Re: [Qemu-devel] [PATCH v5 3/4] Plumb the HAXM-based hardware acceleration support

[Paolo Bonzini <pbonzini@redhat.com>]

On 19/12/2016 17:24, Vincent Palatin wrote:
>  #else /* _WIN32 */
> -    abort();
> +    if (!qemu_cpu_is_self(cpu)) {
> +        CONTEXT context;
> +        if (SuspendThread(cpu->hThread) == (DWORD)(-1)) {
> +            fprintf(stderr, "qemu:%s: GetLastError:%lu\n", __func__,
> +                    GetLastError());
> +            exit(1);
> +        }
> +
> +        /* On multi-core systems, we are not sure that the thread is actually
> +         * suspended until we can get the context.
> +         */
> +        context.ContextFlags = CONTEXT_CONTROL;
> +        while (GetThreadContext(cpu->hThread, &context) != 0) {
> +            continue;
> +        }
> +
> +        if (hax_enabled()) {
> +            cpu->exit_request = 1;
> +        }

As mentioned in the reply to patch 4, please leave the cpu->exit_request
= 1 assignment to the caller.

Apart from the above change, can you check if there are some less
heavyeight methods to force an exit?  I can think of QueueUserAPC with
an empty pfnAPC here, and SleepEx(0, TRUE) in qemu_hax_cpu_thread_fn
before qemu_wait_io_event_common.

> +        if (ResumeThread(cpu->hThread) == (DWORD)(-1)) {
> +            fprintf(stderr, "qemu:%s: GetLastError:%lu\n", __func__,
> +                    GetLastError());
> +            exit(1);
> +        }
> +    }

[...]

> 
> +            /*
> +             * In Hax, the qemu allocate the virtual address, and HAX kernel
> +             * populate the memory with physical memory. Currently we have no
> +             * paging, so user should make sure enough free memory in advance
> +             */
> +            if (hax_enabled()) {
> +                int ret;
> +                ret = hax_populate_ram((uint64_t)(uintptr_t)new_block->host,
> +                                       new_block->max_length);
> +                if (ret < 0) {
> +                    error_setg(errp, "Hax failed to populate ram");
> +                    return;
> +                }
> +            }
> +

Can you check if the interface at
http://marc.info/?l=qemu-devel&m=148225154320642&q=raw would be good for
your purposes, and if so include that patch in your v6?

Otherwise looks great, so I'm confident we can add this in QEMU 2.9.

Paolo