[Xen-devel] [PATCH v3 12/13] vmx: Add VMX RDTSC(P) scaling support

[Haozhong Zhang <haozhong.zhang@xxxxxxxxx>]

This patch adds the initialization and setup code for VMX TSC scaling.

Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
Acked-by: Kevin Tian <kevin.tian@xxxxxxxxx>
---
 xen/arch/x86/hvm/vmx/vmcs.c        | 12 +++++++++---
 xen/arch/x86/hvm/vmx/vmx.c         | 15 +++++++++++++++
 xen/include/asm-x86/hvm/vmx/vmcs.h |  7 +++++++
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index edd4c8d..8f16c3a 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -149,6 +149,7 @@ static void __init vmx_display_features(void)
     P(cpu_has_vmx_vmfunc, "VM Functions");
     P(cpu_has_vmx_virt_exceptions, "Virtualisation Exceptions");
     P(cpu_has_vmx_pml, "Page Modification Logging");
+    P(cpu_has_vmx_tsc_scaling, "TSC Scaling");
 #undef P
 
     if ( !printed )
@@ -242,7 +243,8 @@ static int vmx_init_vmcs_config(void)
                SECONDARY_EXEC_ENABLE_INVPCID |
                SECONDARY_EXEC_ENABLE_VM_FUNCTIONS |
                SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS |
-               SECONDARY_EXEC_XSAVES);
+               SECONDARY_EXEC_XSAVES |
+               SECONDARY_EXEC_TSC_SCALING);
         rdmsrl(MSR_IA32_VMX_MISC, _vmx_misc_cap);
         if ( _vmx_misc_cap & VMX_MISC_VMWRITE_ALL )
             opt |= SECONDARY_EXEC_ENABLE_VMCS_SHADOWING;
@@ -999,7 +1001,7 @@ static int construct_vmcs(struct vcpu *v)
     __vmwrite(PIN_BASED_VM_EXEC_CONTROL, vmx_pin_based_exec_control);
 
     v->arch.hvm_vmx.exec_control = vmx_cpu_based_exec_control;
-    if ( d->arch.vtsc )
+    if ( d->arch.vtsc && !cpu_has_vmx_tsc_scaling )
         v->arch.hvm_vmx.exec_control |= CPU_BASED_RDTSC_EXITING;
 
     v->arch.hvm_vmx.secondary_exec_control = vmx_secondary_exec_control;
@@ -1281,6 +1283,9 @@ static int construct_vmcs(struct vcpu *v)
     if ( cpu_has_vmx_xsaves )
         __vmwrite(XSS_EXIT_BITMAP, 0);
 
+    if ( cpu_has_vmx_tsc_scaling )
+        __vmwrite(TSC_MULTIPLIER, v->arch.hvm_vcpu.tsc_scaling_ratio);
+
     vmx_vmcs_exit(v);
 
     /* PVH: paging mode is updated by arch_set_info_guest(). */
@@ -1863,7 +1868,8 @@ void vmcs_dump_vcpu(struct vcpu *v)
            vmr32(VM_EXIT_REASON), vmr(EXIT_QUALIFICATION));
     printk("IDTVectoring: info=%08x errcode=%08x\n",
            vmr32(IDT_VECTORING_INFO), vmr32(IDT_VECTORING_ERROR_CODE));
-    printk("TSC Offset = 0x%016lx\n", vmr(TSC_OFFSET));
+    printk("TSC Offset = 0x%016lx  TSC Multiplier = 0x%016lx\n",
+           vmr(TSC_OFFSET), vmr(TSC_MULTIPLIER));
     if ( (v->arch.hvm_vmx.exec_control & CPU_BASED_TPR_SHADOW) ||
          (vmx_pin_based_exec_control & PIN_BASED_POSTED_INTERRUPT) )
         printk("TPR Threshold = 0x%02x  PostedIntrVec = 0x%02x\n",
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index f26a1bc..4c7214d 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -115,6 +115,7 @@ static int vmx_vcpu_initialise(struct vcpu *v)
     v->arch.schedule_tail    = vmx_do_resume;
     v->arch.ctxt_switch_from = vmx_ctxt_switch_from;
     v->arch.ctxt_switch_to   = vmx_ctxt_switch_to;
+    v->arch.hvm_vcpu.tsc_scaling_ratio = VMX_TSC_MULTIPLIER_DEFAULT;
 
     if ( (rc = vmx_create_vmcs(v)) != 0 )
     {
@@ -1105,6 +1106,13 @@ static void vmx_handle_cd(struct vcpu *v, unsigned long 
value)
     }
 }
 
+static void vmx_setup_tsc_scaling(struct vcpu *v)
+{
+    vmx_vmcs_enter(v);
+    __vmwrite(TSC_MULTIPLIER, v->arch.hvm_vcpu.tsc_scaling_ratio);
+    vmx_vmcs_exit(v);
+}
+
 static void vmx_set_tsc_offset(struct vcpu *v, u64 offset, u64 at_tsc)
 {
     vmx_vmcs_enter(v);
@@ -2003,6 +2011,10 @@ static struct hvm_function_table __initdata 
vmx_function_table = {
     .altp2m_vcpu_update_vmfunc_ve = vmx_vcpu_update_vmfunc_ve,
     .altp2m_vcpu_emulate_ve = vmx_vcpu_emulate_ve,
     .altp2m_vcpu_emulate_vmfunc = vmx_vcpu_emulate_vmfunc,
+    .default_tsc_scaling_ratio   = VMX_TSC_MULTIPLIER_DEFAULT,
+    .max_tsc_scaling_ratio       = VMX_TSC_MULTIPLIER_MAX,
+    .tsc_scaling_ratio_frac_bits = 48,
+    .setup_tsc_scaling           = vmx_setup_tsc_scaling,
 };
 
 /* Handle VT-d posted-interrupt when VCPU is running. */
@@ -2107,6 +2119,9 @@ const struct hvm_function_table * __init start_vmx(void)
          && cpu_has_vmx_secondary_exec_control )
         vmx_function_table.pvh_supported = 1;
 
+    if ( cpu_has_vmx_tsc_scaling )
+        vmx_function_table.tsc_scaling_supported = 1;
+
     setup_vmcs_dump();
 
     return &vmx_function_table;
diff --git a/xen/include/asm-x86/hvm/vmx/vmcs.h 
b/xen/include/asm-x86/hvm/vmx/vmcs.h
index d1496b8..fdece44 100644
--- a/xen/include/asm-x86/hvm/vmx/vmcs.h
+++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
@@ -236,6 +236,7 @@ extern u32 vmx_vmentry_control;
 #define SECONDARY_EXEC_ENABLE_PML               0x00020000
 #define SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS   0x00040000
 #define SECONDARY_EXEC_XSAVES                   0x00100000
+#define SECONDARY_EXEC_TSC_SCALING              0x02000000
 extern u32 vmx_secondary_exec_control;
 
 #define VMX_EPT_EXEC_ONLY_SUPPORTED                         0x00000001
@@ -258,6 +259,9 @@ extern u64 vmx_ept_vpid_cap;
 #define VMX_MISC_CR3_TARGET                     0x01ff0000
 #define VMX_MISC_VMWRITE_ALL                    0x20000000
 
+#define VMX_TSC_MULTIPLIER_DEFAULT              0x0001000000000000ULL
+#define VMX_TSC_MULTIPLIER_MAX                  0xffffffffffffffffULL
+
 #define cpu_has_wbinvd_exiting \
     (vmx_secondary_exec_control & SECONDARY_EXEC_WBINVD_EXITING)
 #define cpu_has_vmx_virtualize_apic_accesses \
@@ -303,6 +307,8 @@ extern u64 vmx_ept_vpid_cap;
     (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_PML)
 #define cpu_has_vmx_xsaves \
     (vmx_secondary_exec_control & SECONDARY_EXEC_XSAVES)
+#define cpu_has_vmx_tsc_scaling \
+    (vmx_secondary_exec_control & SECONDARY_EXEC_TSC_SCALING)
 
 #define VMCS_RID_TYPE_MASK              0x80000000
 
@@ -378,6 +384,7 @@ enum vmcs_field {
     VMWRITE_BITMAP                  = 0x00002028,
     VIRT_EXCEPTION_INFO             = 0x0000202a,
     XSS_EXIT_BITMAP                 = 0x0000202c,
+    TSC_MULTIPLIER                  = 0x00002032,
     GUEST_PHYSICAL_ADDRESS          = 0x00002400,
     VMCS_LINK_POINTER               = 0x00002800,
     GUEST_IA32_DEBUGCTL             = 0x00002802,
-- 
2.4.8


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