From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
To: Avi Kivity <avi@redhat.com>, Jan Kiszka <jan.kiszka@siemens.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>, KVM <kvm@vger.kernel.org>,
Qemu-devel <qemu-devel@nongnu.org>,
Marcelo Tosatti <mtosatti@redhat.com>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Alexander Graf <agraf@suse.de>
Subject: [Qemu-devel] [PATCH 0/2] QEMU kvm: Adding paravirtual spinlock support for x86.
Date: Fri, 23 Mar 2012 13:52:46 +0530 [thread overview]
Message-ID: <20120323082242.17193.16289.sendpatchset@codeblue> (raw)
The patch, extends KVM-hypervisor and Linux guest running on
KVM-hypervisor to support pv-ticket spinlocks.
PV ticket spinlock helps to solve Lock Holder Preemption problem discussed in
http://www.amd64.org/fileadmin/user_upload/pub/LHP-commented_slides.pdf.
When spinlock is contended,a guest vcpu relinqueshes cpu by halt().
Correspondingly, One hypercall is introduced in KVM hypervisor,that allows
a vcpu to kick the halted vcpu to continue with execution.
Note:
Below patch should be applied only after corresponding
linux-header changes taken into qemu via scripts/update-linux-headers.sh script.
---
Changes in V3:
rename PVLOCK_KICK --> PV_UNHALT
add MSR related changes to aid migration
Changes in V2:
Drop the syncing kernel header changes. (Alex)
rename KICK_VCPU --> PVLOCK_KICK.
Raghavendra K T(2):
add PV_UNHALT feature support.
add support to get/set vcpu unhalt msr to aid migration
target-i386/cpu.h | 1 +
target-i386/kvm.c | 14 +++++++++++++-
2 files changed, 14 insertions(+), 1 deletions(-)
V5 Kernel changes:
https://lkml.org/lkml/2012/3/23/50
V4 kernel changes:
https://lkml.org/lkml/2012/1/14/66
Qemu changes for V4:
http://www.mail-archive.com/kvm@vger.kernel.org/msg66450.html
V3 kernel Changes:
https://lkml.org/lkml/2011/11/30/62
V2 kernel changes :
https://lkml.org/lkml/2011/10/23/207
Previous discussions : (posted by Srivatsa V).
https://lkml.org/lkml/2010/7/26/24
https://lkml.org/lkml/2011/1/19/212
Qemu patch for V3:
http://lists.gnu.org/archive/html/qemu-devel/2011-12/msg00397.html
next reply other threads:[~2012-03-23 8:23 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-23 8:22 Raghavendra K T [this message]
2012-03-23 8:23 ` [Qemu-devel] [PATCH 1/2] QEMU kvm: Add PV_UNHALT feature support Raghavendra K T
2012-03-23 8:23 ` [Qemu-devel] [PATCH 2/2] QEMU kvm: Add support to get/set vcpu unhalt msr to aid migration Raghavendra K T
2012-03-23 8:57 ` Jan Kiszka
2012-03-23 9:38 ` Raghavendra K T
2012-03-23 13:07 ` Raghavendra K T
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