KVM: nVMX: Improve nested msr switch checking

This patch improve checks required by Intel Software Developer Manual.
 - SMM MSRs are not allowed.
 - microcode MSRs are not allowed.
 - check x2apic MSRs only when LAPIC is in x2apic mode.
 - MSR switch areas must be aligned to 16 bytes.
 - address of first and last byte in MSR switch areas should not set any bits
   beyond the processor's physical-address width.

Also it adds warning messages on failures during MSR switch. These messages
are useful for people who debug their VMMs in nVMX.

Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h
index c8aa65d..d0050f25e 100644
--- a/arch/x86/include/uapi/asm/msr-index.h
+++ b/arch/x86/include/uapi/asm/msr-index.h
@@ -356,6 +356,9 @@
 #define MSR_IA32_UCODE_WRITE		0x00000079
 #define MSR_IA32_UCODE_REV		0x0000008b
 
+#define MSR_IA32_SMM_MONITOR_CTL	0x0000009b
+#define MSR_IA32_SMBASE			0x0000009e
+
 #define MSR_IA32_PERF_STATUS		0x00000198
 #define MSR_IA32_PERF_CTL		0x00000199
 #define MSR_AMD_PSTATE_DEF_BASE		0xc0010064