diff options
Diffstat (limited to 'accel')
| -rw-r--r-- | accel/tcg/cpu-exec.c | 15 | ||||
| -rw-r--r-- | accel/tcg/internal-target.h | 1 | ||||
| -rw-r--r-- | accel/tcg/translate-all.c | 27 |
3 files changed, 33 insertions, 10 deletions
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index d48b82a932..8b773d8847 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -249,7 +249,20 @@ static TranslationBlock *tb_htable_lookup(CPUState *cpu, vaddr pc, return qht_lookup_custom(&tb_ctx.htable, &desc, h, tb_lookup_cmp); } -/* Might cause an exception, so have a longjmp destination ready */ +/** + * tb_lookup: + * @cpu: CPU that will execute the returned translation block + * @pc: guest PC + * @cs_base: arch-specific value associated with translation block + * @flags: arch-specific translation block flags + * @cflags: CF_* flags + * + * Look up a translation block inside the QHT using @pc, @cs_base, @flags and + * @cflags. Uses @cpu's tb_jmp_cache. Might cause an exception, so have a + * longjmp destination ready. + * + * Returns: an existing translation block or NULL. + */ static inline TranslationBlock *tb_lookup(CPUState *cpu, vaddr pc, uint64_t cs_base, uint32_t flags, uint32_t cflags) diff --git a/accel/tcg/internal-target.h b/accel/tcg/internal-target.h index a664be02cc..2cdf11c905 100644 --- a/accel/tcg/internal-target.h +++ b/accel/tcg/internal-target.h @@ -12,6 +12,7 @@ #include "exec/exec-all.h" #include "exec/translation-block.h" #include "tb-internal.h" +#include "tcg-target-mo.h" /* * Access to the various translations structures need to be serialised diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index d56ca13cdd..d4189c7386 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -532,9 +532,25 @@ TranslationBlock *tb_gen_code(CPUState *cpu, } /* + * Insert TB into the corresponding region tree before publishing it + * through QHT. Otherwise rewinding happened in the TB might fail to + * lookup itself using host PC. + */ + tcg_tb_insert(tb); + + /* * If the TB is not associated with a physical RAM page then it must be - * a temporary one-insn TB, and we have nothing left to do. Return early - * before attempting to link to other TBs or add to the lookup table. + * a temporary one-insn TB. + * + * Such TBs must be added to region trees in order to make sure that + * restore_state_to_opc() - which on some architectures is not limited to + * rewinding, but also affects exception handling! - is called when such a + * TB causes an exception. + * + * At the same time, temporary one-insn TBs must be executed at most once, + * because subsequent reads from, e.g., I/O memory may return different + * values. So return early before attempting to link to other TBs or add + * to the QHT. */ if (tb_page_addr0(tb) == -1) { assert_no_pages_locked(); @@ -542,13 +558,6 @@ TranslationBlock *tb_gen_code(CPUState *cpu, } /* - * Insert TB into the corresponding region tree before publishing it - * through QHT. Otherwise rewinding happened in the TB might fail to - * lookup itself using host PC. - */ - tcg_tb_insert(tb); - - /* * No explicit memory barrier is required -- tb_link_page() makes the * TB visible in a consistent state. */ |