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* virtio-mmio: Devices parameter parsingPawel Moll2012-05-222-0/+174
| | | | | | | | | | This patch adds an option to instantiate guest virtio-mmio devices basing on a kernel command line (or module) parameter, for example: virtio_mmio.devices=0x100@0x100b0000:48 Signed-off-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Use ida to allocate virtio indexAsias He2012-05-221-2/+9
| | | | | | | | | | | | | | Current index allocation in virtio is based on a monotonically increasing variable "index". This means we'll run out of numbers after a while. E.g. someone crazy doing this in host side. while(1) { hot-plug a virtio device hot-unplug the virito devcie } Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: balloon: separate out common code between remove and freeze functionsAmit Shah2012-05-221-14/+12
| | | | | | | | The remove and freeze functions have a lot of shared code; put it into a common function that gets called by both. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: balloon: drop restore_common()Amit Shah2012-05-221-6/+1
| | | | | | | | | | | | restore_common() was used when there were different thaw and freeze PM callbacks implemented. We removed thaw in commit f38f8387cbdc4138a492ce9f2a5f04fd3cd3cf33. restore_common() can be removed and virtballoon_restore() can itself do the restore ops. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: balloon: let host know of updated balloon size before module removalAmit Shah2012-05-171-0/+1
| | | | | | | | | | | | | When the balloon module is removed, we deflate the balloon, reclaiming all the pages that were given to the host. However, we don't update the config values for the new balloon size, resulting in the host showing outdated balloon values. The size update is done after each leak and fill operation, only the module removal case was left out. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_balloon: fix handling of PAGE_SIZE != 4kMichael S. Tsirkin2012-04-151-10/+41
| | | | | | | | | | | | | | | | | | | As reported by David Gibson, current code handles PAGE_SIZE != 4k completely wrong which can lead to guest memory corruption errors: - page_to_balloon_pfn is wrong: e.g. on system with 64K page size it gives the same pfn value for 16 different pages. - we also need to convert back to linux pfns when we free. - for each linux page we need to tell host about multiple balloon pages, but code only adds one pfn to the array. This patch fixes all that, tested with a 64k ppc64 kernel. Reported-by: David Gibson <david@gibson.dropbear.id.au> Tested-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio_balloon: Fix endian bugDavid Gibson2012-04-151-2/+5
| | | | | | | | | | | | | | Although virtio config space fields are usually in guest-native endian, the spec for the virtio balloon device explicitly states that both fields in its config space are little-endian. However, the current virtio_balloon driver does not have a suitable endian swap for the 'num_pages' field, although it does have one for the 'actual' field. This patch corrects the bug, adding sparse annotation while we're at it. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
* virtio-pci: switch to PM ops macro to initialise PM functionsAmit Shah2012-03-311-6/+1
| | | | | | | Use the SET_SYSTEM_SLEEP_PM_OPS macro to initialise the suspend/resume functions in the new PM API. Signed-off-by: Amit Shah <amit.shah@redhat.com>
* virtio-pci: S3 supportAmit Shah2012-03-311-21/+3
| | | | | | | | | There's no difference in supporting S3 and S4 for virtio devices: the vqs have to be re-created as the device has to be assumed to be reset at restore-time. Since S4 already handles this situation, we can directly use the same code and callbacks for S3 support. Signed-off-by: Amit Shah <amit.shah@redhat.com>
* virtio-pci: drop restore_common()Amit Shah2012-03-311-16/+7
| | | | | | | restore_common() was shared between restore and thaw callbacks. With thaw gone, we don't need restore_common() anymore. Signed-off-by: Amit Shah <amit.shah@redhat.com>
* virtio: drop thaw PM operationAmit Shah2012-03-312-33/+1
| | | | | | | The thaw operation was used by the balloon driver, but after the last commit there's no reason to have separate thaw and restore callbacks. Signed-off-by: Amit Shah <amit.shah@redhat.com>
* virtio: balloon: Allow stats update after restore from S4Amit Shah2012-03-311-8/+0
| | | | | | | | | There's no reason stats update after restore can't work. If a host requested for stats, and before servicing the request, the guest entered S4, upon restore, the stats request can still be processed and sent off to the host. Signed-off-by: Amit Shah <amit.shah@redhat.com>
* Remove all #inclusions of asm/system.hDavid Howells2012-03-281-1/+0
| | | | | | | | | Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
* virtio: balloon: leak / fill balloon across S4Amit Shah2012-03-011-11/+22
| | | | | | | | | | | | | | | | | | | | | | commit e562966dbaf49e7804097cd991e5d3a8934fc148 added support for S4 to the balloon driver. The freeze function did nothing to free the pages, since reclaiming the pages from the host to immediately give them back (if S4 was successful) seemed wasteful. Also, if S4 wasn't successful, the guest would have to re-fill the balloon. On restore, the pages were supposed to be marked freed and the free page counters were incremented to reflect the balloon was totally deflated. However, this wasn't done right. The pages that were earlier taken away from the guest during a balloon inflation operation were just shown as used pages after a successful restore from S4. Just a fancy way of leaking lots of memory. Instead of trying that, just leak the balloon on freeze and fill it on restore/thaw paths. This works properly now. The optimisation to not leak can be added later on after a bit of refactoring of the code. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: correct the memory barrier in virtqueue_kick_prepare()Jason Wang2012-01-281-3/+3
| | | | | | | | | | | | | Use virtio_mb() to make sure the available index to be exposed before checking the the avail event. Otherwise we may get stale value of avail event in guest and never kick the host after. Note: this fixes a bug introduced by ee7cd8981e15bcb365fc762afe3fc47b8242f630. Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
* virtio: fix typos of memory barriersJason Wang2012-01-281-1/+1
| | | | | | | | | Note: this fixes a bug introduced recently in 7b21e34fd1c272e3a8c3846168f2f6287a4cd72b. Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: balloon: Add freeze, restore handlers to support S4Amit Shah2012-01-121-0/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handling balloon hibernate / restore is tricky. If the balloon was inflated before going into the hibernation state, upon resume, the host will not have any memory of that. Any pages that were passed on to the host earlier would most likely be invalid, and the host will have to re-balloon to the previous value to get in the pre-hibernate state. So the only sane thing for the guest to do here is to discard all the pages that were put in the balloon. When to discard the pages is the next question. One solution is to deflate the balloon just before writing the image to the disk (in the freeze() PM callback). However, asking for pages from the host just to discard them immediately after seems wasteful of resources. Hence, it makes sense to do this by just fudging our counters soon after wakeup. This means we don't deflate the balloon before sleep, and also don't put unnecessary pressure on the host. This also helps in the thaw case: if the freeze fails for whatever reason, the balloon should continue to remain in the inflated state. This was tested by issuing 'swapoff -a' and trying to go into the S4 state. That fails, and the balloon stays inflated, as expected. Both the host and the guest are happy. Finally, in the restore() callback, we empty the list of pages that were previously given off to the host, add the appropriate number of pages to the totalram_pages counter, reset the num_pages counter to 0, and all is fine. As a last step, delete the vqs on the freeze callback to prepare for hibernation, and re-create them in the restore and thaw callbacks to resume normal operation. The kthread doesn't race with any operations here, since it's frozen before the freeze() call and is thawed after the thaw() and restore() callbacks, so we're safe with that. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: balloon: Move vq initialization into separate functionAmit Shah2012-01-121-18/+30
| | | | | | | The probe and PM restore functions will share this code. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: pci: add PM notification handlers for restore, freeze, thaw, poweroffAmit Shah2012-01-121-2/+92
| | | | | | | | | | | | | | Handle thaw, restore and freeze notifications from the PM core. Expose these to individual virtio drivers that can quiesce and resume vq operations. For drivers not implementing the thaw() method, use the restore method instead. These functions also save device-specific data so that the device can be put in pre-suspend state after resume, and disable and enable the PCI device in the freeze and resume functions, respectively. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: pci: switch to new PM APIAmit Shah2012-01-121-4/+12
| | | | | | | | The older PM API doesn't have a way to get notifications on hibernate events. Switch to the newer one that gives us those notifications. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: add debugging if driver doesn't kick.Rusty Russell2012-01-121-0/+31
| | | | | | | | | | | Under the existing #ifdef DEBUG, check that they don't have more than 1/10 of a second between an add_buf() and a virtqueue_notify()/virtqueue_kick_prepare() call. We could get false positives on a really busy system, but good for development. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: expose added descriptors immediately.Rusty Russell2012-01-121-6/+14
| | | | | | | | | | | | | | | | A virtio driver does virtqueue_add_buf() multiple times before finally calling virtqueue_kick(); previously we only exposed the added buffers in the virtqueue_kick() call. This means we don't need a memory barrier in virtqueue_add_buf(), but it reduces concurrency as the device (ie. host) can't see the buffers until the kick. In the unusual (but now possible) case where a driver does add_buf() and get_buf() without doing a kick, we do need to insert one before our counter wraps. Otherwise we could wrap num_added, and later on not realize that we have passed the marker where we should have kicked. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: avoid modulus operation.Rusty Russell2012-01-121-4/+6
| | | | | | | Since we know vq->vring.num is a power of 2, modulus is lazy (it's asserted in vring_new_virtqueue()). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: support unlocked queue kickRusty Russell2012-01-121-12/+48
| | | | | | | | | | | | | | | | | | | | Based on patch by Christoph for virtio_blk speedup: Split virtqueue_kick to be able to do the actual notification outside the lock protecting the virtqueue. This patch was originally done by Stefan Hajnoczi, but I can't find the original one anymore and had to recreated it from memory. Pointers to the original or corrections for the commit message are welcome. Stefan's patch was here: https://github.com/stefanha/linux/commit/a6d06644e3a58e57a774e77d7dc34c4a5a2e7496 http://www.spinics.net/lists/linux-virtualization/msg14616.html Third time's the charm! Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: rename virtqueue_add_buf_gfp to virtqueue_add_bufRusty Russell2012-01-122-14/+15
| | | | | | | | | Remove wrapper functions. This makes the allocation type explicit in all callers; I used GPF_KERNEL where it seemed obvious, left it at GFP_ATOMIC otherwise. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Christoph Hellwig <hch@lst.de>
* virtio: document functions better.Rusty Russell2012-01-121-1/+91
| | | | | | | | | | | The old documentation is left over from when we used a structure with strategy pointers. And move the documentation to the C file as per kernel practice. Though I disagree... Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Christoph Hellwig <hch@lst.de>
* virtio-balloon: Trivial cleanupsSasha Levin2012-01-121-3/+3
| | | | | | | | | | Trivial changes to remove forgotten junk, format comments, and correct names. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: virtualization@lists.linux-foundation.org Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: harsher barriers for rpmsg.Rusty Russell2012-01-123-17/+25
| | | | | | | | | | | | | | | | | | We were cheating with our barriers; using the smp ones rather than the real device ones. That was fine, until rpmsg came along, which is used to talk to a real device (a non-SMP CPU). Unfortunately, just putting back the real barriers (reverting d57ed95d) causes a performance regression on virtio-pci. In particular, Amos reports netbench's TCP_RR over virtio_net CPU utilization increased up to 35% while throughput went down by up to 14%. By comparison, this branch is in the noise. Reference: https://lkml.org/lkml/2011/12/11/22 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2011-12-023-2/+20
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| * virtio-pci: make reset operation saferMichael S. Tsirkin2011-11-241-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | virtio pci device reset actually just does an I/O write, which in PCI is really posted, that is it can complete on CPU before the device has received it. Further, interrupts might have been pending on another CPU, so device callback might get invoked after reset. This conflicts with how drivers use reset, which is typically: reset unregister a callback running after reset completed can race with unregister, potentially leading to use after free bugs. Fix by flushing out the write, and flushing pending interrupts. This assumes that device is never reset from its vq/config callbacks, or in parallel with being added/removed, document this assumption. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * virtio-mmio: Correct the name of the guest features selectorSasha Levin2011-11-241-1/+1
| | | | | | | | | | | | | | | | | | | | Guest features selector spelling mistake. Cc: Pawel Moll <pawel.moll@arm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: virtualization@lists.linux-foundation.org Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * virtio: add HAS_IOMEM dependency to MMIO platform bus driverHeiko Carstens2011-11-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Fix this compile error on s390: CC [M] drivers/virtio/virtio_mmio.o drivers/virtio/virtio_mmio.c: In function 'vm_get_features': drivers/virtio/virtio_mmio.c:107:2: error: implicit declaration of function 'writel' Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2011-11-211-5/+6
|\| | | | | | | | | | | | | | | | | | | | | | | The forcedeth changes had a conflict with the conversion over to atomic u64 statistics in net-next. The libertas cfg.c code had a conflict with the bss reference counting fix by John Linville in net-next. Conflicts: drivers/net/ethernet/nvidia/forcedeth.c drivers/net/wireless/libertas/cfg.c
| * virtio-pci: fix use after freeMichael S. Tsirkin2011-11-141-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 31a3ddda166cda86d2b5111e09ba4bda5239fae6 introduced a use after free in virtio-pci. The main issue is that the release method signals removal of the virtio device, while remove signals removal of the pci device. For example, on driver removal or hot-unplug, virtio_pci_release_dev is called before virtio_pci_remove. We then might get a crash as virtio_pci_remove tries to use the device freed by virtio_pci_release_dev. We allocate/free all resources together with the pci device, so we can leave the release method empty. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
* | enable virtio_net to return bus_info in ethtool -i consistent with emulated NICsRick Jones2011-11-162-0/+14
|/ | | | | | | | | | Add a new .bus_name to virtio_config_ops then modify virtio_net to call through to it in an ethtool .get_drvinfo routine to report bus_info in ethtool -i output which is consistent with other emulated NICs and the output of lspci. Signed-off-by: Rick Jones <rick.jones2@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds2011-11-063-0/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
| * virtio: Add module.h to drivers/virtio users.Paul Gortmaker2011-10-313-0/+3
| | | | | | | | | | | | | | | | Up to now, the module.h header was as hard to keep out as sunlight. But we are cleaning that up. Fix the virtio users who simply expect module.h to be there in every C file. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | virtio: Add platform bus driver for memory mapped virtio devicePawel Moll2011-11-023-0/+491
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch, based on virtio PCI driver, adds support for memory mapped (platform) virtio device. This should allow environments like qemu to use virtio-based block & network devices even on platforms without PCI support. One can define and register a platform device which resources will describe memory mapped control registers and "mailbox" interrupt. Such device can be also instantiated using the Device Tree node with compatible property equal "virtio,mmio". Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Michael S.Tsirkin <mst@redhat.com> Signed-off-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | virtio: Dont add "config" to list for !per_vq_vectorKrishna Kumar2011-11-021-3/+7
|/ | | | | | | | | | | | | | | For the MSI but non-per_vq_vector case, the config/change vq also gets added to the list of vqs that need to process the MSI interrupt. This is not needed as config has it's own handler (vp_config_changed). In any case, vring_interrupt() finds nothing needs to be done on this vq. I tested this patch by testing the "Fallback:" and "Finally fall back" cases in vp_find_vqs(). Please review. Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* Add ethtool -g support to virtio_netRick Jones2011-10-241-0/+10
| | | | | | | | | | Add support for reporting ring sizes via ethtool -g to the virtio_net driver. Signed-off-by: Rick Jones <rick.jones2@hp.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* virtio: expose for non-virtualization users tooOhad Ben-Cohen2011-07-231-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | virtio has been so far used only in the context of virtualization, and the virtio Kconfig was sourced directly by the relevant arch Kconfigs when VIRTUALIZATION was selected. Now that we start using virtio for inter-processor communications, we need to source the virtio Kconfig outside of the virtualization scope too. Moreover, some architectures might use virtio for both virtualization and inter-processor communications, so directly sourcing virtio might yield unexpected results due to conflicting selections. The simple solution offered by this patch is to always source virtio's Kconfig in drivers/Kconfig, and remove it from the appropriate arch Kconfigs. Additionally, a virtio menu entry has been added so virtio drivers don't show up in the general drivers menu. This way anyone can use virtio, though it's arguably less accessible (and neat!) for virtualization users now. Note: some architectures (mips and sh) seem to have a VIRTUALIZATION menu merely for sourcing virtio's Kconfig, so that menu is removed too. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: add api for delayed callbacksMichael S. Tsirkin2011-05-301-0/+27
| | | | | | | | | | | | | | | | | | | Add an API that tells the other side that callbacks should be delayed until a lot of work has been done. Implement using the new event_idx feature. Note: it might seem advantageous to let the drivers ask for a callback after a specific capacity has been reached. However, as a single head can free many entries in the descriptor table, we don't really have a clue about capacity until get_buf is called. The API is the simplest to implement at the moment, we'll see what kind of hints drivers can pass when there's more than one user of the feature. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_ring: support event idx featureMichael S. Tsirkin2011-05-301-2/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | Support for the new event idx feature: 1. When enabling interrupts, publish the current avail index value to the host to get interrupts on the next update. 2. Use the new avail_event feature to reduce the number of exits from the guest. Simple test with the simulator: [virtio]# time ./virtio_test spurious wakeus: 0x7 real 0m0.169s user 0m0.140s sys 0m0.019s [virtio]# time ./virtio_test --no-event-idx spurious wakeus: 0x11 real 0m0.649s user 0m0.295s sys 0m0.335s Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio balloon: kill tell-host-first logicDave Hansen2011-05-301-13/+8
| | | | | | | | | | | | | | | | | | | | | | | The virtio balloon driver has a VIRTIO_BALLOON_F_MUST_TELL_HOST feature bit. Whenever the bit is set, the guest kernel must always tell the host before we free pages back to the allocator. Without this feature, we might free a page (and have another user touch it) while the hypervisor is unprepared for it. But, if the bit is _not_ set, we are under no obligation to reverse the order; we're under no obligation to do _anything_. As of now, qemu-kvm defines the bit, but doesn't set it. This patch makes the "tell host first" logic the only case. This should make everybody happy, and reduce the amount of untested or untestable code in the kernel. This _also_ means that we don't have to preserve a pfn list after the pages are freed, which should let us get rid of some temporary storage (vb->pfns) eventually. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio_pci: Prevent double-free of pci regions after device hot-unplugAmit Shah2011-04-211-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | In the case where a virtio-console port is in use (opened by a program) and a virtio-console device is removed, the port is kept around but all the virtio-related state is assumed to be gone. When the port is finally released (close() called), we call device_destroy() on the port's device. This results in the parent device's structures to be freed as well. This includes the PCI regions for the virtio-console PCI device. Once this is done, however, virtio_pci_release_dev() kicks in, as the last ref to the virtio device is now gone, and attempts to do pci_iounmap(pci_dev, vp_dev->ioaddr); pci_release_regions(pci_dev); pci_disable_device(pci_dev); which results in a double-free warning. Move the code that releases regions, etc., to the virtio_pci_remove() function, and all that's now left in release_dev is the final freeing of the vp_dev. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: Decrement avail idx on buffer detachAmit Shah2011-04-211-0/+1
| | | | | | | | | | | | | | | | | | When detaching a buffer from a vq, the avail.idx value should be decremented as well. This was noticed by hot-unplugging a virtio console port and then plugging in a new one on the same number (re-using the vqs which were just 'disowned'). qemu reported 'Guest moved used index from 0 to 256' when any IO was attempted on the new port. CC: stable@kernel.org Reported-by: juzhang <juzhang@redhat.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: remove virtio-pci root deviceMilton Miller2011-01-201-18/+2
| | | | | | | | | | | | | | | | | | | | | | | We sometimes need to map between the virtio device and the given pci device. One such use is OS installer that gets the boot pci device from BIOS and needs to find the relevant block device. Since it can't, installation fails. Instead of creating a top-level devices/virtio-pci directory, create each device under the corresponding pci device node. Symlinks to all virtio-pci devices can be found under the pci driver link in bus/pci/drivers/virtio-pci/devices, and all virtio devices under drivers/bus/virtio/devices. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Gleb Natapov <gleb@redhat.com> Tested-by: "Daniel P. Berrange" <berrange@redhat.com> Cc: stable@kernel.org
* virtio: fix format of sysfs driver/vendor filesStephen Hemminger2010-11-241-3/+3
| | | | | | | | | | | | The sysfs files for virtio produce the wrong format and are missing the required newline. The output for virtio bus vendor/device should have the same format as the corresponding entries for PCI devices. Although this technically changes the ABI for sysfs, these files were broken to start with! Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* virtio: return correct capacity to usersMichael S. Tsirkin2010-11-241-3/+0
| | | | | | | | | | | | | | We can't rely on indirect buffers for capacity calculations because they need a memory allocation which might fail. In particular, virtio_net can get into this situation under stress, and it drops packets and performs badly. So return the number of buffers we can guarantee users. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reported-By: Krishna Kumar2 <krkumar2@in.ibm.com>
* virtio: fix oops on OOMMichael S. Tsirkin2010-07-261-2/+3
| | | | | | | | | | | | | | | | | virtio ring was changed to return an error code on OOM, but one caller was missed and still checks for vq->vring.num. The fix is just to check for <0 error code. Long term it might make sense to change goto add_head to just return an error on oom instead, but let's apply a minimal fix for 2.6.35. Reported-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Tested-by: Chris Mason <chris.mason@oracle.com> Cc: stable@kernel.org # .34.x Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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