Re: [Xen-devel] [PATCH v24 06/15] x86/VPMU: Initialize PMU for PV(H) guests

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

> From: Boris Ostrovsky [mailto:boris.ostrovsky@xxxxxxxxxx]
> Sent: Wednesday, June 10, 2015 11:04 PM
> 
> Code for initializing/tearing down PMU for PV guests
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> Acked-by: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
> Acked-by: Jan Beulich <jbeulich@xxxxxxxx>

Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>

> ---
>  tools/flask/policy/policy/modules/xen/xen.te |   4 +
>  xen/arch/x86/domain.c                        |   2 +
>  xen/arch/x86/hvm/hvm.c                       |   1 +
>  xen/arch/x86/hvm/svm/svm.c                   |   4 +-
>  xen/arch/x86/hvm/svm/vpmu.c                  |  16 +++-
>  xen/arch/x86/hvm/vmx/vmx.c                   |   4 +-
>  xen/arch/x86/hvm/vmx/vpmu_core2.c            |  30 ++++--
>  xen/arch/x86/hvm/vpmu.c                      | 131
> ++++++++++++++++++++++++---
>  xen/common/event_channel.c                   |   1 +
>  xen/include/asm-x86/hvm/vpmu.h               |   2 +
>  xen/include/public/pmu.h                     |   2 +
>  xen/include/public/xen.h                     |   1 +
>  xen/include/xsm/dummy.h                      |   3 +
>  xen/xsm/flask/hooks.c                        |   4 +
>  xen/xsm/flask/policy/access_vectors          |   2 +
>  15 files changed, 181 insertions(+), 26 deletions(-)
> 
> diff --git a/tools/flask/policy/policy/modules/xen/xen.te
> b/tools/flask/policy/policy/modules/xen/xen.te
> index 45b5cb2..f553eb5 100644
> --- a/tools/flask/policy/policy/modules/xen/xen.te
> +++ b/tools/flask/policy/policy/modules/xen/xen.te
> @@ -130,6 +130,10 @@ if (guest_writeconsole) {
>       dontaudit domain_type xen_t : xen writeconsole;
>  }
> 
> +# Allow all domains to use PMU (but not to change its settings --- that's 
> what
> +# pmu_ctrl is for)
> +allow domain_type xen_t:xen2 pmu_use;
> +
> 
> #####################################################
> ##########################
>  #
>  # Domain creation
> diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
> index 8cc3ae7..8e79aca 100644
> --- a/xen/arch/x86/domain.c
> +++ b/xen/arch/x86/domain.c
> @@ -438,6 +438,8 @@ int vcpu_initialise(struct vcpu *v)
>          vmce_init_vcpu(v);
>      }
> 
> +    spin_lock_init(&v->arch.vpmu.vpmu_lock);
> +
>      if ( has_hvm_container_domain(d) )
>      {
>          rc = hvm_vcpu_initialise(v);
> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
> index f354cb7..016e842 100644
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -4914,6 +4914,7 @@ static hvm_hypercall_t *const
> pvh_hypercall64_table[NR_hypercalls] = {
>      HYPERCALL(hvm_op),
>      HYPERCALL(sysctl),
>      HYPERCALL(domctl),
> +    HYPERCALL(xenpmu_op),
>      [ __HYPERVISOR_arch_1 ] = (hvm_hypercall_t *)paging_domctl_continuation
>  };
> 
> diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
> index 6734fb6..49d2ddf 100644
> --- a/xen/arch/x86/hvm/svm/svm.c
> +++ b/xen/arch/x86/hvm/svm/svm.c
> @@ -1165,7 +1165,9 @@ static int svm_vcpu_initialise(struct vcpu *v)
>          return rc;
>      }
> 
> -    vpmu_initialise(v);
> +    /* PVH's VPMU is initialized via hypercall */
> +    if ( is_hvm_vcpu(v) )
> +        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 b60ca40..a8572a6 100644
> --- a/xen/arch/x86/hvm/svm/vpmu.c
> +++ b/xen/arch/x86/hvm/svm/vpmu.c
> @@ -364,13 +364,11 @@ static void amd_vpmu_destroy(struct vcpu *v)
>          amd_vpmu_unset_msr_bitmap(v);
> 
>      xfree(vpmu->context);
> -    vpmu_reset(vpmu, VPMU_CONTEXT_ALLOCATED);
> 
>      if ( vpmu_is_set(vpmu, VPMU_RUNNING) )
> -    {
> -        vpmu_reset(vpmu, VPMU_RUNNING);
>          release_pmu_ownship(PMU_OWNER_HVM);
> -    }
> +
> +    vpmu_clear(vpmu);
>  }
> 
>  /* VPMU part of the 'q' keyhandler */
> @@ -482,6 +480,16 @@ int __init amd_vpmu_init(void)
>          return -EINVAL;
>      }
> 
> +    if ( sizeof(struct xen_pmu_data) +
> +         2 * sizeof(uint64_t) * num_counters > PAGE_SIZE )
> +    {
> +        printk(XENLOG_WARNING
> +               "VPMU: Register bank does not fit into VPMU shared page\n");
> +        counters = ctrls = NULL;
> +        num_counters = 0;
> +        return -ENOSPC;
> +    }
> +
>      return 0;
>  }
> 
> diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
> index af257db..62d99e1 100644
> --- a/xen/arch/x86/hvm/vmx/vmx.c
> +++ b/xen/arch/x86/hvm/vmx/vmx.c
> @@ -140,7 +140,9 @@ static int vmx_vcpu_initialise(struct vcpu *v)
>          }
>      }
> 
> -    vpmu_initialise(v);
> +    /* PVH's VPMU is initialized via hypercall */
> +    if ( is_hvm_vcpu(v) )
> +        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 025c970..e7642e5 100644
> --- a/xen/arch/x86/hvm/vmx/vpmu_core2.c
> +++ b/xen/arch/x86/hvm/vmx/vpmu_core2.c
> @@ -365,13 +365,16 @@ static int core2_vpmu_alloc_resource(struct vcpu *v)
>      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) )
> -        goto out_err;
> +    if ( has_hvm_container_vcpu(v) )
> +    {
> +        wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0);
> +        if ( vmx_add_host_load_msr(MSR_CORE_PERF_GLOBAL_CTRL) )
> +            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);
> +        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(*core2_vpmu_cxt) +
>                                     sizeof(uint64_t) * fixed_pmc_cnt +
> @@ -717,7 +720,7 @@ static void core2_vpmu_destroy(struct vcpu *v)
>      if ( has_hvm_container_vcpu(v) && 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_clear(vpmu);
>  }
> 
>  struct arch_vpmu_ops core2_vpmu_ops = {
> @@ -827,6 +830,10 @@ int vmx_vpmu_initialise(struct vcpu *v)
>      ds_warned = 1;
>   func_out:
> 
> +    /* PV domains can allocate resources immediately */
> +    if ( is_pv_vcpu(v) && !core2_vpmu_alloc_resource(v) )
> +        return -EIO;
> +
>      vpmu->arch_vpmu_ops = &core2_vpmu_ops;
> 
>      return 0;
> @@ -897,6 +904,15 @@ int __init core2_vpmu_init(void)
> 
>      check_pmc_quirk();
> 
> +    if ( sizeof(struct xen_pmu_data) + sizeof(uint64_t) * fixed_pmc_cnt +
> +         sizeof(struct xen_pmu_cntr_pair) * arch_pmc_cnt > PAGE_SIZE )
> +    {
> +        printk(XENLOG_WARNING
> +               "VPMU: Register bank does not fit into VPMU share page\n");
> +        arch_pmc_cnt = fixed_pmc_cnt = 0;
> +        return -ENOSPC;
> +    }
> +
>      return 0;
>  }
> 
> diff --git a/xen/arch/x86/hvm/vpmu.c b/xen/arch/x86/hvm/vpmu.c
> index bb0b2e3..cfaa8c8 100644
> --- a/xen/arch/x86/hvm/vpmu.c
> +++ b/xen/arch/x86/hvm/vpmu.c
> @@ -27,6 +27,7 @@
>  #include <asm/types.h>
>  #include <asm/msr.h>
>  #include <asm/nmi.h>
> +#include <asm/p2m.h>
>  #include <asm/hvm/support.h>
>  #include <asm/hvm/vmx/vmx.h>
>  #include <asm/hvm/vmx/vmcs.h>
> @@ -257,22 +258,25 @@ void vpmu_initialise(struct vcpu *v)
>      struct vpmu_struct *vpmu = vcpu_vpmu(v);
>      uint8_t vendor = current_cpu_data.x86_vendor;
>      int ret;
> +    bool_t is_priv_vpmu = is_hardware_domain(v->domain);
> 
>      BUILD_BUG_ON(sizeof(struct xen_pmu_intel_ctxt) > XENPMU_CTXT_PAD_SZ);
>      BUILD_BUG_ON(sizeof(struct xen_pmu_amd_ctxt) > XENPMU_CTXT_PAD_SZ);
> 
> -    if ( is_pvh_vcpu(v) )
> -        return;
> -
>      ASSERT(!vpmu->flags && !vpmu->context);
> 
> -    /*
> -     * Count active VPMUs so that we won't try to change vpmu_mode while
> -     * they are in use.
> -     */
> -    spin_lock(&vpmu_lock);
> -    vpmu_count++;
> -    spin_unlock(&vpmu_lock);
> +    if ( !is_priv_vpmu )
> +    {
> +        /*
> +         * Count active VPMUs so that we won't try to change vpmu_mode while
> +         * they are in use.
> +         * vpmu_mode can be safely updated while dom0's VPMUs are active and
> +         * so we don't need to include it in the count.
> +         */
> +        spin_lock(&vpmu_lock);
> +        vpmu_count++;
> +        spin_unlock(&vpmu_lock);
> +    }
> 
>      switch ( vendor )
>      {
> @@ -299,7 +303,7 @@ void vpmu_initialise(struct vcpu *v)
>          printk(XENLOG_G_WARNING "VPMU: Initialization failed for %pv\n", v);
> 
>      /* Intel needs to initialize VPMU ops even if VPMU is not in use */
> -    if ( ret || (vpmu_mode == XENPMU_MODE_OFF) )
> +    if ( !is_priv_vpmu && (ret || (vpmu_mode == XENPMU_MODE_OFF)) )
>      {
>          spin_lock(&vpmu_lock);
>          vpmu_count--;
> @@ -332,13 +336,104 @@ void vpmu_destroy(struct vcpu *v)
>                           vpmu_clear_last, v, 1);
> 
>      if ( vpmu->arch_vpmu_ops && vpmu->arch_vpmu_ops->arch_vpmu_destroy )
> -        vpmu->arch_vpmu_ops->arch_vpmu_destroy(v);
> +    {
> +        /* 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);
> +    }
> 
>      spin_lock(&vpmu_lock);
> -    vpmu_count--;
> +    if ( !is_hardware_domain(v->domain) )
> +        vpmu_count--;
>      spin_unlock(&vpmu_lock);
>  }
> 
> +static int pvpmu_init(struct domain *d, xen_pmu_params_t *params)
> +{
> +    struct vcpu *v;
> +    struct vpmu_struct *vpmu;
> +    struct page_info *page;
> +    uint64_t gfn = params->val;
> +
> +    if ( vpmu_mode == XENPMU_MODE_OFF )
> +        return -EINVAL;
> +
> +    if ( (params->vcpu >= d->max_vcpus) || (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];
> +    vpmu = vcpu_vpmu(v);
> +
> +    spin_lock(&vpmu->vpmu_lock);
> +
> +    if ( v->arch.vpmu.xenpmu_data )
> +    {
> +        spin_unlock(&vpmu->vpmu_lock);
> +        put_page_and_type(page);
> +        return -EEXIST;
> +    }
> +
> +    v->arch.vpmu.xenpmu_data = __map_domain_page_global(page);
> +    if ( !v->arch.vpmu.xenpmu_data )
> +    {
> +        spin_unlock(&vpmu->vpmu_lock);
> +        put_page_and_type(page);
> +        return -ENOMEM;
> +    }
> +
> +    vpmu_initialise(v);
> +
> +    spin_unlock(&vpmu->vpmu_lock);
> +
> +    return 0;
> +}
> +
> +static void pvpmu_finish(struct domain *d, xen_pmu_params_t *params)
> +{
> +    struct vcpu *v;
> +    struct vpmu_struct *vpmu;
> +    uint64_t mfn;
> +    void *xenpmu_data;
> +
> +    if ( (params->vcpu >= d->max_vcpus) || (d->vcpu[params->vcpu] == NULL) )
> +        return;
> +
> +    v = d->vcpu[params->vcpu];
> +    if ( v != current )
> +        vcpu_pause(v);
> +
> +    vpmu = vcpu_vpmu(v);
> +    spin_lock(&vpmu->vpmu_lock);
> +
> +    vpmu_destroy(v);
> +    xenpmu_data = vpmu->xenpmu_data;
> +    vpmu->xenpmu_data = NULL;
> +
> +    spin_unlock(&vpmu->vpmu_lock);
> +
> +    if ( xenpmu_data )
> +    {
> +        mfn = domain_page_map_to_mfn(xenpmu_data);
> +        ASSERT(mfn_valid(mfn));
> +        unmap_domain_page_global(xenpmu_data);
> +        put_page_and_type(mfn_to_page(mfn));
> +    }
> +
> +    if ( v != current )
> +        vcpu_unpause(v);
> +}
> +
>  /* Dump some vpmu informations on console. Used in keyhandler 
> dump_domains(). */
>  void vpmu_dump(struct vcpu *v)
>  {
> @@ -365,6 +460,8 @@ long do_xenpmu_op(unsigned int op,
> XEN_GUEST_HANDLE_PARAM(xen_pmu_params_t) arg)
>      {
>      case XENPMU_mode_set:
>      case XENPMU_feature_set:
> +    case XENPMU_init:
> +    case XENPMU_finish:
>          if ( copy_from_guest(&pmu_params, arg, 1) )
>              return -EFAULT;
> 
> @@ -444,6 +541,14 @@ long do_xenpmu_op(unsigned int op,
> XEN_GUEST_HANDLE_PARAM(xen_pmu_params_t) arg)
> 
>          break;
> 
> +    case XENPMU_init:
> +        ret = pvpmu_init(current->domain, &pmu_params);
> +        break;
> +
> +    case XENPMU_finish:
> +        pvpmu_finish(current->domain, &pmu_params);
> +        break;
> +
>      default:
>          ret = -EINVAL;
>      }
> diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
> index fae242d..310f590 100644
> --- a/xen/common/event_channel.c
> +++ b/xen/common/event_channel.c
> @@ -106,6 +106,7 @@ 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 96f7666..642a4b7 100644
> --- a/xen/include/asm-x86/hvm/vpmu.h
> +++ b/xen/include/asm-x86/hvm/vpmu.h
> @@ -64,6 +64,8 @@ struct vpmu_struct {
>      void *context;      /* May be shared with PV guest */
>      void *priv_context; /* hypervisor-only */
>      struct arch_vpmu_ops *arch_vpmu_ops;
> +    struct xen_pmu_data *xenpmu_data;
> +    spinlock_t vpmu_lock;
>  };
> 
>  /* VPMU states */
> diff --git a/xen/include/public/pmu.h b/xen/include/public/pmu.h
> index 50cc048..e6307b5 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 59fb544..1b98d8b 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
> diff --git a/xen/include/xsm/dummy.h b/xen/include/xsm/dummy.h
> index a496116..6456f72 100644
> --- a/xen/include/xsm/dummy.h
> +++ b/xen/include/xsm/dummy.h
> @@ -704,6 +704,9 @@ static XSM_INLINE int xsm_pmu_op (XSM_DEFAULT_ARG struct
> domain *d, int op)
>      case XENPMU_feature_set:
>      case XENPMU_feature_get:
>          return xsm_default_action(XSM_PRIV, d, current->domain);
> +    case XENPMU_init:
> +    case XENPMU_finish:
> +        return xsm_default_action(XSM_HOOK, d, current->domain);
>      default:
>          return -EPERM;
>      }
> diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
> index ac98966..aefcbda 100644
> --- a/xen/xsm/flask/hooks.c
> +++ b/xen/xsm/flask/hooks.c
> @@ -1592,6 +1592,10 @@ static int flask_pmu_op (struct domain *d, unsigned 
> int op)
>      case XENPMU_feature_get:
>          return avc_has_perm(dsid, SECINITSID_XEN, SECCLASS_XEN2,
>                              XEN2__PMU_CTRL, NULL);
> +    case XENPMU_init:
> +    case XENPMU_finish:
> +        return avc_has_perm(dsid, SECINITSID_XEN, SECCLASS_XEN2,
> +                            XEN2__PMU_USE, NULL);
>      default:
>          return -EPERM;
>      }
> diff --git a/xen/xsm/flask/policy/access_vectors 
> b/xen/xsm/flask/policy/access_vectors
> index 3a5d798..a6517a3 100644
> --- a/xen/xsm/flask/policy/access_vectors
> +++ b/xen/xsm/flask/policy/access_vectors
> @@ -89,6 +89,8 @@ class xen2
>      get_symbol
>  # PMU control
>      pmu_ctrl
> +# PMU use (domains, including unprivileged ones, will be using this 
> operation)
> +    pmu_use
>  }
> 
>  # Classes domain and domain2 consist of operations that a domain performs on
> --
> 1.8.1.4


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