kvm: Allow the Hyper-V vendor ID to be specified

According to Microsoft documentation, the signature in the standard
hypervisor CPUID leaf at 0x40000000 identifies the Vendor ID and is
for reporting and diagnostic purposes only.  We can therefore allow
the user to change it to whatever they want, within the 12 character
limit.  Add a new hv-vendor-id option to the -cpu flag to allow
for this, ex:

 -cpu host,hv_time,hv-vendor-id=KeenlyKVM

Link: http://msdn.microsoft.com/library/windows/hardware/hh975392
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Message-Id: <20151016153356.28104.48612.stgit@gimli.home>
[Adjust error message to match the property name, use error_report. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h
index 9eab41b19ef6afdabc013076b2ed3edc9a2185a3..e3bfe9d07e9f63503618a6b8655ded5cb639a865 100644 (file)
--- a/target-i386/cpu-qom.h
+++ b/target-i386/cpu-qom.h
@@ -88,6 +88,7 @@ typedef struct X86CPU {
     bool hyperv_vapic;
     bool hyperv_relaxed_timing;
     int hyperv_spinlock_attempts;
+    char *hyperv_vendor_id;
     bool hyperv_time;
     bool hyperv_crash;
     bool hyperv_reset;

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index d2b06195f0abbce700a1795dff5c9f8e2d40bd73..5f53af248f874aa41f524b5f252aa2438f23fe90 100644 (file)
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -3149,6 +3149,7 @@ static Property x86_cpu_properties[] = {
     DEFINE_PROP_UINT32("level", X86CPU, env.cpuid_level, 0),
     DEFINE_PROP_UINT32("xlevel", X86CPU, env.cpuid_xlevel, 0),
     DEFINE_PROP_UINT32("xlevel2", X86CPU, env.cpuid_xlevel2, 0),
+    DEFINE_PROP_STRING("hv-vendor-id", X86CPU, hyperv_vendor_id),
     DEFINE_PROP_END_OF_LIST()
 };
 

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 010ac515636e7eef6bf3ae628cc794a4d5746c9f..64046cb69d614d52cf5eb02a827c1ff48d574dd4 100644 (file)
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -28,6 +28,7 @@
 #include "exec/gdbstub.h"
 #include "qemu/host-utils.h"
 #include "qemu/config-file.h"
+#include "qemu/error-report.h"
 #include "hw/i386/pc.h"
 #include "hw/i386/apic.h"
 #include "hw/i386/apic_internal.h"
@@ -505,7 +506,18 @@ int kvm_arch_init_vcpu(CPUState *cs)
     if (hyperv_enabled(cpu)) {
         c = &cpuid_data.entries[cpuid_i++];
         c->function = HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
-        memcpy(signature, "Microsoft Hv", 12);
+        if (!cpu->hyperv_vendor_id) {
+            memcpy(signature, "Microsoft Hv", 12);
+        } else {
+            size_t len = strlen(cpu->hyperv_vendor_id);
+
+            if (len > 12) {
+                error_report("hv-vendor-id truncated to 12 characters");
+                len = 12;
+            }
+            memset(signature, 0, 12);
+            memcpy(signature, cpu->hyperv_vendor_id, len);
+        }
         c->eax = HYPERV_CPUID_MIN;
         c->ebx = signature[0];
         c->ecx = signature[1];