x86/cpuid: Drop get_cpu_vendor() completely

get_cpu_vendor() tries to do a number of things, and ends up doing none of
them well.

For calculating the vendor itself, use x86_cpuid_lookup_vendor() which is
implemented in a far more efficient manner than looping over cpu_devs[].

For setting up this_cpu, set it up once on the BSP only, rather than
latest-takes-precident across the APs.  Such a system is probably not going to
boot, but this feels like a less dangerous course of action.  Adjust the
printed errors to be more clear in the mismatch case.

This removes the only user of cpu_dev->c_ident[], so drop that field as well.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c
index c790416f8df85f5302f5e3076804f78abc299bce..7a73d62994109adb51026102570d02015f8aa49f 100644 (file)
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -794,7 +794,6 @@ static void init_amd(struct cpuinfo_x86 *c)
 
 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/centaur.c b/xen/arch/x86/cpu/centaur.c
index 1c760be40d8dc960dfabb2b56a8c1271a9fc7ea2..71f650368226aa42f685dd6eca630513d2d6b646 100644 (file)
--- a/xen/arch/x86/cpu/centaur.c
+++ b/xen/arch/x86/cpu/centaur.c
@@ -56,7 +56,6 @@ static void init_centaur(struct cpuinfo_x86 *c)
 
 static const struct cpu_dev centaur_cpu_dev = {
        .c_vendor       = "Centaur",
-       .c_ident        = { "CentaurHauls" },
        .c_init         = init_centaur,
 };
 

diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
index 53bb0a9e7c4e71dfb36a57ae185fc0aded915425..b2249b5b12f038618bc10a95e2030ad40b8cce85 100644 (file)
--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -247,36 +247,6 @@ void display_cacheinfo(struct cpuinfo_x86 *c)
                       l2size, ecx & 0xFF);
 }
 
-int get_cpu_vendor(uint32_t b, uint32_t c, uint32_t d, enum get_cpu_vendor mode)
-{
-       int i;
-       static int printed;
-
-       for (i = 0; i < X86_VENDOR_NUM; i++) {
-               if (cpu_devs[i]) {
-                       struct {
-                               uint32_t b, d, c;
-                       } *ptr = (void *)cpu_devs[i]->c_ident;
-
-                       if (ptr->b == b && ptr->c == c && ptr->d == d) {
-                               if (mode == gcv_host)
-                                       this_cpu = cpu_devs[i];
-                               return i;
-                       }
-               }
-       }
-       if (mode == gcv_guest)
-               return X86_VENDOR_UNKNOWN;
-       if (!printed) {
-               printed++;
-               printk(KERN_ERR "CPU: Vendor unknown, using generic init.\n");
-               printk(KERN_ERR "CPU: Your system may be unstable.\n");
-       }
-       this_cpu = &default_cpu;
-
-       return X86_VENDOR_UNKNOWN;
-}
-
 static inline u32 _phys_pkg_id(u32 cpuid_apic, int index_msb)
 {
        return cpuid_apic >> index_msb;
@@ -313,7 +283,13 @@ static void __init early_cpu_detect(void)
        *(u32 *)&c->x86_vendor_id[8] = ecx;
        *(u32 *)&c->x86_vendor_id[4] = edx;
 
-       c->x86_vendor = get_cpu_vendor(ebx, ecx, edx, gcv_host);
+       c->x86_vendor = x86_cpuid_lookup_vendor(ebx, ecx, edx);
+       if (c->x86_vendor < ARRAY_SIZE(cpu_devs) && cpu_devs[c->x86_vendor])
+               this_cpu = cpu_devs[c->x86_vendor];
+       else
+               printk(XENLOG_ERR
+                      "Unrecognised or unsupported CPU vendor '%.12s'\n",
+                      c->x86_vendor_id);
 
        cpuid(0x00000001, &eax, &ebx, &ecx, &edx);
        c->x86 = get_cpu_family(eax, &c->x86_model, &c->x86_mask);
@@ -361,7 +337,12 @@ static void generic_identify(struct cpuinfo_x86 *c)
        *(u32 *)&c->x86_vendor_id[8] = ecx;
        *(u32 *)&c->x86_vendor_id[4] = edx;
 
-       c->x86_vendor = get_cpu_vendor(ebx, ecx, edx, gcv_host);
+       c->x86_vendor = x86_cpuid_lookup_vendor(ebx, ecx, edx);
+       if (boot_cpu_data.x86_vendor != c->x86_vendor)
+               printk(XENLOG_ERR "CPU%u vendor %u mismatch against BSP %u\n",
+                      smp_processor_id(), c->x86_vendor,
+                      boot_cpu_data.x86_vendor);
+
        /* Initialize the standard set of capabilities */
        /* Note that the vendor-specific code below might override */
 

diff --git a/xen/arch/x86/cpu/cpu.h b/xen/arch/x86/cpu/cpu.h
index 2fcb93138829f05ebe2edb923376c3be99a3b4da..edc88b1eab742ed68397e9bcb48fd31b8e1f786e 100644 (file)
--- a/xen/arch/x86/cpu/cpu.h
+++ b/xen/arch/x86/cpu/cpu.h
@@ -1,7 +1,6 @@
 /* attempt to consolidate cpu attributes */
 struct cpu_dev {
        char    c_vendor[8];
-       char    c_ident[13];
 
        void            (*c_early_init)(struct cpuinfo_x86 *c);
        void            (*c_init)(struct cpuinfo_x86 * c);

diff --git a/xen/arch/x86/cpu/intel.c b/xen/arch/x86/cpu/intel.c
index 29c6b875128adacc2b6b4b56f4b4d547afeed13c..f9c2ec439a6e6868668150dabad586ed6049a217 100644 (file)
--- a/xen/arch/x86/cpu/intel.c
+++ b/xen/arch/x86/cpu/intel.c
@@ -350,7 +350,6 @@ static void init_intel(struct cpuinfo_x86 *c)
 
 static const struct cpu_dev intel_cpu_dev = {
        .c_vendor       = "Intel",
-       .c_ident        = { "GenuineIntel" },
        .c_early_init   = early_init_intel,
        .c_init         = init_intel,
 };

diff --git a/xen/arch/x86/cpu/shanghai.c b/xen/arch/x86/cpu/shanghai.c
index 9156c850fefe8fb629099b491dcd7a5202128fa8..24af5c82595f3afa0c80d88c755de3c7b6935add 100644 (file)
--- a/xen/arch/x86/cpu/shanghai.c
+++ b/xen/arch/x86/cpu/shanghai.c
@@ -17,7 +17,6 @@ static void init_shanghai(struct cpuinfo_x86 *c)
 
 static const struct cpu_dev shanghai_cpu_dev = {
     .c_vendor   = "  Shang",
-    .c_ident    = {"  Shanghai  "},
     .c_init     = init_shanghai,
 };
 

diff --git a/xen/arch/x86/cpuid.c b/xen/arch/x86/cpuid.c
index ab0aab678c74f183a8e7e1ef3b3d5bcbc5fe8d95..b5eb584a47570f97709bda50ff8b62dc712d4d50 100644 (file)
--- a/xen/arch/x86/cpuid.c
+++ b/xen/arch/x86/cpuid.c
@@ -459,8 +459,8 @@ void recalculate_cpuid_policy(struct domain *d)
     uint32_t fs[FSCAPINTS], max_fs[FSCAPINTS];
     unsigned int i;
 
-    p->x86_vendor = get_cpu_vendor(p->basic.vendor_ebx, p->basic.vendor_ecx,
-                                   p->basic.vendor_edx, gcv_guest);
+    p->x86_vendor = x86_cpuid_lookup_vendor(
+        p->basic.vendor_ebx, p->basic.vendor_ecx, p->basic.vendor_edx);
 
     p->basic.max_leaf   = min(p->basic.max_leaf,   max->basic.max_leaf);
     p->feat.max_subleaf = min(p->feat.max_subleaf, max->feat.max_subleaf);

diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index f3275ca5d3adf609a013aaada5039f921db34978..cef3ffb8b0ba429b46f295987ed62d275dcce15c 100644 (file)
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -579,13 +579,6 @@ int early_microcode_init(void);
 int microcode_init_intel(void);
 int microcode_init_amd(void);
 
-enum get_cpu_vendor {
-    gcv_host,
-    gcv_guest,
-};
-
-int get_cpu_vendor(uint32_t b, uint32_t c, uint32_t d, enum get_cpu_vendor mode);
-
 static inline uint8_t get_cpu_family(uint32_t raw, uint8_t *model,
                                      uint8_t *stepping)
 {