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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>
2011-11-14virtio-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 ↵Linus Torvalds3-0/+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
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 ↵Linus Torvalds2-32/+29
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus * '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 ↵Tejun Heo3-0/+3
implicit slab.h inclusion from percpu.h 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>
2010-02-24virtio: fix balloon without VIRTIO_BALLOON_F_STATS_VQRusty Russell1-0/+1
When running under qemu-kvm-0.11.0: BUG: unable to handle kernel paging request at 56e58955 ... Process vballoon (pid: 1297, ti=c7976000 task=c70a6ca0 task.ti=c7 ... Call Trace: [<c88253a3>] ? balloon+0x1b3/0x440 [virtio_balloon] [<c041c2d7>] ? schedule+0x327/0x9d0 [<c88251f0>] ? balloon+0x0/0x440 [virtio_balloon] [<c014a2d4>] ? kthread+0x74/0x80 [<c014a260>] ? kthread+0x0/0x80 [<c0103b36>] ? kernel_thread_helper+0x6/0x30 need_stats_update should be zero-initialized. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Adam Litke <agl@us.ibm.com>
2010-02-24virtio: Fix scheduling while atomic in virtio_balloon statsAdam Litke1-4/+18
This is a fix for my earlier patch: "virtio: Add memory statistics reporting to the balloon driver (V4)". I discovered that all_vm_events() can sleep and therefore stats collection cannot be done in interrupt context. One solution is to handle the interrupt by noting that stats need to be collected and waking the existing vballoon kthread which will complete the work via stats_handle_request(). Rusty, is this a saner way of doing business? There is one issue that I would like a broader opinion on. In stats_request, I update vb->need_stats_update and then wake up the kthread. The kthread uses vb->need_stats_update as a condition variable. Do I need a memory barrier between the update and wake_up to ensure that my kthread sees the correct value? My testing suggests that it is not needed but I would like some confirmation from the experts. Signed-off-by: Adam Litke <agl@us.ibm.com> To: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@linux.vnet.ibm.com> Cc: linux-kernel@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-02-24virtio: Add memory statistics reporting to the balloon driver (V4)Adam Litke1-8/+86
Changes since V3: - Do not do endian conversions as they will be done in the host - Report stats that reference a quantity of memory in bytes - Minor coding style updates Changes since V2: - Increase stat field size to 64 bits - Report all sizes in kb (not pages) - Drop anon_pages stat and fix endianness conversion Changes since V1: - Use a virtqueue instead of the device config space When using ballooning to manage overcommitted memory on a host, a system for guests to communicate their memory usage to the host can provide information that will minimize the impact of ballooning on the guests. The current method employs a daemon running in each guest that communicates memory statistics to a host daemon at a specified time interval. The host daemon aggregates this information and inflates and/or deflates balloons according to the level of host memory pressure. This approach is effective but overly complex since a daemon must be installed inside each guest and coordinated to communicate with the host. A simpler approach is to collect memory statistics in the virtio balloon driver and communicate them directly to the hypervisor. This patch enables the guest-side support by adding stats collection and reporting to the virtio balloon driver. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Anthony Liguori <anthony@codemonkey.ws> Cc: virtualization@lists.linux-foundation.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (minor fixes)
2010-02-24Add __devexit_p around reference to virtio_pci_removeJamie Lokier1-1/+1
This is needed to compile with CONFIG_VIRTIO_PCI=y, because virtio_pci_remove is marked __devexit. Signed-off-by: Jamie Lokier <jamie@shareable.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-01-16virtio: fix section mismatch warningsJeff Mahoney1-3/+3
Fix fixes the following warnings by renaming the driver structures to be suffixed with _driver. WARNING: drivers/virtio/virtio_balloon.o(.data+0x88): Section mismatch in reference from the variable virtio_balloon to the function .devexit.text:virtballoon_remove() WARNING: drivers/char/hw_random/virtio-rng.o(.data+0x88): Section mismatch in reference from the variable virtio_rng to the function .devexit.text:virtrng_remove() Signed-off-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-29virtio: order used ring after used index readMichael S. Tsirkin1-0/+3
On SMP guests, reads from the ring might bypass used index reads. This causes guest crashes because host writes to used index to signal ring data readiness. Fix this by inserting rmb before used ring reads. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2009-10-29virtio-pci: fix per-vq MSI-X request logicMichael S. Tsirkin1-12/+15
Commit f68d24082e22ccee3077d11aeb6dc5354f0ca7f1 in 2.6.32-rc1 broke requesting IRQs for per-VQ MSI-X vectors: - vector number was used instead of the vector itself - we try to request an IRQ for VQ which does not have a callback handler This is a regression that causes warnings in kernel log, potentially lower performance as we need to scan vq list, and might cause system failure if the interrupt requested is in fact needed by another system. This was not noticed earlier because in most cases we were falling back on shared interrupt for all vqs. The warnings often look like this: virtio-pci 0000:00:03.0: irq 26 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 27 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 28 for MSI/MSI-X IRQ handler type mismatch for IRQ 1 current handler: i8042 Pid: 2400, comm: modprobe Tainted: G W 2.6.32-rc3-11952-gf3ed8d8-dirty #1 Call Trace: [<ffffffff81072aed>] ? __setup_irq+0x299/0x304 [<ffffffff81072ff3>] ? request_threaded_irq+0x144/0x1c1 [<ffffffff813455af>] ? vring_interrupt+0x0/0x30 [<ffffffff81346598>] ? vp_try_to_find_vqs+0x583/0x5c7 [<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net] [<ffffffff81346609>] ? vp_find_vqs+0x2d/0x83 [<ffffffff81345d00>] ? vp_get+0x3c/0x4e [<ffffffffa0016373>] ? virtnet_probe+0x2f1/0x428 [virtio_net] [<ffffffffa0015188>] ? skb_recv_done+0x0/0x34 [virtio_net] [<ffffffffa00150d8>] ? skb_xmit_done+0x0/0x39 [virtio_net] [<ffffffff8110ab92>] ? sysfs_do_create_link+0xcb/0x116 [<ffffffff81345cc2>] ? vp_get_status+0x14/0x16 [<ffffffff81345464>] ? virtio_dev_probe+0xa9/0xc8 [<ffffffff8122b11c>] ? driver_probe_device+0x8d/0x128 [<ffffffff8122b206>] ? __driver_attach+0x4f/0x6f [<ffffffff8122b1b7>] ? __driver_attach+0x0/0x6f [<ffffffff8122a9f9>] ? bus_for_each_dev+0x43/0x74 [<ffffffff8122a374>] ? bus_add_driver+0xea/0x22d [<ffffffff8122b4a3>] ? driver_register+0xa7/0x111 [<ffffffffa001a000>] ? init+0x0/0xc [virtio_net] [<ffffffff81009051>] ? do_one_initcall+0x50/0x148 [<ffffffff8106e117>] ? sys_init_module+0xc5/0x21a [<ffffffff8100af02>] ? system_call_fastpath+0x16/0x1b virtio-pci 0000:00:03.0: irq 26 for MSI/MSI-X virtio-pci 0000:00:03.0: irq 27 for MSI/MSI-X Reported-by: Marcelo Tosatti <mtosatti@redhat.com> Reported-by: Shirley Ma <xma@us.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-10-22move virtballoon_remove to .devexit.textUwe Kleine-König1-1/+1
The function virtballoon_remove is used only wrapped by __devexit_p so define it using __devexit. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-10-22virtio: let header files include virtio_ids.hChristian Borntraeger1-1/+0
Rusty, commit 3ca4f5ca73057a617f9444a91022d7127041970a virtio: add virtio IDs file moved all device IDs into a single file. While the change itself is a very good one, it can break userspace applications. For example if a userspace tool wanted to get the ID of virtio_net it used to include virtio_net.h. This does no longer work, since virtio_net.h does not include virtio_ids.h. This patch moves all "#include <linux/virtio_ids.h>" from the C files into the header files, making the header files compatible with the old ones. In addition, this patch exports virtio_ids.h to userspace. CC: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23virtio: add virtio IDs fileFernando Luis Vazquez Cao1-0/+1
Virtio IDs are spread all over the tree which makes assigning new IDs bothersome. Putting them together should make the process less error-prone. Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23virtio: make add_buf return capacity remainingRusty Russell2-2/+6
This API change means that virtio_net can tell how much capacity remains for buffers. It's necessarily fuzzy, since VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors in one, *if* we can kmalloc. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Dinesh Subhraveti <dineshs@us.ibm.com>
2009-09-23virtio_pci: minor MSI-X cleanupsRusty Russell1-55/+70
1) Rename vp_request_vectors to vp_request_msix_vectors, and take non-MSI-X case out to caller. 2) Comment weird pci_enable_msix API 3) Rename vp_find_vq to setup_vq. 4) Fix spaces to tabs 5) Make nvectors calc internal to vp_try_to_find_vqs() 6) Rename vector to msix_vector for more clarity. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com>
2009-07-30virtio: refactor find_vqsMichael S. Tsirkin1-93/+119
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>
2009-07-30virtio: delete vq from listMichael S. Tsirkin1-1/+5
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>
2009-07-30virtio: fix memory leak on device removalMichael S. Tsirkin1-13/+15
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>