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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 3/3] x86/viridian: Add partition time reference counter MSR support
This patch optionally re-instates support for the partition time reference
counter that was previously introduced by commit
e36cd2cdc9674a7a4855d21fb7b3e6e17c4bb33b and reverted by commit
1cd4fab14ce25859efa4a2af13475e6650a5506c. The previous implementation was
non-optional and flawed.
The counter value used in this implementation properly fulfils the
documented semantics of the MSR.
The per-domain viridian save record is extended to preserve the reference
counter across save/restore. For compatibility therefore, the restore
zero extends any older save record. This is safe as, if the reference
counter substructure is not present, it cannot possibly have been in use
by the guest prior to the domain save and thus will not be accessed after
domain restore.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Cc: Keir Fraser <keir@xxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Ian Campbell <ian.campbell@xxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
docs/man/xl.cfg.pod.5 | 7 ++++
tools/libxl/libxl_dom.c | 2 +
xen/arch/x86/hvm/hvm.c | 3 ++
xen/arch/x86/hvm/viridian.c | 69 +++++++++++++++++++++++++++-----
xen/include/asm-x86/hvm/viridian.h | 22 ++++++++++
xen/include/asm-x86/perfc_defn.h | 1 +
xen/include/public/arch-x86/hvm/save.h | 11 +++++
xen/include/public/hvm/params.h | 9 ++++-
8 files changed, 113 insertions(+), 11 deletions(-)
diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
index a05e831..e4692982 100644
--- a/docs/man/xl.cfg.pod.5
+++ b/docs/man/xl.cfg.pod.5
@@ -1109,6 +1109,13 @@ This set incorporates the TSC and APIC frequency MSRs.
This enlightenment can improve performance of Windows 7 and Windows
Server 2008 R2 onwards.
+=item B<time-ref-count>
+
+This set incorporates Partition Time Reference Counter MSR.
+
+This enlightenment can improve performance of Windows 8 and Windows
+Server 2012 onwards.
+
=back
See the latest version of Microsoft's Hypervisor Top-Level Functional
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index a15c185..1ebdecd 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -222,6 +222,8 @@ static void hvm_set_viridian_features(libxl__gc *gc,
uint32_t domid,
feature_mask |= HVMPV_base_freq;
else if (strcmp(*p, "freq") == 0)
feature_mask &= ~HVMPV_no_freq;
+ else if (strcmp(*p, "time-ref-count") == 0)
+ feature_mask |= HVMPV_time_ref_count;
p++;
}
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 04d43d0..69dec3e 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -5548,6 +5548,9 @@ long do_hvm_op(unsigned long op,
XEN_GUEST_HANDLE_PARAM(void) arg)
!(a.value & HVMPV_base_freq) )
break;
+ if ( !d->arch.hvm_domain.params[a.index] )
+ initialize_viridian(d, a.value);
+
rc = 0;
break;
case HVM_PARAM_IDENT_PT:
diff --git a/xen/arch/x86/hvm/viridian.c b/xen/arch/x86/hvm/viridian.c
index 2d79403..3f9d4ae 100644
--- a/xen/arch/x86/hvm/viridian.c
+++ b/xen/arch/x86/hvm/viridian.c
@@ -36,11 +36,11 @@
#define HvNotifyLongSpinWait 8
/* Viridian CPUID 4000003, Viridian MSR availability. */
-#define CPUID3A_MSR_REF_COUNT (1 << 1)
-#define CPUID3A_MSR_APIC_ACCESS (1 << 4)
-#define CPUID3A_MSR_HYPERCALL (1 << 5)
-#define CPUID3A_MSR_VP_INDEX (1 << 6)
-#define CPUID3A_MSR_FREQ (1 << 11)
+#define CPUID3A_MSR_TIME_REF_COUNT (1 << 1)
+#define CPUID3A_MSR_APIC_ACCESS (1 << 4)
+#define CPUID3A_MSR_HYPERCALL (1 << 5)
+#define CPUID3A_MSR_VP_INDEX (1 << 6)
+#define CPUID3A_MSR_FREQ (1 << 11)
/* Viridian CPUID 4000004, Implementation Recommendations. */
#define CPUID4A_MSR_BASED_APIC (1 << 3)
@@ -51,6 +51,43 @@
#define CPUID6A_MSR_BITMAPS (1 << 1)
#define CPUID6A_NESTED_PAGING (1 << 3)
+static void initialize_time_ref_count(struct domain *d)
+{
+ struct viridian_time_ref_count *trc;
+
+ trc = &d->arch.hvm_domain.viridian.time_ref_count;
+
+ spin_lock_init(&trc->lock);
+}
+
+static s_time_t get_time_ref_count(struct domain *d)
+{
+ s_time_t now = get_s_time() / 100;
+ struct viridian_time_ref_count *trc;
+
+ trc = &d->arch.hvm_domain.viridian.time_ref_count;
+
+ spin_lock(&trc->lock);
+
+ if ( trc->last == 0 )
+ gdprintk(XENLOG_G_INFO, "TIME_REFERENCE_COUNTER accessed\n");
+
+ if ( (now - trc->last) > 0 )
+ trc->last = now;
+ else
+ now = ++trc->last;
+
+ spin_unlock(&trc->lock);
+
+ return now;
+}
+
+void initialize_viridian(struct domain *d, uint64_t feature_mask)
+{
+ if ( feature_mask & HVMPV_time_ref_count )
+ initialize_time_ref_count(d);
+}
+
int cpuid_viridian_leaves(unsigned int leaf, unsigned int *eax,
unsigned int *ebx, unsigned int *ecx,
unsigned int *edx)
@@ -93,6 +130,8 @@ int cpuid_viridian_leaves(unsigned int leaf, unsigned int
*eax,
CPUID3A_MSR_VP_INDEX);
if ( !(viridian_feature_mask(d) & HVMPV_no_freq) )
*eax |= CPUID3A_MSR_FREQ;
+ if ( viridian_feature_mask(d) & HVMPV_time_ref_count )
+ *eax |= CPUID3A_MSR_TIME_REF_COUNT;
break;
case 4:
/* Recommended hypercall usage. */
@@ -344,6 +383,14 @@ int rdmsr_viridian_regs(uint32_t idx, uint64_t *val)
*val = v->arch.hvm_vcpu.viridian.apic_assist.raw;
break;
+ case VIRIDIAN_MSR_TIME_REF_COUNT:
+ if ( !(viridian_feature_mask(d) & HVMPV_time_ref_count) )
+ return 0;
+
+ perfc_incr(mshv_rdmsr_time_ref_count);
+ *val = (uint64_t)get_time_ref_count(d);
+ break;
+
default:
return 0;
}
@@ -431,8 +478,9 @@ static int viridian_save_domain_ctxt(struct domain *d,
hvm_domain_context_t *h)
if ( !is_viridian_domain(d) )
return 0;
- ctxt.hypercall_gpa = d->arch.hvm_domain.viridian.hypercall_gpa.raw;
- ctxt.guest_os_id = d->arch.hvm_domain.viridian.guest_os_id.raw;
+ ctxt.hypercall_gpa = d->arch.hvm_domain.viridian.hypercall_gpa.raw;
+ ctxt.guest_os_id = d->arch.hvm_domain.viridian.guest_os_id.raw;
+ ctxt.time_ref_count = d->arch.hvm_domain.viridian.time_ref_count.last;
return (hvm_save_entry(VIRIDIAN_DOMAIN, 0, h, &ctxt) != 0);
}
@@ -441,11 +489,12 @@ static int viridian_load_domain_ctxt(struct domain *d,
hvm_domain_context_t *h)
{
struct hvm_viridian_domain_context ctxt;
- if ( hvm_load_entry(VIRIDIAN_DOMAIN, h, &ctxt) != 0 )
+ if ( hvm_load_entry_zeroextend(VIRIDIAN_DOMAIN, h, &ctxt) != 0 )
return -EINVAL;
- d->arch.hvm_domain.viridian.hypercall_gpa.raw = ctxt.hypercall_gpa;
- d->arch.hvm_domain.viridian.guest_os_id.raw = ctxt.guest_os_id;
+ d->arch.hvm_domain.viridian.hypercall_gpa.raw = ctxt.hypercall_gpa;
+ d->arch.hvm_domain.viridian.guest_os_id.raw = ctxt.guest_os_id;
+ d->arch.hvm_domain.viridian.time_ref_count.last = ctxt.time_ref_count;
return 0;
}
diff --git a/xen/include/asm-x86/hvm/viridian.h
b/xen/include/asm-x86/hvm/viridian.h
index 496da33..9565eea 100644
--- a/xen/include/asm-x86/hvm/viridian.h
+++ b/xen/include/asm-x86/hvm/viridian.h
@@ -48,12 +48,24 @@ union viridian_hypercall_gpa
} fields;
};
+struct viridian_time_ref_count
+{
+ spinlock_t lock;
+ s_time_t last;
+};
+
struct viridian_domain
{
union viridian_guest_os_id guest_os_id;
union viridian_hypercall_gpa hypercall_gpa;
+ struct viridian_time_ref_count time_ref_count;
};
+void
+initialize_viridian(
+ struct domain *d,
+ uint64_t feature_mask);
+
int
cpuid_viridian_leaves(
unsigned int leaf,
@@ -76,3 +88,13 @@ int
viridian_hypercall(struct cpu_user_regs *regs);
#endif /* __ASM_X86_HVM_VIRIDIAN_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/asm-x86/perfc_defn.h b/xen/include/asm-x86/perfc_defn.h
index 7d802cc..170da00 100644
--- a/xen/include/asm-x86/perfc_defn.h
+++ b/xen/include/asm-x86/perfc_defn.h
@@ -120,6 +120,7 @@ PERFCOUNTER(mshv_rdmsr_hc_page, "MS Hv rdmsr
hypercall page")
PERFCOUNTER(mshv_rdmsr_vp_index, "MS Hv rdmsr vp index")
PERFCOUNTER(mshv_rdmsr_tsc_frequency, "MS Hv rdmsr TSC frequency")
PERFCOUNTER(mshv_rdmsr_apic_frequency, "MS Hv rdmsr APIC frequency")
+PERFCOUNTER(mshv_rdmsr_time_ref_count, "MS Hv rdmsr time ref count")
PERFCOUNTER(mshv_rdmsr_icr, "MS Hv rdmsr icr")
PERFCOUNTER(mshv_rdmsr_tpr, "MS Hv rdmsr tpr")
PERFCOUNTER(mshv_rdmsr_apic_assist, "MS Hv rdmsr APIC assist")
diff --git a/xen/include/public/arch-x86/hvm/save.h
b/xen/include/public/arch-x86/hvm/save.h
index 16d85a3..d1fd11b 100644
--- a/xen/include/public/arch-x86/hvm/save.h
+++ b/xen/include/public/arch-x86/hvm/save.h
@@ -568,6 +568,7 @@ struct hvm_hw_cpu_xsave {
struct hvm_viridian_domain_context {
uint64_t hypercall_gpa;
uint64_t guest_os_id;
+ uint64_t time_ref_count;
};
DECLARE_HVM_SAVE_TYPE(VIRIDIAN_DOMAIN, 15, struct hvm_viridian_domain_context);
@@ -616,3 +617,13 @@ struct hvm_msr {
#define HVM_SAVE_CODE_MAX 20
#endif /* __XEN_PUBLIC_HVM_SAVE_X86_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/public/hvm/params.h b/xen/include/public/hvm/params.h
index 68d26fd..3c51072 100644
--- a/xen/include/public/hvm/params.h
+++ b/xen/include/public/hvm/params.h
@@ -88,7 +88,14 @@
#define _HVMPV_no_freq 1
#define HVMPV_no_freq (1 << _HVMPV_no_freq)
-#define HVMPV_feature_mask (HVMPV_base_freq|HVMPV_no_freq)
+/* Enable Partition Time Reference Counter (HV_X64_MSR_TIME_REF_COUNT) */
+#define _HVMPV_time_ref_count 2
+#define HVMPV_time_ref_count (1 << _HVMPV_time_ref_count)
+
+#define HVMPV_feature_mask \
+ (HVMPV_base_freq | \
+ HVMPV_no_freq | \
+ HVMPV_time_ref_count)
#endif
--
1.7.10.4
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