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2012-01-12virtio: balloon: Add freeze, restore handlers to support S4Amit Shah1-0/+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>
2012-01-12virtio: balloon: Move vq initialization into separate functionAmit Shah1-18/+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>
2012-01-12virtio: pci: add PM notification handlers for restore, freeze, thaw, poweroffAmit Shah1-2/+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>
2012-01-12virtio: pci: switch to new PM APIAmit Shah1-4/+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>
2012-01-12virtio: add debugging if driver doesn't kick.Rusty Russell1-0/+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>
2012-01-12virtio: expose added descriptors immediately.Rusty Russell1-6/+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>
2012-01-12virtio: avoid modulus operation.Rusty Russell1-4/+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>
2012-01-12virtio: support unlocked queue kickRusty Russell1-12/+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>
2012-01-12virtio: rename virtqueue_add_buf_gfp to virtqueue_add_bufRusty Russell2-14/+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>
2012-01-12virtio: document functions better.Rusty Russell1-1/+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>
2012-01-12virtio-balloon: Trivial cleanupsSasha Levin1-3/+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>
2012-01-12virtio: harsher barriers for rpmsg.Rusty Russell3-17/+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>
2011-12-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller3-2/+20
2011-11-24virtio-pci: make reset operation saferMichael S. Tsirkin1-0/+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>
2011-11-24virtio-mmio: Correct the name of the guest features selectorSasha Levin1-1/+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>
2011-11-24virtio: add HAS_IOMEM dependency to MMIO platform bus driverHeiko Carstens1-1/+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>
2011-11-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-5/+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
2011-11-16enable virtio_net to return bus_info in ethtool -i consistent with emulated NICsRick Jones2-0/+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>
2011-11-14virtio-pci: fix use after freeMichael S. Tsirkin1-5/+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
2011-11-06Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linuxLinus Torvalds3-0/+3
* '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
2011-11-02virtio: Add platform bus driver for memory mapped virtio devicePawel Moll3-0/+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>
2011-11-02virtio: Dont add "config" to list for !per_vq_vectorKrishna Kumar1-3/+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>
2011-10-31virtio: Add module.h to drivers/virtio users.Paul Gortmaker3-0/+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>
2011-10-24Add ethtool -g support to virtio_netRick Jones1-0/+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>
2011-07-23virtio: expose for non-virtualization users tooOhad Ben-Cohen1-0/+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>
2011-05-30virtio: add api for delayed callbacksMichael S. Tsirkin1-0/+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>
2011-05-30virtio_ring: support event idx featureMichael S. Tsirkin1-2/+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>
2011-05-30virtio balloon: kill tell-host-first logicDave Hansen1-13/+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>
2011-04-21virtio_pci: Prevent double-free of pci regions after device hot-unplugAmit Shah1-7/+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>
2011-04-21virtio: Decrement avail idx on buffer detachAmit Shah1-0/+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>
2011-01-20virtio: remove virtio-pci root deviceMilton Miller1-18/+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
2010-11-24virtio: fix format of sysfs driver/vendor filesStephen Hemminger1-3/+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>
2010-11-24virtio: return correct capacity to usersMichael S. Tsirkin1-3/+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>
2010-07-26virtio: fix oops on OOMMichael S. Tsirkin1-2/+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>
2010-06-23virtio-pci: disable msi at startupMichael S. Tsirkin1-0/+3
virtio-pci resets the device at startup by writing to the status register, but this does not clear the pci config space, specifically msi enable status which affects register layout. This breaks things like kdump when they try to use e.g. virtio-blk. Fix by forcing msi off at startup. Since pci.c already has a routine to do this, we export and use it instead of duplicating code. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: linux-pci@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2010-06-23virtio: return ENOMEM on out of memoryMichael S. Tsirkin1-1/+1
add_buf returns ring size on out of memory, this is not what devices expect. 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 # .34.x
2010-05-21Merge branch 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds2-32/+29
* 'virtio' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (27 commits) drivers/char: Eliminate use after free virtio: console: Accept console size along with resize control message virtio: console: Store each console's size in the console structure virtio: console: Resize console port 0 on config intr only if multiport is off virtio: console: Add support for nonblocking write()s virtio: console: Rename wait_is_over() to will_read_block() virtio: console: Don't always create a port 0 if using multiport virtio: console: Use a control message to add ports virtio: console: Move code around for future patches virtio: console: Remove config work handler virtio: console: Don't call hvc_remove() on unplugging console ports virtio: console: Return -EPIPE to hvc_console if we lost the connection virtio: console: Let host know of port or device add failures virtio: console: Add a __send_control_msg() that can send messages without a valid port virtio: Revert "virtio: disable multiport console support." virtio: add_buf_gfp trans_virtio: use virtqueue_xxx wrappers virtio-rng: use virtqueue_xxx wrappers virtio_ring: remove a level of indirection virtio_net: use virtqueue_xxx wrappers ... Fix up conflicts in drivers/net/virtio_net.c due to new virtqueue_xxx wrappers changes conflicting with some other cleanups.
2010-05-19virtio: add_buf_gfpMichael S. Tsirkin1-9/+11
Add an add_buf variant that gets gfp parameter. Use that to allocate indirect buffers. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-05-19virtio_ring: remove a level of indirectionMichael S. Tsirkin1-20/+16
We have a single virtqueue_ops implementation, and it seems unlikely we'll get another one at this point. So let's remove an unnecessary level of indirection: it would be very easy to re-add it if another implementation surfaces. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-05-19virtio_balloon: use virtqueue_xxx wrappersMichael S. Tsirkin1-9/+8
Switch virtio_balloon to new virtqueue_xxx wrappers. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-04-23Merge branch 'master' into for-nextJiri Kosina3-1/+5
2010-04-22virtio: Fix GFP flags passed from the virtio balloon driverBalbir Singh1-1/+2
The virtio balloon driver can dig into the reservation pools of the OS to satisfy a balloon request. This is not advisable and other balloon drivers (drivers/xen/balloon.c) avoid this as well. The patch also adds changes to avoid printing a warning if allocation fails, since we retry after sometime anyway. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: kvm <kvm@vger.kernel.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.hTejun Heo3-0/+3
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-16Fix typos in commentsThomas Weber1-1/+1
[Ss]ytem => [Ss]ystem udpate => update paramters => parameters orginal => original Signed-off-by: Thomas Weber <swirl@gmx.li> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-03-02virtio: set pci bus master enable bitMichael S. Tsirkin1-0/+1
As all virtio devices perform DMA, we must enable bus mastering for them to be spec compliant. This patch fixes hotplug of virtio devices with Linux guests and qemu 0.11-0.12. Tested-by: Alexander Graf <agraf@suse.de> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2010-02-28virtio: fix out of range array accessMichael S. Tsirkin1-1/+2
I have observed the following error on virtio-net module unload: ------------[ cut here ]------------ WARNING: at kernel/irq/manage.c:858 __free_irq+0xa0/0x14c() Hardware name: Bochs Trying to free already-free IRQ 0 Modules linked in: virtio_net(-) virtio_blk virtio_pci virtio_ring virtio af_packet e1000 shpchp aacraid uhci_hcd ohci_hcd ehci_hcd [last unloaded: scsi_wait_scan] Pid: 1957, comm: rmmod Not tainted 2.6.33-rc8-vhost #24 Call Trace: [<ffffffff8103e195>] warn_slowpath_common+0x7c/0x94 [<ffffffff8103e204>] warn_slowpath_fmt+0x41/0x43 [<ffffffff810a7a36>] ? __free_pages+0x5a/0x70 [<ffffffff8107cc00>] __free_irq+0xa0/0x14c [<ffffffff8107cceb>] free_irq+0x3f/0x65 [<ffffffffa0081424>] vp_del_vqs+0x81/0xb1 [virtio_pci] [<ffffffffa0091d29>] virtnet_remove+0xda/0x10b [virtio_net] [<ffffffffa0075200>] virtio_dev_remove+0x22/0x4a [virtio] [<ffffffff812709ee>] __device_release_driver+0x66/0xac [<ffffffff81270ab7>] driver_detach+0x83/0xa9 [<ffffffff8126fc66>] bus_remove_driver+0x91/0xb4 [<ffffffff81270fcf>] driver_unregister+0x6c/0x74 [<ffffffffa0075418>] unregister_virtio_driver+0xe/0x10 [virtio] [<ffffffffa0091c4d>] fini+0x15/0x17 [virtio_net] [<ffffffff8106997b>] sys_delete_module+0x1c3/0x230 [<ffffffff81007465>] ? old_ich_force_enable_hpet+0x117/0x164 [<ffffffff813bb720>] ? do_page_fault+0x29c/0x2cc [<ffffffff81028e58>] sysenter_dispatch+0x7/0x27 ---[ end trace 15e88e4c576cc62b ]--- The bug is in virtio-pci: we use msix_vector as array index to get irq entry, but some vqs do not have a dedicated vector so this causes an out of bounds access. By chance, we seem to often get 0 value, which results in this error. Fix by verifying that vector is legal before using it as index. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Anthony Liguori <aliguori@us.ibm.com> Acked-by: Shirley Ma <xma@us.ibm.com> Acked-by: Amit Shah <amit.shah@redhat.com>
2010-02-24virtio: Initialize vq->data entries to NULLAmit Shah1-1/+4
vq operations depend on vq->data[i] being NULL to figure out if the vq entry is in use (since the previous patch). We have to initialize them to NULL to ensure we don't work with junk data and trigger false BUG_ONs. Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Shirley Ma <xma@us.ibm.com>
2010-02-24virtio: Add ability to detach unused buffers from vringsShirley Ma1-0/+25
There's currently no way for a virtio driver to ask for unused buffers, so it has to keep a list itself to reclaim them at shutdown. This is redundant, since virtio_ring stores that information. So add a new hook to do this. Signed-off-by: Shirley Ma <xma@us.ibm.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-02-24virtio: use smp_XX barriers on SMPMichael S. Tsirkin1-4/+22
virtio is communicating with a virtual "device" that actually runs on another host processor. Thus SMP barriers can be used to control memory access ordering. Where possible, we should use SMP barriers which are more lightweight than mandatory barriers, because mandatory barriers also control MMIO effects on accesses through relaxed memory I/O windows (which virtio does not use) (compare specifically smp_rmb and rmb on x86_64). We can't just use smp_mb and friends though, because we must force memory ordering even if guest is UP since host could be running on another CPU, but SMP barriers are defined to barrier() in that configuration. So, for UP fall back to mandatory barriers instead. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-02-24virtio: remove bogus barriers from DEBUG version of virtio_ring.cRusty Russell1-2/+1
With DEBUG defined, we add an ->in_use flag to detect if the caller invokes two virtio methods in parallel. The barriers attempt to ensure timely update of the ->in_use flag. But they're voodoo: if we need these barriers it implies that the calling code doesn't have sufficient synchronization to ensure the code paths aren't invoked at the same time anyway, and we want to detect it. Also, adding barriers changes timing, so turning on debug has more chance of hiding real problems. Thanks to MST for drawing my attention to this code... CC: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>