From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vadim Rozenfeld Subject: Re: [RFC PATCH 2/2] Hyper-V iTSC handler Date: Thu, 16 May 2013 18:58:02 +1000 Message-ID: <1368694682.18400.6.camel@localhost> References: <1368445517-5496-1-git-send-email-vrozenfe@redhat.com> <1368445517-5496-3-git-send-email-vrozenfe@redhat.com> <20130516083349.GL26453@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, mtosatti@redhat.com, pl@dlh.net To: Gleb Natapov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:49201 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756049Ab3EPI6N (ORCPT ); Thu, 16 May 2013 04:58:13 -0400 In-Reply-To: <20130516083349.GL26453@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, 2013-05-16 at 11:33 +0300, Gleb Natapov wrote: > On Mon, May 13, 2013 at 09:45:17PM +1000, Vadim Rozenfeld wrote: > > Signed-off: Vadim Rozenfeld > > > > The following patch allows to activate a partition reference > > time enlightenment that is based on the host platform's support > > for an Invariant Time Stamp Counter (iTSC). > > NOTE: This code will survive migration due to lack of VM stop/resume > > handlers. > > > Do you mean "will _not_ survive migration"? Sorry for typo. Yes, it will not, because offset, scale and sequence must be readjusted. > > > --- > > arch/x86/include/uapi/asm/hyperv.h | 10 ++++++++++ > > arch/x86/kvm/x86.c | 18 +++++++++++++----- > > include/uapi/linux/kvm.h | 1 + > > 3 files changed, 24 insertions(+), 5 deletions(-) > > > > diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h > > index 9711819..2d9e666 100644 > > --- a/arch/x86/include/uapi/asm/hyperv.h > > +++ b/arch/x86/include/uapi/asm/hyperv.h > > @@ -182,6 +182,9 @@ > > #define HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_MASK \ > > (~((1ull << HV_X64_MSR_APIC_ASSIST_PAGE_ADDRESS_SHIFT) - 1)) > > > > +#define HV_X64_MSR_TSC_REFERENCE_ENABLE 0x00000001 > > +#define HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT 12 > > + > > #define HV_PROCESSOR_POWER_STATE_C0 0 > > #define HV_PROCESSOR_POWER_STATE_C1 1 > > #define HV_PROCESSOR_POWER_STATE_C2 2 > > @@ -194,4 +197,11 @@ > > #define HV_STATUS_INVALID_ALIGNMENT 4 > > #define HV_STATUS_INSUFFICIENT_BUFFERS 19 > > > > +typedef struct _HV_REFERENCE_TSC_PAGE { > > + uint32_t TscSequence; > > + uint32_t Rserved1; > > + uint64_t TscScale; > > + int64_t TscOffset; > > +} HV_REFERENCE_TSC_PAGE, * PHV_REFERENCE_TSC_PAGE; > > + > Use kernel types: __u32/__u64/__s64. > > > #endif > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > index 1a4036d..5788e8f 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -1809,14 +1809,21 @@ static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32 msr, u64 data) > > break; > > } > > case HV_X64_MSR_REFERENCE_TSC: { > > - u64 gfn; > > unsigned long addr; > > - u32 tsc_ref; > > - gfn = data >> HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT; > > - addr = gfn_to_hva(kvm, gfn); > > + HV_REFERENCE_TSC_PAGE tsc_ref; > > + tsc_ref.TscSequence = > > + boot_cpu_has(X86_FEATURE_CONSTANT_TSC) ? 1 : 0; > > + tsc_ref.TscScale = > > + ((10000LL << 32) /vcpu->arch.virtual_tsc_khz) << 32; > > + tsc_ref.TscOffset = 0; > > + if (!(data & HV_X64_MSR_TSC_REFERENCE_ENABLE)) { > > + kvm->arch.hv_tsc_page = data; > > + break; > > + } > > + addr = gfn_to_hva(vcpu->kvm, data >> > > + HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT); > > if (kvm_is_error_hva(addr)) > > return 1; > > - tsc_ref = 0; > > if(__copy_to_user((void __user *)addr, &tsc_ref, sizeof(tsc_ref))) > > return 1; > > kvm->arch.hv_tsc_page = data; > > @@ -2553,6 +2560,7 @@ int kvm_dev_ioctl_check_extension(long ext) > > case KVM_CAP_HYPERV: > > case KVM_CAP_HYPERV_VAPIC: > > case KVM_CAP_HYPERV_SPIN: > > + case KVM_CAP_HYPERV_TSC: > > case KVM_CAP_PCI_SEGMENT: > > case KVM_CAP_DEBUGREGS: > > case KVM_CAP_X86_ROBUST_SINGLESTEP: > > diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h > > index a5c86fc..8eff540 100644 > > --- a/include/uapi/linux/kvm.h > > +++ b/include/uapi/linux/kvm.h > > @@ -666,6 +666,7 @@ struct kvm_ppc_smmu_info { > > #define KVM_CAP_IRQ_MPIC 90 > > #define KVM_CAP_PPC_RTAS 91 > > #define KVM_CAP_IRQ_XICS 92 > > +#define KVM_CAP_HYPERV_TSC 93 > > > > #ifdef KVM_CAP_IRQ_ROUTING > > > > -- > > 1.8.1.2 > > -- > Gleb.