diff -r 5145d5840e61 xen/arch/x86/hvm/svm/svm.c
--- a/xen/arch/x86/hvm/svm/svm.c	Wed Jun 09 13:29:22 2010 +0100
+++ b/xen/arch/x86/hvm/svm/svm.c	Wed Jun 09 15:17:27 2010 +0200
@@ -1105,8 +1105,8 @@ static int svm_msr_read_intercept(struct
     case MSR_K7_EVNTSEL1:
     case MSR_K7_EVNTSEL2:
     case MSR_K7_EVNTSEL3:
-        vpmu_do_rdmsr(regs);
-        goto done;
+        vpmu_do_rdmsr(ecx, &msr_content);
+        break;
 
     default:
 
@@ -1126,7 +1126,6 @@ static int svm_msr_read_intercept(struct
     regs->eax = (uint32_t)msr_content;
     regs->edx = (uint32_t)(msr_content >> 32);
 
-done:
     HVMTRACE_3D (MSR_READ, ecx, regs->eax, regs->edx);
     HVM_DBG_LOG(DBG_LEVEL_1, "returns: ecx=%x, eax=%lx, edx=%lx",
                 ecx, (unsigned long)regs->eax, (unsigned long)regs->edx);
@@ -1199,8 +1198,8 @@ static int svm_msr_write_intercept(struc
     case MSR_K7_EVNTSEL1:
     case MSR_K7_EVNTSEL2:
     case MSR_K7_EVNTSEL3:
-        vpmu_do_wrmsr(regs);
-        goto done;
+        vpmu_do_wrmsr(ecx, msr_content);
+        break;
 
     default:
         if ( wrmsr_viridian_regs(ecx, msr_content) )
@@ -1218,7 +1217,6 @@ static int svm_msr_write_intercept(struc
         }
         break;
     }
-done:
     return X86EMUL_OKAY;
 
  gpf:
diff -r 5145d5840e61 xen/arch/x86/hvm/svm/vpmu.c
--- a/xen/arch/x86/hvm/svm/vpmu.c	Wed Jun 09 13:29:22 2010 +0100
+++ b/xen/arch/x86/hvm/svm/vpmu.c	Wed Jun 09 15:17:27 2010 +0200
@@ -167,42 +167,38 @@ static void amd_vpmu_save(struct vcpu *v
     apic_write(APIC_LVTPC,  ctx->hw_lapic_lvtpc | APIC_LVT_MASKED);
 }
 
-static void context_update(struct cpu_user_regs *regs, u64 msr_content)
+static void context_update(unsigned int msr, u64 msr_content)
 {
     int i;
-    u32 addr = regs->ecx;
     struct vcpu *v = current;
     struct vpmu_struct *vpmu = vcpu_vpmu(v);
     struct amd_vpmu_context *ctxt = vpmu->context;
 
     for ( i = 0; i < NUM_COUNTERS; i++ )
-        if ( addr == AMD_F10H_COUNTERS[i] )
+        if ( msr == AMD_F10H_COUNTERS[i] )
             ctxt->counters[i] = msr_content;
 
     for ( i = 0; i < NUM_COUNTERS; i++ )
-        if ( addr == AMD_F10H_CTRLS[i] )
+        if ( msr == AMD_F10H_CTRLS[i] )
             ctxt->ctrls[i] = msr_content;
 
     ctxt->hw_lapic_lvtpc = apic_read(APIC_LVTPC);
 }
 
-static int amd_vpmu_do_wrmsr(struct cpu_user_regs *regs)
+static int amd_vpmu_do_wrmsr(unsigned int msr, uint64_t msr_content)
 {
-    u64 msr_content = 0;
     struct vcpu *v = current;
     struct vpmu_struct *vpmu = vcpu_vpmu(v);
 
-    msr_content = (u32)regs->eax | ((u64)regs->edx << 32);
-
     /* For all counters, enable guest only mode for HVM guest */
-    if ( (get_pmu_reg_type(regs->ecx) == MSR_TYPE_CTRL) &&
+    if ( (get_pmu_reg_type(msr) == MSR_TYPE_CTRL) &&
         !(is_guest_mode(msr_content)) )
     {
         set_guest_mode(msr_content);
     }
 
     /* check if the first counter is enabled */
-    if ( (get_pmu_reg_type(regs->ecx) == MSR_TYPE_CTRL) &&
+    if ( (get_pmu_reg_type(msr) == MSR_TYPE_CTRL) &&
         is_pmu_enabled(msr_content) && !(vpmu->flags & VPMU_RUNNING) )
     {
         if ( !acquire_pmu_ownership(PMU_OWNER_HVM) )
@@ -212,7 +208,7 @@ static int amd_vpmu_do_wrmsr(struct cpu_
     }
 
     /* stop saving & restore if guest stops first counter */
-    if ( (get_pmu_reg_type(regs->ecx) == MSR_TYPE_CTRL) && 
+    if ( (get_pmu_reg_type(msr) == MSR_TYPE_CTRL) && 
         (is_pmu_enabled(msr_content) == 0) && (vpmu->flags & VPMU_RUNNING) )
     {
         apic_write(APIC_LVTPC, PMU_APIC_VECTOR | APIC_LVT_MASKED);
@@ -221,21 +217,16 @@ static int amd_vpmu_do_wrmsr(struct cpu_
     }
 
     /* Update vpmu context immediately */
-    context_update(regs, msr_content);
+    context_update(msr, msr_content);
 
     /* Write to hw counters */
-    wrmsrl(regs->ecx, msr_content);
+    wrmsrl(msr, msr_content);
     return 1;
 }
 
-static int amd_vpmu_do_rdmsr(struct cpu_user_regs *regs)
+static int amd_vpmu_do_rdmsr(unsigned int msr, uint64_t *msr_content)
 {
-    u64 msr_content = 0;
-
-    rdmsrl(regs->ecx, msr_content);
-    regs->eax = msr_content & 0xFFFFFFFF;
-    regs->edx = msr_content >> 32;
-
+    rdmsrl(msr, *msr_content);
     return 1;
 }
 
diff -r 5145d5840e61 xen/arch/x86/hvm/vmx/vmx.c
--- a/xen/arch/x86/hvm/vmx/vmx.c	Wed Jun 09 13:29:22 2010 +0100
+++ b/xen/arch/x86/hvm/vmx/vmx.c	Wed Jun 09 15:17:27 2010 +0200
@@ -1846,8 +1846,8 @@ static int vmx_msr_read_intercept(struct
                        MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL;
         break;
     default:
-        if ( vpmu_do_rdmsr(regs) )
-            goto done;
+        if ( vpmu_do_rdmsr(ecx, &msr_content) )
+            break;
         if ( passive_domain_do_rdmsr(regs) )
             goto done;
         switch ( long_mode_do_msr_read(regs) )
@@ -2015,7 +2015,7 @@ static int vmx_msr_write_intercept(struc
     case MSR_IA32_VMX_BASIC...MSR_IA32_VMX_PROCBASED_CTLS2:
         goto gp_fault;
     default:
-        if ( vpmu_do_wrmsr(regs) )
+        if ( vpmu_do_wrmsr(ecx, msr_content) )
             return X86EMUL_OKAY;
         if ( passive_domain_do_wrmsr(regs) )
             return X86EMUL_OKAY;
diff -r 5145d5840e61 xen/arch/x86/hvm/vmx/vpmu_core2.c
--- a/xen/arch/x86/hvm/vmx/vpmu_core2.c	Wed Jun 09 13:29:22 2010 +0100
+++ b/xen/arch/x86/hvm/vmx/vpmu_core2.c	Wed Jun 09 15:17:27 2010 +0200
@@ -328,10 +328,9 @@ static int core2_vpmu_msr_common_check(u
     return 1;
 }
 
-static int core2_vpmu_do_wrmsr(struct cpu_user_regs *regs)
+static int core2_vpmu_do_wrmsr(unsigned int msr, uint64_t msr_content)
 {
-    u32 ecx = regs->ecx;
-    u64 msr_content, global_ctrl, non_global_ctrl;
+    u64 global_ctrl, non_global_ctrl;
     char pmu_enable = 0;
     int i, tmp;
     int type = -1, index = -1;
@@ -339,12 +338,11 @@ static int core2_vpmu_do_wrmsr(struct cp
     struct vpmu_struct *vpmu = vcpu_vpmu(v);
     struct core2_vpmu_context *core2_vpmu_cxt = NULL;
 
-    if ( !core2_vpmu_msr_common_check(ecx, &type, &index) )
+    if ( !core2_vpmu_msr_common_check(msr, &type, &index) )
         return 0;
 
-    msr_content = (u32)regs->eax | ((u64)regs->edx << 32);
     core2_vpmu_cxt = vpmu->context;
-    switch ( ecx )
+    switch ( msr )
     {
     case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
         core2_vpmu_cxt->global_ovf_status &= ~msr_content;
@@ -395,7 +393,7 @@ static int core2_vpmu_do_wrmsr(struct cp
         }
         break;
     default:
-        tmp = ecx - MSR_P6_EVNTSEL0;
+        tmp = msr - MSR_P6_EVNTSEL0;
         vmx_read_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, &global_ctrl);
         if ( tmp >= 0 && tmp < core2_get_pmc_count() )
             core2_vpmu_cxt->pmu_enable->arch_pmc_enable[tmp] =
@@ -445,7 +443,7 @@ static int core2_vpmu_do_wrmsr(struct cp
         if (inject_gp)
             vmx_inject_hw_exception(TRAP_gp_fault, 0);
         else
-            wrmsrl(ecx, msr_content);
+            wrmsrl(msr, msr_content);
     }
     else
         vmx_write_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, msr_content);
@@ -453,34 +451,32 @@ static int core2_vpmu_do_wrmsr(struct cp
     return 1;
 }
 
-static int core2_vpmu_do_rdmsr(struct cpu_user_regs *regs)
+static int core2_vpmu_do_rdmsr(unsigned int msr, uint64_t *msr_content)
 {
-    u64 msr_content = 0;
     int type = -1, index = -1;
     struct vcpu *v = current;
     struct vpmu_struct *vpmu = vcpu_vpmu(v);
     struct core2_vpmu_context *core2_vpmu_cxt = NULL;
 
-    if ( !core2_vpmu_msr_common_check(regs->ecx, &type, &index) )
+    if ( !core2_vpmu_msr_common_check(msr, &type, &index) )
         return 0;
 
     core2_vpmu_cxt = vpmu->context;
-    switch ( regs->ecx )
+    switch ( msr )
     {
     case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
+        *msr_content = 0;
         break;
     case MSR_CORE_PERF_GLOBAL_STATUS:
-        msr_content = core2_vpmu_cxt->global_ovf_status;
+        *msr_content = core2_vpmu_cxt->global_ovf_status;
         break;
     case MSR_CORE_PERF_GLOBAL_CTRL:
-        vmx_read_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, &msr_content);
+        vmx_read_guest_msr(MSR_CORE_PERF_GLOBAL_CTRL, msr_content);
         break;
     default:
-        rdmsrl(regs->ecx, msr_content);
+        rdmsrl(msr, *msr_content);
     }
 
-    regs->eax = msr_content & 0xFFFFFFFF;
-    regs->edx = msr_content >> 32;
     return 1;
 }
 
diff -r 5145d5840e61 xen/arch/x86/hvm/vpmu.c
--- a/xen/arch/x86/hvm/vpmu.c	Wed Jun 09 13:29:22 2010 +0100
+++ b/xen/arch/x86/hvm/vpmu.c	Wed Jun 09 15:17:27 2010 +0200
@@ -36,21 +36,21 @@
 static int __read_mostly opt_vpmu_enabled;
 boolean_param("vpmu", opt_vpmu_enabled);
 
-int vpmu_do_wrmsr(struct cpu_user_regs *regs)
+int vpmu_do_wrmsr(unsigned int msr, uint64_t msr_content)
 {
     struct vpmu_struct *vpmu = vcpu_vpmu(current);
 
     if ( vpmu->arch_vpmu_ops )
-        return vpmu->arch_vpmu_ops->do_wrmsr(regs);
+        return vpmu->arch_vpmu_ops->do_wrmsr(msr, msr_content);
     return 0;
 }
 
-int vpmu_do_rdmsr(struct cpu_user_regs *regs)
+int vpmu_do_rdmsr(unsigned int msr, uint64_t *msr_content)
 {
     struct vpmu_struct *vpmu = vcpu_vpmu(current);
 
     if ( vpmu->arch_vpmu_ops )
-        return vpmu->arch_vpmu_ops->do_rdmsr(regs);
+        return vpmu->arch_vpmu_ops->do_rdmsr(msr, msr_content);
     return 0;
 }
 
diff -r 5145d5840e61 xen/include/asm-x86/hvm/vpmu.h
--- a/xen/include/asm-x86/hvm/vpmu.h	Wed Jun 09 13:29:22 2010 +0100
+++ b/xen/include/asm-x86/hvm/vpmu.h	Wed Jun 09 15:17:27 2010 +0200
@@ -47,8 +47,8 @@ struct msr_load_store_entry {
 
 /* Arch specific operations shared by all vpmus */
 struct arch_vpmu_ops {
-    int (*do_wrmsr)(struct cpu_user_regs *regs);
-    int (*do_rdmsr)(struct cpu_user_regs *regs);
+    int (*do_wrmsr)(unsigned int msr, uint64_t msr_content);
+    int (*do_rdmsr)(unsigned int msr, uint64_t *msr_content);
     int (*do_interrupt)(struct cpu_user_regs *regs);
     void (*arch_vpmu_initialise)(struct vcpu *v);
     void (*arch_vpmu_destroy)(struct vcpu *v);
@@ -66,8 +66,8 @@ struct vpmu_struct {
 #define VPMU_CONTEXT_LOADED                 0x2
 #define VPMU_RUNNING                        0x4
 #define PASSIVE_DOMAIN_ALLOCATED	    0x8
-int vpmu_do_wrmsr(struct cpu_user_regs *regs);
-int vpmu_do_rdmsr(struct cpu_user_regs *regs);
+int vpmu_do_wrmsr(unsigned int msr, uint64_t msr_content);
+int vpmu_do_rdmsr(unsigned int msr, uint64_t *msr_content);
 int vpmu_do_interrupt(struct cpu_user_regs *regs);
 void vpmu_initialise(struct vcpu *v);
 void vpmu_destroy(struct vcpu *v);