aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/virtio
Commit message (Collapse)AuthorAge
* virtio: refactor find_vqsMichael S. Tsirkin2009-07-30
| | | | | | | | | | | | This refactors find_vqs, making it more readable and robust, and fixing two regressions from 2.6.30: - double free_irq causing BUG_ON on device removal - probe failure when vq can't be assigned to msi-x vector (reported on old host kernels) Tested-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: delete vq from listMichael S. Tsirkin2009-07-30
| | | | | | | | | This makes delete vq the reverse of find vq. This is required to make it possible to retry find_vqs after a failure, otherwise the list gets corrupted. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix memory leak on device removalMichael S. Tsirkin2009-07-30
| | | | | | | Make vp_free_vectors do the reverse of vq_request_vectors. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio-pci: correctly unregister root device on errorMark McLoughlin2009-07-17
| | | | | | | | | If pci_register_driver() fails we're incorrectly unregistering the root device with device_unregister() rather than root_device_unregister(). Reported-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: enhance id_matching for virtio driversChristian Borntraeger2009-06-12
| | | | | | | | | This patch allows a virtio driver to use VIRTIO_DEV_ANY_ID for the device id. This will be used by a test module that can be bound to any virtio device. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix id_matching for virtio driversChristian Borntraeger2009-06-12
| | | | | | | | | | This bug never appeared, since all current virtio drivers use VIRTIO_DEV_ANY_ID for the vendor field. If a real vendor would be used, the check in virtio_id_match is wrong - it returns 0 if id->vendor == dev->id.vendor. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: indirect ring entries (VIRTIO_RING_F_INDIRECT_DESC)Mark McLoughlin2009-06-12
| | | | | | | | | | | | | | | | | | Add a new feature flag for indirect ring entries. These are ring entries which point to a table of buffer descriptors. The idea here is to increase the ring capacity by allowing a larger effective ring size whereby the ring size dictates the number of requests that may be outstanding, rather than the size of those requests. This should be most effective in the case of block I/O where we can potentially benefit by concurrently dispatching a large number of large requests. Even in the simple case of single segment block requests, this results in a threefold increase in ring capacity. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: expose features in sysfsRusty Russell2009-06-12
| | | | | | | Each device negotiates feature bits; expose these in sysfs to help diagnostics and debugging. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_pci: optional MSI-X supportMichael S. Tsirkin2009-06-12
| | | | | | | | | | | | This implements optional MSI-X support in virtio_pci. MSI-X is used whenever the host supports at least 2 MSI-X vectors: 1 for configuration changes and 1 for virtqueues. Per-virtqueue vectors are allocated if enough vectors available. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ whitespace, style)
* virtio_pci: split up vp_interruptMichael S. Tsirkin2009-06-12
| | | | | | | | This reorganizes virtio-pci code in vp_interrupt slightly, so that it's easier to add per-vq MSI support on top. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: find_vqs/del_vqs virtio operationsMichael S. Tsirkin2009-06-12
| | | | | | | | | This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations, and updates all drivers. This is needed for MSI support, because MSI needs to know the total number of vectors upfront. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)
* virtio: add names to virtqueue struct, mapping from devices to queues.Rusty Russell2009-06-12
| | | | | | | | | Add a linked list of all virtqueues for a virtio device: this helps for debugging and is also needed for upcoming interface change. Also, add a "name" field for clearer debug messages. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: meet virtio spec by finalizing features before using deviceRusty Russell2009-06-12
| | | | | | | | | | | | | | Virtio devices are supposed to negotiate features before they start using the device, but the current code doesn't do this. This is because the driver's probe() function invariably has to add buffers to a virtqueue, or probe the disk (virtio_blk). This currently doesn't matter since no existing backend is strict about the feature negotiation. But it's possible to imagine a future feature which completely changes how a device operates: in this case, we'd need to acknowledge it before using the device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix suspend when using virtio_balloonMarcelo Tosatti2009-04-19
| | | | | | | | | | Break out of wait_event_interruptible() if freezing has been requested, in the vballoon thread. Without this change vballoon refuses to stop and the system can't suspend. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
* virtio: more neatening of virtio_ring macros.Rusty Russell2009-03-30
| | | | | | | | | | | | Impact: cleanup Roel Kluin drew attention to these macros with his patch: here I neaten them a little further: 1) Add a comment on what START_USE and END_USE are checking, 2) Brackets around _vq in BAD_RING, 3) Neaten formatting for START_USE so it's less than 80 cols. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix BAD_RING, START_US and END_USE macrosRoel Kluin2009-03-30
| | | | | | | | | | | | Impact: cleanup fix BAD_RING, START_US and END_USE macros When these macros aren't called with a variable named vq as first argument, this would result in a build failure. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio-pci: do not oops on config change if driver not loadedMark McLoughlin2009-02-02
| | | | | | | | | | | | | | | | | | The host really shouldn't be notifying us of config changes before the device status is VIRTIO_CONFIG_S_DRIVER or VIRTIO_CONFIG_S_DRIVER_OK. However, if we do happen to be interrupted while we're not attached to a driver, we really shouldn't oops. Prevent this simply by checking that device->driver is non-NULL before trying to notify the driver of config changes. Problem observed by doing a "set_link virtio.0 down" with QEMU before the net driver had been loaded. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio: do not statically allocate root deviceMark McLoughlin2009-01-06
| | | | | | | | | | | | | | | | We shouldn't be statically allocating the root device object, so dynamically allocate it using root_device_register() instead. Also avoids this warning from 'rmmod virtio_pci': Device 'virtio-pci' does not have a release() function, it is broken and must be fixed Signed-off-by: Mark McLoughlin <markmc@redhat.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* virtio: add PCI device release() functionMark McLoughlin2008-12-29
| | | | | | | | | | | | | | | | Add a release() function for virtio_pci devices so as to avoid: Device 'virtio0' does not have a release() function, it is broken and must be fixed Move the code to free the resources associated with the device from virtio_pci_remove() into this new function. virtio_pci_remove() now merely unregisters the device which should cause the final ref to be dropped and virtio_pci_release_dev() to be called. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Reported-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: avoid implicit use of Linux page size in balloon interfaceHollis Blanchard2008-12-29
| | | | | | | | | Make the balloon interface always use 4K pages, and convert Linux pfns if necessary. This patch assumes that Linux's PAGE_SHIFT will never be less than 12. Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (modified)
* virtio: hand virtio ring alignment as argument to vring_new_virtqueueRusty Russell2008-12-29
| | | | | | | | This allows each virtio user to hand in the alignment appropriate to their virtio_ring structures. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
* virtio: Don't use PAGE_SIZE for vring alignment in virtio_pci.Rusty Russell2008-12-29
| | | | | | That doesn't work for non-4k guests which are now appearing. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Don't use PAGE_SIZE in virtio_pci.cRusty Russell2008-12-29
| | | | | | | The virtio PCI devices don't depend on the guest page size. This matters now PowerPC virtio is gaining ground (they like 64k pages). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers2008-12-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is part of a larger patch series which will remove the "char bus_id[20]" name string from struct device. The device name is managed in the kobject anyway, and without any size limitation, and just needlessly copied into "struct device". To set and read the device name dev_name(dev) and dev_set_name(dev) must be used. If your code uses static kobjects, which it shouldn't do, "const char *init_name" can be used to statically provide the name the registered device should have. At registration time, the init_name field is cleared, to enforce the use of dev_name(dev) to access the device name at a later time. We need to get rid of all occurrences of bus_id in the entire tree to be able to enable the new interface. Please apply this patch, and possibly convert any remaining remaining occurrences of bus_id. We want to submit a patch to -next, which will remove bus_id from "struct device", to find the remaining pieces to convert, and finally switch over to the new api, which will remove the 20 bytes array and does no longer have a size limitation. Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio-pci queue allocation not page-alignedHollis Blanchard2008-12-29
| | | | | | | | | | | kzalloc() does not guarantee page alignment, and in fact this broke when I enabled CONFIG_SLUB_DEBUG_ON. (Thanks to Anthony Liguori for spotting the missing kfree sub) Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (fixed kfree) Tested-by: Anthony Liguori <aliguori@us.ibm.com>
* virtio_balloon: fix towards_target when deflating balloonAnthony Liguori2008-08-25
| | | | | | | | | | | | | | | | Both v and vb->num_pages are u32 and unsigned int respectively. If v is less than vb->num_pages (and it is, when deflating the balloon), the result is a very large 32-bit number. Since we're returning a s64, instead of getting the same negative number we desire, we get a very large positive number. This handles the case where v < vb->num_pages and ensures we get a small, negative, s64 as the result. Rusty: please push this for 2.6.27-rc4. It's probably appropriate for the stable tree too as it will cause an unexpected OOM when ballooning. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (simplified)
* virtio: Add transport feature handling stub for virtio_ring.Rusty Russell2008-07-24
| | | | | | | | To prepare for virtio_ring transport feature bits, hook in a call in all the users to manipulate them. This currently just clears all the bits, since it doesn't understand any features. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Rename set_features to finalize_featuresRusty Russell2008-07-24
| | | | | | | | | Rather than explicitly handing the features to the lower-level, we just hand the virtio_device and have it set the features. This make it clear that it has the chance to manipulate the features of the device at this point (and that all feature negotiation is already done). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Formally reserve bits 28-31 to be 'transport' features.Rusty Russell2008-07-24
| | | | | | | We assign feature bits as required, but it makes sense to reserve some for the particular transport, rather than the particular device. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Use bus_type probe and remove methodsMark McLoughlin2008-07-24
| | | | | | | | | Hook up to the probe() and remove() methods in bus_type rather than device_driver. The latter has been preferred since 2.6.16. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: don't always force a notification when ring is fullRusty Russell2008-07-24
| | | | | | | | | | | | | | | | | | | | | We force notification when the ring is full, even if the host has indicated it doesn't want to know. This seemed like a good idea at the time: if we fill the transmit ring, we should tell the host immediately. Unfortunately this logic also applies to the receiving ring, which is refilled constantly. We should introduce real notification thesholds to replace this logic. Meanwhile, removing the logic altogether breaks the heuristics which KVM uses, so we use a hack: only notify if there are outgoing parts of the new buffer. Here are the number of exits with lguest's crappy network implementation: Before: network xmit 7859051 recv 236420 After: network xmit 7858610 recv 118136 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Complete feature negotation before updating statusMark McLoughlin2008-06-15
| | | | | | | | | | | | lguest (in rusty's use-tun-ringfd patch) assumes that the guest has updated its feature bits before setting its status to VIRTIO_CONFIG_S_DRIVER_OK. That's pretty reasonable, so let's make it so. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio: force callback on empty.Rusty Russell2008-05-30
| | | | | | | | | | | | | | | | | | | | virtio allows drivers to suppress callbacks (ie. interrupts) for efficiency (no locking, it's just an optimization). There's a similar mechanism for the host to suppress notifications coming from the guest: in that case, we ignore the suppression if the ring is completely full. It turns out that life is simpler if the host similarly ignores callback suppression when the ring is completely empty: the network driver wants to free up old packets in a timely manner, and otherwise has to use a timer to poll. We have to remove the code which ignores interrupts when the driver has disabled them (again, it had no locking and hence was unreliable anyway). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_net: another race with virtio_net and enable_cbChristian Borntraeger2008-05-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hello Rusty, seems that we still have a problem with virtio_net and the enable_cb callback. During a long running network stress tests with virtio and got the following oops: ------------[ cut here ]------------ kernel BUG at drivers/virtio/virtio_ring.c:230! illegal operation: 0001 [#1] SMP Modules linked in: CPU: 0 Not tainted 2.6.26-rc2-kvm-00436-gc94c08b-dirty #34 Process netserver (pid: 2582, task: 000000000fbc4c68, ksp: 000000000f42b990) Krnl PSW : 0704c00180000000 00000000002d0ec8 (vring_enable_cb+0x1c/0x60) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 EA:3 Krnl GPRS: 0000000000000000 0000000000000000 000000000ef3d000 0000000010009800 0000000000000000 0000000000419ce0 0000000000000080 000000000000007b 000000000adb5538 000000000ef40900 000000000ef40000 000000000ef40920 0000000000000000 0000000000000005 000000000029c1b0 000000000fea7d18 Krnl Code: 00000000002d0ebc: a7110001 tmll %r1,1 00000000002d0ec0: a7740004 brc 7,2d0ec8 00000000002d0ec4: a7f40001 brc 15,2d0ec6 >00000000002d0ec8: a517fffe nill %r1,65534 00000000002d0ecc: 40103000 sth %r1,0(%r3) 00000000002d0ed0: 07f0 bcr 15,%r0 00000000002d0ed2: e31020380004 lg %r1,56(%r2) 00000000002d0ed8: a7480000 lhi %r4,0 Call Trace: ([<000000000029c0fc>] virtnet_poll+0x290/0x3b8) [<0000000000333fb8>] net_rx_action+0x9c/0x1b8 [<00000000001394bc>] __do_softirq+0x74/0x108 [<000000000010d16a>] do_softirq+0x92/0xac [<0000000000139826>] irq_exit+0x72/0xc8 [<000000000010a7b6>] do_extint+0xe2/0x104 [<0000000000110508>] ext_no_vtime+0x16/0x1a Last Breaking-Event-Address: [<00000000002d0ec4>] vring_enable_cb+0x18/0x60 I looked into the virtio_net code for some time and I think the following scenario happened. Please look at virtnet_poll: [...] /* Out of packets? */ if (received < budget) { netif_rx_complete(vi->dev, napi); if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq)) && napi_schedule_prep(napi)) { vi->rvq->vq_ops->disable_cb(vi->rvq); __netif_rx_schedule(vi->dev, napi); goto again; } } If an interrupt arrives after netif_rx_complete, a second poll routine can run on a different cpu. The second check for napi_schedule_prep would prevent any harm in the network stack, but we have called enable_cb possibly after the disable_cb in skb_recv_done. static void skb_recv_done(struct virtqueue *rvq) { struct virtnet_info *vi = rvq->vdev->priv; /* Schedule NAPI, Suppress further interrupts if successful. */ if (netif_rx_schedule_prep(vi->dev, &vi->napi)) { rvq->vq_ops->disable_cb(rvq); __netif_rx_schedule(vi->dev, &vi->napi); } } That means that the second poll routine runs with interrupts enabled, which is ok, since we can handle additional interrupts. The problem is now that the second poll routine might also call enable_cb, triggering the BUG. The only solution I can come up with, is to remove the BUG statement in enable_cb - similar to disable_cb. Opinions or better ideas where the oops could come from? Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: set device index in common code.Rusty Russell2008-05-30
| | | | | | | | | | | | | | | | | | | | | | | Anthony Liguori points out that three different transports use the virtio code, but each one keeps its own counter to set the virtio_device's index field. In theory (though not in current practice) this means that names could be duplicated, and that risk grows as more transports are created. So we move the selection of the unique virtio_device.index into the common code in virtio.c, which has the side-benefit of removing duplicate code. The only complexity is that lguest and S/390 use the index to uniquely identify the device in case of catastrophic failure before register_virtio_device() is called: now we use the offset within the descriptor page as a unique identifier for the printks. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chris Lalancette <clalance@redhat.com> Cc: Anthony Liguori <anthony@codemonkey.ws>
* virtio: virtio_pci should not set bus_id.Rusty Russell2008-05-30
| | | | | | | | | | | | | The common virtio code sets the bus_id, overriding anything virtio_pci sets anyway. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chris Lalancette <clalance@redhat.com> Cc: Anthony Liguori <anthony@codemonkey.ws>
* virtio: bus_id for devices should contain 'virtio'Rusty Russell2008-05-30
| | | | | | | | | | | | | | Chris Lalancette <clalance@redhat.com> points out that virtio.c sets all device names to '0', '1', etc, which looks silly in /proc/interrupts. We change this from '%d' to 'virtio%d'. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chris Lalancette <clalance@redhat.com> Cc: Anthony Liguori <anthony@codemonkey.ws>
* virtio: explicit advertisement of driver featuresRusty Russell2008-05-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | A recent proposed feature addition to the virtio block driver revealed some flaws in the API: in particular, we assume that feature negotiation is complete once a driver's probe function returns. There is nothing in the API to require this, however, and even I didn't notice when it was violated. So instead, we require the driver to specify what features it supports in a table, we can then move the feature negotiation into the virtio core. The intersection of device and driver features are presented in a new 'features' bitmap in the struct virtio_device. Note that this highlights the difference between Linux unsigned-long bitmaps where each unsigned long is in native endian, and a straight-forward little-endian array of bytes. Drivers can still remove feature bits in their probe routine if they really have to. API changes: - dev->config->feature() no longer gets and acks a feature. - drivers should advertise their features in the 'feature_table' field - use virtio_has_feature() for extra sanity when checking feature bits Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: change config to guest endian.Rusty Russell2008-05-02
| | | | | | | | | | | | | | | | | | A recent proposed feature addition to the virtio block driver revealed some flaws in the API, in particular how easy it is to break big endian machines. The virtio config space was originally chosen to be little-endian, because we thought the config might be part of the PCI config space for virtio_pci. It's actually a separate mmio region, so that argument holds little water; as only x86 is currently using the virtio mechanism, we can change this (but must do so now, before the impending s390 merge). API changes: - __virtio_config_val() just becomes a striaght vdev->config_get() call. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix sparse return void-valued expression warningsHarvey Harrison2008-05-02
| | | | | | | | drivers/virtio/virtio_pci.c:148:2: warning: returning void-valued expression drivers/virtio/virtio_pci.c:155:2: warning: returning void-valued expression Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: ignore corrupted virtqueues rather than spinning.Rusty Russell2008-05-02
| | | | | | | | A corrupt virtqueue (caused by the other end screwing up) can have strange results such as a driver spinning: just bail when we try to get a buffer from a known-broken queue. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: remove overzealous BUG_ON.Rusty Russell2008-04-07
| | | | | | | | | | | | | | | | The 'disable_cb' callback is designed as an optimization to tell the host we don't need callbacks now. As it is not reliable, the debug check is overzealous: it can happen on two CPUs at the same time. Document this. Even if it were reliable, the virtio_net driver doesn't disable callbacks on transmit so the START_USE/END_USE debugging reentrance protection can be easily tripped even on UP. Thanks to Balaji Rao for the bug report and testing. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> CC: Balaji Rao <balajirrao@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio_pci iomem annotationsAl Viro2008-03-30
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio_pci: unregister virtio device at device removeAnthony Liguori2008-03-27
| | | | | | | | | | Make sure to call unregister_virtio_device() when a virtio device is removed. Otherwise, virtio_pci.ko cannot be rmmod'd. This was spotted by Marcelo Tosatti. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: fix race in enable_cbChristian Borntraeger2008-03-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a race in virtio_net, dealing with disabling/enabling the callback. I saw the following oops: kernel BUG at /space/kvm/drivers/virtio/virtio_ring.c:218! illegal operation: 0001 [#1] SMP Modules linked in: sunrpc dm_mod CPU: 2 Not tainted 2.6.25-rc1zlive-host-10623-gd358142-dirty #99 Process swapper (pid: 0, task: 000000000f85a610, ksp: 000000000f873c60) Krnl PSW : 0404300180000000 00000000002b81a6 (vring_disable_cb+0x16/0x20) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:3 PM:0 EA:3 Krnl GPRS: 0000000000000001 0000000000000001 0000000010005800 0000000000000001 000000000f3a0900 000000000f85a610 0000000000000000 0000000000000000 0000000000000000 000000000f870000 0000000000000000 0000000000001237 000000000f3a0920 000000000010ff74 00000000002846f6 000000000fa0bcd8 Krnl Code: 00000000002b819a: a7110001 tmll %r1,1 00000000002b819e: a7840004 brc 8,2b81a6 00000000002b81a2: a7f40001 brc 15,2b81a4 >00000000002b81a6: a51b0001 oill %r1,1 00000000002b81aa: 40102000 sth %r1,0(%r2) 00000000002b81ae: 07fe bcr 15,%r14 00000000002b81b0: eb7ff0380024 stmg %r7,%r15,56(%r15) 00000000002b81b6: a7f13e00 tmll %r15,15872 Call Trace: ([<000000000fa0bcd0>] 0xfa0bcd0) [<00000000002b8350>] vring_interrupt+0x5c/0x6c [<000000000010ab08>] do_extint+0xb8/0xf0 [<0000000000110716>] ext_no_vtime+0x16/0x1a [<0000000000107e72>] cpu_idle+0x1c2/0x1e0 The problem can be triggered with a high amount of host->guest traffic. I think its the following race: poll says netif_rx_complete poll calls enable_cb enable_cb opens the interrupt mask a new packet comes, an interrupt is triggered----\ enable_cb sees that there is more work | enable_cb disables the interrupt | . V . interrupt is delivered . skb_recv_done does atomic napi test, ok some waiting disable_cb is called->check fails->bang! . poll would do napi check poll would do disable_cb The fix is to let enable_cb not disable the interrupt again, but expect the caller to do the cleanup if it returns false. In that case, the interrupt is only disabled, if the napi test_set_bit was successful. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cleaned up doco)
* virtio: handle > 2 billion page balloon targetsRusty Russell2008-03-17
| | | | | | | | If the host asks for a huge target towards_target() can overflow, and we up oops as we try to release more pages than we have. The simple fix is to use a 64-bit value. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Use spin_lock_irqsave/restore for virtio-pciAnthony Liguori2008-03-17
| | | | | | | | | virtio-pci acquires its spin lock in an interrupt context so it's necessary to use spin_lock_irqsave/restore variants. This patch fixes guest SMP when using virtio devices in KVM. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: add missing #include <linux/delay.h>Johann Felix Soden2008-02-06
| | | | | | | | | | | | Include linux/delay.h to fix compiler error: drivers/virtio/virtio_balloon.c: In function 'fill_balloon': drivers/virtio/virtio_balloon.c:98: error: implicit declaration of function 'msleep' Signed-off-by: Johann Felix Soden <johfel@users.sourceforge.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* virtio: balloon driverRusty Russell2008-02-04
| | | | | | | | | | | | | | | | | | | | After discussions with Anthony Liguori, it seems that the virtio balloon can be made even simpler. Here's my attempt. The device configuration tells the driver how much memory it should take from the guest (ie. balloon size). The guest feeds the page numbers it has taken via one virtqueue. A second virtqueue feeds the page numbers the driver wants back: if the device has the VIRTIO_BALLOON_F_MUST_TELL_HOST bit, then this queue is compulsory, otherwise it's advisory (and the guest can simply fault the pages back in). This driver can be enhanced later to deflate the balloon via a shrinker, oom callback or we could even go for a complete set of in-guest regulators. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Use PCI revision field to indicate virtio PCI ABI versionAnthony Liguori2008-02-04
| | | | | | | | | | | | As Avi pointed out, as we continue to massage the virtio PCI ABI, we can make things a little more friendly to users by utilizing the PCI revision field to indicate which version of the ABI we're using. This is a hard ABI version and incrementing it will cause the guest driver to break. This is the necessary changes to virtio_pci to support this. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-27 04:10:53 -0500