[PATCH 07/16] x86/cpu: Call the vendor early_init() hook in early_cpu_init()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

... which is in practice much earlier on boot.

Currently, beyond basic vendor family and model information, the Intel hook
needs the SELF_SNOOP CPUID bit which is collected by early_cpu_init() already.
The AMD hook needs CPUID_USER_DIS, so the collection of leaf e21a needs to
move too.  (identify_cpu() has a second collection of this leaf, which
remains.)

In order to facilitate this, have early_cpu_init() calculate
c->extended_cpuid_level in the usual way.

No practical change.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Julian Vetter <julian.vetter@xxxxxxxxxx>
CC: Teddy Astie <teddy.astie@xxxxxxxxxx>
---
 xen/arch/x86/cpu/common.c | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
index 39e64f3a5f88..d70f9cf87dc8 100644
--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -413,8 +413,12 @@ void __init early_cpu_init(bool verbose)
        }
 
        eax = cpuid_eax(0x80000000);
-       if ((eax >> 16) == 0x8000 && eax >= 0x80000008) {
-               ebx = eax >= 0x8000001f ? cpuid_ebx(0x8000001f) : 0;
+       if ((eax >> 16) == 0x8000)
+               c->extended_cpuid_level = eax;
+
+       if (c->extended_cpuid_level >= 0x80000008) {
+               ebx = c->extended_cpuid_level >= 0x8000001f
+                       ? cpuid_ebx(0x8000001f) : 0;
                eax = cpuid_eax(0x80000008);
 
                paddr_bits = eax & 0xff;
@@ -433,6 +437,19 @@ void __init early_cpu_init(bool verbose)
                paddr_bits -= (ebx >> 6) & 0x3f;
        }
 
+       if (c->extended_cpuid_level >= 0x80000021)
+               c->x86_capability[FEATURESET_e21a] = cpuid_eax(0x80000021);
+
+       /*
+        * Abuse 'verbose' to signal the first pass thought this function.
+        *
+        * Besides basic vendor, family and model information, the hooks need
+        * certain words of x86_capability[] already scanned, as they may take
+        * action to cause features to reappear.
+        */
+       if (verbose && actual_cpu.c_early_init)
+               actual_cpu.c_early_init();
+
        if (!(c->x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON)))
                park_offline_cpus = opt_mce;
 
@@ -485,10 +502,6 @@ void identify_cpu(struct cpuinfo_x86 *c)
        c->x86_clflush_size = ((ebx >> 8) & 0xff) * 8;
        c->phys_proc_id = c->apicid;
 
-       /*
-        * Early init of Self Snoop support requires 0x1.edx, while there also
-        * set 0x1.ecx as the value is in context.
-        */
        c->x86_capability[FEATURESET_1c] = ecx;
        c->x86_capability[FEATURESET_1d] = edx;
 
@@ -496,16 +509,6 @@ void identify_cpu(struct cpuinfo_x86 *c)
        if ((eax >> 16) == 0x8000)
                c->extended_cpuid_level = eax;
 
-       /*
-        * These AMD-defined flags are out of place, but we need
-        * them early for the CPUID faulting probe code
-        */
-       if (c->extended_cpuid_level >= 0x80000021)
-               c->x86_capability[FEATURESET_e21a] = cpuid_eax(0x80000021);
-
-       if (c == &boot_cpu_data && actual_cpu.c_early_init)
-               alternative_vcall(actual_cpu.c_early_init);
-
        /* AMD-defined flags: level 0x80000001 */
        if (c->extended_cpuid_level >= 0x80000001)
                cpuid(0x80000001, &tmp, &tmp,
-- 
2.39.5