From: "Luck, Tony" <tony.luck@intel.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: "Yu, Fenghua" <fenghua.yu@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
H Peter Anvin <hpa@zytor.com>,
David Woodhouse <dwmw2@infradead.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Frederic Barrat <fbarrat@linux.ibm.com>,
"Andrew Donnellan" <ajd@linux.ibm.com>,
Felix Kuehling <Felix.Kuehling@amd.com>,
Joerg Roedel <joro@8bytes.org>,
"Hansen, Dave" <dave.hansen@intel.com>,
"Raj, Ashok" <ashok.raj@intel.com>,
"Pan, Jacob jun" <jacob.jun.pan@intel.com>,
"Jiang, Dave" <dave.jiang@intel.com>,
"Yu, Yu-cheng" <yu-cheng.yu@intel.com>,
"Mehta, Sohil" <sohil.mehta@intel.com>,
"Shankar, Ravi V" <ravi.v.shankar@intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>, x86 <x86@kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>,
amd-gfx <amd-gfx@lists.freedesktop.org>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: RE: [PATCH v2 12/12] x86/traps: Fix up invalid PASID
Date: Mon, 15 Jun 2020 21:24:59 +0000 [thread overview]
Message-ID: <3908561D78D1C84285E8C5FCA982C28F7F66C93C@ORSMSX115.amr.corp.intel.com> (raw)
In-Reply-To: <E39A5DE2-5615-41FF-9953-4F4C4E8499D8@amacapital.net>
> So what’s the RDMSR for? Surely you
> have some state somewhere that says “this task has a PASID.”
> Can’t you just make sure that stays in sync with the MSR? Then, on #GP, if the task already has a PASID, you know the MSR is set.
We have state that says the process ("mm") has been allocated a PASID. But not for each task.
E.g. a process may clone a bunch of tasks, then one of them opens a device that needs
a PASID. We did internally have patches to go hunt down all those other tasks and
force a PASID onto each. But the code was big and ugly. Also maybe the wrong thing
to do if those threads didn't ever need to access the device.
PeterZ suggested that we can add a bit to the task structure for this purpose.
Fenghua is hesitant about adding an x86 only bit there.
-Tony
next prev parent reply other threads:[~2020-06-15 21:25 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-13 0:41 [PATCH v2 00/12] x86: tag application address space for devices Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 01/12] iommu: Change type of pasid to unsigned int Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 02/12] ocxl: " Fenghua Yu
2020-06-18 8:05 ` Frederic Barrat
2020-06-18 15:37 ` Fenghua Yu
2020-06-18 16:56 ` Frederic Barrat
2020-06-13 0:41 ` [PATCH v2 03/12] iommu/vt-d: Change flags type to unsigned int in binding mm Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 04/12] docs: x86: Add documentation for SVA (Shared Virtual Addressing) Fenghua Yu
2020-06-13 12:17 ` Lu Baolu
2020-06-15 23:16 ` Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 05/12] x86/cpufeatures: Enumerate ENQCMD and ENQCMDS instructions Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 06/12] x86/fpu/xstate: Add supervisor PASID state for ENQCMD feature Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 07/12] x86/msr-index: Define IA32_PASID MSR Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 08/12] mm: Define pasid in mm Fenghua Yu
2020-06-16 8:28 ` Jean-Philippe Brucker
2020-06-16 15:11 ` Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 09/12] fork: Clear PASID for new mm Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 10/12] x86/process: Clear PASID state for a newly forked/cloned thread Fenghua Yu
2020-06-13 0:41 ` [PATCH v2 11/12] x86/mmu: Allocate/free PASID Fenghua Yu
2020-06-13 13:07 ` Lu Baolu
2020-06-15 2:13 ` Lu Baolu
2020-06-13 0:41 ` [PATCH v2 12/12] x86/traps: Fix up invalid PASID Fenghua Yu
2020-06-15 7:53 ` Peter Zijlstra
2020-06-15 7:56 ` Peter Zijlstra
2020-06-15 15:48 ` Fenghua Yu
2020-06-15 16:03 ` Peter Zijlstra
2020-06-15 17:11 ` Luck, Tony
2020-06-15 18:12 ` Fenghua Yu
2020-06-15 18:31 ` Peter Zijlstra
2020-06-15 18:55 ` Fenghua Yu
2020-06-15 19:09 ` Peter Zijlstra
2020-06-15 20:17 ` Fenghua Yu
2020-06-15 20:51 ` Andy Lutomirski
2020-06-15 20:56 ` Luck, Tony
2020-06-15 21:18 ` Andy Lutomirski
2020-06-15 21:24 ` Luck, Tony [this message]
2020-06-15 21:53 ` Peter Zijlstra
2020-06-16 23:23 ` Fenghua Yu
2020-06-17 8:31 ` Peter Zijlstra
2020-06-15 18:19 ` Raj, Ashok
2020-06-15 18:32 ` Peter Zijlstra
2020-06-15 7:52 ` [PATCH v2 00/12] x86: tag application address space for devices Peter Zijlstra
2020-06-15 14:53 ` Fenghua Yu
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