[Xen-devel] [PATCH v2 for 4.13 1/2] x86/boot: allow early usage of cpu_has_hypervisor

[Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>]

Move early_cpu_init() to be near the top of __start_xen(). Since there
is no serial / vga output at that stage, introduce a new function
to print CPU information at the usual place during boot.

Finally, convert users of cpuid_ecx(1) & X86_FEATURE_HYPERVISOR.

Signed-off-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>
---
CC: Jan Beulich <jbeulich@xxxxxxxx>
CC: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: "Roger Pau Monné" <roger.pau@xxxxxxxxxx>
CC: Juergen Gross <jgross@xxxxxxxx>
---
 xen/arch/x86/cpu/common.c   | 25 +++++++++++++++++--------
 xen/arch/x86/guest/xen.c    |  3 +--
 xen/arch/x86/mm.c           |  2 +-
 xen/arch/x86/setup.c        |  4 +++-
 xen/include/asm-x86/setup.h |  1 +
 5 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
index 6c6bd63301..4f336f64d3 100644
--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -109,6 +109,7 @@ static const struct cpu_dev default_cpu = {
        .c_init = default_init,
 };
 static const struct cpu_dev *this_cpu = &default_cpu;
+static bool __initdata unrecognised_cpu;
 
 static DEFINE_PER_CPU(uint64_t, msr_misc_features);
 void (* __read_mostly ctxt_switch_masking)(const struct vcpu *next);
@@ -301,9 +302,7 @@ void __init early_cpu_init(void)
        case X86_VENDOR_SHANGHAI: this_cpu = &shanghai_cpu_dev; break;
        case X86_VENDOR_HYGON:    this_cpu = &hygon_cpu_dev;    break;
        default:
-               printk(XENLOG_ERR
-                      "Unrecognised or unsupported CPU vendor '%.12s'\n",
-                      c->x86_vendor_id);
+               unrecognised_cpu = true;
        }
 
        cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
@@ -317,11 +316,6 @@ void __init early_cpu_init(void)
        c->x86_capability[cpufeat_word(X86_FEATURE_FPU)] = edx;
        c->x86_capability[cpufeat_word(X86_FEATURE_SSE3)] = ecx;
 
-       printk(XENLOG_INFO
-              "CPU Vendor: %s, Family %u (%#x), Model %u (%#x), Stepping %u 
(raw %08x)\n",
-              x86_cpuid_vendor_to_str(c->x86_vendor), c->x86, c->x86,
-              c->x86_model, c->x86_model, c->x86_mask, eax);
-
        eax = cpuid_eax(0x80000000);
        if ((eax >> 16) == 0x8000 && eax >= 0x80000008) {
                eax = cpuid_eax(0x80000008);
@@ -342,6 +336,21 @@ void __init early_cpu_init(void)
        initialize_cpu_data(0);
 }
 
+void __init early_cpu_print_info(void)
+{
+       struct cpuinfo_x86 *c = &boot_cpu_data;
+
+       if (unrecognised_cpu)
+               printk(XENLOG_ERR
+                      "Unrecognised or unsupported CPU vendor '%.12s'\n",
+                      c->x86_vendor_id);
+
+       printk(XENLOG_INFO "CPU Vendor: %s, Family %u (%#x), Model %u (%#x), "
+                          "Stepping %u (raw %08x)\n",
+              x86_cpuid_vendor_to_str(c->x86_vendor), c->x86, c->x86,
+              c->x86_model, c->x86_model, c->x86_mask, cpuid_eax(0x00000001));
+}
+
 static void generic_identify(struct cpuinfo_x86 *c)
 {
        u32 eax, ebx, ecx, edx, tmp;
diff --git a/xen/arch/x86/guest/xen.c b/xen/arch/x86/guest/xen.c
index 7b7a5badab..9b776afed9 100644
--- a/xen/arch/x86/guest/xen.c
+++ b/xen/arch/x86/guest/xen.c
@@ -72,8 +72,7 @@ void __init probe_hypervisor(void)
     if ( xen_guest )
         return;
 
-    /* Too early to use cpu_has_hypervisor */
-    if ( !(cpuid_ecx(1) & cpufeat_mask(X86_FEATURE_HYPERVISOR)) )
+    if ( !cpu_has_hypervisor )
         return;
 
     find_xen_leaves();
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 99816fc67c..4cdccab8c8 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5943,7 +5943,7 @@ const struct platform_bad_page *__init 
get_platform_badpages(unsigned int *array
     case 0x000806e0: /* erratum KBL??? */
     case 0x000906e0: /* errata KBL??? / KBW114 / CFW103 */
         *array_size = (cpuid_eax(0) >= 7 &&
-                       !(cpuid_ecx(1) & cpufeat_mask(X86_FEATURE_HYPERVISOR)) 
&&
+                       !cpu_has_hypervisor &&
                        (cpuid_count_ebx(7, 0) & 
cpufeat_mask(X86_FEATURE_HLE)));
         return &hle_bad_page;
     }
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index dec60d0301..07adfed566 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -723,6 +723,8 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     /* Enable NMIs.  Our loader (e.g. Tboot) may have left them disabled. */
     enable_nmis();
 
+    early_cpu_init();
+
     if ( pvh_boot )
     {
         /*
@@ -1519,7 +1521,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     softirq_init();
     tasklet_subsys_init();
 
-    early_cpu_init();
+    early_cpu_print_info();
 
     paging_init();
 
diff --git a/xen/include/asm-x86/setup.h b/xen/include/asm-x86/setup.h
index 861d46d6ac..251151508d 100644
--- a/xen/include/asm-x86/setup.h
+++ b/xen/include/asm-x86/setup.h
@@ -15,6 +15,7 @@ extern char __2M_rwdata_start[], __2M_rwdata_end[];
 extern unsigned long xenheap_initial_phys_start;
 
 void early_cpu_init(void);
+void early_cpu_print_info(void);
 void early_time_init(void);
 
 void set_nr_cpu_ids(unsigned int max_cpus);
-- 
2.17.1


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