From: Peter Dinda <pdinda@northwestern.edu>
Date: Tue, 26 Nov 2013 01:35:07 +0000 (-0600)
Subject: Allow strict MSR semantics
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=commitdiff_plain;h=99578627551cadf5f5c5b60b9700c4a1272d38f6

Allow strict MSR semantics

When enabled, reads/writes to MSRs we do not handle cause GPF to be injected.
This is the architecturally specified reaction.

When disabled, our more lenient behavior is used (read=0, write=ignored)
---

diff --git a/palacios/src/palacios/vmm_msr.c b/palacios/src/palacios/vmm_msr.c
index 0ed99ed..7331a59 100644
--- a/palacios/src/palacios/vmm_msr.c
+++ b/palacios/src/palacios/vmm_msr.c
@@ -110,15 +110,24 @@ int v3_handle_msr_read(struct guest_info * info) {
 int v3_msr_unhandled_read(struct guest_info * core, uint32_t msr, struct v3_msr * dst, void * priv_data) {
     V3_Print(core->vm_info, core, "Palacios: Unhandled MSR Read (MSR=0x%x) - returning zero\n", msr);
 
+#ifdef V3_CONFIG_STRICT_MSR_SEMANTICS
+    v3_raise_exception(core,GPF_EXCEPTION);
+#else
     dst->value = 0;
-
-    // should produce GPF for unsupported msr
+#endif
+    
     return 0;
 }
 
 int v3_msr_unhandled_write(struct guest_info * core, uint32_t msr, struct v3_msr src, void * priv_data) {
     V3_Print(core->vm_info, core, "Palacios: Unhandled MSR Write (MSR=0x%x) - ignored\n", msr);
-    // should produce GPF for unsupported msr
+
+#ifdef V3_CONFIG_STRICT_MSR_SEMANTICS
+    v3_raise_exception(core,GPF_EXCEPTION);
+#else
+    // write ignored
+#endif
+
     return 0;
 }