added initial attempt at emulator

diff --git a/palacios/src/palacios/vmm_instr_emulator.c b/palacios/src/palacios/vmm_instr_emulator.c
new file mode 100644 (file)
index 0000000..f89d4e6
--- /dev/null
+++ b/palacios/src/palacios/vmm_instr_emulator.c
@@ -0,0 +1,101 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define addr_t unsigned long
+
+
+
+
+void test() {
+  int a = 10;
+  int b;
+
+  asm ("movl %1, %%eax\n\t"
+       "movl %%eax, %0\n\t"
+       :"=r"(b)        /* output */
+       :"r"(a)         /* input */
+       :"%eax"         /* clobbered register */
+       );       
+
+}
+
+void get_flags(addr_t * flags) {
+  addr_t tmp;
+  asm  ("pushfq\n\t"
+       "pop %0\n\t"
+       :"=r"(tmp)
+       : 
+       );
+
+  *flags = tmp;
+}
+
+void adc64(int * dst, int * src, addr_t * flags) {
+  int tmp_dst = *dst, tmp_src = *src;
+  addr_t tmp_flags = *flags;
+
+  char * inst = "adcl";
+
+  // Some of the flags values are not copied out in a pushf, we save them here
+  addr_t flags_rsvd = *flags & ~0xfffe7fff;
+
+  asm volatile (
+       "pushfq\r\n"
+       "push %3\r\n"
+       "popfq\r\n"
+       "adcl %2, %0\r\n"
+       "pushfq\r\n"
+       "pop %1\r\n"
+       "popfq\r\n"
+       : "=a"(tmp_dst),"=c"(tmp_flags)
+       : "b"(tmp_src),"c"(tmp_flags), "0"(tmp_dst)
+    );
+
+  *dst = tmp_dst;
+  *flags = tmp_flags;
+  *flags |= flags_rsvd;
+
+}
+
+
+void adc32(int * dst, int * src, addr_t * flags) {
+  int tmp_dst = *dst, tmp_src = *src;
+  addr_t tmp_flags = *flags;
+
+  
+  asm volatile (
+       "pushfd\r\n"
+       "push %3\r\n"
+       "popfd\r\n"
+       "adcl %2, %0\r\n"
+       "pushfd\r\n"
+       "pop %1\r\n"
+       "popfd\r\n"
+       : "=a"(tmp_dst),"=c"(tmp_flags)
+       : "b"(tmp_src),"c"(tmp_flags), "0"(tmp_dst)
+    );
+
+  *dst = tmp_dst;
+  *flags = tmp_flags;
+
+}
+
+
+int main(int argc, char ** argv) {
+  addr_t flags;
+  int dest = 4;
+  int src = 5;
+  
+  printf("sizeof ulong: %d\n", sizeof(unsigned long));
+
+  printf("Getting flags\n");
+  get_flags(&flags);
+  flags = flags | 0x1;
+
+  printf("Flags=0x%x\n", flags);
+  test();
+  printf("Adding\n");
+  adc64(&dest, &src, &flags);
+  printf("Result=%d\n", dest);
+
+}