[Xen-changelog] [xen-unstable] svm: Do not intercept RDTSC(P) when TSC scaling is supported by hardware

[Xen patchbot-unstable <patchbot@xxxxxxx>]

# HG changeset patch
# User Boris Ostrovsky <boris.ostrovsky@xxxxxxx>
# Date 1335358394 -3600
# Node ID ed9c557f8a35a6deb7e6df0679f24a2121fd1172
# Parent  7ba11d9b1d23633b5c42fadddad17b6dcb686141
svm: Do not intercept RDTSC(P) when TSC scaling is supported by hardware

When running in TSC_MODE_ALWAYS_EMULATE mode on processors that
support TSC scaling we don't need to intercept RDTSC/RDTSCP
instructions.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxx>
Acked-by: Wei Huang <wei.huang2@xxxxxxx>
Tested-by: Wei Huang <wei.huang2@xxxxxxx>
Committed-by: Keir Fraser <keir@xxxxxxx>
---


diff -r 7ba11d9b1d23 -r ed9c557f8a35 xen/arch/x86/hvm/svm/svm.c
--- a/xen/arch/x86/hvm/svm/svm.c        Wed Apr 25 12:00:08 2012 +0100
+++ b/xen/arch/x86/hvm/svm/svm.c        Wed Apr 25 13:53:14 2012 +0100
@@ -724,12 +724,19 @@ static void svm_set_rdtsc_exiting(struct
 {
     struct vmcb_struct *vmcb = v->arch.hvm_svm.vmcb;
     u32 general1_intercepts = vmcb_get_general1_intercepts(vmcb);
+    u32 general2_intercepts = vmcb_get_general2_intercepts(vmcb);
 
     general1_intercepts &= ~GENERAL1_INTERCEPT_RDTSC;
-    if ( enable )
+    general2_intercepts &= ~GENERAL2_INTERCEPT_RDTSCP;
+
+    if ( enable && !cpu_has_tsc_ratio )
+    {
         general1_intercepts |= GENERAL1_INTERCEPT_RDTSC;
+        general2_intercepts |= GENERAL2_INTERCEPT_RDTSCP;
+    }
 
     vmcb_set_general1_intercepts(vmcb, general1_intercepts);
+    vmcb_set_general2_intercepts(vmcb, general2_intercepts);
 }
 
 static unsigned int svm_get_insn_bytes(struct vcpu *v, uint8_t *buf)

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