qemu

host-cpu.c (5979B)

---

 /*
  * x86 host CPU functions, and "host" cpu type initialization
  *
  * Copyright 2021 SUSE LLC
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  */
 
 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "host-cpu.h"
 #include "qapi/error.h"
 #include "sysemu/sysemu.h"
 
 /* Note: Only safe for use on x86(-64) hosts */
 static uint32_t host_cpu_phys_bits(void)
 {
     uint32_t eax;
     uint32_t host_phys_bits;
 
     host_cpuid(0x80000000, 0, &eax, NULL, NULL, NULL);
     if (eax >= 0x80000008) {
         host_cpuid(0x80000008, 0, &eax, NULL, NULL, NULL);
         /*
          * Note: According to AMD doc 25481 rev 2.34 they have a field
          * at 23:16 that can specify a maximum physical address bits for
          * the guest that can override this value; but I've not seen
          * anything with that set.
          */
         host_phys_bits = eax & 0xff;
     } else {
         /*
          * It's an odd 64 bit machine that doesn't have the leaf for
          * physical address bits; fall back to 36 that's most older
          * Intel.
          */
         host_phys_bits = 36;
     }
 
     return host_phys_bits;
 }
 
 static void host_cpu_enable_cpu_pm(X86CPU *cpu)
 {
     CPUX86State *env = &cpu->env;
 
     host_cpuid(5, 0, &cpu->mwait.eax, &cpu->mwait.ebx,
                &cpu->mwait.ecx, &cpu->mwait.edx);
     env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR;
 }
 
 static uint32_t host_cpu_adjust_phys_bits(X86CPU *cpu)
 {
     uint32_t host_phys_bits = host_cpu_phys_bits();
     uint32_t phys_bits = cpu->phys_bits;
     static bool warned;
 
     /*
      * Print a warning if the user set it to a value that's not the
      * host value.
      */
     if (phys_bits != host_phys_bits && phys_bits != 0 &&
         !warned) {
         warn_report("Host physical bits (%u)"
                     " does not match phys-bits property (%u)",
                     host_phys_bits, phys_bits);
         warned = true;
     }
 
     if (cpu->host_phys_bits) {
         /* The user asked for us to use the host physical bits */
         phys_bits = host_phys_bits;
         if (cpu->host_phys_bits_limit &&
             phys_bits > cpu->host_phys_bits_limit) {
             phys_bits = cpu->host_phys_bits_limit;
         }
     }
 
     return phys_bits;
 }
 
 bool host_cpu_realizefn(CPUState *cs, Error **errp)
 {
     X86CPU *cpu = X86_CPU(cs);
     CPUX86State *env = &cpu->env;
 
     if (cpu->max_features && enable_cpu_pm) {
         host_cpu_enable_cpu_pm(cpu);
     }
     if (env->features[FEAT_8000_0001_EDX] & CPUID_EXT2_LM) {
         uint32_t phys_bits = host_cpu_adjust_phys_bits(cpu);
 
         if (phys_bits &&
             (phys_bits > TARGET_PHYS_ADDR_SPACE_BITS ||
              phys_bits < 32)) {
             error_setg(errp, "phys-bits should be between 32 and %u "
                        " (but is %u)",
                        TARGET_PHYS_ADDR_SPACE_BITS, phys_bits);
             return false;
         }
         cpu->phys_bits = phys_bits;
     }
     return true;
 }
 
 #define CPUID_MODEL_ID_SZ 48
 /**
  * cpu_x86_fill_model_id:
  * Get CPUID model ID string from host CPU.
  *
  * @str should have at least CPUID_MODEL_ID_SZ bytes
  *
  * The function does NOT add a null terminator to the string
  * automatically.
  */
 static int host_cpu_fill_model_id(char *str)
 {
     uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;
     int i;
 
     for (i = 0; i < 3; i++) {
         host_cpuid(0x80000002 + i, 0, &eax, &ebx, &ecx, &edx);
         memcpy(str + i * 16 +  0, &eax, 4);
         memcpy(str + i * 16 +  4, &ebx, 4);
         memcpy(str + i * 16 +  8, &ecx, 4);
         memcpy(str + i * 16 + 12, &edx, 4);
     }
     return 0;
 }
 
 void host_cpu_vendor_fms(char *vendor, int *family, int *model, int *stepping)
 {
     uint32_t eax, ebx, ecx, edx;
 
     host_cpuid(0x0, 0, &eax, &ebx, &ecx, &edx);
     x86_cpu_vendor_words2str(vendor, ebx, edx, ecx);
 
     host_cpuid(0x1, 0, &eax, &ebx, &ecx, &edx);
     if (family) {
         *family = ((eax >> 8) & 0x0F) + ((eax >> 20) & 0xFF);
     }
     if (model) {
         *model = ((eax >> 4) & 0x0F) | ((eax & 0xF0000) >> 12);
     }
     if (stepping) {
         *stepping = eax & 0x0F;
     }
 }
 
 void host_cpu_instance_init(X86CPU *cpu)
 {
     X86CPUClass *xcc = X86_CPU_GET_CLASS(cpu);
 
     if (xcc->model) {
         uint32_t ebx = 0, ecx = 0, edx = 0;
         char vendor[CPUID_VENDOR_SZ + 1];
 
         host_cpuid(0, 0, NULL, &ebx, &ecx, &edx);
         x86_cpu_vendor_words2str(vendor, ebx, edx, ecx);
         object_property_set_str(OBJECT(cpu), "vendor", vendor, &error_abort);
     }
 }
 
 void host_cpu_max_instance_init(X86CPU *cpu)
 {
     char vendor[CPUID_VENDOR_SZ + 1] = { 0 };
     char model_id[CPUID_MODEL_ID_SZ + 1] = { 0 };
     int family, model, stepping;
 
     /* Use max host physical address bits if -cpu max option is applied */
     object_property_set_bool(OBJECT(cpu), "host-phys-bits", true, &error_abort);
 
     host_cpu_vendor_fms(vendor, &family, &model, &stepping);
     host_cpu_fill_model_id(model_id);
 
     object_property_set_str(OBJECT(cpu), "vendor", vendor, &error_abort);
     object_property_set_int(OBJECT(cpu), "family", family, &error_abort);
     object_property_set_int(OBJECT(cpu), "model", model, &error_abort);
     object_property_set_int(OBJECT(cpu), "stepping", stepping,
                             &error_abort);
     object_property_set_str(OBJECT(cpu), "model-id", model_id,
                             &error_abort);
 }
 
 static void host_cpu_class_init(ObjectClass *oc, void *data)
 {
     X86CPUClass *xcc = X86_CPU_CLASS(oc);
 
     xcc->host_cpuid_required = true;
     xcc->ordering = 8;
     xcc->model_description =
         g_strdup_printf("processor with all supported host features ");
 }
 
 static const TypeInfo host_cpu_type_info = {
     .name = X86_CPU_TYPE_NAME("host"),
     .parent = X86_CPU_TYPE_NAME("max"),
     .class_init = host_cpu_class_init,
 };
 
 static void host_cpu_type_init(void)
 {
     type_register_static(&host_cpu_type_info);
 }
 
 type_init(host_cpu_type_init);