x86: Add support for m5ops through a memory mapped interface

In order to support m5ops in virtualized environments, we need to use
a memory mapped interface. This changeset adds support for that by
reserving 0xFFFF0000-0xFFFFFFFF and mapping those to the generic IPR
interface for m5ops. The mapping is done in the
X86ISA::TLB::finalizePhysical() which means that it just works for all
of the CPU models, including virtualized ones.

1 files changed, 27 insertions, 0 deletions

diff --git a/util/m5/m5.c b/util/m5/m5.c
index 021816ce3..1ddaaf66d 100644
--- a/util/m5/m5.c
+++ b/util/m5/m5.c
@@ -51,10 +51,15 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <unistd.h>
 
 #include "m5op.h"
 
+void *m5_mem = NULL;
+
 char *progname;
 char *command = "unspecified";
 void usage();
@@ -315,6 +320,26 @@ usage()
     exit(1);
 }
 
+static void
+map_m5_mem()
+{
+#ifdef M5OP_ADDR
+    int fd;
+
+    fd = open("/dev/mem", O_RDWR | O_SYNC);
+    if (fd == -1) {
+        perror("Can't open /dev/mem");
+        exit(1);
+    }
+
+    m5_mem = mmap(NULL, 0x10000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, M5OP_ADDR);
+    if (!m5_mem) {
+        perror("Can't mmap /dev/mem");
+        exit(1);
+    }
+#endif
+}
+
 int
 main(int argc, char *argv[])
 {
@@ -322,6 +347,8 @@ main(int argc, char *argv[])
     if (argc < 2)
         usage(1);
 
+    map_m5_mem();
+
     command = argv[1];
 
     argv += 2;