On 10/28/21 4:48 AM, Pavel Dovgalyuk wrote:
+ if (cpu->cflags_next_tb == -1
+ && (!use_icount || !(tb->cflags & CF_USE_ICOUNT)
+ || cpu_neg(cpu)->icount_decr.u16.low >= tb->icount)) {
+ /*
+ * icount is disabled or there are enough instructions
+ * in the budget, do not retranslate this block with
+ * different parameters.
+ */
+ cpu->cflags_next_tb = tb->cflags;
+ }
I can't see that this will work.
We've been asked to exit to the main loop; probably for an interrupt. The next thing
that's likely to happen is that cpu_cc->do_interrupt will adjust cpu state to continue in
the guest interrupt handler. The cflags_next_tb flag that you're setting up is not
relevant to that context.
This seems related to Phil's reported problem
https://gitlab.com/qemu-project/qemu/-/issues/245
in which an interrupt arrives before we finish processing the watchpoint.
I *think* we need to make cflags_next_tb != -1 be treated like any other interrupt disable
bit, and delay delivery of the interrupt. Which also means that we should not check for
exit_tb at the beginning of any TB we generate for the watchpoint step.
I simply haven't taken the time to investigate this properly.
r~
