freebsd-dev/sys/dev/virtio/virtio_ring.h

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Catch up with Bryan Venteicher's virtio Hg repo: c162516 Remove vtblk_sector_size c162515 Wrap long license lines c162514 Remove vtblk_unit c162513 Wrap long lines in the license. c162512 Remove verbose messages when link goes up/down. A similar message is printed elsewhere as a result of if_link_state_change(). c162511 Explicity compare pointer to NULL c162510 Allocate the mac filter table at attach time. c162509 Add real BSD licenses to the header files copied from Linux. The chases upstream changes made in Linux awhile ago. c162508 Only notify if we actually dequeued something. c162507 Change a couple of if () { KASSERT(...) } to just KASSERTs. In non-debug kernels, the if() { } probably get optomized away, but I guess this is clearer. c162506 Remove VIRTIO_BLK_F_TOPOLOGY fields in the config. TOPOLOGY has since been removed from the spec, and the FreeBSD didn't really do anything with the fields anyways. c162505 Move vtblk_enqueue_request() outside the locks when getting the ident. c162504 Remove soon to be uneeded trylock during dump [1]. http://lists.freebsd.org/pipermail/freebsd-current/2011-November/029226.html c162503 Remove emtpy line c162502 Drop frame if cannot allocate a vtnet_tx_header. If we don't, we set OACTIVE, but if there are no other frames in flight, vtnet_txeof() will never be called to unset OACTIVE. The interface would have to be down/up'ed in order to become usable. We could be cuter here and only do this if the virtqueue is emtpy, but its probably not worth the complication. c162501 Start mbuf replacement loop at 1 for clarity Obtained from: Bryan Venteicher bryanv at daemoninthecloset dot org
2011-12-06 06:28:32 +00:00
/*-
* Copyright Rusty Russell IBM Corporation 2007.
Catch up with Bryan Venteicher's virtio Hg repo: c162516 Remove vtblk_sector_size c162515 Wrap long license lines c162514 Remove vtblk_unit c162513 Wrap long lines in the license. c162512 Remove verbose messages when link goes up/down. A similar message is printed elsewhere as a result of if_link_state_change(). c162511 Explicity compare pointer to NULL c162510 Allocate the mac filter table at attach time. c162509 Add real BSD licenses to the header files copied from Linux. The chases upstream changes made in Linux awhile ago. c162508 Only notify if we actually dequeued something. c162507 Change a couple of if () { KASSERT(...) } to just KASSERTs. In non-debug kernels, the if() { } probably get optomized away, but I guess this is clearer. c162506 Remove VIRTIO_BLK_F_TOPOLOGY fields in the config. TOPOLOGY has since been removed from the spec, and the FreeBSD didn't really do anything with the fields anyways. c162505 Move vtblk_enqueue_request() outside the locks when getting the ident. c162504 Remove soon to be uneeded trylock during dump [1]. http://lists.freebsd.org/pipermail/freebsd-current/2011-November/029226.html c162503 Remove emtpy line c162502 Drop frame if cannot allocate a vtnet_tx_header. If we don't, we set OACTIVE, but if there are no other frames in flight, vtnet_txeof() will never be called to unset OACTIVE. The interface would have to be down/up'ed in order to become usable. We could be cuter here and only do this if the virtqueue is emtpy, but its probably not worth the complication. c162501 Start mbuf replacement loop at 1 for clarity Obtained from: Bryan Venteicher bryanv at daemoninthecloset dot org
2011-12-06 06:28:32 +00:00
*
* This header is BSD licensed so anyone can use the definitions to implement
* compatible drivers/servers.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of IBM nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef VIRTIO_RING_H
#define VIRTIO_RING_H
/* This marks a buffer as continuing via the next field. */
#define VRING_DESC_F_NEXT 1
/* This marks a buffer as write-only (otherwise read-only). */
#define VRING_DESC_F_WRITE 2
/* This means the buffer contains a list of buffer descriptors. */
#define VRING_DESC_F_INDIRECT 4
/* The Host uses this in used->flags to advise the Guest: don't kick me
* when you add a buffer. It's unreliable, so it's simply an
* optimization. Guest will still kick if it's out of buffers. */
#define VRING_USED_F_NO_NOTIFY 1
/* The Guest uses this in avail->flags to advise the Host: don't
* interrupt me when you consume a buffer. It's unreliable, so it's
* simply an optimization. */
#define VRING_AVAIL_F_NO_INTERRUPT 1
/* VirtIO ring descriptors: 16 bytes.
* These can chain together via "next". */
struct vring_desc {
/* Address (guest-physical). */
uint64_t addr;
/* Length. */
uint32_t len;
/* The flags as indicated above. */
uint16_t flags;
/* We chain unused descriptors via this, too. */
uint16_t next;
};
struct vring_avail {
uint16_t flags;
uint16_t idx;
uint16_t ring[0];
};
/* uint32_t is used here for ids for padding reasons. */
struct vring_used_elem {
/* Index of start of used descriptor chain. */
uint32_t id;
/* Total length of the descriptor chain which was written to. */
uint32_t len;
};
struct vring_used {
uint16_t flags;
uint16_t idx;
struct vring_used_elem ring[0];
};
struct vring {
unsigned int num;
struct vring_desc *desc;
struct vring_avail *avail;
struct vring_used *used;
};
/* The standard layout for the ring is a continuous chunk of memory which
* looks like this. We assume num is a power of 2.
*
* struct vring {
* // The actual descriptors (16 bytes each)
* struct vring_desc desc[num];
*
* // A ring of available descriptor heads with free-running index.
* __u16 avail_flags;
* __u16 avail_idx;
* __u16 available[num];
Catch up with Bryan Venteicher's virtio git repo: a8af6270bd96be6ccd86f70b60fa6512b710e4f0 virtio_blk: Include function name in panic string cbdb03a694b76c5253d7ae3a59b9995b9afbb67a virtio_balloon: Do the notify outside of the lock By the time we return from virtqueue_notify(), the descriptor will be in the used ring so we shouldn't have to sleep. 10ba392e60692529a5cbc1e9987e4064e0128447 virtio: Use DEVMETHOD_END 80cbcc4d6552cac758be67f0c99c36f23ce62110 virtqueue: Add support for VIRTIO_F_RING_EVENT_IDX This can be used to reduce the number of guest/host and host/guest interrupts by delaying the interrupt until a certain index value is reached. Actual use by the network driver will come along later. 8fc465969acc0c58477153e4c3530390db436c02 virtqueue: Simplify virtqueue_nused() Since the values just wrap naturally at UINT16_MAX, we can just subtract the two values directly, rather than doing 2's complement math. a8aa22f25959e2767d006cd621b69050e7ffb0ae virtio_blk: Remove debugging crud from 75dd732a There seems to be an issue with Qemu (or FreeBSD VirtIO) that sets the PCI register space for the device config to bogus values. This only seems to happen after unloading and reloading the module. d404800661cb2a9769c033f8a50b2133934501aa virtio_blk: Use better variable name 75dd732a97743d96e7c63f7ced3c2169696dadd3 virtio_blk: Partially revert 92ba40e65 Just use the virtqueue to determine if any requests are still inflight. 06661ed66b7a9efaea240f99f414c368f1bbcdc7 virtio_blk: error if allowed too few segments Should never happen unless the host provides use with a bogus seg_max value. 4b33e5085bc87a818433d7e664a0a2c8f56a1a89 virtio_blk: Sort function declarations 426b9f5cac892c9c64cc7631966461514f7e08c6 virtio_blk: Cleanup whitespace 617c23e12c61e3c2233d942db713c6b8ff0bd112 virtio_blk: Call disk_err() on error'd completed requests 081a5712d4b2e0abf273be4d26affcf3870263a9 virtio_blk: ASSERT the ready and inflight request queues are empty a9be2631a4f770a84145c18ee03a3f103bed4ca8 virtio_blk: Simplify check for too many segments At the cost of a small style violation. e00ec09da014f2e60cc75542d0ab78898672d521 virtio_blk: Add beginnings of suspend/resume Still not sure if we need to virtio_stop()/virtio_reinit() the device before/after a suspend. Don't start additional IO when marked as suspending. 47c71dc6ce8c238aa59ce8afd4bda5aa294bc884 virtio_blk: Panic when dealt an unhandled BIO cmd 1055544f90fb8c0cc6a2395f5b6104039606aafe virtio_blk: Add VQ enqueue/dequeue wrappers Wrapper functions managed the added/removing to the in-flight list of requests. Normally biodone() any completed IO when draining the virtqueue. 92ba40e65b3bb5e4acb9300ece711f1ea8f3f7f4 virtio_blk: Add in-flight list of requests 74f6d260e075443544522c0833dc2712dd93f49b virtio_blk: Rename VTBLK_FLAG_DETACHING to VTBLK_FLAG_DETACH 7aa549050f6fc6551c09c6362ed6b2a0728956ef virtio_blk: Finish all BIOs through vtblk_finish_bio() Also properly set bio_resid in the case of errors. Most geom_disk providers seem to do the same. 9eef6d0e6f7e5dd362f71ba097f2e2e4c3744882 Added function to translate VirtIO status to error code ef06adc337f31e1129d6d5f26de6d8d1be27bcd2 Reset dumping flag when given unexpected parameters 393b3e390c644193a2e392220dcc6a6c50b212d9 Added missing VTBLK_LOCK() in dump handler Obtained from: Bryan Venteicher bryanv at daemoninthecloset dot org
2012-04-14 05:48:04 +00:00
* __u16 used_event_idx;
*
* // Padding to the next align boundary.
* char pad[];
*
* // A ring of used descriptor heads with free-running index.
* __u16 used_flags;
* __u16 used_idx;
* struct vring_used_elem used[num];
Catch up with Bryan Venteicher's virtio git repo: a8af6270bd96be6ccd86f70b60fa6512b710e4f0 virtio_blk: Include function name in panic string cbdb03a694b76c5253d7ae3a59b9995b9afbb67a virtio_balloon: Do the notify outside of the lock By the time we return from virtqueue_notify(), the descriptor will be in the used ring so we shouldn't have to sleep. 10ba392e60692529a5cbc1e9987e4064e0128447 virtio: Use DEVMETHOD_END 80cbcc4d6552cac758be67f0c99c36f23ce62110 virtqueue: Add support for VIRTIO_F_RING_EVENT_IDX This can be used to reduce the number of guest/host and host/guest interrupts by delaying the interrupt until a certain index value is reached. Actual use by the network driver will come along later. 8fc465969acc0c58477153e4c3530390db436c02 virtqueue: Simplify virtqueue_nused() Since the values just wrap naturally at UINT16_MAX, we can just subtract the two values directly, rather than doing 2's complement math. a8aa22f25959e2767d006cd621b69050e7ffb0ae virtio_blk: Remove debugging crud from 75dd732a There seems to be an issue with Qemu (or FreeBSD VirtIO) that sets the PCI register space for the device config to bogus values. This only seems to happen after unloading and reloading the module. d404800661cb2a9769c033f8a50b2133934501aa virtio_blk: Use better variable name 75dd732a97743d96e7c63f7ced3c2169696dadd3 virtio_blk: Partially revert 92ba40e65 Just use the virtqueue to determine if any requests are still inflight. 06661ed66b7a9efaea240f99f414c368f1bbcdc7 virtio_blk: error if allowed too few segments Should never happen unless the host provides use with a bogus seg_max value. 4b33e5085bc87a818433d7e664a0a2c8f56a1a89 virtio_blk: Sort function declarations 426b9f5cac892c9c64cc7631966461514f7e08c6 virtio_blk: Cleanup whitespace 617c23e12c61e3c2233d942db713c6b8ff0bd112 virtio_blk: Call disk_err() on error'd completed requests 081a5712d4b2e0abf273be4d26affcf3870263a9 virtio_blk: ASSERT the ready and inflight request queues are empty a9be2631a4f770a84145c18ee03a3f103bed4ca8 virtio_blk: Simplify check for too many segments At the cost of a small style violation. e00ec09da014f2e60cc75542d0ab78898672d521 virtio_blk: Add beginnings of suspend/resume Still not sure if we need to virtio_stop()/virtio_reinit() the device before/after a suspend. Don't start additional IO when marked as suspending. 47c71dc6ce8c238aa59ce8afd4bda5aa294bc884 virtio_blk: Panic when dealt an unhandled BIO cmd 1055544f90fb8c0cc6a2395f5b6104039606aafe virtio_blk: Add VQ enqueue/dequeue wrappers Wrapper functions managed the added/removing to the in-flight list of requests. Normally biodone() any completed IO when draining the virtqueue. 92ba40e65b3bb5e4acb9300ece711f1ea8f3f7f4 virtio_blk: Add in-flight list of requests 74f6d260e075443544522c0833dc2712dd93f49b virtio_blk: Rename VTBLK_FLAG_DETACHING to VTBLK_FLAG_DETACH 7aa549050f6fc6551c09c6362ed6b2a0728956ef virtio_blk: Finish all BIOs through vtblk_finish_bio() Also properly set bio_resid in the case of errors. Most geom_disk providers seem to do the same. 9eef6d0e6f7e5dd362f71ba097f2e2e4c3744882 Added function to translate VirtIO status to error code ef06adc337f31e1129d6d5f26de6d8d1be27bcd2 Reset dumping flag when given unexpected parameters 393b3e390c644193a2e392220dcc6a6c50b212d9 Added missing VTBLK_LOCK() in dump handler Obtained from: Bryan Venteicher bryanv at daemoninthecloset dot org
2012-04-14 05:48:04 +00:00
* __u16 avail_event_idx;
* };
*
* NOTE: for VirtIO PCI, align is 4096.
*/
Catch up with Bryan Venteicher's virtio git repo: a8af6270bd96be6ccd86f70b60fa6512b710e4f0 virtio_blk: Include function name in panic string cbdb03a694b76c5253d7ae3a59b9995b9afbb67a virtio_balloon: Do the notify outside of the lock By the time we return from virtqueue_notify(), the descriptor will be in the used ring so we shouldn't have to sleep. 10ba392e60692529a5cbc1e9987e4064e0128447 virtio: Use DEVMETHOD_END 80cbcc4d6552cac758be67f0c99c36f23ce62110 virtqueue: Add support for VIRTIO_F_RING_EVENT_IDX This can be used to reduce the number of guest/host and host/guest interrupts by delaying the interrupt until a certain index value is reached. Actual use by the network driver will come along later. 8fc465969acc0c58477153e4c3530390db436c02 virtqueue: Simplify virtqueue_nused() Since the values just wrap naturally at UINT16_MAX, we can just subtract the two values directly, rather than doing 2's complement math. a8aa22f25959e2767d006cd621b69050e7ffb0ae virtio_blk: Remove debugging crud from 75dd732a There seems to be an issue with Qemu (or FreeBSD VirtIO) that sets the PCI register space for the device config to bogus values. This only seems to happen after unloading and reloading the module. d404800661cb2a9769c033f8a50b2133934501aa virtio_blk: Use better variable name 75dd732a97743d96e7c63f7ced3c2169696dadd3 virtio_blk: Partially revert 92ba40e65 Just use the virtqueue to determine if any requests are still inflight. 06661ed66b7a9efaea240f99f414c368f1bbcdc7 virtio_blk: error if allowed too few segments Should never happen unless the host provides use with a bogus seg_max value. 4b33e5085bc87a818433d7e664a0a2c8f56a1a89 virtio_blk: Sort function declarations 426b9f5cac892c9c64cc7631966461514f7e08c6 virtio_blk: Cleanup whitespace 617c23e12c61e3c2233d942db713c6b8ff0bd112 virtio_blk: Call disk_err() on error'd completed requests 081a5712d4b2e0abf273be4d26affcf3870263a9 virtio_blk: ASSERT the ready and inflight request queues are empty a9be2631a4f770a84145c18ee03a3f103bed4ca8 virtio_blk: Simplify check for too many segments At the cost of a small style violation. e00ec09da014f2e60cc75542d0ab78898672d521 virtio_blk: Add beginnings of suspend/resume Still not sure if we need to virtio_stop()/virtio_reinit() the device before/after a suspend. Don't start additional IO when marked as suspending. 47c71dc6ce8c238aa59ce8afd4bda5aa294bc884 virtio_blk: Panic when dealt an unhandled BIO cmd 1055544f90fb8c0cc6a2395f5b6104039606aafe virtio_blk: Add VQ enqueue/dequeue wrappers Wrapper functions managed the added/removing to the in-flight list of requests. Normally biodone() any completed IO when draining the virtqueue. 92ba40e65b3bb5e4acb9300ece711f1ea8f3f7f4 virtio_blk: Add in-flight list of requests 74f6d260e075443544522c0833dc2712dd93f49b virtio_blk: Rename VTBLK_FLAG_DETACHING to VTBLK_FLAG_DETACH 7aa549050f6fc6551c09c6362ed6b2a0728956ef virtio_blk: Finish all BIOs through vtblk_finish_bio() Also properly set bio_resid in the case of errors. Most geom_disk providers seem to do the same. 9eef6d0e6f7e5dd362f71ba097f2e2e4c3744882 Added function to translate VirtIO status to error code ef06adc337f31e1129d6d5f26de6d8d1be27bcd2 Reset dumping flag when given unexpected parameters 393b3e390c644193a2e392220dcc6a6c50b212d9 Added missing VTBLK_LOCK() in dump handler Obtained from: Bryan Venteicher bryanv at daemoninthecloset dot org
2012-04-14 05:48:04 +00:00
/*
* We publish the used event index at the end of the available ring, and vice
* versa. They are at the end for backwards compatibility.
*/
#define vring_used_event(vr) ((vr)->avail->ring[(vr)->num])
#define vring_avail_event(vr) (*(uint16_t *)&(vr)->used->ring[(vr)->num])
Catch up with Bryan Venteicher's virtio git repo: a8af6270bd96be6ccd86f70b60fa6512b710e4f0 virtio_blk: Include function name in panic string cbdb03a694b76c5253d7ae3a59b9995b9afbb67a virtio_balloon: Do the notify outside of the lock By the time we return from virtqueue_notify(), the descriptor will be in the used ring so we shouldn't have to sleep. 10ba392e60692529a5cbc1e9987e4064e0128447 virtio: Use DEVMETHOD_END 80cbcc4d6552cac758be67f0c99c36f23ce62110 virtqueue: Add support for VIRTIO_F_RING_EVENT_IDX This can be used to reduce the number of guest/host and host/guest interrupts by delaying the interrupt until a certain index value is reached. Actual use by the network driver will come along later. 8fc465969acc0c58477153e4c3530390db436c02 virtqueue: Simplify virtqueue_nused() Since the values just wrap naturally at UINT16_MAX, we can just subtract the two values directly, rather than doing 2's complement math. a8aa22f25959e2767d006cd621b69050e7ffb0ae virtio_blk: Remove debugging crud from 75dd732a There seems to be an issue with Qemu (or FreeBSD VirtIO) that sets the PCI register space for the device config to bogus values. This only seems to happen after unloading and reloading the module. d404800661cb2a9769c033f8a50b2133934501aa virtio_blk: Use better variable name 75dd732a97743d96e7c63f7ced3c2169696dadd3 virtio_blk: Partially revert 92ba40e65 Just use the virtqueue to determine if any requests are still inflight. 06661ed66b7a9efaea240f99f414c368f1bbcdc7 virtio_blk: error if allowed too few segments Should never happen unless the host provides use with a bogus seg_max value. 4b33e5085bc87a818433d7e664a0a2c8f56a1a89 virtio_blk: Sort function declarations 426b9f5cac892c9c64cc7631966461514f7e08c6 virtio_blk: Cleanup whitespace 617c23e12c61e3c2233d942db713c6b8ff0bd112 virtio_blk: Call disk_err() on error'd completed requests 081a5712d4b2e0abf273be4d26affcf3870263a9 virtio_blk: ASSERT the ready and inflight request queues are empty a9be2631a4f770a84145c18ee03a3f103bed4ca8 virtio_blk: Simplify check for too many segments At the cost of a small style violation. e00ec09da014f2e60cc75542d0ab78898672d521 virtio_blk: Add beginnings of suspend/resume Still not sure if we need to virtio_stop()/virtio_reinit() the device before/after a suspend. Don't start additional IO when marked as suspending. 47c71dc6ce8c238aa59ce8afd4bda5aa294bc884 virtio_blk: Panic when dealt an unhandled BIO cmd 1055544f90fb8c0cc6a2395f5b6104039606aafe virtio_blk: Add VQ enqueue/dequeue wrappers Wrapper functions managed the added/removing to the in-flight list of requests. Normally biodone() any completed IO when draining the virtqueue. 92ba40e65b3bb5e4acb9300ece711f1ea8f3f7f4 virtio_blk: Add in-flight list of requests 74f6d260e075443544522c0833dc2712dd93f49b virtio_blk: Rename VTBLK_FLAG_DETACHING to VTBLK_FLAG_DETACH 7aa549050f6fc6551c09c6362ed6b2a0728956ef virtio_blk: Finish all BIOs through vtblk_finish_bio() Also properly set bio_resid in the case of errors. Most geom_disk providers seem to do the same. 9eef6d0e6f7e5dd362f71ba097f2e2e4c3744882 Added function to translate VirtIO status to error code ef06adc337f31e1129d6d5f26de6d8d1be27bcd2 Reset dumping flag when given unexpected parameters 393b3e390c644193a2e392220dcc6a6c50b212d9 Added missing VTBLK_LOCK() in dump handler Obtained from: Bryan Venteicher bryanv at daemoninthecloset dot org
2012-04-14 05:48:04 +00:00
static inline int
vring_size(unsigned int num, unsigned long align)
{
int size;
size = num * sizeof(struct vring_desc);
size += sizeof(struct vring_avail) + (num * sizeof(uint16_t)) +
sizeof(uint16_t);
size = (size + align - 1) & ~(align - 1);
size += sizeof(struct vring_used) +
(num * sizeof(struct vring_used_elem)) + sizeof(uint16_t);
return (size);
}
static inline void
vring_init(struct vring *vr, unsigned int num, uint8_t *p,
unsigned long align)
{
vr->num = num;
vr->desc = (struct vring_desc *) p;
vr->avail = (struct vring_avail *) (p +
num * sizeof(struct vring_desc));
vr->used = (void *)
(((unsigned long) &vr->avail->ring[num] + align-1) & ~(align-1));
}
Catch up with Bryan Venteicher's virtio git repo: a8af6270bd96be6ccd86f70b60fa6512b710e4f0 virtio_blk: Include function name in panic string cbdb03a694b76c5253d7ae3a59b9995b9afbb67a virtio_balloon: Do the notify outside of the lock By the time we return from virtqueue_notify(), the descriptor will be in the used ring so we shouldn't have to sleep. 10ba392e60692529a5cbc1e9987e4064e0128447 virtio: Use DEVMETHOD_END 80cbcc4d6552cac758be67f0c99c36f23ce62110 virtqueue: Add support for VIRTIO_F_RING_EVENT_IDX This can be used to reduce the number of guest/host and host/guest interrupts by delaying the interrupt until a certain index value is reached. Actual use by the network driver will come along later. 8fc465969acc0c58477153e4c3530390db436c02 virtqueue: Simplify virtqueue_nused() Since the values just wrap naturally at UINT16_MAX, we can just subtract the two values directly, rather than doing 2's complement math. a8aa22f25959e2767d006cd621b69050e7ffb0ae virtio_blk: Remove debugging crud from 75dd732a There seems to be an issue with Qemu (or FreeBSD VirtIO) that sets the PCI register space for the device config to bogus values. This only seems to happen after unloading and reloading the module. d404800661cb2a9769c033f8a50b2133934501aa virtio_blk: Use better variable name 75dd732a97743d96e7c63f7ced3c2169696dadd3 virtio_blk: Partially revert 92ba40e65 Just use the virtqueue to determine if any requests are still inflight. 06661ed66b7a9efaea240f99f414c368f1bbcdc7 virtio_blk: error if allowed too few segments Should never happen unless the host provides use with a bogus seg_max value. 4b33e5085bc87a818433d7e664a0a2c8f56a1a89 virtio_blk: Sort function declarations 426b9f5cac892c9c64cc7631966461514f7e08c6 virtio_blk: Cleanup whitespace 617c23e12c61e3c2233d942db713c6b8ff0bd112 virtio_blk: Call disk_err() on error'd completed requests 081a5712d4b2e0abf273be4d26affcf3870263a9 virtio_blk: ASSERT the ready and inflight request queues are empty a9be2631a4f770a84145c18ee03a3f103bed4ca8 virtio_blk: Simplify check for too many segments At the cost of a small style violation. e00ec09da014f2e60cc75542d0ab78898672d521 virtio_blk: Add beginnings of suspend/resume Still not sure if we need to virtio_stop()/virtio_reinit() the device before/after a suspend. Don't start additional IO when marked as suspending. 47c71dc6ce8c238aa59ce8afd4bda5aa294bc884 virtio_blk: Panic when dealt an unhandled BIO cmd 1055544f90fb8c0cc6a2395f5b6104039606aafe virtio_blk: Add VQ enqueue/dequeue wrappers Wrapper functions managed the added/removing to the in-flight list of requests. Normally biodone() any completed IO when draining the virtqueue. 92ba40e65b3bb5e4acb9300ece711f1ea8f3f7f4 virtio_blk: Add in-flight list of requests 74f6d260e075443544522c0833dc2712dd93f49b virtio_blk: Rename VTBLK_FLAG_DETACHING to VTBLK_FLAG_DETACH 7aa549050f6fc6551c09c6362ed6b2a0728956ef virtio_blk: Finish all BIOs through vtblk_finish_bio() Also properly set bio_resid in the case of errors. Most geom_disk providers seem to do the same. 9eef6d0e6f7e5dd362f71ba097f2e2e4c3744882 Added function to translate VirtIO status to error code ef06adc337f31e1129d6d5f26de6d8d1be27bcd2 Reset dumping flag when given unexpected parameters 393b3e390c644193a2e392220dcc6a6c50b212d9 Added missing VTBLK_LOCK() in dump handler Obtained from: Bryan Venteicher bryanv at daemoninthecloset dot org
2012-04-14 05:48:04 +00:00
/*
* The following is used with VIRTIO_RING_F_EVENT_IDX.
*
* Assuming a given event_idx value from the other size, if we have
* just incremented index from old to new_idx, should we trigger an
* event?
*/
static inline int
vring_need_event(uint16_t event_idx, uint16_t new_idx, uint16_t old)
{
return (uint16_t)(new_idx - event_idx - 1) < (uint16_t)(new_idx - old);
}
#endif /* VIRTIO_RING_H */