[Xen-devel] [PATCH 10/13] vmx: Detect and initialize VMX RDTSC(P) scaling

[Haozhong Zhang <haozhong.zhang@xxxxxxxxx>]

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

Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
---
 xen/arch/x86/hvm/vmx/vmcs.c        | 11 +++++++++--
 xen/arch/x86/hvm/vmx/vmx.c         |  9 +++++++++
 xen/include/asm-x86/hvm/vmx/vmcs.h |  7 +++++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index 08f2078..7172b27 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -144,6 +144,7 @@ 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, "RDTSC(P) Scaling");
 #undef P
 
     if ( !printed )
@@ -236,7 +237,8 @@ static int vmx_init_vmcs_config(void)
                SECONDARY_EXEC_PAUSE_LOOP_EXITING |
                SECONDARY_EXEC_ENABLE_INVPCID |
                SECONDARY_EXEC_ENABLE_VM_FUNCTIONS |
-               SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS);
+               SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS |
+               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;
@@ -965,7 +967,7 @@ 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;
@@ -1239,6 +1241,9 @@ static int construct_vmcs(struct vcpu *v)
         __vmwrite(GUEST_PAT, guest_pat);
     }
 
+    if ( cpu_has_vmx_tsc_scaling )
+        __vmwrite(TSC_MULTIPLIER, VMX_TSC_MULTIPLIER_DEFAULT);
+
     vmx_vmcs_exit(v);
 
     /* PVH: paging mode is updated by arch_set_info_guest(). */
@@ -1805,6 +1810,8 @@ void vmcs_dump_vcpu(struct vcpu *v)
     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));
+    if ( v->arch.hvm_vmx.secondary_exec_control & SECONDARY_EXEC_TSC_SCALING )
+        printk("TSC Multiplier = 0x%016lx\n", 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 624db1c..454440e 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -151,6 +151,8 @@ static int vmx_vcpu_initialise(struct vcpu *v)
     if ( v->vcpu_id == 0 )
         v->arch.user_regs.eax = 1;
 
+    v->arch.tsc_scaling_ratio = VMX_TSC_MULTIPLIER_DEFAULT;
+
     return 0;
 }
 
@@ -1965,6 +1967,10 @@ static struct hvm_function_table __initdata 
vmx_function_table = {
     .altp2m_vcpu_emulate_vmfunc = vmx_vcpu_emulate_vmfunc,
     /* support for VMX RDTSC(P) scaling */
     .tsc_scaling_supported       = 0,
+    .default_tsc_scaling_ratio   = VMX_TSC_MULTIPLIER_DEFAULT,
+    .max_tsc_scaling_ratio       = VMX_TSC_MULTIPLIER_MAX,
+    .tsc_scaling_ratio_frac_bits = 48,
+    .tsc_scaling_ratio_rsvd      = 0x0ULL,
 };
 
 const struct hvm_function_table * __init start_vmx(void)
@@ -2017,6 +2023,9 @@ 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 f1126d4..d478584 100644
--- a/xen/include/asm-x86/hvm/vmx/vmcs.h
+++ b/xen/include/asm-x86/hvm/vmx/vmcs.h
@@ -225,6 +225,7 @@ extern u32 vmx_vmentry_control;
 #define SECONDARY_EXEC_ENABLE_VMCS_SHADOWING    0x00004000
 #define SECONDARY_EXEC_ENABLE_PML               0x00020000
 #define SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS   0x00040000
+#define SECONDARY_EXEC_TSC_SCALING              0x02000000
 extern u32 vmx_secondary_exec_control;
 
 #define VMX_EPT_EXEC_ONLY_SUPPORTED             0x00000001
@@ -248,6 +249,9 @@ extern u32 vmx_secondary_exec_control;
 
 #define VMX_MISC_CR3_TARGET             0x1ff0000
 
+#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 \
@@ -291,6 +295,8 @@ extern u32 vmx_secondary_exec_control;
     (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_VIRT_EXCEPTIONS)
 #define cpu_has_vmx_pml \
     (vmx_secondary_exec_control & SECONDARY_EXEC_ENABLE_PML)
+#define cpu_has_vmx_tsc_scaling \
+    (vmx_secondary_exec_control & SECONDARY_EXEC_TSC_SCALING)
 
 #define VMCS_RID_TYPE_MASK              0x80000000
 
@@ -365,6 +371,7 @@ enum vmcs_field {
     VMREAD_BITMAP                   = 0x00002026,
     VMWRITE_BITMAP                  = 0x00002028,
     VIRT_EXCEPTION_INFO             = 0x0000202a,
+    TSC_MULTIPLIER                  = 0x00002032,
     GUEST_PHYSICAL_ADDRESS          = 0x00002400,
     VMCS_LINK_POINTER               = 0x00002800,
     GUEST_IA32_DEBUGCTL             = 0x00002802,
-- 
2.4.8


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