221f715d90
Okay, I started looking into how to handle scsi-generic I/O in the new world order. I think the best is to use the SG_IO ioctl instead of the read/write interface as that allows us to support scsi passthrough on disk/cdrom devices, too. See Hannes patch on the kvm list from August for an example. Now that we always do ioctls we don't need another abstraction than bdrv_ioctl for the synchronous requests for now, and for asynchronous requests I've added a aio_ioctl abstraction keeping it simple. Long-term we might want to move the ops to a higher-level abstraction and let the low-level code fill out the request header, but I'm lazy enough to leave that to the people trying to support scsi-passthrough on a non-Linux OS. Tested lightly by issuing various sg_ commands from sg3-utils in a guest to a host CDROM device. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6895 c046a42c-6fe2-441c-8c8c-71466251a162
62 lines
1.4 KiB
C
62 lines
1.4 KiB
C
/*
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* QEMU posix-aio emulation
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*
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* Copyright IBM, Corp. 2008
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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*/
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#ifndef QEMU_POSIX_AIO_COMPAT_H
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#define QEMU_POSIX_AIO_COMPAT_H
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#include <sys/types.h>
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#include <unistd.h>
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#include <signal.h>
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#include "sys-queue.h"
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#define QEMU_PAIO_CANCELED 0x01
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#define QEMU_PAIO_NOTCANCELED 0x02
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#define QEMU_PAIO_ALLDONE 0x03
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struct qemu_paiocb
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{
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int aio_fildes;
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void *aio_buf;
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size_t aio_nbytes;
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#define aio_ioctl_cmd aio_nbytes /* for QEMU_PAIO_IOCTL */
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int ev_signo;
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off_t aio_offset;
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/* private */
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TAILQ_ENTRY(qemu_paiocb) node;
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int aio_type;
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#define QEMU_PAIO_READ 0x01
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#define QEMU_PAIO_WRITE 0x02
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#define QEMU_PAIO_IOCTL 0x03
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ssize_t ret;
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int active;
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};
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struct qemu_paioinit
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{
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unsigned int aio_threads;
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unsigned int aio_num;
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unsigned int aio_idle_time;
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};
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int qemu_paio_init(struct qemu_paioinit *aioinit);
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int qemu_paio_read(struct qemu_paiocb *aiocb);
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int qemu_paio_write(struct qemu_paiocb *aiocb);
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int qemu_paio_ioctl(struct qemu_paiocb *aiocb);
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int qemu_paio_error(struct qemu_paiocb *aiocb);
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ssize_t qemu_paio_return(struct qemu_paiocb *aiocb);
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int qemu_paio_cancel(int fd, struct qemu_paiocb *aiocb);
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#endif
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