[Xen-devel] [PATCH 12/13] vmx: Add a call-back to apply TSC scaling ratio to hardware

[Haozhong Zhang <haozhong.zhang@xxxxxxxxx>]

This patch adds a new call-back setup_tsc_scaling in struct
hvm_function_table to apply the TSC scaling ratio to hardware. For VMX,
it writes the TSC scaling ratio to VMCS field TSC_MULTIPLIER.

Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
---
 xen/arch/x86/hvm/hvm.c        | 1 +
 xen/arch/x86/hvm/svm/svm.c    | 5 +++++
 xen/arch/x86/hvm/vmx/vmx.c    | 8 ++++++++
 xen/include/asm-x86/hvm/hvm.h | 3 +++
 4 files changed, 17 insertions(+)

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 3522d20..2d8a148 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -376,6 +376,7 @@ void hvm_setup_tsc_scaling(struct vcpu *v)
     }
 
     v->arch.tsc_scaling_ratio = ratio;
+    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/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index 73bc863..d890c1f 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2236,6 +2236,10 @@ static void svm_invlpg_intercept(unsigned long vaddr)
     svm_asid_g_invlpg(curr, vaddr);
 }
 
+static void svm_setup_tsc_scaling(struct vcpu *v)
+{
+}
+
 static struct hvm_function_table __initdata svm_function_table = {
     .name                 = "SVM",
     .cpu_up_prepare       = svm_cpu_up_prepare,
@@ -2289,6 +2293,7 @@ static struct hvm_function_table __initdata 
svm_function_table = {
     .max_tsc_scaling_ratio       = MAX_TSC_RATIO,
     .tsc_scaling_ratio_frac_bits = 32,
     .tsc_scaling_ratio_rsvd      = TSC_RATIO_RSVD_BITS,
+    .setup_tsc_scaling           = svm_setup_tsc_scaling,
 };
 
 void svm_vmexit_handler(struct cpu_user_regs *regs)
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 163974d..c4a7b81 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1100,6 +1100,13 @@ 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.tsc_scaling_ratio);
+    vmx_vmcs_exit(v);
+}
+
 static void vmx_set_tsc_offset(struct vcpu *v, u64 offset, u64 at_tsc)
 {
     uint64_t host_tsc, guest_tsc;
@@ -1986,6 +1993,7 @@ static struct hvm_function_table __initdata 
vmx_function_table = {
     .max_tsc_scaling_ratio       = VMX_TSC_MULTIPLIER_MAX,
     .tsc_scaling_ratio_frac_bits = 48,
     .tsc_scaling_ratio_rsvd      = 0x0ULL,
+    .setup_tsc_scaling           = vmx_setup_tsc_scaling,
 };
 
 const struct hvm_function_table * __init start_vmx(void)
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index f63fe93..9f8b6d5 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -226,6 +226,9 @@ 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);
+
+    /* setup TSC scaling */
+    void (*setup_tsc_scaling)(struct vcpu *v);
 };
 
 extern struct hvm_function_table hvm_funcs;
-- 
2.4.8


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