Re: [PATCH v11 for-xen-4.5 12/20] x86/VPMU: Initialize PMU for PV(H) guests

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Sep 22, 2014 at 07:57:53PM -0400, Boris Ostrovsky wrote:
> Code for initializing/tearing down PMU for PV guests
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>


Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>


> ---
>  xen/arch/x86/hvm/hvm.c            |  3 +-
>  xen/arch/x86/hvm/svm/svm.c        |  4 +-
>  xen/arch/x86/hvm/svm/vpmu.c       | 43 +++++++++++++-------
>  xen/arch/x86/hvm/vmx/vmx.c        |  4 +-
>  xen/arch/x86/hvm/vmx/vpmu_core2.c | 83 ++++++++++++++++++++++++++++-----------
>  xen/arch/x86/hvm/vpmu.c           | 83 ++++++++++++++++++++++++++++++++++++++-
>  xen/common/event_channel.c        |  1 +
>  xen/include/asm-x86/hvm/vpmu.h    |  1 +
>  xen/include/public/pmu.h          |  2 +
>  xen/include/public/xen.h          |  1 +
>  10 files changed, 183 insertions(+), 42 deletions(-)
> 
> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
> index 83e6fae..5b34689 100644
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -4832,7 +4832,8 @@ static hvm_hypercall_t *const pvh_hypercall64_table[NR_hypercalls] = {
>      [ __HYPERVISOR_physdev_op ]      = (hvm_hypercall_t *)hvm_physdev_op,
>      HYPERCALL(hvm_op),
>      HYPERCALL(sysctl),
> -    HYPERCALL(domctl)
> +    HYPERCALL(domctl),
> +    HYPERCALL(xenpmu_op)
>  };
>  
>  int hvm_do_hypercall(struct cpu_user_regs *regs)
> diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
> index b5188e6..8b9a34e 100644
> --- a/xen/arch/x86/hvm/svm/svm.c
> +++ b/xen/arch/x86/hvm/svm/svm.c
> @@ -1158,7 +1158,9 @@ static int svm_vcpu_initialise(struct vcpu *v)
>          return rc;
>      }
>  
> -    vpmu_initialise(v);
> +    /* PVH's VPMU is initialized via hypercall */
> +    if ( is_hvm_domain(v->domain) )
> +        vpmu_initialise(v);
>  
>      svm_guest_osvw_init(v);
>  
> diff --git a/xen/arch/x86/hvm/svm/vpmu.c b/xen/arch/x86/hvm/svm/vpmu.c
> index 37d8228..be3ab27 100644
> --- a/xen/arch/x86/hvm/svm/vpmu.c
> +++ b/xen/arch/x86/hvm/svm/vpmu.c
> @@ -362,6 +362,7 @@ static int amd_vpmu_initialise(struct vcpu *v)
>      struct xen_pmu_amd_ctxt *ctxt;
>      struct vpmu_struct *vpmu = vcpu_vpmu(v);
>      uint8_t family = current_cpu_data.x86;
> +    unsigned int regs_size;
>  
>      if ( vpmu_is_set(vpmu, VPMU_CONTEXT_ALLOCATED) )
>          return 0;
> @@ -389,14 +390,26 @@ static int amd_vpmu_initialise(struct vcpu *v)
>  	 }
>      }
>  
> -    ctxt = xzalloc_bytes(sizeof(struct xen_pmu_amd_ctxt) +
> -                         2 * sizeof(uint64_t) * AMD_MAX_COUNTERS);
> -    if ( !ctxt )
> +    regs_size = 2 * sizeof(uint64_t) * AMD_MAX_COUNTERS;
> +    if ( is_hvm_domain(v->domain) )
>      {
> -        gdprintk(XENLOG_WARNING, "Insufficient memory for PMU, "
> -            " PMU feature is unavailable on domain %d vcpu %d.\n",
> -            v->vcpu_id, v->domain->domain_id);
> -        return -ENOMEM;
> +        ctxt = xzalloc_bytes(sizeof(struct xen_pmu_amd_ctxt) + regs_size);
> +        if ( !ctxt )
> +        {
> +            gdprintk(XENLOG_WARNING, "Insufficient memory for PMU, "
> +                "PMU feature is unavailable\n");
> +            return -ENOMEM;
> +        }
> +    }
> +    else
> +    {
> +        if ( sizeof(struct xen_pmu_data) + regs_size > PAGE_SIZE )
> +        {
> +            gdprintk(XENLOG_WARNING,
> +                    "Register bank does not fit into VPMU shared page\n");
> +            return -ENOSPC;
> +        }
> +        ctxt = &v->arch.vpmu.xenpmu_data->pmu.c.amd;
>      }
>  
>      ctxt->counters = sizeof(struct xen_pmu_amd_ctxt);
> @@ -415,17 +428,19 @@ static void amd_vpmu_destroy(struct vcpu *v)
>      if ( !vpmu_is_set(vpmu, VPMU_CONTEXT_ALLOCATED) )
>          return;
>  
> -    if ( has_hvm_container_domain(v->domain) && is_msr_bitmap_on(vpmu) )
> -        amd_vpmu_unset_msr_bitmap(v);
> +    if ( has_hvm_container_domain(v->domain) )
> +    {
> +        if ( is_msr_bitmap_on(vpmu) )
> +            amd_vpmu_unset_msr_bitmap(v);
>  
> -    xfree(vpmu->context);
> -    vpmu_reset(vpmu, VPMU_CONTEXT_ALLOCATED);
> +        if ( is_hvm_domain(v->domain) )
> +            xfree(vpmu->context);
>  
> -    if ( vpmu_is_set(vpmu, VPMU_RUNNING) )
> -    {
> -        vpmu_reset(vpmu, VPMU_RUNNING);
>          release_pmu_ownship(PMU_OWNER_HVM);
>      }
> +
> +    vpmu->context = NULL;
> +    vpmu_clear(vpmu);
>  }
>  
>  /* VPMU part of the 'q' keyhandler */
> diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
> index 26b1ad5..09e30ed 100644
> --- a/xen/arch/x86/hvm/vmx/vmx.c
> +++ b/xen/arch/x86/hvm/vmx/vmx.c
> @@ -116,7 +116,9 @@ static int vmx_vcpu_initialise(struct vcpu *v)
>          return rc;
>      }
>  
> -    vpmu_initialise(v);
> +    /* PVH's VPMU is initialized via hypercall */
> +    if ( is_hvm_domain(v->domain) )
> +        vpmu_initialise(v);
>  
>      vmx_install_vlapic_mapping(v);
>  
> diff --git a/xen/arch/x86/hvm/vmx/vpmu_core2.c b/xen/arch/x86/hvm/vmx/vpmu_core2.c
> index 215336f..392867b 100644
> --- a/xen/arch/x86/hvm/vmx/vpmu_core2.c
> +++ b/xen/arch/x86/hvm/vmx/vpmu_core2.c
> @@ -356,25 +356,45 @@ static int core2_vpmu_alloc_resource(struct vcpu *v)
>      struct vpmu_struct *vpmu = vcpu_vpmu(v);
>      struct xen_pmu_intel_ctxt *core2_vpmu_cxt = NULL;
>      uint64_t *p = NULL;
> +    unsigned int regs_size;
>  
> -    if ( !acquire_pmu_ownership(PMU_OWNER_HVM) )
> -        return 0;
> -
> -    wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
> -    if ( vmx_add_host_load_msr(MSR_CORE_PERF_GLOBAL_CTRL) )
> +    p = xzalloc_bytes(sizeof(uint64_t));
> +    if ( !p )
>          goto out_err;
>  
> -    if ( vmx_add_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL) )
> -        goto out_err;
> -    vmx_write_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, 0);
> -
> -    core2_vpmu_cxt = xzalloc_bytes(sizeof(struct xen_pmu_intel_ctxt) +
> -                                   sizeof(uint64_t) * fixed_pmc_cnt +
> -                                   sizeof(struct xen_pmu_cntr_pair) *
> -                                   arch_pmc_cnt);
> -    p = xzalloc(uint64_t);
> -    if ( !core2_vpmu_cxt || !p )
> -        goto out_err;
> +    if ( has_hvm_container_domain(v->domain) )
> +    {
> +        if ( is_hvm_domain(v->domain) && !acquire_pmu_ownership(PMU_OWNER_HVM) )
> +            goto out_err;
> +
> +        wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
> +        if ( vmx_add_host_load_msr(MSR_CORE_PERF_GLOBAL_CTRL) )
> +            goto out_err_hvm;
> +        if ( vmx_add_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL) )
> +            goto out_err_hvm;
> +        vmx_write_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, 0);
> +    }
> +
> +    regs_size = sizeof(uint64_t) * fixed_pmc_cnt +
> +                sizeof(struct xen_pmu_cntr_pair) * arch_pmc_cnt;
> +    if ( is_hvm_domain(v->domain) )
> +    {
> +        core2_vpmu_cxt = xzalloc_bytes(sizeof(struct xen_pmu_intel_ctxt) +
> +                                       regs_size);
> +        if ( !core2_vpmu_cxt )
> +            goto out_err_hvm;
> +    }
> +    else
> +    {
> +        if ( sizeof(struct xen_pmu_data) + regs_size > PAGE_SIZE )
> +        {
> +            printk(XENLOG_WARNING
> +                   "Register bank does not fit into VPMU share page\n");
> +            goto out_err_hvm;
> +        }
> +
> +        core2_vpmu_cxt = &v->arch.vpmu.xenpmu_data->pmu.c.intel;
> +    }
>  
>      core2_vpmu_cxt->fixed_counters = sizeof(struct xen_pmu_intel_ctxt);
>      core2_vpmu_cxt->arch_counters = core2_vpmu_cxt->fixed_counters +
> @@ -387,10 +407,12 @@ static int core2_vpmu_alloc_resource(struct vcpu *v)
>  
>      return 1;
>  
> -out_err:
> -    release_pmu_ownship(PMU_OWNER_HVM);
> -
> + out_err_hvm:
>      xfree(core2_vpmu_cxt);
> +    if ( is_hvm_domain(v->domain) )
> +        release_pmu_ownship(PMU_OWNER_HVM);
> +
> + out_err:
>      xfree(p);
>  
>      printk("Failed to allocate VPMU resources for domain %u vcpu %u\n",
> @@ -756,6 +778,11 @@ static int core2_vpmu_initialise(struct vcpu *v)
>      arch_pmc_cnt = core2_get_arch_pmc_count();
>      fixed_pmc_cnt = core2_get_fixed_pmc_count();
>      check_pmc_quirk();
> +
> +    /* PV domains can allocate resources immediately */
> +    if ( is_pv_domain(v->domain) && !core2_vpmu_alloc_resource(v) )
> +        return -EIO;
> +
>      return 0;
>  }
>  
> @@ -766,12 +793,20 @@ static void core2_vpmu_destroy(struct vcpu *v)
>      if ( !vpmu_is_set(vpmu, VPMU_CONTEXT_ALLOCATED) )
>          return;
>  
> -    xfree(vpmu->context);
> +    if ( has_hvm_container_domain(v->domain) )
> +    {
> +        if ( cpu_has_vmx_msr_bitmap )
> +            core2_vpmu_unset_msr_bitmap(v->arch.hvm_vmx.msr_bitmap);
> +
> +        if ( is_hvm_domain(v->domain) )
> +            xfree(vpmu->context);
> +
> +        release_pmu_ownship(PMU_OWNER_HVM);
> +    }
> +
>      xfree(vpmu->priv_context);
> -    if ( has_hvm_container_domain(v->domain) && cpu_has_vmx_msr_bitmap )
> -        core2_vpmu_unset_msr_bitmap(v->arch.hvm_vmx.msr_bitmap);
> -    release_pmu_ownship(PMU_OWNER_HVM);
> -    vpmu_reset(vpmu, VPMU_CONTEXT_ALLOCATED);
> +    vpmu->context = NULL;
> +    vpmu_clear(vpmu);
>  }
>  
>  struct arch_vpmu_ops core2_vpmu_ops = {
> diff --git a/xen/arch/x86/hvm/vpmu.c b/xen/arch/x86/hvm/vpmu.c
> index ebc3802..73180df 100644
> --- a/xen/arch/x86/hvm/vpmu.c
> +++ b/xen/arch/x86/hvm/vpmu.c
> @@ -26,6 +26,7 @@
>  #include <asm/regs.h>
>  #include <asm/types.h>
>  #include <asm/msr.h>
> +#include <asm/p2m.h>
>  #include <asm/hvm/support.h>
>  #include <asm/hvm/vmx/vmx.h>
>  #include <asm/hvm/vmx/vmcs.h>
> @@ -255,6 +256,7 @@ void vpmu_initialise(struct vcpu *v)
>          vpmu_destroy(v);
>      vpmu_clear(vpmu);
>      vpmu->context = NULL;
> +    vpmu->hw_lapic_lvtpc = PMU_APIC_VECTOR | APIC_LVT_MASKED;
>  
>      switch ( vendor )
>      {
> @@ -281,7 +283,74 @@ void vpmu_destroy(struct vcpu *v)
>      struct vpmu_struct *vpmu = vcpu_vpmu(v);
>  
>      if ( vpmu->arch_vpmu_ops && vpmu->arch_vpmu_ops->arch_vpmu_destroy )
> +    {
> +        /* Unload VPMU first. This will stop counters */
> +        on_selected_cpus(cpumask_of(vcpu_vpmu(v)->last_pcpu),
> +                         vpmu_save_force, v, 1);
> +
>          vpmu->arch_vpmu_ops->arch_vpmu_destroy(v);
> +    }
> +}
> +
> +static int pvpmu_init(struct domain *d, xen_pmu_params_t *params)
> +{
> +    struct vcpu *v;
> +    struct page_info *page;
> +    uint64_t gfn = params->val;
> +
> +    if ( (params->vcpu >= d->max_vcpus) || (d->vcpu == NULL) ||
> +         (d->vcpu[params->vcpu] == NULL) )
> +        return -EINVAL;
> +
> +    page = get_page_from_gfn(d, gfn, NULL, P2M_ALLOC);
> +    if ( !page )
> +        return -EINVAL;
> +
> +    if ( !get_page_type(page, PGT_writable_page) )
> +    {
> +        put_page(page);
> +        return -EINVAL;
> +    }
> +
> +    v = d->vcpu[params->vcpu];
> +    v->arch.vpmu.xenpmu_data = __map_domain_page_global(page);
> +    if ( !v->arch.vpmu.xenpmu_data )
> +    {
> +        put_page_and_type(page);
> +        return -EINVAL;
> +    }
> +
> +    vpmu_initialise(v);
> +
> +    return 0;
> +}
> +
> +static void pvpmu_finish(struct domain *d, xen_pmu_params_t *params)
> +{
> +    struct vcpu *v;
> +    uint64_t mfn;
> +
> +    if ( (params->vcpu >= d->max_vcpus) || (d->vcpu == NULL) ||
> +         (d->vcpu[params->vcpu] == NULL) )
> +        return;
> +
> +    v = d->vcpu[params->vcpu];
> +    if ( v != current )
> +        vcpu_pause(v);
> +
> +    if ( v->arch.vpmu.xenpmu_data )
> +    {
> +        mfn = domain_page_map_to_mfn(v->arch.vpmu.xenpmu_data);
> +        if ( mfn_valid(mfn) )
> +        {
> +            unmap_domain_page_global(v->arch.vpmu.xenpmu_data);
> +            put_page_and_type(mfn_to_page(mfn));
> +        }
> +    }
> +    vpmu_destroy(v);
> +
> +    if ( v != current )
> +        vcpu_unpause(v);
>  }
>  
>  /* Dump some vpmu informations on console. Used in keyhandler dump_domains(). */
> @@ -466,7 +535,19 @@ long do_xenpmu_op(int op, XEN_GUEST_HANDLE_PARAM(xen_pmu_params_t) arg)
>              return -EFAULT;
>          ret = 0;
>          break;
> -     }
> +
> +    case XENPMU_init:
> +        if ( copy_from_guest(&pmu_params, arg, 1) )
> +            return -EFAULT;
> +        ret = pvpmu_init(current->domain, &pmu_params);
> +        break;
> +
> +    case XENPMU_finish:
> +        if ( copy_from_guest(&pmu_params, arg, 1) )
> +            return -EFAULT;
> +        pvpmu_finish(current->domain, &pmu_params);
> +        break;
> +    }
>  
>      return ret;
>  }
> diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
> index 7d6de54..a991b2d 100644
> --- a/xen/common/event_channel.c
> +++ b/xen/common/event_channel.c
> @@ -108,6 +108,7 @@ static int virq_is_global(uint32_t virq)
>      case VIRQ_TIMER:
>      case VIRQ_DEBUG:
>      case VIRQ_XENOPROF:
> +    case VIRQ_XENPMU:
>          rc = 0;
>          break;
>      case VIRQ_ARCH_0 ... VIRQ_ARCH_7:
> diff --git a/xen/include/asm-x86/hvm/vpmu.h b/xen/include/asm-x86/hvm/vpmu.h
> index c612e1a..93f1fc2 100644
> --- a/xen/include/asm-x86/hvm/vpmu.h
> +++ b/xen/include/asm-x86/hvm/vpmu.h
> @@ -62,6 +62,7 @@ struct vpmu_struct {
>      void *context;      /* May be shared with PV guest */
>      void *priv_context; /* hypervisor-only */
>      struct arch_vpmu_ops *arch_vpmu_ops;
> +    xen_pmu_data_t *xenpmu_data;
>  };
>  
>  /* VPMU states */
> diff --git a/xen/include/public/pmu.h b/xen/include/public/pmu.h
> index c2293be..b8c5682 100644
> --- a/xen/include/public/pmu.h
> +++ b/xen/include/public/pmu.h
> @@ -25,6 +25,8 @@
>  #define XENPMU_mode_set        1
>  #define XENPMU_feature_get     2
>  #define XENPMU_feature_set     3
> +#define XENPMU_init            4
> +#define XENPMU_finish          5
>  /* ` } */
>  
>  /* Parameters structure for HYPERVISOR_xenpmu_op call */
> diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
> index 0766790..e4d0b79 100644
> --- a/xen/include/public/xen.h
> +++ b/xen/include/public/xen.h
> @@ -161,6 +161,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_ulong_t);
>  #define VIRQ_MEM_EVENT  10 /* G. (DOM0) A memory event has occured           */
>  #define VIRQ_XC_RESERVED 11 /* G. Reserved for XenClient                     */
>  #define VIRQ_ENOMEM     12 /* G. (DOM0) Low on heap memory       */
> +#define VIRQ_XENPMU     13 /* V.  PMC interrupt                              */
>  
>  /* Architecture-specific VIRQ definitions. */
>  #define VIRQ_ARCH_0    16
> -- 
> 1.8.1.4
> 
> 
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