cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

gen-icount.h (2534B)

      1#ifndef GEN_ICOUNT_H
      2#define GEN_ICOUNT_H
      3
      4#include "exec/exec-all.h"
      5#include "qemu/timer.h"
      6
      7/* Helpers for instruction counting code generation.  */
      8
      9static TCGOp *icount_start_insn;
     10
     11static inline void gen_io_start(void)
     12{
     13    TCGv_i32 tmp = tcg_const_i32(1);
     14    tcg_gen_st_i32(tmp, cpu_env,
     15                   offsetof(ArchCPU, parent_obj.can_do_io) -
     16                   offsetof(ArchCPU, env));
     17    tcg_temp_free_i32(tmp);
     18}
     19
     20static inline void gen_tb_start(const TranslationBlock *tb)
     21{
     22    TCGv_i32 count;
     23
     24    tcg_ctx->exitreq_label = gen_new_label();
     25    if (tb_cflags(tb) & CF_USE_ICOUNT) {
     26        count = tcg_temp_local_new_i32();
     27    } else {
     28        count = tcg_temp_new_i32();
     29    }
     30
     31    tcg_gen_ld_i32(count, cpu_env,
     32                   offsetof(ArchCPU, neg.icount_decr.u32) -
     33                   offsetof(ArchCPU, env));
     34
     35    if (tb_cflags(tb) & CF_USE_ICOUNT) {
     36        /*
     37         * We emit a sub with a dummy immediate argument. Keep the insn index
     38         * of the sub so that we later (when we know the actual insn count)
     39         * can update the argument with the actual insn count.
     40         */
     41        tcg_gen_sub_i32(count, count, tcg_constant_i32(0));
     42        icount_start_insn = tcg_last_op();
     43    }
     44
     45    tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, tcg_ctx->exitreq_label);
     46
     47    if (tb_cflags(tb) & CF_USE_ICOUNT) {
     48        tcg_gen_st16_i32(count, cpu_env,
     49                         offsetof(ArchCPU, neg.icount_decr.u16.low) -
     50                         offsetof(ArchCPU, env));
     51        /*
     52         * cpu->can_do_io is cleared automatically here at the beginning of
     53         * each translation block.  The cost is minimal and only paid for
     54         * -icount, plus it would be very easy to forget doing it in the
     55         * translator. Doing it here means we don't need a gen_io_end() to
     56         * go with gen_io_start().
     57         */
     58        tcg_gen_st_i32(tcg_constant_i32(0), cpu_env,
     59                       offsetof(ArchCPU, parent_obj.can_do_io) -
     60                       offsetof(ArchCPU, env));
     61    }
     62
     63    tcg_temp_free_i32(count);
     64}
     65
     66static inline void gen_tb_end(const TranslationBlock *tb, int num_insns)
     67{
     68    if (tb_cflags(tb) & CF_USE_ICOUNT) {
     69        /*
     70         * Update the num_insn immediate parameter now that we know
     71         * the actual insn count.
     72         */
     73        tcg_set_insn_param(icount_start_insn, 2,
     74                           tcgv_i32_arg(tcg_constant_i32(num_insns)));
     75    }
     76
     77    gen_set_label(tcg_ctx->exitreq_label);
     78    tcg_gen_exit_tb(tb, TB_EXIT_REQUESTED);
     79}
     80
     81#endif