[PATCH v23 06/15] x86/VPMU: Initialize PMU for PV(H) guests

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

Code for initializing/tearing down PMU for PV guests

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
 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 2f4e419..5bc1958 100644
--- a/tools/flask/policy/policy/modules/xen/xen.te
+++ b/tools/flask/policy/policy/modules/xen/xen.te
@@ -120,6 +120,10 @@ domain_comms(dom0_t, dom0_t)
 # Allow all domains to use (unprivileged parts of) the tmem hypercall
 allow domain_type xen_t:xen tmem_op;
 
+# 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 89423fa..0e5669d 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4911,6 +4911,7 @@ 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 74f563f..9ebff99 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -139,7 +139,9 @@ 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 1d301a2..d850903 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