cpuid: better implementation

kernel-src/arch/x86-64/cpu.c

@@ -2,12 +2,8 @@
 #include <arch/apic.h>
 #include <cpuid.h>
 #include <logging.h>
+#include <arch/cpuid.h>
 
-#define CPUID_VENDOR_AMD "AuthenticAMD"
-#define CPUID_VENDOR_INTEL "GenuineIntel"
-
-#define CPUID_SYSCALL (1 << 11)
-#define CPUID_LEAF_1_EDX_HTT (1 << 28)
 #define EFER_SYSCALLENABLE 1
 
 void arch_syscall_entry();
@@ -43,34 +39,6 @@ static void x87isr(isr_t *self, context_t *ctx) {
 	}
 }
 
-static bool cpuid_leaf_0xb_available(void) {
-	if (current_cpu()->cpuid_max < 0xb)
-		return false;
-
-	unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
-	__get_cpuid_count(0xb, 0, &eax, &ebx, &ecx, &edx);
-	return ebx != 0;
-}
-
-static bool cpuid_leaf_0x80000008_available(void) {
-	unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
-	__get_cpuid(0x80000000, &eax, &ebx, &ecx, &edx);
-
-	if (eax < 0x80000008)
-		return false;
-
-	return true;
-}
-
-static bool cpuid_leaf_0x4_available(void) {
-	if (current_cpu()->cpuid_max < 0x4)
-		return false;
-
-	unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
-	__get_cpuid_count(0xb, 0, &eax, &ebx, &ecx, &edx);
-	return eax != 0;
-}
-
 #define TOPOLOGY_TYPE_THREAD 1
 #define TOPOLOGY_TYPE_CORE   2
 #define TOPOLOGY_TYPE_PACKAGE 0xffffffff
@@ -183,7 +151,7 @@ void cpu_initstate() {
 	unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
 	__get_cpuid(0x80000001, &eax, &ebx, &ecx, &edx);
 
-	__assert(edx & CPUID_SYSCALL);
+	__assert(edx & CPUID_LEAF_0x80000001_EDX_SYSCALL);
 	uint64_t efer = rdmsr(MSR_EFER);
 	efer |= EFER_SYSCALLENABLE;
 	wrmsr(MSR_EFER, efer);

kernel-src/include/x86-64/arch/cpuid.h

@@ -0,0 +1,98 @@
+#ifndef _CPUID_H
+#define _CPUID_H
+
+typedef struct {
+	uint32_t eax;
+	uint32_t ebx;
+	uint32_t ecx;
+	uint32_t edx;
+} cpuid_results_t;
+
+#define CPUID_HYPERVISOR_KVM_EBX 0x4b4d564b
+#define CPUID_HYPERVISOR_KVM_ECX 0x564b4d56
+#define CPUID_HYPERVISOR_KVM_EDX 0x4d
+
+#define CPUID_HYPERVISOR_IS_KVM(ebx, ecx, edx) ((ebx) == CPUID_HYPERVISOR_KVM && (ecx) == CPUID_HYPERVISOR_KVM_ECX && (edx) == CPUID_HYPERVISOR_KVM_EDX)
+
+#define CPUID_VENDOR_AMD "AuthenticAMD"
+#define CPUID_VENDOR_INTEL "GenuineIntel"
+
+#define CPUID_LEAF_0x80000001_EDX_SYSCALL (1 << 11)
+#define CPUID_LEAF_1_EDX_HTT (1 << 28)
+
+static inline void cpuid_with_ecx(uint32_t leaf, uint32_t ecx, cpuid_results_t *cpuid_results) {
+	asm volatile ("cpuid"
+			:
+			"=a"(cpuid_results->eax),
+			"=b"(cpuid_results->ebx),
+			"=c"(cpuid_results->ecx),
+			"=d"(cpuid_results->edx)
+			:
+			"a"(leaf),
+			"c"(ecx));
+}
+
+static inline void cpuid(uint32_t leaf, cpuid_results_t *cpuid_results) {
+	return cpuid_with_ecx(leaf, 0, cpuid_results);
+}
+
+static inline uint32_t cpuid_find_hypervisor_base(uint32_t ebx, uint32_t ecx, uint32_t edx) {
+	uint32_t return_base = 0;
+	cpuid_results_t cpuid_results = {0};
+
+	for (uint32_t base = 0x40000000; base < 0x40001000; base += 0x100) {
+		cpuid(base, &cpuid_results);
+		if (cpuid_results.ebx == ebx && cpuid_results.ecx == ecx && cpuid_results.edx == edx) {
+			return_base = base;
+			break;
+		}
+	}
+
+	return return_base;
+}
+
+static inline uint32_t cpuid_find_hypervisor_base_kvm(void) {
+	return cpuid_find_hypervisor_base(CPUID_HYPERVISOR_KVM_EBX, CPUID_HYPERVISOR_KVM_ECX, CPUID_HYPERVISOR_KVM_EDX);
+}
+
+static inline uint32_t cpuid_base_max_leaf(void) {
+	cpuid_results_t cpuid_results;
+	cpuid(0, &cpuid_results);
+	return cpuid_results.eax;
+}
+
+static inline uint32_t cpuid_hypervisor_max_leaf(uint32_t base) {
+	cpuid_results_t cpuid_results;
+	cpuid(base, &cpuid_results);
+	return cpuid_results.eax;
+}
+
+static inline uint32_t cpuid_extended_max_leaf(void) {
+	cpuid_results_t cpuid_results;
+	cpuid(0x80000000, &cpuid_results);
+	return cpuid_results.eax;
+}
+
+static inline bool cpuid_leaf_0xb_available(void) {
+	if (cpuid_base_max_leaf() < 0xb)
+		return false;
+
+	cpuid_results_t cpuid_results;
+	cpuid(0xb, &cpuid_results);
+	return cpuid_results.ebx != 0;
+}
+
+static inline bool cpuid_leaf_0x80000008_available(void) {
+	return cpuid_extended_max_leaf() >= 0x80000008;
+}
+
+static inline bool cpuid_leaf_0x4_available(void) {
+	if (cpuid_base_max_leaf() < 0x4)
+		return false;
+
+	unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
+	__get_cpuid_count(0x4, 0, &eax, &ebx, &ecx, &edx);
+	return eax != 0;
+}
+
+#endif