[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 30/38] ivshmem: Simplify memory regions for BAR
From: |
Markus Armbruster |
Subject: |
Re: [Qemu-devel] [PATCH 30/38] ivshmem: Simplify memory regions for BAR 2 (shared memory) |
Date: |
Wed, 02 Mar 2016 12:06:03 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) |
Paolo Bonzini <address@hidden> writes:
> On 01/03/2016 15:06, Markus Armbruster wrote:
>> Paolo Bonzini <address@hidden> writes:
>>
>>> On 29/02/2016 19:40, Markus Armbruster wrote:
>>>> - memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s),
>>>> + s->ivshmem_bar2 = g_new(MemoryRegion, 1);
>>>> + memory_region_init_ram_ptr(s->ivshmem_bar2, OBJECT(s),
>>>> "ivshmem.bar2", s->ivshmem_size, ptr);
>>>> - qemu_set_ram_fd(s->ivshmem.ram_addr, fd);
>>>> - vmstate_register_ram(&s->ivshmem, DEVICE(s));
>>>> - memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
>>>> + qemu_set_ram_fd(s->ivshmem_bar2->ram_addr, fd);
>>>
>>> This is missing an instance_finalize callback to do
>>>
>>> if (s->ivshmem_bar2) {
>>> object_unparent(s->ivshmem_bar2);
>>> g_free(s->ivshmem_bar2);
>>> }
>>
>> Since it's allocated within ivshmem_realize(), I guess I could free it
>> in ivshmem_exit().
>
> Unfortunately you can't, because the guest might be using it at the time
> of hot-unplug (e.g. DMAing from disk to it). Unrealize is the place
> where you hide stuff, and in this case the PCI core does it for you;
> finalize is the place where you free stuff.
>
> This is mentioned (though not really in these terms) in docs/memory.txt.
You mean I'm supposed to have read and understood that?!? ;-}
Thanks!
[...]