Commit a5e99826 authored by KONRAD Frederic's avatar KONRAD Frederic Committed by Paolo Bonzini
Browse files

tcg: protect translation related stuff with tb_lock. 



This protects all translation related work with tb_lock() too ensure
thread safety. This effectively serialises all code generation. In
addition to the code generation we also take the lock for TB
invalidation. This has a knock on effect of meaning tb_lock() is held
for modification of the SoftMMU TLB by non-self threads which will be
used in later patches.

Signed-off-by: default avatarKONRAD Frederic <fred.konrad@greensocs.com>
Message-Id: <1439220437-23957-8-git-send-email-fred.konrad@greensocs.com>
Signed-off-by: default avatarEmilio G. Cota <cota@braap.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
[AJB: moved into tree, clean-up history]
Signed-off-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: default avatarRichard Henderson <rth@twiddle.net>
Message-Id: <20161027151030.20863-10-alex.bennee@linaro.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e505a063

cpu-exec.c

+6 −0
Original line number Diff line number Diff line
@@ -211,15 +211,21 @@ static void cpu_exec_nocache(CPUState *cpu, int max_cycles, 
    if (max_cycles > CF_COUNT_MASK)

        max_cycles = CF_COUNT_MASK;



    tb_lock();

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

                     max_cycles | CF_NOCACHE

                         | (ignore_icount ? CF_IGNORE_ICOUNT : 0));

    tb->orig_tb = orig_tb;

    tb_unlock();



    /* execute the generated code */

    trace_exec_tb_nocache(tb, tb->pc);

    cpu_tb_exec(cpu, tb);



    tb_lock();

    tb_phys_invalidate(tb, -1);

    tb_free(tb);

    tb_unlock();

}

#endif

exec.c

+6 −0
Original line number Diff line number Diff line
@@ -2064,6 +2064,12 @@ static void check_watchpoint(int offset, int len, MemTxAttrs attrs, int flags) 
                    continue;

                }

                cpu->watchpoint_hit = wp;



                /* The tb_lock will be reset when cpu_loop_exit or

                 * cpu_loop_exit_noexc longjmp back into the cpu_exec

                 * main loop.

                 */

                tb_lock();

                tb_check_watchpoint(cpu);

                if (wp->flags & BP_STOP_BEFORE_ACCESS) {

                    cpu->exception_index = EXCP_DEBUG;

hw/i386/kvmvapic.c

+4 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include "sysemu/kvm.h"

#include "hw/i386/apic_internal.h"

#include "hw/sysbus.h"

#include "tcg/tcg.h"



#define VAPIC_IO_PORT           0x7e
@@ -449,6 +450,9 @@ static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip) 
    resume_all_vcpus();



    if (!kvm_enabled()) {

        /* tb_lock will be reset when cpu_loop_exit_noexc longjmps

         * back into the cpu_exec loop. */

        tb_lock();

        tb_gen_code(cs, current_pc, current_cs_base, current_flags, 1);

        cpu_loop_exit_noexc(cs);

    }

translate-all.c

+28 −6
Original line number Diff line number Diff line
@@ -363,7 +363,9 @@ static int cpu_restore_state_from_tb(CPUState *cpu, TranslationBlock *tb, 
bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr)

{

    TranslationBlock *tb;

    bool r = false;



    tb_lock();

    tb = tb_find_pc(retaddr);

    if (tb) {

        cpu_restore_state_from_tb(cpu, tb, retaddr);
@@ -372,9 +374,11 @@ bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr) 
            tb_phys_invalidate(tb, -1);

            tb_free(tb);

        }

        return true;

        r = true;

    }

    return false;

    tb_unlock();



    return r;

}



void page_size_init(void)
@@ -1456,6 +1460,7 @@ void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end, 
    /* we remove all the TBs in the range [start, end[ */

    /* XXX: see if in some cases it could be faster to invalidate all

       the code */

    tb_lock();

    tb = p->first_tb;

    while (tb != NULL) {

        n = (uintptr_t)tb & 3;
@@ -1515,6 +1520,7 @@ void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end, 
        cpu_loop_exit_noexc(cpu);

    }

#endif

    tb_unlock();

}



#ifdef CONFIG_SOFTMMU
@@ -1584,6 +1590,8 @@ static bool tb_invalidate_phys_page(tb_page_addr_t addr, uintptr_t pc) 
    if (!p) {

        return false;

    }



    tb_lock();

    tb = p->first_tb;

#ifdef TARGET_HAS_PRECISE_SMC

    if (tb && pc != 0) {
@@ -1621,9 +1629,13 @@ static bool tb_invalidate_phys_page(tb_page_addr_t addr, uintptr_t pc) 
           modifying the memory. It will ensure that it cannot modify

           itself */

        tb_gen_code(cpu, current_pc, current_cs_base, current_flags, 1);

        /* tb_lock will be reset after cpu_loop_exit_noexc longjmps

         * back into the cpu_exec loop. */

        return true;

    }

#endif

    tb_unlock();



    return false;

}

#endif
@@ -1718,6 +1730,7 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr) 
    target_ulong pc, cs_base;

    uint32_t flags;



    tb_lock();

    tb = tb_find_pc(retaddr);

    if (!tb) {

        cpu_abort(cpu, "cpu_io_recompile: could not find TB for pc=%p",
@@ -1769,11 +1782,16 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr) 
    /* FIXME: In theory this could raise an exception.  In practice

       we have already translated the block once so it's probably ok.  */

    tb_gen_code(cpu, pc, cs_base, flags, cflags);



    /* TODO: If env->pc != tb->pc (i.e. the faulting instruction was not

       the first in the TB) then we end up generating a whole new TB and

       repeating the fault, which is horribly inefficient.

       Better would be to execute just this insn uncached, or generate a

       second new TB.  */

     * the first in the TB) then we end up generating a whole new TB and

     *  repeating the fault, which is horribly inefficient.

     *  Better would be to execute just this insn uncached, or generate a

     *  second new TB.

     *

     * cpu_loop_exit_noexc will longjmp back to cpu_exec where the

     * tb_lock gets reset.

     */

    cpu_loop_exit_noexc(cpu);

}
@@ -1837,6 +1855,8 @@ void dump_exec_info(FILE *f, fprintf_function cpu_fprintf) 
    TranslationBlock *tb;

    struct qht_stats hst;



    tb_lock();



    target_code_size = 0;

    max_target_code_size = 0;

    cross_page = 0;
@@ -1898,6 +1918,8 @@ void dump_exec_info(FILE *f, fprintf_function cpu_fprintf) 
            tcg_ctx.tb_ctx.tb_phys_invalidate_count);

    cpu_fprintf(f, "TLB flush count     %d\n", tlb_flush_count);

    tcg_dump_info(f, cpu_fprintf);



    tb_unlock();

}



void dump_opcount_info(FILE *f, fprintf_function cpu_fprintf)