[Xen-devel] [PATCH 03/13] x86/hvm: Collect information of TSC scaling ratio

[Haozhong Zhang <haozhong.zhang@xxxxxxxxx>]

Both VMX TSC scaling and SVM TSC ratio use the 64-bit TSC scaling ratio,
but the number of fractional bits of the ratio is different between VMX
and SVM. This patch makes the architecture code to collect the number of
fractional bits and other related information into fields of struct
hvm_function_table so that they can be used in the common code.

Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
---
 xen/arch/x86/hvm/svm/svm.c        |  9 +++++++++
 xen/arch/x86/hvm/vmx/vmx.c        |  2 ++
 xen/include/asm-x86/hvm/hvm.h     | 13 +++++++++++++
 xen/include/asm-x86/hvm/svm/svm.h |  1 +
 4 files changed, 25 insertions(+)

diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index 8de41fa..94b9618 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -1428,6 +1428,9 @@ const struct hvm_function_table * __init start_svm(void)
     if ( !cpu_has_svm_nrips )
         clear_bit(SVM_FEATURE_DECODEASSISTS, &svm_feature_flags);
 
+    if ( cpu_has_tsc_ratio )
+        svm_function_table.tsc_scaling_supported = 1;
+
 #define P(p,s) if ( p ) { printk(" - %s\n", s); printed = 1; }
     P(cpu_has_svm_npt, "Nested Page Tables (NPT)");
     P(cpu_has_svm_lbrv, "Last Branch Record (LBR) Virtualisation");
@@ -2283,6 +2286,12 @@ static struct hvm_function_table __initdata 
svm_function_table = {
     .nhvm_vmcx_hap_enabled = nsvm_vmcb_hap_enabled,
     .nhvm_intr_blocked = nsvm_intr_blocked,
     .nhvm_hap_walk_L1_p2m = nsvm_hap_walk_L1_p2m,
+
+    .tsc_scaling_supported       = 0,
+    .default_tsc_scaling_ratio   = DEFAULT_TSC_RATIO,
+    .max_tsc_scaling_ratio       = MAX_TSC_RATIO,
+    .tsc_scaling_ratio_frac_bits = 32,
+    .tsc_scaling_ratio_rsvd      = TSC_RATIO_RSVD_BITS,
 };
 
 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 bbec0e8..4edb099 100644
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -1968,6 +1968,8 @@ 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,
+    /* support for VMX RDTSC(P) scaling */
+    .tsc_scaling_supported       = 0,
 };
 
 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 0693706..7dddfa0 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -99,6 +99,19 @@ struct hvm_function_table {
     /* Indicate HAP capabilities. */
     int hap_capabilities;
 
+    /*
+     * Parameters of hardware-assisted TSC scaling.
+     */
+    /* is TSC scaling supported? */
+    bool_t   tsc_scaling_supported;
+    /* number of bits of the fractional part of TSC scaling ratio */
+    uint8_t  tsc_scaling_ratio_frac_bits;
+    /* mask of reserved bits of TSC scaling ratio */
+    uint64_t tsc_scaling_ratio_rsvd;
+    /* default TSC scaling ratio (no scaling) */
+    uint64_t default_tsc_scaling_ratio;
+    /* maxmimum-allowed TSC scaling ratio */
+    uint64_t max_tsc_scaling_ratio;
 
     /*
      * Initialise/destroy HVM domain/vcpu resources
diff --git a/xen/include/asm-x86/hvm/svm/svm.h 
b/xen/include/asm-x86/hvm/svm/svm.h
index d60ec23..a4832d9 100644
--- a/xen/include/asm-x86/hvm/svm/svm.h
+++ b/xen/include/asm-x86/hvm/svm/svm.h
@@ -96,6 +96,7 @@ extern u32 svm_feature_flags;
 
 /* TSC rate */
 #define DEFAULT_TSC_RATIO       0x0000000100000000ULL
+#define MAX_TSC_RATIO           0x000000ffffffffffULL
 #define TSC_RATIO_RSVD_BITS     0xffffff0000000000ULL
 #define TSC_RATIO(g_khz, h_khz) ( (((u64)(g_khz)<<32)/(u64)(h_khz)) & \
                                   ~TSC_RATIO_RSVD_BITS )
-- 
2.4.8


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