Add utility to find hypervisor vendor

2 files changed, 78 insertions, 0 deletions

diff --git a/Makefile.am b/Makefile.am
index 23bdc3a1..3a05c0a5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -76,9 +76,11 @@ sbin_SCRIPTS += scripts/vyatta-update-grub.pl
 
 sbin_PROGRAMS = src/valid_address
 sbin_PROGRAMS += src/local_ip
+sbin_PROGRAMS += src/hypervisor_vendor
 
 src_valid_address = src/valid_address.c
 src_local_ip = src/local_ip.c
+src_hypervisor_vendor = src/hypervisor_vendor.c
 
 share_perl5_DATA = lib/Vyatta/Login/User.pm
 share_perl5_DATA += lib/Vyatta/Login/RadiusServer.pm
diff --git a/src/hypervisor_vendor.c b/src/hypervisor_vendor.c
new file mode 100644
index 00000000..03ce1663
--- /dev/null
+++ b/src/hypervisor_vendor.c
@@ -0,0 +1,76 @@
+/*
+ * Identify hypervisor vendor
+ *
+ * based on code from util-linux lscpu
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+/*
+ * This CPUID leaf returns the information about the hypervisor.
+ * EAX : maximum input value for CPUID supported by the hypervisor.
+ * EBX, ECX, EDX : Hypervisor vendor ID signature. E.g. VMwareVMware.
+ */
+#define HYPERVISOR_INFO_LEAF   0x40000000
+
+static inline void
+cpuid(unsigned int op, unsigned int *eax, unsigned int *ebx,
+			 unsigned int *ecx, unsigned int *edx)
+{
+	__asm__(
+#if defined(__PIC__) && defined(__i386__)
+		/* x86 PIC cannot clobber ebx -- gcc bitches */
+		"pushl %%ebx;"
+		"cpuid;"
+		"movl %%ebx, %%esi;"
+		"popl %%ebx;"
+		: "=S" (*ebx),
+#else
+		"cpuid;"
+		: "=b" (*ebx),
+#endif
+		  "=a" (*eax),
+		  "=c" (*ecx),
+		  "=d" (*edx)
+		: "1" (op), "c"(0));
+}
+
+static const char *get_hypervisor(void)
+{
+	unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
+	char hyper_vendor_id[13];
+
+	memset(hyper_vendor_id, 0, sizeof(hyper_vendor_id));
+
+	cpuid(HYPERVISOR_INFO_LEAF, &eax, &ebx, &ecx, &edx);
+	memcpy(hyper_vendor_id + 0, &ebx, 4);
+	memcpy(hyper_vendor_id + 4, &ecx, 4);
+	memcpy(hyper_vendor_id + 8, &edx, 4);
+	hyper_vendor_id[12] = '\0';
+
+	if (!hyper_vendor_id[0])
+		return NULL;
+
+	else if (!strncmp("XenVMMXenVMM", hyper_vendor_id, 12))
+		return "Xen";
+	else if (!strncmp("KVMKVMKVM", hyper_vendor_id, 9))
+		return "KVM";
+	else if (!strncmp("Microsoft Hv", hyper_vendor_id, 12))
+		return "Microsoft HyperV";
+	else if (!strncmp("VMwareVMware", hyper_vendor_id, 12))
+		return "VMware";
+	else
+		return "Unknown";
+}
+
+int main(int argc, char **argv)
+{
+	const char *vm = get_hypervisor();
+
+	if (vm) {
+		printf("%s\n", vm);
+		return 0;
+	} else
+		return 1;
+}