Assure that unhandled IO reads get back zeros

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

diff --git a/palacios/src/palacios/vmx_io.c b/palacios/src/palacios/vmx_io.c
index 4e94f69..46de7ca 100644 (file)
--- a/palacios/src/palacios/vmx_io.c
+++ b/palacios/src/palacios/vmx_io.c
@@ -25,7 +25,7 @@
 #include <palacios/vm_guest_mem.h>
 #include <palacios/vmm_decoder.h>
 
-#ifndef CONFIG_DEBUG_IO
+#ifndef V3_CONFIG_DEBUG_IO
 #undef PrintDebug
 #define PrintDebug(fmt, args...)
 #endif
@@ -50,35 +50,42 @@ int v3_init_vmx_io_map(struct v3_vm_info * vm) {
     vm->io_map.update_map = update_map;
     
     vm->io_map.arch_data = V3_VAddr(V3_AllocPages(2));
-    memset(vm->io_map.arch_data, 0, PAGE_SIZE_4KB * 2);
+    memset(vm->io_map.arch_data, 0xff, PAGE_SIZE_4KB * 2);
 
     v3_refresh_io_map(vm);
 
     return 0;
 }
 
+int v3_deinit_vmx_io_map(struct v3_vm_info * vm) {
+    V3_FreePages(V3_PAddr(vm->io_map.arch_data), 2);
+    return 0;
+}
+
+
 int v3_handle_vmx_io_in(struct guest_info * core, struct vmx_exit_info * exit_info) {
     struct vmx_exit_io_qual io_qual = *(struct vmx_exit_io_qual *)&(exit_info->exit_qual);;
     struct v3_io_hook * hook = NULL;
     int read_size = 0;
 
-
     hook = v3_get_io_hook(core->vm_info, io_qual.port);
 
-    if (hook == NULL) {
-        PrintError("Hook not present for IN on port %x\n", io_qual.port);
-        return -1;
-    }
-
     read_size = io_qual.access_size + 1;
 
     PrintDebug("IN of %d bytes on port %d (0x%x)\n", read_size, io_qual.port, io_qual.port);
 
-    if (hook->read(core, io_qual.port, &(core->vm_regs.rax), read_size, hook->priv_data) != read_size) {
-        PrintError("Read failure for IN on port %x\n", io_qual.port);
-        return -1;
-    }
+    if (hook == NULL) {
+       PrintDebug("IN operation on unhooked IO port 0x%x - returning zeros\n", io_qual.port);
+       core->vm_regs.rax >>= 8*read_size;
+       core->vm_regs.rax <<= 8*read_size;
 
+    } else {
+       if (hook->read(core, io_qual.port, &(core->vm_regs.rax), read_size, hook->priv_data) != read_size) {
+           PrintError("Read failure for IN on port %x\n", io_qual.port);
+           return -1;
+       }
+    }
+    
 
     core->rip += exit_info->instr_len;
 
@@ -97,10 +104,6 @@ int v3_handle_vmx_io_ins(struct guest_info * core, struct vmx_exit_info * exit_i
 
     hook = v3_get_io_hook(core->vm_info, io_qual.port);
 
-    if (hook == NULL) {
-        PrintError("Hook not present for INS on port 0x%x\n", io_qual.port);
-        return -1;
-    }
 
     PrintDebug("INS on port 0x%x\n", io_qual.port);
 
@@ -131,16 +134,25 @@ int v3_handle_vmx_io_ins(struct guest_info * core, struct vmx_exit_info * exit_i
 
 
 
-    if (guest_va_to_host_va(core, guest_va, &host_addr) == -1) {
+    if (v3_gva_to_hva(core, guest_va, &host_addr) == -1) {
         PrintError("Could not convert Guest VA to host VA\n");
         return -1;
     }
 
     do {
-        if (hook->read(core, io_qual.port, (char *)host_addr, read_size, hook->priv_data) != read_size) {
-            PrintError("Read Failure for INS on port 0x%x\n", io_qual.port);
-            return -1;
-        }
+
+       if (hook == NULL) {
+           PrintDebug("INS operation on unhooked IO port 0x%x - returning zeros\n", io_qual.port);
+           
+           memset((char*)host_addr,0,read_size);
+
+       } else {
+           if (hook->read(core, io_qual.port, (char *)host_addr, read_size, hook->priv_data) != read_size) {
+               PrintError("Read Failure for INS on port 0x%x\n", io_qual.port);
+               return -1;
+           }
+       }
+       
 
         host_addr += rdi_change;
         core->vm_regs.rdi += rdi_change;
@@ -166,22 +178,20 @@ int v3_handle_vmx_io_out(struct guest_info * core, struct vmx_exit_info * exit_i
 
     hook =  v3_get_io_hook(core->vm_info, io_qual.port);
 
-    if (hook == NULL) {
-        PrintError("Hook not present for out on port %x\n", io_qual.port);
-        return -1;
-    }
 
     write_size = io_qual.access_size + 1;
     
     PrintDebug("OUT of %d bytes on port %d (0x%x)\n", write_size, io_qual.port, io_qual.port);
 
-    if (hook->write(core, io_qual.port, &(core->vm_regs.rax), write_size, hook->priv_data) != write_size) {
-        PrintError("Write failure for out on port %x\n",io_qual.port);
-        return -1;
+    if (hook == NULL) {
+       PrintDebug("OUT operation on unhooked IO port 0x%x - ignored\n", io_qual.port);
+    } else {  
+       if (hook->write(core, io_qual.port, &(core->vm_regs.rax), write_size, hook->priv_data) != write_size) {
+           PrintError("Write failure for out on port %x\n",io_qual.port);
+           return -1;
+       }
     }
 
-
-
     core->rip += exit_info->instr_len;
 
     return 0;
@@ -201,11 +211,6 @@ int v3_handle_vmx_io_outs(struct guest_info * core, struct vmx_exit_info * exit_
 
     hook = v3_get_io_hook(core->vm_info, io_qual.port);
 
-    if (hook == NULL) {
-        PrintError("Hook not present for OUTS on port 0x%x\n", io_qual.port);
-        return -1;
-    }
-
     PrintDebug("OUTS on port 0x%x\n", io_qual.port);
 
     write_size = io_qual.access_size + 1;
@@ -236,16 +241,22 @@ int v3_handle_vmx_io_outs(struct guest_info * core, struct vmx_exit_info * exit_
 
     PrintDebug("OUTS size=%d for %ld steps\n", write_size, rep_num);
 
-    if (guest_va_to_host_va(core, guest_va, &host_addr) == -1) {
+    if (v3_gva_to_hva(core, guest_va, &host_addr) == -1) {
         PrintError("Could not convert guest VA to host VA\n");
         return -1;
     }
 
     do {
-       if (hook->write(core, io_qual.port, (char *)host_addr, write_size, hook->priv_data) != write_size) {
-           PrintError("Read failure for INS on port 0x%x\n", io_qual.port);
-           return -1;
-       }
+
+       if (hook == NULL) {
+           PrintDebug("OUTS operation on unhooked IO port 0x%x - ignored\n", io_qual.port);
+       } else {
+           if (hook->write(core, io_qual.port, (char *)host_addr, write_size, hook->priv_data) != write_size) {
+               PrintError("Read failure for INS on port 0x%x\n", io_qual.port);
+               return -1;
+           }
+       }
+       
 
        host_addr += rsi_change;
        core->vm_regs.rsi += rsi_change;