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From: Glauber Costa <glommer@redhat.com>
To: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH v3 6/6] Describe KVM_MSR_STEAL_TIME
Date: Fri, 11 Feb 2011 13:19:24 -0500	[thread overview]
Message-ID: <1297448364-14051-7-git-send-email-glommer@redhat.com> (raw)
In-Reply-To: <1297448364-14051-1-git-send-email-glommer@redhat.com>

This patch adds documentation about usage of the newly
introduced KVM_MSR_STEAL_TIME.

Signed-off-by: Glauber Costa <glommer@redhat.com>
---
 Documentation/kvm/msr.txt |   33 +++++++++++++++++++++++++++++++++
 1 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/Documentation/kvm/msr.txt b/Documentation/kvm/msr.txt
index d079aed..79c12a7 100644
--- a/Documentation/kvm/msr.txt
+++ b/Documentation/kvm/msr.txt
@@ -185,3 +185,36 @@ MSR_KVM_ASYNC_PF_EN: 0x4b564d02
 
 	Currently type 2 APF will be always delivered on the same vcpu as
 	type 1 was, but guest should not rely on that.
+
+MSR_KVM_STEAL_TIME: 0x4b564d03
+
+	data: 64-byte alignment physical address of a memory area which must be
+	in guest RAM, plus an enable bit in bit 0. This memory is expected to
+	hold a copy of the following structure:
+
+	struct kvm_steal_time {
+	  	__u64 steal;
+ 		__u32 version;
+ 		__u32 flags;
+	 	__u32 pad[6];
+	}
+
+	whose data will be filled in by the hypervisor periodically. Only one
+	write, or registration, is needed for each VCPU. The interval between
+	updates of this structure is arbitrary and implementation-dependent.
+	The hypervisor may update this structure at any time it sees fit until
+	anything with bit0 == 0 is written to it. Guest is required to make sure
+	this structure is initialized to zero.
+
+	Fields have the following meanings:
+
+		version: guest has to check version before and after grabbing
+		time information and check that they are both equal and even.
+		An odd version indicates an in-progress update.
+
+		flags: At this point, always zero. May be used to indicate
+		changes in this structure in the future.
+
+		steal: the amount of time in which this vCPU did not run, in
+		nanoseconds.
+
-- 
1.7.2.3


      parent reply	other threads:[~2011-02-11 18:21 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-11 18:19 [PATCH v3 0/6] Steal time for KVM Glauber Costa
2011-02-11 18:19 ` [PATCH v3 1/6] KVM-HDR: KVM Steal time implementation Glauber Costa
2011-02-15 14:25   ` Avi Kivity
2011-02-11 18:19 ` [PATCH v3 2/6] KVM-HV: " Glauber Costa
2011-02-15 14:34   ` Avi Kivity
2011-02-11 18:19 ` [PATCH v3 3/6] KVM-GST: KVM Steal time accounting Glauber Costa
2011-02-11 19:05   ` Peter Zijlstra
2011-02-12 23:46     ` Glauber Costa
2011-02-15 14:35   ` Avi Kivity
2011-02-15 14:45     ` Peter Zijlstra
2011-02-15 15:17       ` Avi Kivity
2011-02-15 15:24         ` Rik van Riel
2011-02-15 15:26           ` Avi Kivity
2011-02-15 15:27         ` Peter Zijlstra
2011-02-11 18:19 ` [PATCH v3 4/6] KVM-GST: KVM Steal time registration Glauber Costa
2011-02-15 14:41   ` Avi Kivity
2011-02-15 15:48     ` Peter Zijlstra
2011-02-11 18:19 ` [PATCH v3 5/6] KVM-GST: adjust scheduler cpu power Glauber Costa
2011-02-11 19:05   ` Peter Zijlstra
2011-02-11 18:19 ` Glauber Costa [this message]

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