[Xen-devel] [PATCH v2 07/30] xen/x86: Collect more cpuid feature leaves

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

New words are:
 * 0x80000007.edx - Contains Invarient TSC
 * 0x80000008.ebx - Newly used for AMD Zen processors

In addition, replace some open-coded ITSC and EFRO manipulation.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>

v2:
 * Rely on ordering of generic_identify() to simplify init_amd()
 * Remove opencoded EFRO manipulation as well
---
 xen/arch/x86/cpu/amd.c    | 21 +++------------------
 xen/arch/x86/cpu/common.c |  6 ++++++
 xen/arch/x86/cpu/intel.c  |  2 +-
 xen/arch/x86/domain.c     |  2 +-
 4 files changed, 11 insertions(+), 20 deletions(-)

diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c
index c184f57..f9dc532 100644
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -294,21 +294,6 @@ int cpu_has_amd_erratum(const struct cpuinfo_x86 *cpu, int 
osvw_id, ...)
        return 0;
 }
 
-/* Can this system suffer from TSC drift due to C1 clock ramping? */
-static int c1_ramping_may_cause_clock_drift(struct cpuinfo_x86 *c) 
-{ 
-       if (cpuid_edx(0x80000007) & (1<<8)) {
-               /*
-                * CPUID.AdvPowerMgmtInfo.TscInvariant
-                * EDX bit 8, 8000_0007
-                * Invariant TSC on 8th Gen or newer, use it
-                * (assume all cores have invariant TSC)
-                */
-               return 0;
-       }
-       return 1;
-}
-
 /*
  * Disable C1-Clock ramping if enabled in PMM7.CpuLowPwrEnh on 8th-generation
  * cores only. Assume BIOS has setup all Northbridges equivalently.
@@ -475,7 +460,7 @@ static void init_amd(struct cpuinfo_x86 *c)
        }
 
        if (c->extended_cpuid_level >= 0x80000007) {
-               if (cpuid_edx(0x80000007) & (1<<8)) {
+               if (cpu_has(c, X86_FEATURE_ITSC)) {
                        __set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
                        __set_bit(X86_FEATURE_NONSTOP_TSC, c->x86_capability);
                        if (c->x86 != 0x11)
@@ -600,14 +585,14 @@ static void init_amd(struct cpuinfo_x86 *c)
                wrmsrl(MSR_K7_PERFCTR3, 0);
        }
 
-       if (cpuid_edx(0x80000007) & (1 << 10)) {
+       if (cpu_has(c, X86_FEATURE_EFRO)) {
                rdmsr(MSR_K7_HWCR, l, h);
                l |= (1 << 27); /* Enable read-only APERF/MPERF bit */
                wrmsr(MSR_K7_HWCR, l, h);
        }
 
        /* Prevent TSC drift in non single-processor, single-core platforms. */
-       if ((smp_processor_id() == 1) && c1_ramping_may_cause_clock_drift(c))
+       if ((smp_processor_id() == 1) && !cpu_has(c, X86_FEATURE_ITSC))
                disable_c1_ramping();
 
        set_cpuidmask(c);
diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
index 335f044..a99cc7c 100644
--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -269,6 +269,12 @@ static void generic_identify(struct cpuinfo_x86 *c)
 
        if (c->extended_cpuid_level >= 0x80000004)
                get_model_name(c); /* Default name */
+       if (c->extended_cpuid_level >= 0x80000007)
+               c->x86_capability[cpufeat_word(X86_FEATURE_ITSC)]
+                       = cpuid_edx(0x80000007);
+       if (c->extended_cpuid_level >= 0x80000008)
+               c->x86_capability[cpufeat_word(X86_FEATURE_CLZERO)]
+                       = cpuid_ebx(0x80000008);
 
        /* Intel-defined flags: level 0x00000007 */
        if ( c->cpuid_level >= 0x00000007 )
diff --git a/xen/arch/x86/cpu/intel.c b/xen/arch/x86/cpu/intel.c
index d4f574b..bdf89f6 100644
--- a/xen/arch/x86/cpu/intel.c
+++ b/xen/arch/x86/cpu/intel.c
@@ -281,7 +281,7 @@ static void init_intel(struct cpuinfo_x86 *c)
        if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
                (c->x86 == 0x6 && c->x86_model >= 0x0e))
                __set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
-       if (cpuid_edx(0x80000007) & (1u<<8)) {
+       if (cpu_has(c, X86_FEATURE_ITSC)) {
                __set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
                __set_bit(X86_FEATURE_NONSTOP_TSC, c->x86_capability);
                __set_bit(X86_FEATURE_TSC_RELIABLE, c->x86_capability);
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 9d43f7b..8f2c0b6 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -2605,7 +2605,7 @@ void domain_cpuid(
              */
             if ( (input == 0x80000007) && /* Advanced Power Management */
                  !d->disable_migrate && !d->arch.vtsc )
-                *edx &= ~(1u<<8); /* TSC Invariant */
+                *edx &= ~cpufeat_mask(X86_FEATURE_ITSC);
 
             return;
         }
-- 
2.1.4


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