i386: introduce hv_cpuid_cache

Just like with cpuid_cache, it makes no sense to call
KVM_GET_SUPPORTED_HV_CPUID more than once and instead of (ab)using
env->features[] and/or trying to keep all the code in one place, it is
better to introduce persistent hv_cpuid_cache and hv_cpuid_get_host()
accessor to it.

Note, hv_cpuid_get_fw() is converted to using hv_cpuid_get_host()
just to be removed later with Hyper-V specific feature words.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20210422161130.652779-9-vkuznets@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 56 insertions, 53 deletions

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 6d6afd8..2dd60fc 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -129,6 +129,7 @@ static int has_exception_payload;
 static bool has_msr_mcg_ext_ctl;
 
 static struct kvm_cpuid2 *cpuid_cache;
+static struct kvm_cpuid2 *hv_cpuid_cache;
 static struct kvm_msr_list *kvm_feature_msrs;
 
 int kvm_has_pit_state2(void)
@@ -1067,10 +1068,25 @@ static struct kvm_cpuid2 *get_supported_hv_cpuid_legacy(CPUState *cs)
     return cpuid;
 }
 
-static uint32_t hv_cpuid_get_host(struct kvm_cpuid2 *cpuid, uint32_t func,
-                                  int reg)
+static uint32_t hv_cpuid_get_host(CPUState *cs, uint32_t func, int reg)
 {
     struct kvm_cpuid_entry2 *entry;
+    struct kvm_cpuid2 *cpuid;
+
+    if (hv_cpuid_cache) {
+        cpuid = hv_cpuid_cache;
+    } else {
+        if (kvm_check_extension(kvm_state, KVM_CAP_HYPERV_CPUID) > 0) {
+            cpuid = get_supported_hv_cpuid(cs);
+        } else {
+            cpuid = get_supported_hv_cpuid_legacy(cs);
+        }
+        hv_cpuid_cache = cpuid;
+    }
+
+    if (!cpuid) {
+        return 0;
+    }
 
     entry = cpuid_find_entry(cpuid, func, 0);
     if (!entry) {
@@ -1080,7 +1096,7 @@ static uint32_t hv_cpuid_get_host(struct kvm_cpuid2 *cpuid, uint32_t func,
     return cpuid_entry_get_reg(entry, reg);
 }
 
-static bool hyperv_feature_supported(struct kvm_cpuid2 *cpuid, int feature)
+static bool hyperv_feature_supported(CPUState *cs, int feature)
 {
     uint32_t func, bits;
     int i, reg;
@@ -1095,7 +1111,7 @@ static bool hyperv_feature_supported(struct kvm_cpuid2 *cpuid, int feature)
             continue;
         }
 
-        if ((hv_cpuid_get_host(cpuid, func, reg) & bits) != bits) {
+        if ((hv_cpuid_get_host(cs, func, reg) & bits) != bits) {
             return false;
         }
     }
@@ -1103,8 +1119,7 @@ static bool hyperv_feature_supported(struct kvm_cpuid2 *cpuid, int feature)
     return true;
 }
 
-static int hv_cpuid_check_and_set(CPUState *cs, struct kvm_cpuid2 *cpuid,
-                                  int feature)
+static int hv_cpuid_check_and_set(CPUState *cs, int feature)
 {
     X86CPU *cpu = X86_CPU(cs);
     uint64_t deps;
@@ -1127,7 +1142,7 @@ static int hv_cpuid_check_and_set(CPUState *cs, struct kvm_cpuid2 *cpuid,
         deps &= ~(1ull << dep_feat);
     }
 
-    if (!hyperv_feature_supported(cpuid, feature)) {
+    if (!hyperv_feature_supported(cs, feature)) {
         if (hyperv_feat_enabled(cpu, feature)) {
             fprintf(stderr,
                     "Hyper-V %s is not supported by kernel\n",
@@ -1180,7 +1195,6 @@ static int hyperv_handle_properties(CPUState *cs,
                                     struct kvm_cpuid_entry2 *cpuid_ent)
 {
     X86CPU *cpu = X86_CPU(cs);
-    struct kvm_cpuid2 *cpuid;
     struct kvm_cpuid_entry2 *c;
     uint32_t cpuid_i = 0;
     int r;
@@ -1206,19 +1220,13 @@ static int hyperv_handle_properties(CPUState *cs,
         }
     }
 
-    if (kvm_check_extension(cs->kvm_state, KVM_CAP_HYPERV_CPUID) > 0) {
-        cpuid = get_supported_hv_cpuid(cs);
-    } else {
-        cpuid = get_supported_hv_cpuid_legacy(cs);
-    }
-
     if (cpu->hyperv_passthrough) {
         cpu->hyperv_vendor_id[0] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_VENDOR_AND_MAX_FUNCTIONS, R_EBX);
+            hv_cpuid_get_host(cs, HV_CPUID_VENDOR_AND_MAX_FUNCTIONS, R_EBX);
         cpu->hyperv_vendor_id[1] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_VENDOR_AND_MAX_FUNCTIONS, R_ECX);
+            hv_cpuid_get_host(cs, HV_CPUID_VENDOR_AND_MAX_FUNCTIONS, R_ECX);
         cpu->hyperv_vendor_id[2] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_VENDOR_AND_MAX_FUNCTIONS, R_EDX);
+            hv_cpuid_get_host(cs, HV_CPUID_VENDOR_AND_MAX_FUNCTIONS, R_EDX);
         cpu->hyperv_vendor = g_realloc(cpu->hyperv_vendor,
                                        sizeof(cpu->hyperv_vendor_id) + 1);
         memcpy(cpu->hyperv_vendor, cpu->hyperv_vendor_id,
@@ -1226,52 +1234,52 @@ static int hyperv_handle_properties(CPUState *cs,
         cpu->hyperv_vendor[sizeof(cpu->hyperv_vendor_id)] = 0;
 
         cpu->hyperv_interface_id[0] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_INTERFACE, R_EAX);
+            hv_cpuid_get_host(cs, HV_CPUID_INTERFACE, R_EAX);
         cpu->hyperv_interface_id[1] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_INTERFACE, R_EBX);
+            hv_cpuid_get_host(cs, HV_CPUID_INTERFACE, R_EBX);
         cpu->hyperv_interface_id[2] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_INTERFACE, R_ECX);
+            hv_cpuid_get_host(cs, HV_CPUID_INTERFACE, R_ECX);
         cpu->hyperv_interface_id[3] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_INTERFACE, R_EDX);
+            hv_cpuid_get_host(cs, HV_CPUID_INTERFACE, R_EDX);
 
         cpu->hyperv_version_id[0] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_VERSION, R_EAX);
+            hv_cpuid_get_host(cs, HV_CPUID_VERSION, R_EAX);
         cpu->hyperv_version_id[1] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_VERSION, R_EBX);
+            hv_cpuid_get_host(cs, HV_CPUID_VERSION, R_EBX);
         cpu->hyperv_version_id[2] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_VERSION, R_ECX);
+            hv_cpuid_get_host(cs, HV_CPUID_VERSION, R_ECX);
         cpu->hyperv_version_id[3] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_VERSION, R_EDX);
+            hv_cpuid_get_host(cs, HV_CPUID_VERSION, R_EDX);
 
-        cpu->hv_max_vps = hv_cpuid_get_host(cpuid, HV_CPUID_IMPLEMENT_LIMITS,
+        cpu->hv_max_vps = hv_cpuid_get_host(cs, HV_CPUID_IMPLEMENT_LIMITS,
                                             R_EAX);
         cpu->hyperv_limits[0] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_IMPLEMENT_LIMITS, R_EBX);
+            hv_cpuid_get_host(cs, HV_CPUID_IMPLEMENT_LIMITS, R_EBX);
         cpu->hyperv_limits[1] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_IMPLEMENT_LIMITS, R_ECX);
+            hv_cpuid_get_host(cs, HV_CPUID_IMPLEMENT_LIMITS, R_ECX);
         cpu->hyperv_limits[2] =
-            hv_cpuid_get_host(cpuid, HV_CPUID_IMPLEMENT_LIMITS, R_EDX);
+            hv_cpuid_get_host(cs, HV_CPUID_IMPLEMENT_LIMITS, R_EDX);
 
         cpu->hyperv_spinlock_attempts =
-            hv_cpuid_get_host(cpuid, HV_CPUID_ENLIGHTMENT_INFO, R_EBX);
+            hv_cpuid_get_host(cs, HV_CPUID_ENLIGHTMENT_INFO, R_EBX);
     }
 
     /* Features */
-    r = hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_RELAXED);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_VAPIC);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_TIME);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_CRASH);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_RESET);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_VPINDEX);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_RUNTIME);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_SYNIC);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_STIMER);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_FREQUENCIES);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_REENLIGHTENMENT);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_TLBFLUSH);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_EVMCS);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_IPI);
-    r |= hv_cpuid_check_and_set(cs, cpuid, HYPERV_FEAT_STIMER_DIRECT);
+    r = hv_cpuid_check_and_set(cs, HYPERV_FEAT_RELAXED);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_VAPIC);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_TIME);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_CRASH);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_RESET);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_VPINDEX);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_RUNTIME);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_SYNIC);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_STIMER);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_FREQUENCIES);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_REENLIGHTENMENT);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_TLBFLUSH);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_EVMCS);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_IPI);
+    r |= hv_cpuid_check_and_set(cs, HYPERV_FEAT_STIMER_DIRECT);
 
     /* Additional dependencies not covered by kvm_hyperv_properties[] */
     if (hyperv_feat_enabled(cpu, HYPERV_FEAT_SYNIC) &&
@@ -1284,8 +1292,7 @@ static int hyperv_handle_properties(CPUState *cs,
     }
 
     if (r) {
-        r = -ENOSYS;
-        goto free;
+        return -ENOSYS;
     }
 
     c = &cpuid_ent[cpuid_i++];
@@ -1327,7 +1334,7 @@ static int hyperv_handle_properties(CPUState *cs,
     if (cpu->hyperv_no_nonarch_cs == ON_OFF_AUTO_ON) {
         c->eax |= HV_NO_NONARCH_CORESHARING;
     } else if (cpu->hyperv_no_nonarch_cs == ON_OFF_AUTO_AUTO) {
-        c->eax |= hv_cpuid_get_host(cpuid, HV_CPUID_ENLIGHTMENT_INFO, R_EAX) &
+        c->eax |= hv_cpuid_get_host(cs, HV_CPUID_ENLIGHTMENT_INFO, R_EAX) &
             HV_NO_NONARCH_CORESHARING;
     }
 
@@ -1352,12 +1359,8 @@ static int hyperv_handle_properties(CPUState *cs,
         c->function = HV_CPUID_NESTED_FEATURES;
         c->eax = cpu->hyperv_nested[0];
     }
-    r = cpuid_i;
 
-free:
-    g_free(cpuid);
-
-    return r;
+    return cpuid_i;
 }
 
 static Error *hv_passthrough_mig_blocker;