From: Glauber Costa <glommer@redhat.com>
To: Zachary Amsden <zamsden@redhat.com>
Cc: kvm@vger.kernel.org, Avi Kivity <avi@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
John Stultz <johnstul@us.ibm.com>,
linux-kernel@vger.kernel.org
Subject: Re: [KVM timekeeping 30/35] IOCTL for setting TSC rate
Date: Fri, 20 Aug 2010 14:56:20 -0300 [thread overview]
Message-ID: <20100820175620.GJ2937@mothafucka.localdomain> (raw)
In-Reply-To: <1282291669-25709-31-git-send-email-zamsden@redhat.com>
On Thu, Aug 19, 2010 at 10:07:44PM -1000, Zachary Amsden wrote:
> Add an IOCTL for setting the TSC rate for a VM, intended to
> be used to migrate non-kvmclock based VMs which rely on TSC
> rate staying stable across host migration.
>
> Signed-off-by: Zachary Amsden <zamsden@redhat.com>
> ---
> arch/x86/kvm/x86.c | 36 ++++++++++++++++++++++++++++++++++++
> include/linux/kvm.h | 4 ++++
> 2 files changed, 40 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 887e30f..e618265 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1017,6 +1017,10 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
> kvm_x86_ops->adjust_tsc_offset(v, tsc-tsc_timestamp);
> local_irq_restore(flags);
>
> + /* hw_tsc_khz unknown at creation time, check for overrun */
> + if (this_tsc_khz > v->kvm->arch.virtual_tsc_khz)
> + vcpu->tsc_overrun = 1;
> +
> /* Now, see if we need to switch into trap mode */
> if (vcpu->tsc_overrun && !vcpu->tsc_trapping)
> kvm_x86_ops->set_tsc_trap(v, 1);
> @@ -1846,6 +1850,7 @@ int kvm_dev_ioctl_check_extension(long ext)
> case KVM_CAP_DEBUGREGS:
> case KVM_CAP_X86_ROBUST_SINGLESTEP:
> case KVM_CAP_XSAVE:
> + case KVM_CAP_SET_TSC_RATE:
> r = 1;
> break;
> case KVM_CAP_COALESCED_MMIO:
> @@ -3413,6 +3418,37 @@ long kvm_arch_vm_ioctl(struct file *filp,
> r = 0;
> break;
> }
> + case KVM_X86_GET_TSC_RATE: {
> + u32 rate = kvm->arch.virtual_tsc_khz;
> + r = -EFAULT;
> + if (copy_to_user(argp, &rate, sizeof(rate)))
> + goto out;
> + r = 0;
> + break;
> + }
> + case KVM_X86_SET_TSC_RATE: {
> + u32 rate;
> + int i;
> + struct kvm_vcpu *vcpu;
> + r = -EFAULT;
> + if (copy_from_user(&rate, argp, sizeof rate))
> + goto out;
> + if (rate == 0 || rate > (1ULL << 40)) {
> + r = -EINVAL;
> + break;
> + }
> + /*
> + * This is intended to be called once, during VM creation.
> + * Calling this with running VCPUs to dynamically change
> + * speed is risky; there is no synchronization with the
> + * compensation loop, so computations using virtual_tsc_khz
> + * conversions may go haywire. Use at your own risk.
> + */
> + kvm_arch_set_tsc_khz(kvm, rate);
> + kvm_for_each_vcpu(i, vcpu, kvm)
> + kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
> + break;
> + }
>
> default:
> ;
> diff --git a/include/linux/kvm.h b/include/linux/kvm.h
> index 3707704..22d27f2 100644
> --- a/include/linux/kvm.h
> +++ b/include/linux/kvm.h
> @@ -539,6 +539,7 @@ struct kvm_ppc_pvinfo {
> #define KVM_CAP_XCRS 56
> #endif
> #define KVM_CAP_PPC_GET_PVINFO 57
> +#define KVM_CAP_SET_TSC_RATE 58
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
> @@ -675,6 +676,9 @@ struct kvm_clock_data {
> #define KVM_SET_PIT2 _IOW(KVMIO, 0xa0, struct kvm_pit_state2)
> /* Available with KVM_CAP_PPC_GET_PVINFO */
> #define KVM_PPC_GET_PVINFO _IOW(KVMIO, 0xa1, struct kvm_ppc_pvinfo)
> +/* Available with KVM_CAP_SET_TSC_RATE */
> +#define KVM_X86_GET_TSC_RATE _IOR(KVMIO, 0xa2, __u32)
> +#define KVM_X86_SET_TSC_RATE _IOW(KVMIO, 0xa3, __u32)
wrap this into a struct?
next prev parent reply other threads:[~2010-08-20 17:56 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-20 8:07 KVM timekeeping and TSC virtualization Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 01/35] Drop vm_init_tsc Zachary Amsden
2010-08-20 16:54 ` Glauber Costa
2010-08-20 8:07 ` [KVM timekeeping 02/35] Convert TSC writes to TSC offset writes Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 03/35] Move TSC offset writes to common code Zachary Amsden
2010-08-20 17:06 ` Glauber Costa
2010-08-24 0:51 ` Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 04/35] Fix SVM VMCB reset Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 05/35] Move TSC reset out of vmcb_init Zachary Amsden
2010-08-20 17:08 ` Glauber Costa
2010-08-24 0:52 ` Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 06/35] TSC reset compensation Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 07/35] Make cpu_tsc_khz updates use local CPU Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 08/35] Warn about unstable TSC Zachary Amsden
2010-08-20 17:28 ` Glauber Costa
2010-08-24 0:56 ` Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 09/35] Unify TSC logic Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 10/35] Fix deep C-state TSC desynchronization Zachary Amsden
2010-08-20 17:30 ` Glauber Costa
2010-09-14 9:10 ` Jan Kiszka
2010-09-14 9:27 ` Avi Kivity
2010-09-14 10:40 ` Jan Kiszka
2010-09-14 10:47 ` Avi Kivity
2010-09-14 19:32 ` Zachary Amsden
2010-09-14 22:26 ` Jan Kiszka
2010-09-14 23:40 ` Zachary Amsden
2010-09-15 5:34 ` Jan Kiszka
2010-09-15 7:55 ` Avi Kivity
2010-09-15 8:04 ` Jan Kiszka
2010-09-15 12:29 ` Glauber Costa
2010-09-15 4:07 ` Zachary Amsden
2010-09-15 8:09 ` Jan Kiszka
2010-09-15 12:32 ` Glauber Costa
2010-09-15 18:27 ` Jan Kiszka
2010-09-17 22:09 ` Zachary Amsden
2010-09-17 22:31 ` Zachary Amsden
2010-09-18 23:53 ` Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 11/35] Add helper functions for time computation Zachary Amsden
2010-08-20 17:34 ` Glauber Costa
2010-08-24 0:58 ` Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 12/35] Robust TSC compensation Zachary Amsden
2010-08-20 17:40 ` Glauber Costa
2010-08-24 1:01 ` Zachary Amsden
2010-08-24 21:33 ` Daniel Verkamp
2010-08-20 8:07 ` [KVM timekeeping 13/35] Perform hardware_enable in CPU_STARTING callback Zachary Amsden
2010-08-27 16:32 ` Jan Kiszka
2010-08-27 23:43 ` Zachary Amsden
2010-08-30 9:10 ` Jan Kiszka
2010-08-20 8:07 ` [KVM timekeeping 14/35] Add clock sync request to hardware enable Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 15/35] Move scale_delta into common header Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 16/35] Fix a possible backwards warp of kvmclock Zachary Amsden
2011-09-02 18:34 ` Philipp Hahn
2011-09-05 14:06 ` [BUG, PATCH-2.6.32] " Philipp Hahn
2011-09-12 11:32 ` Marcelo Tosatti
2010-08-20 8:07 ` [KVM timekeeping 17/35] Implement getnsboottime kernel API Zachary Amsden
2010-08-20 18:39 ` john stultz
2010-08-20 23:37 ` Zachary Amsden
2010-08-21 0:02 ` john stultz
2010-08-21 0:52 ` Zachary Amsden
2010-08-21 1:04 ` john stultz
2010-08-21 1:22 ` Zachary Amsden
2010-08-27 18:05 ` Jan Kiszka
2010-08-27 23:48 ` Zachary Amsden
2010-08-30 18:07 ` Jan Kiszka
2010-08-20 8:07 ` [KVM timekeeping 18/35] Use getnsboottime in KVM Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 19/35] Add timekeeping documentation Zachary Amsden
2010-08-20 17:50 ` Glauber Costa
2010-08-20 8:07 ` [KVM timekeeping 20/35] Make math work for other scales Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 21/35] Track max tsc_khz Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 22/35] Track tsc last write in vcpu Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 23/35] Set initial TSC rate conversion factors Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 24/35] Timer request function renaming Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 25/35] Add clock catchup mode Zachary Amsden
2010-08-25 17:27 ` Marcelo Tosatti
2010-08-25 20:48 ` Zachary Amsden
2010-08-25 22:01 ` Marcelo Tosatti
2010-08-25 23:38 ` Glauber Costa
2010-08-26 0:17 ` Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 26/35] Catchup slower TSC to guest rate Zachary Amsden
2010-09-07 3:44 ` Dong, Eddie
2010-09-07 22:14 ` Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 27/35] Add TSC trapping Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 28/35] Unstable TSC write compensation Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 29/35] TSC overrun protection Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 30/35] IOCTL for setting TSC rate Zachary Amsden
2010-08-20 17:56 ` Glauber Costa [this message]
2010-08-21 16:11 ` Arnd Bergmann
2010-08-20 8:07 ` [KVM timekeeping 31/35] Exit conditions for TSC trapping Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 32/35] Entry " Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 33/35] Indicate reliable TSC in kvmclock Zachary Amsden
2010-08-20 17:45 ` Glauber Costa
2010-08-24 1:14 ` Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 34/35] Remove dead code Zachary Amsden
2010-08-20 8:07 ` [KVM timekeeping 35/35] Add some debug stuff Zachary Amsden
2010-08-20 13:26 ` KVM timekeeping and TSC virtualization David S. Ahern
2010-08-20 23:24 ` Zachary Amsden
2010-08-22 1:32 ` David S. Ahern
2010-08-24 1:44 ` Zachary Amsden
2010-08-24 3:04 ` David S. Ahern
2010-08-24 5:47 ` Zachary Amsden
2010-08-24 13:32 ` David S. Ahern
2010-08-24 23:01 ` Zachary Amsden
2010-08-25 16:55 ` Marcelo Tosatti
2010-08-25 20:32 ` Zachary Amsden
2010-08-24 22:13 ` Marcelo Tosatti
2010-08-25 4:04 ` Zachary Amsden
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