org>,
	Joerg Roedel <joro@8bytes.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>,
	X86 ML <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Juergen Gross <jgross@suse.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Brian Gerst <brgerst@gmail.com>,
	David Laight <David.Laight@aculab.com>,
	Denys Vlasenko <dvlasenk@redhat.com>,
	Eduardo Valentin <eduval@amazon.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	Will Deacon <will.deacon@arm.com>,
	"Liguori, Anthony" <aliguori@amazon.com>,
	Daniel Gruss <daniel.gruss@iaik.tugraz.at>,
	Hugh Dickins <hughd@google.com>, Kees Cook <keescook@google.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Waiman Long <llong@redhat.com>, Pavel Machek <pavel@ucw.cz>
Subject: Re: [PATCH 00/31 v2] PTI support for x86_32
Date: Sun, 11 Feb 2018 14:12:40 -0800	[thread overview]
Message-ID: <1518387160.3979.10.camel@HansenPartnership.com> (raw)
In-Reply-To: <0C6EFF56-F135-480C-867C-B117F114A99F@amacapital.net>

On Sun, 2018-02-11 at 11:42 -0800, Andy Lutomirski wrote:
> 
> On Feb 11, 2018, at 9:40 AM, Mark D Rustad <mrustad@gmail.com> wrote:
> 
> > 
> > > 
> > > On Feb 11, 2018, at 2:59 AM, Adam Borowski <kilobyte@angband.pl>
> > > wrote:
> > > 
> > > > 
> > > > Does Debian make it easy to upgrade to a 64-bit kernel if you
> > > > have a
> > > > 32-bit install?
> > > 
> > > Quite easy, yeah.A A Crossgrading userspace is not for the faint of
> > > the heart,
> > > but changing just the kernel is fine.
> > 
> > ISTR that iscsi doesn't work when running a 64-bit kernel with a
> > 32-bit userspace. I remember someone offered kernel patches to fix
> > it, but I think they were rejected. I haven't messed with that
> > stuff in many years, so perhaps the userspace side now has
> > accommodation for it. It might be something to check on.
> > 
> 
> At the risk of suggesting heresy, should we consider removing x86_32
> support at some point?

Hey, my cloud server is 32 bit:

bedivere:~# cat /proc/cpuinfoA 
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 15
model		: 2
model name	: Intel(R) Pentium(R) 4 CPU 2.80GHz
stepping	: 9
microcode	: 0x2e
cpu MHz		: 2813.464
[...]

I suspect a lot of people are in the same position: grandfathered in on
an old hosting plan, but not really willing to switch to a new 64 bit
box because the monthly cost about doubles and nothing it does is
currently anywhere up to (let alone over) the capacity of the single
686 processor.

The thing which is making me consider it is actually getting a TPM to
protect the private keys, but doubling the monthly cost is still a huge
disincentive.

James

--
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  parent reply	other threads:[~2018-02-11 22:12 UTC|newest]

Thread overview: 183+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-09  9:25 [PATCH 00/31 v2] PTI support for x86_32 Joerg Roedel
2018-02-09  9:25 ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 01/31] x86/asm-offsets: Move TSS_sp0 and TSS_sp1 to asm-offsets.c Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 02/31] x86/entry/32: Rename TSS_sysenter_sp0 to TSS_entry_stack Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 03/31] x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 04/31] x86/entry/32: Put ESPFIX code into a macro Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 05/31] x86/entry/32: Unshare NMI return path Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 06/31] x86/entry/32: Split off return-to-kernel path Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 07/31] x86/entry/32: Restore segments before int registers Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 08/31] x86/entry/32: Enter the kernel via trampoline stack Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 09/31] x86/entry/32: Leave " Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09 17:05   ` Linus Torvalds
2018-02-09 17:05     ` Linus Torvalds
2018-02-09 17:17     ` Denys Vlasenko
2018-02-09 17:17       ` Denys Vlasenko
2018-02-10 15:26       ` David Laight
2018-02-10 15:26         ` David Laight
2018-02-10 20:18         ` Linus Torvalds
2018-02-10 20:18           ` Linus Torvalds
2018-02-09 17:43     ` Andy Lutomirski
2018-02-09 17:43       ` Andy Lutomirski
2018-02-09 19:06       ` Joerg Roedel
2018-02-09 19:06         ` Joerg Roedel
2018-02-09 19:02     ` Joerg Roedel
2018-02-09 19:02       ` Joerg Roedel
2018-02-09 19:17       ` Linus Torvalds
2018-02-09 19:17         ` Linus Torvalds
2018-02-09 19:25         ` Joerg Roedel
2018-02-09 19:25           ` Joerg Roedel
2018-02-09 19:48           ` Linus Torvalds
2018-02-09 19:48             ` Linus Torvalds
2018-02-10 15:41             ` David Laight
2018-02-10 15:41               ` David Laight
2018-02-09 19:30       ` Denys Vlasenko
2018-02-09 19:30         ` Denys Vlasenko
2018-02-09  9:25 ` [PATCH 10/31] x86/entry/32: Introduce SAVE_ALL_NMI and RESTORE_ALL_NMI Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 11/31] x86/entry/32: Add PTI cr3 switches to NMI handler code Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 12/31] x86/entry/32: Add PTI cr3 switch to non-NMI entry/exit points Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-27 19:18   ` Waiman Long
2018-02-27 19:18     ` Waiman Long
2018-03-01 12:03     ` Joerg Roedel
2018-03-01 12:03       ` Joerg Roedel
2018-03-01 13:34     ` Joerg Roedel
2018-03-01 13:34       ` Joerg Roedel
2018-03-01 14:33       ` Waiman Long
2018-03-01 14:33         ` Waiman Long
2018-03-01 16:50         ` Joerg Roedel
2018-03-01 16:50           ` Joerg Roedel
2018-03-01 18:24           ` Brian Gerst
2018-03-01 18:24             ` Brian Gerst
2018-03-01 18:36             ` Dave Hansen
2018-03-01 18:36               ` Dave Hansen
2018-03-01 18:38             ` Linus Torvalds
2018-03-01 18:38               ` Linus Torvalds
2018-03-02  9:10               ` Joerg Roedel
2018-03-02  9:10                 ` Joerg Roedel
2018-03-16 20:55                 ` Andy Lutomirski
2018-03-02  9:07             ` Joerg Roedel
2018-03-02  9:07               ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 13/31] x86/entry/32: Handle Entry from Kernel-Mode on Entry-Stack Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 14/31] x86/pgtable/pae: Unshare kernel PMDs when PTI is enabled Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 15/31] x86/pgtable/32: Allocate 8k page-tables " Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 16/31] x86/pgtable: Move pgdp kernel/user conversion functions to pgtable.h Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 17/31] x86/pgtable: Move pti_set_user_pgd() " Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 18/31] x86/pgtable: Move two more functions from pgtable_64.h " Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 19/31] x86/mm/pae: Populate valid user PGD entries Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-14  9:45   ` Juergen Gross
2018-02-14  9:45     ` Juergen Gross
2018-02-14 10:00     ` Joerg Roedel
2018-02-14 10:00       ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 20/31] x86/mm/pae: Populate the user page-table with user pgd's Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09 17:48   ` Andy Lutomirski
2018-02-09 17:48     ` Andy Lutomirski
2018-02-09 19:09     ` Joerg Roedel
2018-02-09 19:09       ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 21/31] x86/mm/legacy: " Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 22/31] x86/mm/pti: Add an overflow check to pti_clone_pmds() Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 23/31] x86/mm/pti: Define X86_CR3_PTI_PCID_USER_BIT on x86_32 Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09 17:42   ` Andy Lutomirski
2018-02-09 17:42     ` Andy Lutomirski
2018-02-09  9:25 ` [PATCH 24/31] x86/mm/pti: Clone CPU_ENTRY_AREA on PMD level " Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 25/31] x86/mm/dump_pagetables: Define INIT_PGD Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 26/31] x86/pgtable/pae: Use separate kernel PMDs for user page-table Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 27/31] x86/ldt: Reserve address-space range on 32 bit for the LDT Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 28/31] x86/ldt: Define LDT_END_ADDR Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 29/31] x86/ldt: Split out sanity check in map_ldt_struct() Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 30/31] x86/ldt: Enable LDT user-mapping for PAE Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09  9:25 ` [PATCH 31/31] x86/pti: Allow CONFIG_PAGE_TABLE_ISOLATION for x86_32 Joerg Roedel
2018-02-09  9:25   ` Joerg Roedel
2018-02-09 12:11 ` [PATCH 00/31 v2] PTI support " Juergen Gross
2018-02-09 12:11   ` Juergen Gross
2018-02-09 13:35   ` Joerg Roedel
2018-02-09 13:35     ` Joerg Roedel
2018-02-09 13:54     ` Andrew Cooper
2018-02-09 13:54       ` Andrew Cooper
2018-02-09 17:47 ` Andy Lutomirski
2018-02-09 17:47   ` Andy Lutomirski
2018-02-09 19:11   ` Joerg Roedel
2018-02-09 19:11     ` Joerg Roedel
2018-02-10  9:15     ` Adam Borowski
2018-02-10  9:15       ` Adam Borowski
2018-02-10 20:22       ` Linus Torvalds
2018-02-10 20:22         ` Linus Torvalds
2018-02-11 10:59         ` Adam Borowski
2018-02-11 10:59           ` Adam Borowski
2018-02-11 17:40           ` Mark D Rustad
2018-02-11 19:42             ` Andy Lutomirski
2018-02-11 19:42               ` Andy Lutomirski
2018-02-11 20:14               ` Linus Torvalds
2018-02-11 20:14                 ` Linus Torvalds
2018-02-11 22:12               ` James Bottomley [this message]
2018-02-11 22:12                 ` James Bottomley
2018-02-11 22:30                 ` Andy Lutomirski
2018-02-11 22:30                   ` Andy Lutomirski
2018-02-11 23:47                   ` James Bottomley
2018-02-11 23:47                     ` James Bottomley
2018-02-11 22:34               ` Pavel Machek
2018-02-11 22:34                 ` Pavel Machek
2018-02-11 23:25               ` Alan Cox
2018-02-11 23:25                 ` Alan Cox
2018-02-12 10:16                 ` Anders Larsen
2018-02-12 10:16                   ` Anders Larsen
2018-02-14 10:43               ` Pavel Machek
2018-02-15  3:44                 ` joe.korty
2018-02-16 14:34                   ` Pavel Machek
2018-02-13  8:54             ` Greg KH
2018-02-13  8:54               ` Greg KH
2018-02-13 17:25               ` Linus Torvalds
2018-02-13 17:25                 ` Linus Torvalds
2018-02-14  8:54                 ` Greg KH
2018-02-14  8:54                   ` Greg KH
2018-02-21 10:26                   ` Lorenzo Colitti
2018-02-21 10:26                     ` Lorenzo Colitti
2018-02-21 16:59                     ` Arnd Bergmann
2018-02-21 16:59                       ` Arnd Bergmann
2018-02-22 11:10                       ` Greg KH
2018-02-22 11:10                         ` Greg KH
2018-02-22 11:18                         ` Arnd Bergmann
2018-02-22 11:18                           ` Arnd Bergmann
2018-03-06 15:39                 ` Jason A. Donenfeld
2018-03-06 15:39                   ` Jason A. Donenfeld
2018-03-06 15:39                   ` Jason A. Donenfeld
2018-02-11 19:13     ` Ingo Molnar
2018-02-11 19:13       ` Ingo Molnar
2018-02-12 14:51       ` Joerg Roedel
2018-02-12 14:51         ` Joerg Roedel
2018-02-09 21:09   ` Pavel Machek
2018-02-09 21:11     ` Linus Torvalds
2018-02-09 21:11       ` Linus Torvalds
2018-02-09 21:28     ` Andrew Cooper
2018-02-09 21:28       ` Andrew Cooper
2018-02-20  3:45 David H. Gutteridge
2018-02-20  8:40 ` Joerg Roedel

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