Assure that unhandled MSR reads get back zeros

[palacios.git] / palacios / src / palacios / vmm_msr.c

diff --git a/palacios/src/palacios/vmm_msr.c b/palacios/src/palacios/vmm_msr.c
index e70b5bb..4163145 100644 (file)
--- a/palacios/src/palacios/vmm_msr.c
+++ b/palacios/src/palacios/vmm_msr.c
@@ -48,26 +48,26 @@ int v3_deinit_msr_map(struct v3_vm_info * vm) {
 }
 
 int v3_handle_msr_write(struct guest_info * info) {
-    uint_t msr_num = info->vm_regs.rcx;
+    uint32_t msr_num = info->vm_regs.rcx;
     struct v3_msr msr_val;
     struct v3_msr_hook * hook = NULL;
+    
+    msr_val.value = 0;
 
     PrintDebug("MSR write for msr 0x%x\n", msr_num);
 
     hook = v3_get_msr_hook(info->vm_info, msr_num);
 
-    if (!hook) {
-        PrintError("Hook for MSR write %d not found\n", msr_num);
-        return -1;
-    }
-
-    msr_val.value = 0;
-    msr_val.lo = info->vm_regs.rax;
-    msr_val.hi = info->vm_regs.rdx;
-
-    if (hook->write(info, msr_num, msr_val, hook->priv_data) == -1) {
-        PrintError("Error in MSR hook Write\n");
-        return -1;
+    if (hook == NULL) {
+       v3_msr_unhandled_write(info, msr_num, msr_val, NULL);
+    } else {
+       msr_val.lo = info->vm_regs.rax;
+       msr_val.hi = info->vm_regs.rdx;
+       
+       if (hook->write(info, msr_num, msr_val, hook->priv_data) == -1) {
+           PrintError("Error in MSR hook Write\n");
+           return -1;
+       }
     }
 
     info->rip += 2;
@@ -77,24 +77,23 @@ int v3_handle_msr_write(struct guest_info * info) {
 
 
 int v3_handle_msr_read(struct guest_info * info) {
-    uint_t msr_num = info->vm_regs.rcx;
+    uint32_t msr_num = info->vm_regs.rcx;
     struct v3_msr msr_val;
     struct v3_msr_hook * hook = NULL;
 
-    hook = v3_get_msr_hook(info->vm_info, msr_num);
-
-    if (!hook) {
-        PrintError("Hook for MSR read %d not found\n", msr_num);
-        return -1;
-    }
-
     msr_val.value = 0;
 
-    if (hook->read(info, msr_num, &msr_val, hook->priv_data) == -1) {
-        PrintError("Error in MSR hook Read\n");
-        return -1;
+    hook = v3_get_msr_hook(info->vm_info, msr_num);
+    
+    if (hook == NULL) {
+       v3_msr_unhandled_read(info, msr_num, &msr_val, NULL);
+    } else {
+       if (hook->read(info, msr_num, &msr_val, hook->priv_data) == -1) {
+           PrintError("Error in MSR hook Read\n");
+           return -1;
+       }
     }
-
+    
     info->vm_regs.rax = msr_val.lo;
     info->vm_regs.rdx = msr_val.hi;
 
@@ -102,9 +101,25 @@ int v3_handle_msr_read(struct guest_info * info) {
     return 0;
 }
 
-int v3_hook_msr(struct v3_vm_info * vm, uint_t msr, 
-               int (*read)(struct guest_info * core, uint_t msr, struct v3_msr * dst, void * priv_data),
-               int (*write)(struct guest_info * core, uint_t msr, struct v3_msr src, void * priv_data),
+
+
+int v3_msr_unhandled_read(struct guest_info * core, uint32_t msr, struct v3_msr * dst, void * priv_data) {
+    V3_Print("Palacios: Unhandled MSR Read (MSR=0x%x) - returning zero\n", msr);
+    dst->lo=dst->hi=0;
+    // should produce GPF for unsupported msr
+    return 0;
+}
+
+int v3_msr_unhandled_write(struct guest_info * core, uint32_t msr, struct v3_msr src, void * priv_data) {
+    V3_Print("Palacios: Unhandled MSR Write (MSR=0x%x) - ignored\n", msr);
+    // should produce GPF for unsupported msr
+    return 0;
+}
+
+
+int v3_hook_msr(struct v3_vm_info * vm, uint32_t msr, 
+               int (*read)(struct guest_info * core, uint32_t msr, struct v3_msr * dst, void * priv_data),
+               int (*write)(struct guest_info * core, uint32_t msr, struct v3_msr src, void * priv_data),
                void * priv_data) {
 
     struct v3_msr_map * msr_map = &(vm->msr_map);
@@ -113,7 +128,7 @@ int v3_hook_msr(struct v3_vm_info * vm, uint_t msr,
     hook = (struct v3_msr_hook *)V3_Malloc(sizeof(struct v3_msr_hook));
 
     if (hook == NULL) {
-       PrintError("Could not allocate msr hook for MSR %d\n", msr);
+       PrintError("Could not allocate msr hook for MSR 0x%x\n", msr);
        return -1;
     }
 
@@ -135,6 +150,10 @@ int v3_hook_msr(struct v3_vm_info * vm, uint_t msr,
     return 0;
 }
 
+
+
+
+
 static int free_hook(struct v3_vm_info * vm, struct v3_msr_hook * hook) {
     list_del(&(hook->link));
 
@@ -148,7 +167,7 @@ static int free_hook(struct v3_vm_info * vm, struct v3_msr_hook * hook) {
 }
 
 
-int v3_unhook_msr(struct v3_vm_info * vm, uint_t msr) {
+int v3_unhook_msr(struct v3_vm_info * vm, uint32_t msr) {
     struct v3_msr_hook * hook = v3_get_msr_hook(vm, msr);
 
     if (hook == NULL) {
@@ -163,7 +182,7 @@ int v3_unhook_msr(struct v3_vm_info * vm, uint_t msr) {
 
 
 
-struct v3_msr_hook * v3_get_msr_hook(struct v3_vm_info * vm, uint_t msr) {
+struct v3_msr_hook * v3_get_msr_hook(struct v3_vm_info * vm, uint32_t msr) {
     struct v3_msr_map * msr_map = &(vm->msr_map);
     struct v3_msr_hook * hook = NULL;
 
@@ -187,7 +206,7 @@ void v3_refresh_msr_map(struct v3_vm_info * vm) {
     }
 
     list_for_each_entry(hook, &(msr_map->hook_list), link) {
-       PrintDebug("updating MSR map for msr %d\n", hook->msr);
+       PrintDebug("updating MSR map for msr 0x%x\n", hook->msr);
        msr_map->update_map(vm, hook->msr,      
                            (hook->read == NULL) ? 0 : 1,
                            (hook->write == NULL) ? 0 : 1);