x86/cpu: Don't update this_cpu for get_cpu_vendor(, gcv_guest)

Otherwise booting a cross-vendor guest would cause PCPU hotplug to
malfunction, because of trying to use the wrong CPU driver.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
index a89cf0763e3ed62001487b73a73fe2e5b6027ea8..537ad356ad3ddfe232d9331712297827d0918ffe 100644 (file)
--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -166,7 +166,8 @@ int get_cpu_vendor(const char v[], enum get_cpu_vendor mode)
                        if (!strcmp(v,cpu_devs[i]->c_ident[0]) ||
                            (cpu_devs[i]->c_ident[1] && 
                             !strcmp(v,cpu_devs[i]->c_ident[1]))) {
-                               this_cpu = cpu_devs[i];
+                               if (mode == gcv_host)
+                                       this_cpu = cpu_devs[i];
                                return i;
                        }
                }