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@xxxxxxxxxxxxxxx/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 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
