hv: refine handler to 'rdpmc' vmexit

 PMC is hidden from guest and hypervisor should
 inject UD to guest when 'rdpmc' vmexit.

Tracked-On: #3453
Signed-off-by: Yonghua Huang <yonghua.huang@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>

Author: yonghuah

hypervisor/arch/x86/guest/vmexit.c

@@ -65,7 +65,7 @@ static const struct vm_exit_dispatch dispatch_table[NR_VMX_EXIT_REASONS] = {
 	[VMX_EXIT_REASON_INVLPG] = {
 		.handler = unhandled_vmexit_handler,},
 	[VMX_EXIT_REASON_RDPMC] = {
-		.handler = unhandled_vmexit_handler},
+		.handler = undefined_vmexit_handler},
 	[VMX_EXIT_REASON_RDTSC] = {
 		.handler = unhandled_vmexit_handler},
 	[VMX_EXIT_REASON_RSM] = {