Messages in this thread Patch in this message | | | Date | Tue, 09 Mar 2010 00:50:26 +0300 | From | Michael Tokarev <> | Subject | Re: aio: compat_ioctl issue? |
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Jeff Moyer wrote: > Michael Tokarev <mjt@tls.msk.ru> writes: > >> Hello. >> >> I just come across a situation (next in a long row :) >> when on x86, 32bit userspace does not work with 64bit >> kernel. This time this is about aio requests. >> >> An application submits some aio job, and it is returned >> immediately (from io_getevents()) with EINVAL error. [] > Can you post the program, please?
The program which I'm trying is quite big - it's qemu-kvm v. 0.12.3 compiled with --enable-linux-aio. I bugged kvm folks about non-working aio support but immediately realized it's 32/64bit issue in the kernel, since 64bit kvm works just fine on the same kernel (which is 64bits). So I added 2 printfs into its linux-aio.c and re-run it.
The diff against upstream qemu-kvm is this one:
---- cut ----- diff --git a/linux-aio.c b/linux-aio.c index 5e892b0..e856873 100644 --- a/linux-aio.c +++ b/linux-aio.c @@ -60,6 +60,9 @@ static void qemu_laio_process_completion(struct qemu_laio_state *s,
ret = laiocb->ret; if (ret != -ECANCELED) { +if (ret != laiocb->nbytes) +fprintf(stderr, "io_getevents: exp %d got %d %s\n", laiocb->nbytes, ret, +strerror(ret)); if (ret == laiocb->nbytes) ret = 0; else if (ret >= 0) @@ -223,6 +226,12 @@ BlockDriverAIOCB *laio_submit(BlockDriverState *bs, void *aio_ctx, int fd, io_set_eventfd(&laiocb->iocb, s->efd); s->count++;
+{ struct iovec *v = (struct iovec*)iocbs->u.c.buf; +printf("io_submit: lio_opcode=%d reqprio=%d iov=%p{%p,%d}, niov=%lu, offset=%Ld\n", +iocbs->aio_lio_opcode, iocbs->aio_reqprio, iocbs->u.c.buf, +v->iov_base, v->iov_len, +iocbs->u.c.nbytes, iocbs->u.c.offset); +} if (io_submit(s->ctx, 1, &iocbs) < 0) goto out_dec_count; return &laiocb->common; ---- cut ----- I'm not sure if it's useful or not.
Qemu-kvm git tree is at git://git.kernel.org/pub/scm/virt/kvm/qemu-kvm.git
I never dealt with aio before, so I'll need to familiarize myself with it before trying to create a smaller testcase.
Thanks!
/mjt
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