[Xen-changelog] [xen master] x86/hvm: scale host TSC when setting/getting guest TSC

[patchbot@xxxxxxx]

commit 52fd9a46f6e9eb050a6b402ce3b04fa57907acc5
Author:     Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
AuthorDate: Tue Jan 19 16:07:15 2016 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Jan 19 16:07:15 2016 +0100

    x86/hvm: scale host TSC when setting/getting guest TSC
    
    The existing hvm_[set|get]_guest_tsc_fixed() calculate the guest TSC by
    adding the TSC offset to the host TSC. When the TSC scaling is enabled,
    the host TSC should be scaled first. This patch adds the scaling logic
    to those two functions.
    
    Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
    Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
---
 xen/arch/x86/hvm/hvm.c        |   17 +++++++----------
 xen/arch/x86/hvm/svm/svm.c    |    9 +++++++++
 xen/include/asm-x86/hvm/hvm.h |    2 ++
 3 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index f646c1e..e0cb82d 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -60,6 +60,7 @@
 #include <asm/hvm/nestedhvm.h>
 #include <asm/hvm/event.h>
 #include <asm/hvm/vmx/vmx.h>
+#include <asm/hvm/svm/svm.h> /* for cpu_has_tsc_ratio */
 #include <asm/altp2m.h>
 #include <asm/mtrr.h>
 #include <asm/apic.h>
@@ -310,13 +311,11 @@ void hvm_set_guest_tsc_fixed(struct vcpu *v, u64 
guest_tsc, u64 at_tsc)
         tsc = hvm_get_guest_time_fixed(v, at_tsc);
         tsc = gtime_to_gtsc(v->domain, tsc);
     }
-    else if ( at_tsc )
-    {
-        tsc = at_tsc;
-    }
     else
     {
-        tsc = rdtsc();
+        tsc = at_tsc ?: rdtsc();
+        if ( cpu_has_tsc_ratio )
+            tsc = hvm_funcs.scale_tsc(v, tsc);
     }
 
     delta_tsc = guest_tsc - tsc;
@@ -344,13 +343,11 @@ u64 hvm_get_guest_tsc_fixed(struct vcpu *v, uint64_t 
at_tsc)
         tsc = hvm_get_guest_time_fixed(v, at_tsc);
         tsc = gtime_to_gtsc(v->domain, tsc);
     }
-    else if ( at_tsc )
-    {
-        tsc = at_tsc;
-    }
     else
     {
-        tsc = rdtsc();
+        tsc = at_tsc ?: rdtsc();
+        if ( cpu_has_tsc_ratio )
+            tsc = hvm_funcs.scale_tsc(v, tsc);
     }
 
     return tsc + v->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 a66d854..a46bc98 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -804,6 +804,13 @@ static uint64_t scale_tsc(uint64_t host_tsc, uint64_t 
ratio)
     return scaled_host_tsc;
 }
 
+static uint64_t svm_scale_tsc(const struct vcpu *v, uint64_t tsc)
+{
+    ASSERT(cpu_has_tsc_ratio && !v->domain->arch.vtsc);
+
+    return scale_tsc(tsc, vcpu_tsc_ratio(v));
+}
+
 static uint64_t svm_get_tsc_offset(uint64_t host_tsc, uint64_t guest_tsc,
     uint64_t ratio)
 {
@@ -2272,6 +2279,8 @@ static struct hvm_function_table __initdata 
svm_function_table = {
     .nhvm_vmcx_hap_enabled = nsvm_vmcb_hap_enabled,
     .nhvm_intr_blocked = nsvm_intr_blocked,
     .nhvm_hap_walk_L1_p2m = nsvm_hap_walk_L1_p2m,
+
+    .scale_tsc            = svm_scale_tsc,
 };
 
 void svm_vmexit_handler(struct cpu_user_regs *regs)
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index b9d893d..a87224b 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -212,6 +212,8 @@ struct hvm_function_table {
     void (*altp2m_vcpu_update_vmfunc_ve)(struct vcpu *v);
     bool_t (*altp2m_vcpu_emulate_ve)(struct vcpu *v);
     int (*altp2m_vcpu_emulate_vmfunc)(struct cpu_user_regs *regs);
+
+    uint64_t (*scale_tsc)(const struct vcpu *v, uint64_t tsc);
 };
 
 extern struct hvm_function_table hvm_funcs;
--
generated by git-patchbot for /home/xen/git/xen.git#master

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