[Xen-devel] [PATCH 04/13] x86/hvm: Setup TSC scaling ratio

[Haozhong Zhang <haozhong.zhang@xxxxxxxxx>]

This patch adds a field tsc_scaling_ratio in struct arch_vcpu to
represent the TSC scaling ratio, and sets it up when tsc_set_info() is
called for a vcpu or a vcpu is restored or reset.

Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
---
 xen/arch/x86/hvm/hvm.c        | 34 ++++++++++++++++++++++++++++++++++
 xen/arch/x86/hvm/svm/svm.c    |  2 ++
 xen/arch/x86/time.c           | 10 +++++++++-
 xen/include/asm-x86/domain.h  |  2 ++
 xen/include/asm-x86/hvm/hvm.h |  2 ++
 5 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 6afc344..63ce4de 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -297,6 +297,34 @@ int hvm_set_guest_pat(struct vcpu *v, u64 guest_pat)
     return 1;
 }
 
+void hvm_setup_tsc_scaling(struct vcpu *v)
+{
+    u64 ratio, khz;
+       s8 shift;
+
+    if ( !hvm_funcs.tsc_scaling_supported )
+        return;
+
+    khz = v->domain->arch.tsc_khz;
+    shift = (hvm_funcs.tsc_scaling_ratio_frac_bits <= 32) ?
+        hvm_funcs.tsc_scaling_ratio_frac_bits : 32;
+    ratio = khz << shift;
+    do_div(ratio, cpu_khz);
+    ratio <<= hvm_funcs.tsc_scaling_ratio_frac_bits - shift;
+
+    if ( ratio == 0 ||
+         ratio > hvm_funcs.max_tsc_scaling_ratio ||
+         ratio & hvm_funcs.tsc_scaling_ratio_rsvd )
+    {
+        printk(XENLOG_WARNING
+               "Invalid TSC scaling ratio - virtual tsc khz=%lu\n",
+               khz);
+        return;
+    }
+
+    v->arch.tsc_scaling_ratio = ratio;
+}
+
 void hvm_set_guest_tsc_fixed(struct vcpu *v, u64 guest_tsc, u64 at_tsc)
 {
     uint64_t tsc;
@@ -2023,6 +2051,9 @@ static int hvm_load_cpu_ctxt(struct domain *d, 
hvm_domain_context_t *h)
     if ( hvm_funcs.load_cpu_ctxt(v, &ctxt) < 0 )
         return -EINVAL;
 
+    if ( !v->domain->arch.vtsc && hvm_funcs.tsc_scaling_supported )
+        hvm_setup_tsc_scaling(v);
+
     v->arch.hvm_vcpu.msr_tsc_aux = ctxt.msr_tsc_aux;
 
     seg.limit = ctxt.idtr_limit;
@@ -5458,6 +5489,9 @@ void hvm_vcpu_reset_state(struct vcpu *v, uint16_t cs, 
uint16_t ip)
     hvm_set_segment_register(v, x86_seg_gdtr, &reg);
     hvm_set_segment_register(v, x86_seg_idtr, &reg);
 
+    if ( !v->domain->arch.vtsc && hvm_funcs.tsc_scaling_supported )
+        hvm_setup_tsc_scaling(v);
+
     /* Sync AP's TSC with BSP's. */
     v->arch.hvm_vcpu.cache_tsc_offset =
         v->domain->vcpu[0]->arch.hvm_vcpu.cache_tsc_offset;
diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index 94b9618..a7465c6 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -1170,6 +1170,8 @@ static int svm_vcpu_initialise(struct vcpu *v)
 
     svm_guest_osvw_init(v);
 
+    v->arch.tsc_scaling_ratio = DEFAULT_TSC_RATIO;
+
     return 0;
 }
 
diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index 92dd8a1..64f4e31 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -1956,6 +1956,8 @@ void tsc_set_info(struct domain *d,
         {
     case TSC_MODE_NEVER_EMULATE:
             d->arch.vtsc = 0;
+            if ( tsc_mode == TSC_MODE_NEVER_EMULATE )
+                d->arch.tsc_khz = cpu_khz;
             break;
         }
         d->arch.vtsc = 1;
@@ -1981,8 +1983,14 @@ void tsc_set_info(struct domain *d,
     if ( is_hvm_domain(d) )
     {
         hvm_set_rdtsc_exiting(d, d->arch.vtsc);
-        if ( d->vcpu && d->vcpu[0] && incarnation == 0 )
+        if ( d->vcpu && d->vcpu[0] )
         {
+            if ( !d->arch.vtsc && hvm_funcs.tsc_scaling_supported )
+                hvm_setup_tsc_scaling(d->vcpu[0]);
+
+            if ( incarnation )
+                return;
+
             /*
              * set_tsc_offset() is called from hvm_vcpu_initialise() before
              * tsc_set_info(). New vtsc mode may require recomputing TSC
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index f0aeade..fffd519 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -533,6 +533,8 @@ struct arch_vcpu
     XEN_GUEST_HANDLE(vcpu_time_info_t) time_info_guest;
 
     struct arch_vm_event *vm_event;
+
+    uint64_t tsc_scaling_ratio;
 };
 
 smap_check_policy_t smap_policy_change(struct vcpu *v,
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 7dddfa0..55e7f64 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -261,6 +261,8 @@ void hvm_set_guest_tsc_fixed(struct vcpu *v, u64 guest_tsc, 
u64 at_tsc);
 u64 hvm_get_guest_tsc_fixed(struct vcpu *v, u64 at_tsc);
 #define hvm_get_guest_tsc(v) hvm_get_guest_tsc_fixed(v, 0)
 
+void hvm_setup_tsc_scaling(struct vcpu *v);
+
 int hvm_set_mode(struct vcpu *v, int mode);
 void hvm_init_guest_time(struct domain *d);
 void hvm_set_guest_time(struct vcpu *v, u64 guest_time);
-- 
2.4.8


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