From: Waiman Long <waiman.long@hp.com>
To: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Arnd Bergmann <arnd@arndb.de>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Andrew Morton <akpm@linux-foundation.org>,
Michel Lespinasse <walken@google.com>,
Andi Kleen <andi@firstfloor.org>, Rik van Riel <riel@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
George Spelvin <linux@horizon.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Daniel J Blueman <daniel@numascale.com>,
Alexander Fyodorov <halcy@yandex.ru>,
Aswin Chandramouleeswaran <aswin@hp.com>,
Scott J Norton <scott.norton@hp.com>,
Thavatchai
Subject: Re: [PATCH v4 0/3] qspinlock: Introducing a 4-byte queue spinlock
Date: Fri, 21 Feb 2014 12:02:26 -0500 [thread overview]
Message-ID: <530786A2.6080406@hp.com> (raw)
In-Reply-To: <53065838.90102@linux.vnet.ibm.com>
On 02/20/2014 02:32 PM, Raghavendra K T wrote:
> On 02/20/2014 11:24 PM, Waiman Long wrote:
>
>> Now the key is how to detect if a kernel is really running in a PV
>> environment. I need to ask some virtualization experts on that.
>>
>
> For kvm you could just follow,
> kvm_spinlock_init_jump() and KVM_FEATURE_* encoding in cpuid
> part __do_cpuid_ent().
>
I saw that in the arch/x86/kernel/kvm.c file. So I think I can use the
returned value of kvm_para_available() to decide if it is running in a
KVM guest. However, I am not so sure of what to use in xen.
-Longman
WARNING: multiple messages have this Message-ID (diff)
From: Waiman Long <waiman.long@hp.com>
To: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Arnd Bergmann <arnd@arndb.de>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Andrew Morton <akpm@linux-foundation.org>,
Michel Lespinasse <walken@google.com>,
Andi Kleen <andi@firstfloor.org>, Rik van Riel <riel@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
George Spelvin <linux@horizon.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Daniel J Blueman <daniel@numascale.com>,
Alexander Fyodorov <halcy@yandex.ru>,
Aswin Chandramouleeswaran <aswin@hp.com>,
Scott J Norton <scott.norton@hp.com>,
Thavatchai Makphaibulchoke <thavatchai.makpahibulchoke@hp.com>
Subject: Re: [PATCH v4 0/3] qspinlock: Introducing a 4-byte queue spinlock
Date: Fri, 21 Feb 2014 12:02:26 -0500 [thread overview]
Message-ID: <530786A2.6080406@hp.com> (raw)
Message-ID: <20140221170226.b33PvaNYw5Feq4oy6KLSXrcOWEzjtLxJkTxXmn8yLU8@z> (raw)
In-Reply-To: <53065838.90102@linux.vnet.ibm.com>
On 02/20/2014 02:32 PM, Raghavendra K T wrote:
> On 02/20/2014 11:24 PM, Waiman Long wrote:
>
>> Now the key is how to detect if a kernel is really running in a PV
>> environment. I need to ask some virtualization experts on that.
>>
>
> For kvm you could just follow,
> kvm_spinlock_init_jump() and KVM_FEATURE_* encoding in cpuid
> part __do_cpuid_ent().
>
I saw that in the arch/x86/kernel/kvm.c file. So I think I can use the
returned value of kvm_para_available() to decide if it is running in a
KVM guest. However, I am not so sure of what to use in xen.
-Longman
next prev parent reply other threads:[~2014-02-21 17:02 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-17 20:41 [PATCH v4 0/3] qspinlock: Introducing a 4-byte queue spinlock Waiman Long
2014-02-17 20:41 ` [PATCH v4 1/3] qspinlock: Introducing a 4-byte queue spinlock implementation Waiman Long
2014-02-17 20:41 ` Waiman Long
2014-02-18 7:30 ` Peter Zijlstra
2014-02-18 19:29 ` Waiman Long
2014-02-18 19:29 ` Waiman Long
2014-02-18 7:33 ` Peter Zijlstra
2014-02-18 19:31 ` Waiman Long
2014-02-18 19:31 ` Waiman Long
2014-02-18 7:39 ` Peter Zijlstra
2014-02-18 7:39 ` Peter Zijlstra
2014-02-18 19:39 ` Waiman Long
2014-02-18 21:34 ` Peter Zijlstra
2014-02-19 0:50 ` Waiman Long
2014-02-19 0:50 ` Waiman Long
2014-02-19 8:52 ` Peter Zijlstra
2014-02-19 8:52 ` Peter Zijlstra
2014-02-19 19:26 ` Waiman Long
2014-02-18 21:37 ` Peter Zijlstra
2014-02-19 0:58 ` Waiman Long
2014-02-19 0:58 ` Waiman Long
2014-02-19 8:55 ` Peter Zijlstra
2014-02-19 19:30 ` Waiman Long
2014-02-19 19:30 ` Waiman Long
2014-02-17 20:41 ` [PATCH v4 2/3] qspinlock, x86: Enable x86-64 to use queue spinlock Waiman Long
2014-02-17 20:41 ` [PATCH v4 3/3] qspinlock, x86: Add x86 specific optimization for 2 contending tasks Waiman Long
2014-02-17 20:41 ` Waiman Long
2014-02-21 12:12 ` Peter Zijlstra
2014-02-21 17:08 ` Waiman Long
2014-02-21 17:09 ` Waiman Long
2014-02-21 17:26 ` Peter Zijlstra
2014-02-21 17:26 ` Peter Zijlstra
2014-02-22 1:36 ` Waiman Long
2014-02-21 17:28 ` Peter Zijlstra
2014-02-22 1:39 ` Waiman Long
2014-02-17 22:47 ` [PATCH v4 0/3] qspinlock: Introducing a 4-byte queue spinlock H. Peter Anvin
2014-02-18 7:31 ` Peter Zijlstra
2014-02-18 7:39 ` H. Peter Anvin
2014-02-18 7:39 ` H. Peter Anvin
2014-02-18 19:30 ` Waiman Long
2014-02-18 21:28 ` Peter Zijlstra
2014-02-18 21:28 ` Peter Zijlstra
2014-02-19 0:42 ` Waiman Long
2014-02-19 7:09 ` Raghavendra K T
2014-02-19 8:51 ` Peter Zijlstra
2014-02-19 19:24 ` Waiman Long
2014-02-19 19:48 ` Peter Zijlstra
2014-02-20 17:37 ` Waiman Long
2014-02-20 17:44 ` Linus Torvalds
2014-02-20 17:44 ` Linus Torvalds
2014-02-20 18:15 ` Peter Zijlstra
2014-02-19 20:17 ` Linus Torvalds
2014-02-19 20:17 ` Linus Torvalds
2014-02-20 17:54 ` Waiman Long
2014-02-20 17:54 ` Waiman Long
2014-02-20 18:42 ` Linus Torvalds
2014-02-20 18:42 ` Linus Torvalds
2014-02-20 19:21 ` Waiman Long
2014-02-20 19:21 ` Waiman Long
2014-02-20 19:32 ` Raghavendra K T
2014-02-20 19:32 ` Raghavendra K T
2014-02-21 17:02 ` Waiman Long [this message]
2014-02-21 17:02 ` Waiman Long
2014-02-21 17:05 ` Linus Torvalds
2014-02-21 17:05 ` Linus Torvalds
2014-02-19 21:29 ` H. Peter Anvin
2014-02-18 7:38 ` Peter Zijlstra
2014-02-22 16:56 ` Ingo Molnar
2014-02-25 3:37 ` Waiman Long
2014-02-25 3:37 ` Waiman Long
2014-02-18 19:27 ` Waiman Long
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