[Xen-devel] [PATCH v4 12/26] x86/cpu: Move set_cpumask() calls into c_early_init()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Before c/s 44e24f8567 "x86: don't call generic_identify() redundantly", the
commandline-provided masks would take effect in Xen's view of the features.

As the masks got applied after the query for features, the redundant call to
generic_identify() would clobber the pre-masking feature information with the
post-masking information.

Move the set_cpumask() calls into c_early_init() so their effects take place
before the main query for features in generic_identify().

The cpuid_mask_* command line parameters now limit the entire system, a
feature XenServer was relying on for testing purposes.  Subsequent changes
will cause the mask MSRs to be context switched per-domain, removing the need
to use the command line parameters for heterogeneous levelling purposes.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
---
 xen/arch/x86/cpu/amd.c   |  8 ++++++--
 xen/arch/x86/cpu/intel.c | 34 +++++++++++++++++-----------------
 2 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c
index 47a38c6..5516777 100644
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -407,6 +407,11 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
                                                          c->cpu_core_id);
 }
 
+static void early_init_amd(struct cpuinfo_x86 *c)
+{
+       set_cpuidmask(c);
+}
+
 static void init_amd(struct cpuinfo_x86 *c)
 {
        u32 l, h;
@@ -595,14 +600,13 @@ static void init_amd(struct cpuinfo_x86 *c)
        if ((smp_processor_id() == 1) && !cpu_has(c, X86_FEATURE_ITSC))
                disable_c1_ramping();
 
-       set_cpuidmask(c);
-
        check_syscfg_dram_mod_en();
 }
 
 static const struct cpu_dev amd_cpu_dev = {
        .c_vendor       = "AMD",
        .c_ident        = { "AuthenticAMD" },
+       .c_early_init   = early_init_amd,
        .c_init         = init_amd,
 };
 
diff --git a/xen/arch/x86/cpu/intel.c b/xen/arch/x86/cpu/intel.c
index bdf89f6..ad22375 100644
--- a/xen/arch/x86/cpu/intel.c
+++ b/xen/arch/x86/cpu/intel.c
@@ -189,6 +189,23 @@ static void early_init_intel(struct cpuinfo_x86 *c)
        if (boot_cpu_data.x86 == 0xF && boot_cpu_data.x86_model == 3 &&
            (boot_cpu_data.x86_mask == 3 || boot_cpu_data.x86_mask == 4))
                paddr_bits = 36;
+
+       if (c == &boot_cpu_data && c->x86 == 6) {
+               if (probe_intel_cpuid_faulting())
+                       __set_bit(X86_FEATURE_CPUID_FAULTING,
+                                 c->x86_capability);
+       } else if (boot_cpu_has(X86_FEATURE_CPUID_FAULTING)) {
+               BUG_ON(!probe_intel_cpuid_faulting());
+               __set_bit(X86_FEATURE_CPUID_FAULTING, c->x86_capability);
+       }
+
+       if (!cpu_has_cpuid_faulting)
+               set_cpuidmask(c);
+       else if ((c == &boot_cpu_data) &&
+                (~(opt_cpuid_mask_ecx & opt_cpuid_mask_edx &
+                   opt_cpuid_mask_ext_ecx & opt_cpuid_mask_ext_edx &
+                   opt_cpuid_mask_xsave_eax)))
+               printk("No CPUID feature masking support available\n");
 }
 
 /*
@@ -258,23 +275,6 @@ static void init_intel(struct cpuinfo_x86 *c)
                detect_ht(c);
        }
 
-       if (c == &boot_cpu_data && c->x86 == 6) {
-               if (probe_intel_cpuid_faulting())
-                       __set_bit(X86_FEATURE_CPUID_FAULTING,
-                                 c->x86_capability);
-       } else if (boot_cpu_has(X86_FEATURE_CPUID_FAULTING)) {
-               BUG_ON(!probe_intel_cpuid_faulting());
-               __set_bit(X86_FEATURE_CPUID_FAULTING, c->x86_capability);
-       }
-
-       if (!cpu_has_cpuid_faulting)
-               set_cpuidmask(c);
-       else if ((c == &boot_cpu_data) &&
-                (~(opt_cpuid_mask_ecx & opt_cpuid_mask_edx &
-                   opt_cpuid_mask_ext_ecx & opt_cpuid_mask_ext_edx &
-                   opt_cpuid_mask_xsave_eax)))
-               printk("No CPUID feature masking support available\n");
-
        /* Work around errata */
        Intel_errata_workarounds(c);
 
-- 
2.1.4


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