search for: kvm_hc_kick_cpu

This series forms the kvm host part of paravirtual spinlock based against kvm tree. Please refer to https://lkml.org/lkml/2013/8/9/265 for kvm guest and Xen, x86 part merged to -tip spinlocks. Please note that: kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi is a common patch for both guest and host. Changes since V12: fold the patch 3 into patch 2 for bisection. (Eric Northup)

This series forms the kvm host part of paravirtual spinlock based against kvm tree. Please refer to https://lkml.org/lkml/2013/8/9/265 for kvm guest and Xen, x86 part merged to -tip spinlocks. Please note that: kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi is a common patch for both guest and host. Changes since V12: fold the patch 3 into patch 2 for bisection. (Eric Northup)

KVM_HC_KICK_CPU hypercall added to wakeup halted vcpu in paravirtual spinlock enabled guest. KVM_FEATURE_PV_UNHALT enables guest to check whether pv spinlock can be enabled in guest. Thanks Vatsa for rewriting KVM_HC_KICK_CPU Cc: Rob Landley <rob at landley.net> Signed-off-by: Srivatsa Vaddagiri <vatsa...

This series forms the kvm host part of paravirtual spinlock based against kvm tree. Please refer https://lkml.org/lkml/2013/8/6/178 for kvm guest part of the series. Please note that: kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi is a common patch for both guest and host. Srivatsa Vaddagiri (1): kvm hypervisor : Add a hypercall to KVM hypervisor to support pv-ticketlocks

This series forms the kvm host part of paravirtual spinlock based against kvm tree. Please refer https://lkml.org/lkml/2013/8/6/178 for kvm guest part of the series. Please note that: kvm uapi: Add KICK_CPU and PV_UNHALT definition to uapi is a common patch for both guest and host. Srivatsa Vaddagiri (1): kvm hypervisor : Add a hypercall to KVM hypervisor to support pv-ticketlocks

...- use APIC ID for kicking the vcpu and use kvm_apic_match_dest for matching (Avi) - fold vcpu->kicked flag into vcpu->requests (KVM_REQ_PVLOCK_KICK) and related changes for UNHALT path to make pv ticket spinlock migration friendly(Avi, Marcello) - Added Documentation for CPUID, Hypercall (KVM_HC_KICK_CPU) and capabilty (KVM_CAP_PVLOCK_KICK) (Avi) - Remove unneeded kvm_arch_vcpu_ioctl_set_mpstate call. (Marcello) - cumulative variable type changed (int ==> u32) in add_stat (Konrad) - remove unneeded kvm_guest_init for !CONFIG_KVM_GUEST case Changes in V3: - rebased to 3.2-rc1 - use halt() inst...

...- use APIC ID for kicking the vcpu and use kvm_apic_match_dest for matching (Avi) - fold vcpu->kicked flag into vcpu->requests (KVM_REQ_PVLOCK_KICK) and related changes for UNHALT path to make pv ticket spinlock migration friendly(Avi, Marcello) - Added Documentation for CPUID, Hypercall (KVM_HC_KICK_CPU) and capabilty (KVM_CAP_PVLOCK_KICK) (Avi) - Remove unneeded kvm_arch_vcpu_ioctl_set_mpstate call. (Marcello) - cumulative variable type changed (int ==> u32) in add_stat (Konrad) - remove unneeded kvm_guest_init for !CONFIG_KVM_GUEST case Changes in V3: - rebased to 3.2-rc1 - use halt() inst...

...- use APIC ID for kicking the vcpu and use kvm_apic_match_dest for matching (Avi) - fold vcpu->kicked flag into vcpu->requests (KVM_REQ_PVLOCK_KICK) and related changes for UNHALT path to make pv ticket spinlock migration friendly(Avi, Marcello) - Added Documentation for CPUID, Hypercall (KVM_HC_KICK_CPU) and capabilty (KVM_CAP_PVLOCK_KICK) (Avi) - Remove unneeded kvm_arch_vcpu_ioctl_set_mpstate call. (Marcello) - cumulative variable type changed (int ==> u32) in add_stat (Konrad) - remove unneeded kvm_guest_init for !CONFIG_KVM_GUEST case Changes in V3: - rebased to 3.2-rc1 - use halt() inst...

...- use APIC ID for kicking the vcpu and use kvm_apic_match_dest for matching (Avi) - fold vcpu->kicked flag into vcpu->requests (KVM_REQ_PVLOCK_KICK) and related changes for UNHALT path to make pv ticket spinlock migration friendly(Avi, Marcello) - Added Documentation for CPUID, Hypercall (KVM_HC_KICK_CPU) and capabilty (KVM_CAP_PVLOCK_KICK) (Avi) - Remove unneeded kvm_arch_vcpu_ioctl_set_mpstate call. (Marcello) - cumulative variable type changed (int ==> u32) in add_stat (Konrad) - remove unneeded kvm_guest_init for !CONFIG_KVM_GUEST case Changes in V3: - rebased to 3.2-rc1 - use halt() inst...

...use APIC ID for kicking the vcpu and use kvm_apic_match_dest for matching. (Avi) - fold vcpu->kicked flag into vcpu->requests (KVM_REQ_PVLOCK_KICK) and related changes for UNHALT path to make pv ticket spinlock migration friendly. (Avi, Marcello) - Added Documentation for CPUID, Hypercall (KVM_HC_KICK_CPU) and capabilty (KVM_CAP_PVLOCK_KICK) (Avi) - Remove unneeded kvm_arch_vcpu_ioctl_set_mpstate call. (Marcello) - cumulative variable type changed (int ==> u32) in add_stat (Konrad) - remove unneeded kvm_guest_init for !CONFIG_KVM_GUEST case Changes in V3: - rebased to 3.2-rc1 - use halt() inst...

...use APIC ID for kicking the vcpu and use kvm_apic_match_dest for matching. (Avi) - fold vcpu->kicked flag into vcpu->requests (KVM_REQ_PVLOCK_KICK) and related changes for UNHALT path to make pv ticket spinlock migration friendly. (Avi, Marcello) - Added Documentation for CPUID, Hypercall (KVM_HC_KICK_CPU) and capabilty (KVM_CAP_PVLOCK_KICK) (Avi) - Remove unneeded kvm_arch_vcpu_ioctl_set_mpstate call. (Marcello) - cumulative variable type changed (int ==> u32) in add_stat (Konrad) - remove unneeded kvm_guest_init for !CONFIG_KVM_GUEST case Changes in V3: - rebased to 3.2-rc1 - use halt() inst...

...a guest can keep one of its VCPUs > running by repeatedly kicking it? This is not possible under Xen and I > doubt it's possible under KVM or any other hypervisor. KVM allows any VCPU to wake up a currently halted VCPU of its choice, see Documentation/virtual/kvm/hypercalls.txt. 5. KVM_HC_KICK_CPU ------------------------ Architecture: x86 Status: active Purpose: Hypercall used to wakeup a vcpu from HLT state Usage example : A vcpu of a paravirtualized guest that is busywaiting in guest kernel mode for an event to occur (ex: a spinlock to become available) can execute HL...

...; +/* > + * Enable unfair lock if running in a real para-virtualized environment > + */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; > + kvm_kick_cpu_type() in patch 8 assumes that host has support for kick hypercall (KVM_HC_KICK_CPU). I think for that we need explicit check of this kvm_para_has_feature(KVM_FEATURE_PV_UNHALT). otherwise things may break for unlikely case of running a new guest on a old host? > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlo...

...; +/* > + * Enable unfair lock if running in a real para-virtualized environment > + */ > +static __init int kvm_unfair_locks_init_jump(void) > +{ > + if (!kvm_para_available()) > + return 0; > + kvm_kick_cpu_type() in patch 8 assumes that host has support for kick hypercall (KVM_HC_KICK_CPU). I think for that we need explicit check of this kvm_para_has_feature(KVM_FEATURE_PV_UNHALT). otherwise things may break for unlikely case of running a new guest on a old host? > + static_key_slow_inc(&paravirt_unfairlocks_enabled); > + printk(KERN_INFO "KVM setup unfair spinlo...

On 26/02/14 15:14, Waiman Long wrote: > This patch adds para-virtualization support to the queue spinlock code > by enabling the queue head to kick the lock holder CPU, if known, > in when the lock isn't released for a certain amount of time. It > also enables the mutual monitoring of the queue head CPU and the > following node CPU in the queue to make sure that their CPUs will

On 26/02/14 15:14, Waiman Long wrote: > This patch adds para-virtualization support to the queue spinlock code > by enabling the queue head to kick the lock holder CPU, if known, > in when the lock isn't released for a certain amount of time. It > also enables the mutual monitoring of the queue head CPU and the > following node CPU in the queue to make sure that their CPUs will

The 4-patch series to follow this email extends KVM-hypervisor and Linux guest running on KVM-hypervisor to support pv-ticket spinlocks, based on Xen's implementation. One hypercall is introduced in KVM hypervisor,that allows a vcpu to kick another vcpu out of halt state. The blocking of vcpu is done using halt() in (lock_spinning) slowpath. The V2 change discussion was in:

The 4-patch series to follow this email extends KVM-hypervisor and Linux guest running on KVM-hypervisor to support pv-ticket spinlocks, based on Xen's implementation. One hypercall is introduced in KVM hypervisor,that allows a vcpu to kick another vcpu out of halt state. The blocking of vcpu is done using halt() in (lock_spinning) slowpath. The V2 change discussion was in:

...- use APIC ID for kicking the vcpu and use kvm_apic_match_dest for matching (Avi) - fold vcpu->kicked flag into vcpu->requests (KVM_REQ_PVLOCK_KICK) and related changes for UNHALT path to make pv ticket spinlock migration friendly(Avi, Marcello) - Added Documentation for CPUID, Hypercall (KVM_HC_KICK_CPU) and capabilty (KVM_CAP_PVLOCK_KICK) (Avi) - Remove unneeded kvm_arch_vcpu_ioctl_set_mpstate call. (Marcello) - cumulative variable type changed (int ==> u32) in add_stat (Konrad) - remove unneeded kvm_guest_init for !CONFIG_KVM_GUEST case Changes in V3: - rebased to 3.2-rc1 - use halt() inst...

...- use APIC ID for kicking the vcpu and use kvm_apic_match_dest for matching (Avi) - fold vcpu->kicked flag into vcpu->requests (KVM_REQ_PVLOCK_KICK) and related changes for UNHALT path to make pv ticket spinlock migration friendly(Avi, Marcello) - Added Documentation for CPUID, Hypercall (KVM_HC_KICK_CPU) and capabilty (KVM_CAP_PVLOCK_KICK) (Avi) - Remove unneeded kvm_arch_vcpu_ioctl_set_mpstate call. (Marcello) - cumulative variable type changed (int ==> u32) in add_stat (Konrad) - remove unneeded kvm_guest_init for !CONFIG_KVM_GUEST case Changes in V3: - rebased to 3.2-rc1 - use halt() inst...