On Sat, 24 May 2025 15:40:31 +0100
Richard Henderson <richard.hender...@linaro.org> wrote:
> When we moved TLB_MMIO and TLB_DISCARD_WRITE to TLB_SLOW_FLAGS_MASK,
> we failed to update atomic_mmu_lookup to properly reconstruct flags.
>
> Fixes: 24b5e0fdb543 ("include/exec: Move TLB_MMIO, TLB_DISCARD_WRITE to slow
> flags")
> Reported-by: Jonathan Cameron <jonathan.came...@huawei.com>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
I've run basic tests (the ones that were tripping over this 100% of the time)
and all looks good. Thanks! I'll run some more comprehensive testing this
afternoon
but looking good.
Tested-by: Jonathan Cameron <jonathan.came...@huawei.com>
Way outside my comfort zone so not appropriate for me to say more than
I tested it!
> ---
> accel/tcg/cputlb.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
> index 5f6d7c601c..86d0deb08c 100644
> --- a/accel/tcg/cputlb.c
> +++ b/accel/tcg/cputlb.c
> @@ -1871,8 +1871,12 @@ static void *atomic_mmu_lookup(CPUState *cpu, vaddr
> addr, MemOpIdx oi,
> goto stop_the_world;
> }
>
> - /* Collect tlb flags for read. */
> + /* Finish collecting tlb flags for both read and write. */
> + full = &cpu->neg.tlb.d[mmu_idx].fulltlb[index];
> tlb_addr |= tlbe->addr_read;
> + tlb_addr &= TLB_FLAGS_MASK & ~TLB_FORCE_SLOW;
> + tlb_addr |= full->slow_flags[MMU_DATA_STORE];
> + tlb_addr |= full->slow_flags[MMU_DATA_LOAD];
>
> /* Notice an IO access or a needs-MMU-lookup access */
> if (unlikely(tlb_addr & (TLB_MMIO | TLB_DISCARD_WRITE))) {
> @@ -1882,13 +1886,12 @@ static void *atomic_mmu_lookup(CPUState *cpu, vaddr
> addr, MemOpIdx oi,
> }
>
> hostaddr = (void *)((uintptr_t)addr + tlbe->addend);
> - full = &cpu->neg.tlb.d[mmu_idx].fulltlb[index];
>
> if (unlikely(tlb_addr & TLB_NOTDIRTY)) {
> notdirty_write(cpu, addr, size, full, retaddr);
> }
>
> - if (unlikely(tlb_addr & TLB_FORCE_SLOW)) {
> + if (unlikely(tlb_addr & TLB_WATCHPOINT)) {
> int wp_flags = 0;
>
> if (full->slow_flags[MMU_DATA_STORE] & TLB_WATCHPOINT) {
> @@ -1897,10 +1900,8 @@ static void *atomic_mmu_lookup(CPUState *cpu, vaddr
> addr, MemOpIdx oi,
> if (full->slow_flags[MMU_DATA_LOAD] & TLB_WATCHPOINT) {
> wp_flags |= BP_MEM_READ;
> }
> - if (wp_flags) {
> - cpu_check_watchpoint(cpu, addr, size,
> - full->attrs, wp_flags, retaddr);
> - }
> + cpu_check_watchpoint(cpu, addr, size,
> + full->attrs, wp_flags, retaddr);
> }
>
> return hostaddr;
