From: Randy Dunlap <rdunlap@infradead.org>
To: "Chang S. Bae" <chang.seok.bae@intel.com>,
tglx@linutronix.de, mingo@kernel.org, bp@suse.de,
luto@kernel.org, x86@kernel.org
Cc: len.brown@intel.com, dave.hansen@intel.com, jing2.liu@intel.com,
ravi.v.shankar@intel.com, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org
Subject: Re: [RFC PATCH 22/22] x86/fpu/xstate: Introduce boot-parameters for control some state component support
Date: Thu, 1 Oct 2020 19:09:48 -0700 [thread overview]
Message-ID: <5e9b73bf-5334-189e-753e-f1f766375024@infradead.org> (raw)
In-Reply-To: <20201001203913.9125-23-chang.seok.bae@intel.com>
Hi--
On 10/1/20 1:39 PM, Chang S. Bae wrote:
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index a1068742a6df..742167c6f789 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -5838,6 +5838,21 @@
> which allow the hypervisor to 'idle' the guest on lock
> contention.
>
> + xstate.enable= [X86-64]
> + xstate.disable= [X86-64]
> + The kernel is compiled with a default xstate bitmask --
> + enabling it to use the XSAVE hardware to efficiently
> + save and restore thread states on context switch.
> + xstate.enable allows adding to that default mask at
> + boot-time without recompiling the kernel just to support
> + the new thread state. (Note that the kernel will ignore
> + any bits in the mask that do not correspond to features
> + that are actually available in CPUID) xstate.disable
in CPUID.)
> + allows clearing bits in the default mask, forcing the
> + kernel to forget that it supports the specified thread
> + state. When a bit set for both, the kernel takes
> + xstate.disable in a priority.
as a priority.
What do these bitmasks look like? what do the bits mean?
Where does a user find this info?
thanks.
--
~Randy
next prev parent reply other threads:[~2020-10-02 2:10 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-01 20:38 [RFC PATCH 00/22] x86: Support Intel Advanced Matrix Extensions Chang S. Bae
2020-10-01 20:38 ` [RFC PATCH 01/22] x86/fpu/xstate: Modify area init helper prototypes to access all the possible areas Chang S. Bae
2020-10-01 20:38 ` [RFC PATCH 02/22] x86/fpu/xstate: Modify xstate copy " Chang S. Bae
2020-10-01 20:38 ` [RFC PATCH 03/22] x86/fpu/xstate: Modify address finder " Chang S. Bae
2020-10-01 20:38 ` [RFC PATCH 04/22] x86/fpu/xstate: Modify save and restore helper " Chang S. Bae
2020-10-01 20:38 ` [RFC PATCH 05/22] x86/fpu/xstate: Introduce a new variable for dynamic user states Chang S. Bae
2020-10-01 20:38 ` [RFC PATCH 06/22] x86/fpu/xstate: Outline dynamic xstate area size in the task context Chang S. Bae
2020-10-01 20:38 ` [RFC PATCH 07/22] x86/fpu/xstate: Introduce helpers to manage an xstate area dynamically Chang S. Bae
2020-10-01 23:41 ` Andy Lutomirski
2020-10-13 22:00 ` Brown, Len
2020-10-01 20:38 ` [RFC PATCH 08/22] x86/fpu/xstate: Define the scope of the initial xstate data Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 09/22] x86/fpu/xstate: Introduce wrapper functions for organizing xstate area access Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 10/22] x86/fpu/xstate: Update xstate save function for supporting dynamic user xstate Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 11/22] x86/fpu/xstate: Update xstate area address finder " Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 12/22] x86/fpu/xstate: Update xstate context copy function for supporting dynamic area Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 13/22] x86/fpu/xstate: Expand dynamic user state area on first use Chang S. Bae
2020-10-01 23:39 ` Andy Lutomirski
2020-10-13 22:31 ` Brown, Len
2020-10-13 22:43 ` Dave Hansen
2020-10-14 1:11 ` Andy Lutomirski
2020-10-14 6:03 ` Dave Hansen
2020-10-14 16:10 ` Andy Lutomirski
2020-10-14 16:29 ` Dave Hansen
2020-11-03 21:32 ` Bae, Chang Seok
2020-11-03 21:41 ` Dave Hansen
2020-11-03 21:53 ` Bae, Chang Seok
2020-10-14 10:41 ` Peter Zijlstra
2020-10-14 1:47 ` Andy Lutomirski
2020-10-01 20:39 ` [RFC PATCH 14/22] x86/fpu/xstate: Inherit dynamic user state when used in the parent Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 15/22] x86/fpu/xstate: Support ptracer-induced xstate area expansion Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 16/22] x86/fpu/xstate: Support dynamic user state in the signal handling path Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 17/22] x86/fpu/xstate: Extend the table for mapping xstate components with features Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 18/22] x86/cpufeatures/amx: Enumerate Advanced Matrix Extension (AMX) feature bits Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 19/22] x86/fpu/amx: Define AMX state components and have it used for boot-time checks Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 20/22] x86/fpu/amx: Enable the AMX feature in 64-bit mode Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 21/22] selftest/x86/amx: Include test cases for the AMX state management Chang S. Bae
2020-10-01 20:39 ` [RFC PATCH 22/22] x86/fpu/xstate: Introduce boot-parameters for control some state component support Chang S. Bae
2020-10-02 2:09 ` Randy Dunlap [this message]
2020-10-13 23:00 ` Brown, Len
2020-10-02 17:15 ` Andy Lutomirski
2020-10-02 17:26 ` Dave Hansen
2020-10-13 23:38 ` Brown, Len
2020-10-02 17:25 ` Dave Hansen
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