Commit b4ac20b4 authored by Pavel Dovgalyuk's avatar Pavel Dovgalyuk Committed by Paolo Bonzini
Browse files

cpu-exec: fix cpu_exec_nocache 



In icount mode cpu_exec_nocache function is used to execute part of the
existing TB. At the end of cpu_exec_nocache newly created TB is deleted.
Sometimes io_read function needs to recompile current TB and restart TB
lookup and execution. After that tb_find_fast function finds old (bigger)
TB again. This TB cannot be executed (because icount is not big enough)
and cpu_exec_nocache is called again. Such a loop continues over and over.
This patch deletes old TB and avoids finding it in the TB cache.

Signed-off-by: default avatarPavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f8e1f533

cpu-exec.c

+6 −1
Original line number Diff line number Diff line
@@ -202,13 +202,18 @@ static void cpu_exec_nocache(CPUArchState *env, int max_cycles, 
{

    CPUState *cpu = ENV_GET_CPU(env);

    TranslationBlock *tb;

    target_ulong pc = orig_tb->pc;

    target_ulong cs_base = orig_tb->cs_base;

    uint64_t flags = orig_tb->flags;



    /* Should never happen.

       We only end up here when an existing TB is too long.  */

    if (max_cycles > CF_COUNT_MASK)

        max_cycles = CF_COUNT_MASK;



    tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base, orig_tb->flags,

    /* tb_gen_code can flush our orig_tb, invalidate it now */

    tb_phys_invalidate(orig_tb, -1);

    tb = tb_gen_code(cpu, pc, cs_base, flags,

                     max_cycles);

    cpu->current_tb = tb;

    /* execute the generated code */