diff options
Diffstat (limited to 'gitlab/issues_text/target_missing/host_missing/accel_TCG/2683')
| -rw-r--r-- | gitlab/issues_text/target_missing/host_missing/accel_TCG/2683 | 39 |
1 files changed, 0 insertions, 39 deletions
diff --git a/gitlab/issues_text/target_missing/host_missing/accel_TCG/2683 b/gitlab/issues_text/target_missing/host_missing/accel_TCG/2683 deleted file mode 100644 index 105ef56a2..000000000 --- a/gitlab/issues_text/target_missing/host_missing/accel_TCG/2683 +++ /dev/null @@ -1,39 +0,0 @@ -TCG: probe_access() has inconsistent behavior -Description of problem: -In full-system mode, probe_access() will return NULL when the flag is TLB_MMIO. - -accel/tcg/cputlb.c: probe_access_internal() -``` - if (unlikely(flags & ~(TLB_WATCHPOINT | TLB_NOTDIRTY | TLB_CHECK_ALIGNED)) - || (access_type != MMU_INST_FETCH && force_mmio)) { - *phost = NULL; - return TLB_MMIO; - } -``` -But in linux-user mode, it will return correct address when the flag is TLB_MMIO. - -accel/tcg/user-exec.c: probe_access() -``` - return size ? g2h(env_cpu(env), addr) : NULL; -``` -This will lead to some different behaviors, like cbo.zero in RISC-V. - -target/riscv/op_helper.c: helper_cbo_zero() -``` - mem = probe_write(env, address, cbozlen, mmu_idx, ra); - - if (likely(mem)) { - memset(mem, 0, cbozlen); - } else { - for (int i = 0; i < cbozlen; i++) { - cpu_stb_mmuidx_ra(env, address + i, 0, mmu_idx, ra); - } - } -``` -When the current instruction has memory callback by plugin: - -Full-system mode uses slow-path(cpu_stb_mmuidx_ra) and inject mem_cbs correctly. - -Linux-user mode uses fast-path(memset) and doesn't inject callbacks. - -To ensure consistent results, probe_access() should return NULL when the flag is TLB_MMIO in linux-user mode. |