[Qemu-devel] address translation

[Shashidhar Mysore]

Hello group,

I have two questions, both regarding the virtual-physical translation of
addresses (all in the virtual machine context).

1>
Can somebody tell me if the program counter value available in the following
snippet from target-i386/translate.c
is virtual or physical? I learnt it may be virtual, in which case is there a
way to extract the physical address corresponding to the
virtual address, or if it is physical, then is there a way to translate to
its virtual address (within the virtual machine context)?

************************************************
/* convert one instruction. s->is_jmp is set if the translation must
  be stopped. Return the next pc value */
static target_ulong disas_insn(DisasContext *s, target_ulong pc_start)
{
   int b, prefixes, aflag, dflag;
   int shift, ot;
   int modrm, reg, rm, mod, reg_addr, op, opreg, offset_addr, val;
   target_ulong next_eip, tval;
   int rex_w, rex_r;

   s->pc = pc_start;   // This s->pc is what I am using to extract all
executed PC values
************************************************


2>
Second question I have is - Within the functions from target-i386/ops_mem.h
for example,

void OPPROTO glue(glue(op_ldub, MEMSUFFIX), _T0_A0)(void)
{
   T0 = glue(ldub, MEMSUFFIX)(A0);
}

Is A0 the physical address? or is it virtual?
And how to I translate from one to another in either case?


Thanks in advance.
-Shashi.