diff mbox

[RESEND,v4,09/10] vmx: Add VMX RDTSC(P) scaling support

Message ID 20160119025516.GA7885@hz-desktop.sh.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Haozhong Zhang Jan. 19, 2016, 2:55 a.m. UTC 
This patch adds the initialization and setup code for VMX TSC scaling.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
---
I forgot to remove the hardcoded TSC scaling parameters in 
vmx_function_table. Resend this patch with them removed.

Changes in v4:
 (addressing Jan Beulich's comments)
 * Set TSC scaling parameters in hvm_funcs conditionally.

 xen/arch/x86/hvm/hvm.c             |  3 +++
 xen/arch/x86/hvm/vmx/vmcs.c        | 12 +++++++++---
 xen/arch/x86/hvm/vmx/vmx.c         | 16 ++++++++++++++++
 xen/include/asm-x86/hvm/hvm.h      |  3 +++
 xen/include/asm-x86/hvm/vmx/vmcs.h |  7 +++++++
 5 files changed, 38 insertions(+), 3 deletions(-)

Comments

Jan Beulich Feb. 5, 2016, 2:06 p.m. UTC | #1 
>>> On 19.01.16 at 03:55, <haozhong.zhang@intel.com> wrote:
> @@ -2107,6 +2115,14 @@ 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.default_tsc_scaling_ratio = VMX_TSC_MULTIPLIER_DEFAULT;
> +        vmx_function_table.max_tsc_scaling_ratio = VMX_TSC_MULTIPLIER_MAX;
> +        vmx_function_table.tsc_scaling_ratio_frac_bits = 48;
> +        vmx_function_table.setup_tsc_scaling = vmx_setup_tsc_scaling;
> +    }

Same comments here as on the earlier patch - it indeed looks as if
tsc_scaling_ratio_frac_bits would be the ideal field to dynamically
initialize, as it being zero will not yield any bad behavior afaict.

Also please consider making all fields together a sub-structure
of struct hvm_function_table, such that the above would become

        vmx_function_table.tsc_scaling.default_ratio = VMX_TSC_MULTIPLIER_DEFAULT;
        vmx_function_table.tsc_scaling.max_ratio = VMX_TSC_MULTIPLIER_MAX;
        vmx_function_table.tsc_scaling.ratio_frac_bits = 48;
        vmx_function_table.tsc_scaling.setup = vmx_setup_tsc_scaling;

keeping everything nicely together.

> @@ -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

Considering this and the respective SVM value - do we really
need the separate field in struct hvm_function_table? Both are
1ULL << tsc_scaling.ratio_frac_bits after all.

Jan
Haozhong Zhang Feb. 16, 2016, 7:59 a.m. UTC | #2 
On 02/05/16 22:06, Jan Beulich wrote:
> >>> On 19.01.16 at 03:55, <haozhong.zhang@intel.com> wrote:
> > @@ -2107,6 +2115,14 @@ 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.default_tsc_scaling_ratio = VMX_TSC_MULTIPLIER_DEFAULT;
> > +        vmx_function_table.max_tsc_scaling_ratio = VMX_TSC_MULTIPLIER_MAX;
> > +        vmx_function_table.tsc_scaling_ratio_frac_bits = 48;
> > +        vmx_function_table.setup_tsc_scaling = vmx_setup_tsc_scaling;
> > +    }
> 
> Same comments here as on the earlier patch - it indeed looks as if
> tsc_scaling_ratio_frac_bits would be the ideal field to dynamically
> initialize, as it being zero will not yield any bad behavior afaict.
>

Yes, I'll make changes similar to my reply under patch 4.

> Also please consider making all fields together a sub-structure
> of struct hvm_function_table, such that the above would become
> 
>         vmx_function_table.tsc_scaling.default_ratio = VMX_TSC_MULTIPLIER_DEFAULT;
>         vmx_function_table.tsc_scaling.max_ratio = VMX_TSC_MULTIPLIER_MAX;
>         vmx_function_table.tsc_scaling.ratio_frac_bits = 48;
>         vmx_function_table.tsc_scaling.setup = vmx_setup_tsc_scaling;
> 
> keeping everything nicely together.
>

OK, I'll put them in a sub-structure by the earlier patch that
introduces those fields.

> > @@ -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
> 
> Considering this and the respective SVM value - do we really
> need the separate field in struct hvm_function_table? Both are
> 1ULL << tsc_scaling.ratio_frac_bits after all.
>

I'll remove VMX_TSC_MULTIPLIER_DEFAULT and DEFAULT_TSC_RATIO (for SVM),
and use ratio_frac_bits to initialize default_ratio.

Thanks,
Haozhong
diff mbox

Patch

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index ddc60a7..2469a5e 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -338,6 +338,9 @@  void hvm_setup_tsc_scaling(struct vcpu *v)
 {
     v->arch.hvm_vcpu.tsc_scaling_ratio =
         hvm_get_tsc_scaling_ratio(v->domain->arch.tsc_khz);
+
+    if ( hvm_funcs.setup_tsc_scaling )
+        hvm_funcs.setup_tsc_scaling(v);
 }
 
 void hvm_set_guest_tsc_fixed(struct vcpu *v, u64 guest_tsc, u64 at_tsc)
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 6285689..1ad1f83 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);
@@ -2107,6 +2115,14 @@  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.default_tsc_scaling_ratio = VMX_TSC_MULTIPLIER_DEFAULT;
+        vmx_function_table.max_tsc_scaling_ratio = VMX_TSC_MULTIPLIER_MAX;
+        vmx_function_table.tsc_scaling_ratio_frac_bits = 48;
+        vmx_function_table.setup_tsc_scaling = vmx_setup_tsc_scaling;
+    }
+
     setup_vmcs_dump();
 
     return &vmx_function_table;
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 5588b92..10b9457 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -223,6 +223,9 @@  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);
+
+    /* Architecture function to setup TSC scaling ratio */
+    void (*setup_tsc_scaling)(struct vcpu *v);
 };
 
 extern struct hvm_function_table hvm_funcs;
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,