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2020-04-17virtio-balloon: Avoid using the word 'report' when referring to free page ↵Alexander Duyck
hinting It can be confusing to have multiple features within the same driver that are using the same verbage. As such this patch is creating a union of free_page_report_cmd_id with free_page_hint_cmd_id so that we can clean-up the userspace code a bit in terms of readability while maintaining the functionality of legacy code. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Link: https://lore.kernel.org/r/20200415174318.13597.99753.stgit@localhost.localdomain Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-17virtio-balloon: make virtballoon_free_page_report() staticJason Yan
Fix the following sparse warning: drivers/virtio/virtio_balloon.c:168:5: warning: symbol 'virtballoon_free_page_report' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Link: https://lore.kernel.org/r/20200409085047.45483-1-yanaijie@huawei.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-17vdpa: make vhost, virtio depend on menuMichael S. Tsirkin
If user did not configure any vdpa drivers, neither vhost nor virtio vdpa are going to be useful. So there's no point in prompting for these and selecting vdpa core automatically. Simplify configuration by making virtio and vhost vdpa drivers depend on vdpa menu entry. Once done, we no longer need a separate menu entry, so also get rid of this. While at it, fix up the IFC entry: VDPA->vDPA for consistency with other places. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2020-04-17virtio_input: pull in slab.hMichael S. Tsirkin
In preparation to virtio header changes, include slab.h directly as this module is using it. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-08Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio updates from Michael Tsirkin: - Some bug fixes - The new vdpa subsystem with two first drivers * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio-balloon: Revert "virtio-balloon: Switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOM" vdpa: move to drivers/vdpa virtio: Intel IFC VF driver for VDPA vdpasim: vDPA device simulator vhost: introduce vDPA-based backend virtio: introduce a vDPA based transport vDPA: introduce vDPA bus vringh: IOTLB support vhost: factor out IOTLB vhost: allow per device message handler vhost: refine vhost and vringh kconfig virtio-balloon: Switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOM virtio-net: Introduce hash report feature virtio-net: Introduce RSS receive steering feature virtio-net: Introduce extended RSC feature tools/virtio: option to build an out of tree module
2020-04-07virtio-balloon: switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOMDavid Hildenbrand
Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") changed the behavior when deflation happens automatically. Instead of deflating when called by the OOM handler, the shrinker is used. However, the balloon is not simply some other slab cache that should be shrunk when under memory pressure. The shrinker does not have a concept of priorities yet, so this behavior cannot be configured. Eventually once that is in place, we might want to switch back after doing proper testing. There was a report that this results in undesired side effects when inflating the balloon to shrink the page cache. [1] "When inflating the balloon against page cache (i.e. no free memory remains) vmscan.c will both shrink page cache, but also invoke the shrinkers -- including the balloon's shrinker. So the balloon driver allocates memory which requires reclaim, vmscan gets this memory by shrinking the balloon, and then the driver adds the memory back to the balloon. Basically a busy no-op." The name "deflate on OOM" makes it pretty clear when deflation should happen - after other approaches to reclaim memory failed, not while reclaiming. This allows to minimize the footprint of a guest - memory will only be taken out of the balloon when really needed. Keep using the shrinker for VIRTIO_BALLOON_F_FREE_PAGE_HINT, because this has no such side effects. Always register the shrinker with VIRTIO_BALLOON_F_FREE_PAGE_HINT now. We are always allowed to reuse free pages that are still to be processed by the guest. The hypervisor takes care of identifying and resolving possible races between processing a hinting request and the guest reusing a page. In contrast to pre commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker"), don't add a module parameter to configure the number of pages to deflate on OOM. Can be re-added if really needed. Also, pay attention that leak_balloon() returns the number of 4k pages - convert it properly in virtio_balloon_oom_notify(). Testing done by Tyler for future reference: Test setup: VM with 16 CPU, 64GB RAM. Running Debian 10. We have a 42 GB file full of random bytes that we continually cat to /dev/null. This fills the page cache as the file is read. Meanwhile, we trigger the balloon to inflate, with a target size of 53 GB. This setup causes the balloon inflation to pressure the page cache as the page cache is also trying to grow. Afterwards we shrink the balloon back to zero (so total deflate == total inflate). Without this patch (kernel 4.19.0-5): Inflation never reaches the target until we stop the "cat file > /dev/null" process. Total inflation time was 542 seconds. The longest period that made no net forward progress was 315 seconds. Result of "grep balloon /proc/vmstat" after the test: balloon_inflate 154828377 balloon_deflate 154828377 With this patch (kernel 5.6.0-rc4+): Total inflation duration was 63 seconds. No deflate-queue activity occurs when pressuring the page-cache. Result of "grep balloon /proc/vmstat" after the test: balloon_inflate 12968539 balloon_deflate 12968539 Conclusion: This patch fixes the issue. In the test it reduced inflate/deflate activity by 12x, and reduced inflation time by 8.6x. But more importantly, if we hadn't killed the "cat file > /dev/null" process then, without the patch, the inflation process would never reach the target. [1] https://www.spinics.net/lists/linux-virtualization/msg40863.html Link: http://lkml.kernel.org/r/20200311135523.18512-2-david@redhat.com Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Tyler Sanderson <tysand@google.com> Tested-by: Tyler Sanderson <tysand@google.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Nadav Amit <namit@vmware.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07virtio-balloon: add support for providing free page reports to hostAlexander Duyck
Add support for the page reporting feature provided by virtio-balloon. Reporting differs from the regular balloon functionality in that is is much less durable than a standard memory balloon. Instead of creating a list of pages that cannot be accessed the pages are only inaccessible while they are being indicated to the virtio interface. Once the interface has acknowledged them they are placed back into their respective free lists and are once again accessible by the guest system. Unlike a standard balloon we don't inflate and deflate the pages. Instead we perform the reporting, and once the reporting is completed it is assumed that the page has been dropped from the guest and will be faulted back in the next time the page is accessed. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pagupta@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Yang Zhang <yang.zhang.wz@gmail.com> Cc: wei qi <weiqi4@huawei.com> Link: http://lkml.kernel.org/r/20200211224657.29318.68624.stgit@localhost.localdomain Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07virtio-balloon: pull page poisoning config out of free page hintingAlexander Duyck
Currently the page poisoning setting wasn't being enabled unless free page hinting was enabled. However we will need the page poisoning tracking logic as well for free page reporting. As such pull it out and make it a separate bit of config in the probe function. In addition we need to add support for the more recent init_on_free feature which expects a behavior similar to page poisoning in that we expect the page to be pre-zeroed. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pagupta@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Yang Zhang <yang.zhang.wz@gmail.com> Cc: wei qi <weiqi4@huawei.com> Link: http://lkml.kernel.org/r/20200211224646.29318.695.stgit@localhost.localdomain Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07virtio-balloon: Revert "virtio-balloon: Switch back to OOM handler for ↵Michael S. Tsirkin
VIRTIO_BALLOON_F_DEFLATE_ON_OOM" This reverts commit 5a6b4cc5b7a1892a8d7f63d6cbac6e0ae2a9d031. It has been queued properly in the akpm tree, this version is just creating conflicts. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-02vdpa: move to drivers/vdpaMichael S. Tsirkin
We have both vhost and virtio drivers that depend on vdpa. It's easier to locate it at a top level directory otherwise we run into issues e.g. if vhost is built-in but virtio is modular. Let's just move it up a level. Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-02virtio: Intel IFC VF driver for VDPAZhu Lingshan
This commit introduced two layers to drive IFC VF: (1) ifcvf_base layer, which handles IFC VF NIC hardware operations and configurations. (2) ifcvf_main layer, which complies to VDPA bus framework, implemented device operations for VDPA bus, handles device probe, bus attaching, vring operations, etc. Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Signed-off-by: Bie Tiwei <tiwei.bie@intel.com> Signed-off-by: Wang Xiao <xiao.w.wang@intel.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200326140125.19794-10-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-02vdpasim: vDPA device simulatorJason Wang
This patch implements a software vDPA networking device. The datapath is implemented through vringh and workqueue. The device has an on-chip IOMMU which translates IOVA to PA. For kernel virtio drivers, vDPA simulator driver provides dma_ops. For vhost driers, set_map() methods of vdpa_config_ops is implemented to accept mappings from vhost. Currently, vDPA device simulator will loopback TX traffic to RX. So the main use case for the device is vDPA feature testing, prototyping and development. Note, there's no management API implemented, a vDPA device will be registered once the module is probed. We need to handle this in the future development. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200326140125.19794-9-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-01virtio: introduce a vDPA based transportJason Wang
This patch introduces a vDPA transport for virtio. This is used to use kernel virtio driver to drive the vDPA device that is capable of populating virtqueue directly. A new virtio-vdpa driver will be registered to the vDPA bus, when a new virtio-vdpa device is probed, it will register the device with vdpa based config ops. This means it is a software transport between vDPA driver and vDPA device. The transport was implemented through bus_ops of vDPA parent. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200326140125.19794-7-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-01vDPA: introduce vDPA busJason Wang
vDPA device is a device that uses a datapath which complies with the virtio specifications with vendor specific control path. vDPA devices can be both physically located on the hardware or emulated by software. vDPA hardware devices are usually implemented through PCIE with the following types: - PF (Physical Function) - A single Physical Function - VF (Virtual Function) - Device that supports single root I/O virtualization (SR-IOV). Its Virtual Function (VF) represents a virtualized instance of the device that can be assigned to different partitions - ADI (Assignable Device Interface) and its equivalents - With technologies such as Intel Scalable IOV, a virtual device (VDEV) composed by host OS utilizing one or more ADIs. Or its equivalent like SF (Sub function) from Mellanox. >From a driver's perspective, depends on how and where the DMA translation is done, vDPA devices are split into two types: - Platform specific DMA translation - From the driver's perspective, the device can be used on a platform where device access to data in memory is limited and/or translated. An example is a PCIE vDPA whose DMA request was tagged via a bus (e.g PCIE) specific way. DMA translation and protection are done at PCIE bus IOMMU level. - Device specific DMA translation - The device implements DMA isolation and protection through its own logic. An example is a vDPA device which uses on-chip IOMMU. To hide the differences and complexity of the above types for a vDPA device/IOMMU options and in order to present a generic virtio device to the upper layer, a device agnostic framework is required. This patch introduces a software vDPA bus which abstracts the common attributes of vDPA device, vDPA bus driver and the communication method (vdpa_config_ops) between the vDPA device abstraction and the vDPA bus driver. This allows multiple types of drivers to be used for vDPA device like the virtio_vdpa and vhost_vdpa driver to operate on the bus and allow vDPA device could be used by either kernel virtio driver or userspace vhost drivers as: virtio drivers vhost drivers | | [virtio bus] [vhost uAPI] | | virtio device vhost device virtio_vdpa drv vhost_vdpa drv \ / [vDPA bus] | vDPA device hardware drv | [hardware bus] | vDPA hardware With the abstraction of vDPA bus and vDPA bus operations, the difference and complexity of the under layer hardware is hidden from upper layer. The vDPA bus drivers on top can use a unified vdpa_config_ops to control different types of vDPA device. Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200326140125.19794-6-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-03-23virtio-balloon: Switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOMDavid Hildenbrand
Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") changed the behavior when deflation happens automatically. Instead of deflating when called by the OOM handler, the shrinker is used. However, the balloon is not simply some slab cache that should be shrunk when under memory pressure. The shrinker does not have a concept of priorities, so this behavior cannot be configured. There was a report that this results in undesired side effects when inflating the balloon to shrink the page cache. [1] "When inflating the balloon against page cache (i.e. no free memory remains) vmscan.c will both shrink page cache, but also invoke the shrinkers -- including the balloon's shrinker. So the balloon driver allocates memory which requires reclaim, vmscan gets this memory by shrinking the balloon, and then the driver adds the memory back to the balloon. Basically a busy no-op." The name "deflate on OOM" makes it pretty clear when deflation should happen - after other approaches to reclaim memory failed, not while reclaiming. This allows to minimize the footprint of a guest - memory will only be taken out of the balloon when really needed. Especially, a drop_slab() will result in the whole balloon getting deflated - undesired. While handling it via the OOM handler might not be perfect, it keeps existing behavior. If we want a different behavior, then we need a new feature bit and document it properly (although, there should be a clear use case and the intended effects should be well described). Keep using the shrinker for VIRTIO_BALLOON_F_FREE_PAGE_HINT, because this has no such side effects. Always register the shrinker with VIRTIO_BALLOON_F_FREE_PAGE_HINT now. We are always allowed to reuse free pages that are still to be processed by the guest. The hypervisor takes care of identifying and resolving possible races between processing a hinting request and the guest reusing a page. In contrast to pre commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker"), don't add a moodule parameter to configure the number of pages to deflate on OOM. Can be re-added if really needed. Also, pay attention that leak_balloon() returns the number of 4k pages - convert it properly in virtio_balloon_oom_notify(). Note1: using the OOM handler is frowned upon, but it really is what we need for this feature. Note2: without VIRTIO_BALLOON_F_MUST_TELL_HOST (iow, always with QEMU) we could actually skip sending deflation requests to our hypervisor, making the OOM path *very* simple. Besically freeing pages and updating the balloon. If the communication with the host ever becomes a problem on this call path. [1] https://www.spinics.net/lists/linux-virtualization/msg40863.html Test report by Tyler Sanderson: Test setup: VM with 16 CPU, 64GB RAM. Running Debian 10. We have a 42 GB file full of random bytes that we continually cat to /dev/null. This fills the page cache as the file is read. Meanwhile we trigger the balloon to inflate, with a target size of 53 GB. This setup causes the balloon inflation to pressure the page cache as the page cache is also trying to grow. Afterwards we shrink the balloon back to zero (so total deflate = total inflate). Without patch (kernel 4.19.0-5): Inflation never reaches the target until we stop the "cat file > /dev/null" process. Total inflation time was 542 seconds. The longest period that made no net forward progress was 315 seconds (see attached graph). Result of "grep balloon /proc/vmstat" after the test: balloon_inflate 154828377 balloon_deflate 154828377 With patch (kernel 5.6.0-rc4+): Total inflation duration was 63 seconds. No deflate-queue activity occurs when pressuring the page-cache. Result of "grep balloon /proc/vmstat" after the test: balloon_inflate 12968539 balloon_deflate 12968539 Conclusion: This patch fixes the issue. In the test it reduced inflate/deflate activity by 12x, and reduced inflation time by 8.6x. But more importantly, if we hadn't killed the "grep balloon /proc/vmstat" process then, without the patch, the inflation process would never reach the target. Attached [1] is a png of a graph showing the problematic behavior without this patch. It shows deflate-queue activity increasing linearly while balloon size stays constant over the course of more than 8 minutes of the test. [1] https://lore.kernel.org/linux-mm/CAJuQAmphPcfew1v_EOgAdSFiprzjiZjmOf3iJDmFX0gD6b9TYQ@mail.gmail.com/2-without_patch.png Full test report and discussion [2]: [2] https://lore.kernel.org/r/CAJuQAmphPcfew1v_EOgAdSFiprzjiZjmOf3iJDmFX0gD6b9TYQ@mail.gmail.com Tested-by: Tyler Sanderson <tysand@google.com> Reported-by: Tyler Sanderson <tysand@google.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Nadav Amit <namit@vmware.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200205163402.42627-4-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-03-08virtio_balloon: Adjust label in virtballoon_probeNathan Chancellor
Clang warns when CONFIG_BALLOON_COMPACTION is unset: ../drivers/virtio/virtio_balloon.c:963:1: warning: unused label 'out_del_vqs' [-Wunused-label] out_del_vqs: ^~~~~~~~~~~~ 1 warning generated. Move the label within the preprocessor block since it is only used when CONFIG_BALLOON_COMPACTION is set. Fixes: 1ad6f58ea936 ("virtio_balloon: Fix memory leaks on errors in virtballoon_probe()") Link: https://github.com/ClangBuiltLinux/linux/issues/886 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://lore.kernel.org/r/20200216004039.23464-1-natechancellor@gmail.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2020-03-08virtio_ring: Fix mem leak with vring_new_virtqueue()Suman Anna
The functions vring_new_virtqueue() and __vring_new_virtqueue() are used with split rings, and any allocations within these functions are managed outside of the .we_own_ring flag. The commit cbeedb72b97a ("virtio_ring: allocate desc state for split ring separately") allocates the desc state within the __vring_new_virtqueue() but frees it only when the .we_own_ring flag is set. This leads to a memory leak when freeing such allocated virtqueues with the vring_del_virtqueue() function. Fix this by moving the desc_state free code outside the flag and only for split rings. Issue was discovered during testing with remoteproc and virtio_rpmsg. Fixes: cbeedb72b97a ("virtio_ring: allocate desc state for split ring separately") Signed-off-by: Suman Anna <s-anna@ti.com> Link: https://lore.kernel.org/r/20200224212643.30672-1-s-anna@ti.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2020-02-06virtio_balloon: Fix memory leaks on errors in virtballoon_probe()David Hildenbrand
We forget to put the inode and unmount the kernfs used for compaction. Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Liang Li <liang.z.li@intel.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200205163402.42627-3-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-02-06virtio-balloon: Fix memory leak when unloading while hinting is in progressDavid Hildenbrand
When unloading the driver while hinting is in progress, we will not release the free page blocks back to MM, resulting in a memory leak. Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Liang Li <liang.z.li@intel.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200205163402.42627-2-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-02-06virtio_balloon: prevent pfn array overflowMichael S. Tsirkin
Make sure, at build time, that pfn array is big enough to hold a single page. It happens to be true since the PAGE_SHIFT value at the moment is 20, which is 1M - exactly 256 4K balloon pages. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2020-02-06virtio-pci: check name when counting MSI-X vectorsDaniel Verkamp
VQs without a name specified are not valid; they are skipped in the later loop that assigns MSI-X vectors to queues, but the per_vq_vectors loop above that counts the required number of vectors previously still counted any queue with a non-NULL callback as needing a vector. Add a check to the per_vq_vectors loop so that vectors with no name are not counted to make the two loops consistent. This prevents over-counting unnecessary vectors (e.g. for features which were not negotiated with the device). Cc: stable@vger.kernel.org Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Wang, Wei W <wei.w.wang@intel.com>
2020-02-06virtio-balloon: initialize all vq callbacksDaniel Verkamp
Ensure that elements of the callbacks array that correspond to unavailable features are set to NULL; previously, they would be left uninitialized. Since the corresponding names array elements were explicitly set to NULL, the uninitialized callback pointers would not actually be dereferenced; however, the uninitialized callbacks elements would still be read in vp_find_vqs_msix() and used to calculate the number of MSI-X vectors required. Cc: stable@vger.kernel.org Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Daniel Verkamp <dverkamp@chromium.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-02-06virtio-mmio: convert to devm_platform_ioremap_resourceYangtao Li
Use devm_platform_ioremap_resource() to simplify code, which contains platform_get_resource, devm_request_mem_region and devm_ioremap. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-12-11virtio_balloon: divide/multiply instead of shiftsMichael S. Tsirkin
We managed to get confused about the shift direction at least once. Let's switch to division/multiplcation instead. Add a number of pages macro for this purpose. We still keep the order macro around too since this is what alloc/free pages want. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Wei Wang <wei.w.wang@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2019-12-11virtio_balloon: name cleanupsMichael S. Tsirkin
free_page_order is a confusing name. It's not a page order actually, it's the order of the block of memory we are hinting. Rename to hint_block_order. Also, rename SIZE to BYTES to make it clear it's the block size in bytes. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Wei Wang <wei.w.wang@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2019-12-11virtio-balloon: fix managed page counts when migrating pages between zonesDavid Hildenbrand
In case we have to migrate a ballon page to a newpage of another zone, the managed page count of both zones is wrong. Paired with memory offlining (which will adjust the managed page count), we can trigger kernel crashes and all kinds of different symptoms. One way to reproduce: 1. Start a QEMU guest with 4GB, no NUMA 2. Hotplug a 1GB DIMM and online the memory to ZONE_NORMAL 3. Inflate the balloon to 1GB 4. Unplug the DIMM (be quick, otherwise unmovable data ends up on it) 5. Observe /proc/zoneinfo Node 0, zone Normal pages free 16810 min 24848885473806 low 18471592959183339 high 36918337032892872 spanned 262144 present 262144 managed 18446744073709533486 6. Do anything that requires some memory (e.g., inflate the balloon some more). The OOM goes crazy and the system crashes [ 238.324946] Out of memory: Killed process 537 (login) total-vm:27584kB, anon-rss:860kB, file-rss:0kB, shmem-rss:00 [ 238.338585] systemd invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0 [ 238.339420] CPU: 0 PID: 1 Comm: systemd Tainted: G D W 5.4.0-next-20191204+ #75 [ 238.340139] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu4 [ 238.341121] Call Trace: [ 238.341337] dump_stack+0x8f/0xd0 [ 238.341630] dump_header+0x61/0x5ea [ 238.341942] oom_kill_process.cold+0xb/0x10 [ 238.342299] out_of_memory+0x24d/0x5a0 [ 238.342625] __alloc_pages_slowpath+0xd12/0x1020 [ 238.343024] __alloc_pages_nodemask+0x391/0x410 [ 238.343407] pagecache_get_page+0xc3/0x3a0 [ 238.343757] filemap_fault+0x804/0xc30 [ 238.344083] ? ext4_filemap_fault+0x28/0x42 [ 238.344444] ext4_filemap_fault+0x30/0x42 [ 238.344789] __do_fault+0x37/0x1a0 [ 238.345087] __handle_mm_fault+0x104d/0x1ab0 [ 238.345450] handle_mm_fault+0x169/0x360 [ 238.345790] do_user_addr_fault+0x20d/0x490 [ 238.346154] do_page_fault+0x31/0x210 [ 238.346468] async_page_fault+0x43/0x50 [ 238.346797] RIP: 0033:0x7f47eba4197e [ 238.347110] Code: Bad RIP value. [ 238.347387] RSP: 002b:00007ffd7c0c1890 EFLAGS: 00010293 [ 238.347834] RAX: 0000000000000002 RBX: 000055d196a20a20 RCX: 00007f47eba4197e [ 238.348437] RDX: 0000000000000033 RSI: 00007ffd7c0c18c0 RDI: 0000000000000004 [ 238.349047] RBP: 00007ffd7c0c1c20 R08: 0000000000000000 R09: 0000000000000033 [ 238.349660] R10: 00000000ffffffff R11: 0000000000000293 R12: 0000000000000001 [ 238.350261] R13: ffffffffffffffff R14: 0000000000000000 R15: 00007ffd7c0c18c0 [ 238.350878] Mem-Info: [ 238.351085] active_anon:3121 inactive_anon:51 isolated_anon:0 [ 238.351085] active_file:12 inactive_file:7 isolated_file:0 [ 238.351085] unevictable:0 dirty:0 writeback:0 unstable:0 [ 238.351085] slab_reclaimable:5565 slab_unreclaimable:10170 [ 238.351085] mapped:3 shmem:111 pagetables:155 bounce:0 [ 238.351085] free:720717 free_pcp:2 free_cma:0 [ 238.353757] Node 0 active_anon:12484kB inactive_anon:204kB active_file:48kB inactive_file:28kB unevictable:0kB iss [ 238.355979] Node 0 DMA free:11556kB min:36kB low:48kB high:60kB reserved_highatomic:0KB active_anon:152kB inactivB [ 238.358345] lowmem_reserve[]: 0 2955 2884 2884 2884 [ 238.358761] Node 0 DMA32 free:2677864kB min:7004kB low:10028kB high:13052kB reserved_highatomic:0KB active_anon:0B [ 238.361202] lowmem_reserve[]: 0 0 72057594037927865 72057594037927865 72057594037927865 [ 238.361888] Node 0 Normal free:193448kB min:99395541895224kB low:73886371836733356kB high:147673348131571488kB reB [ 238.364765] lowmem_reserve[]: 0 0 0 0 0 [ 238.365101] Node 0 DMA: 7*4kB (U) 5*8kB (UE) 6*16kB (UME) 2*32kB (UM) 1*64kB (U) 2*128kB (UE) 3*256kB (UME) 2*512B [ 238.366379] Node 0 DMA32: 0*4kB 1*8kB (U) 2*16kB (UM) 2*32kB (UM) 2*64kB (UM) 1*128kB (U) 1*256kB (U) 1*512kB (U)B [ 238.367654] Node 0 Normal: 1985*4kB (UME) 1321*8kB (UME) 844*16kB (UME) 524*32kB (UME) 300*64kB (UME) 138*128kB (B [ 238.369184] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB [ 238.369915] 130 total pagecache pages [ 238.370241] 0 pages in swap cache [ 238.370533] Swap cache stats: add 0, delete 0, find 0/0 [ 238.370981] Free swap = 0kB [ 238.371239] Total swap = 0kB [ 238.371488] 1048445 pages RAM [ 238.371756] 0 pages HighMem/MovableOnly [ 238.372090] 306992 pages reserved [ 238.372376] 0 pages cma reserved [ 238.372661] 0 pages hwpoisoned In another instance (older kernel), I was able to observe this (negative page count :/): [ 180.896971] Offlined Pages 32768 [ 182.667462] Offlined Pages 32768 [ 184.408117] Offlined Pages 32768 [ 186.026321] Offlined Pages 32768 [ 187.684861] Offlined Pages 32768 [ 189.227013] Offlined Pages 32768 [ 190.830303] Offlined Pages 32768 [ 190.833071] Built 1 zonelists, mobility grouping on. Total pages: -36920272750453009 In another instance (older kernel), I was no longer able to start any process: [root@vm ~]# [ 214.348068] Offlined Pages 32768 [ 215.973009] Offlined Pages 32768 cat /proc/meminfo -bash: fork: Cannot allocate memory [root@vm ~]# cat /proc/meminfo -bash: fork: Cannot allocate memory Fix it by properly adjusting the managed page count when migrating if the zone changed. The managed page count of the zones now looks after unplug of the DIMM (and after deflating the balloon) just like before inflating the balloon (and plugging+onlining the DIMM). We'll temporarily modify the totalram page count. If this ever becomes a problem, we can fine tune by providing helpers that don't touch the totalram pages (e.g., adjust_zone_managed_page_count()). Please note that fixing up the managed page count is only necessary when we adjusted the managed page count when inflating - only if we don't have VIRTIO_BALLOON_F_DEFLATE_ON_OOM. With that feature, the managed page count is not touched when inflating/deflating. Reported-by: Yumei Huang <yuhuang@redhat.com> Fixes: 3dcc0571cd64 ("mm: correctly update zone->managed_pages") Cc: <stable@vger.kernel.org> # v3.11+ Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: virtualization@lists.linux-foundation.org Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-11-20virtio_balloon: fix shrinker countWei Wang
Instead of multiplying by page order, virtio balloon divided by page order. The result is that it can return 0 if there are a bit less than MAX_ORDER - 1 pages in use, and then shrinker scan won't be called. Cc: stable@vger.kernel.org Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Signed-off-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2019-11-20virtio_balloon: fix shrinker scan number of pagesMichael S. Tsirkin
virtio_balloon_shrinker_scan should return number of system pages freed, but because it's calling functions that deal with balloon pages, it gets confused and sometimes returns the number of balloon pages. It does not matter practically as the exact number isn't used, but it seems better to be consistent in case someone starts using this API. Further, if we ever tried to iteratively leak pages as virtio_balloon_shrinker_scan tries to do, we'd run into issues - this is because freed_pages was accumulating total freed pages, but was also subtracted on each iteration from pages_to_free, which can result in either leaking less memory than we were supposed to free, or more if pages_to_free underruns. On a system with 4K pages we are lucky that we are never asked to leak more than 128 pages while we can leak up to 256 at a time, but it looks like a real issue for systems with page size != 4K. Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Reported-by: Khazhismel Kumykov <khazhy@google.com> Reviewed-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-11-19virtio_ring: fix return code on DMA mapping failsHalil Pasic
Commit 780bc7903a32 ("virtio_ring: Support DMA APIs") makes virtqueue_add() return -EIO when we fail to map our I/O buffers. This is a very realistic scenario for guests with encrypted memory, as swiotlb may run out of space, depending on it's size and the I/O load. The virtio-blk driver interprets -EIO form virtqueue_add() as an IO error, despite the fact that swiotlb full is in absence of bugs a recoverable condition. Let us change the return code to -ENOMEM, and make the block layer recover form these failures when virtio-blk encounters the condition described above. Cc: stable@vger.kernel.org Fixes: 780bc7903a32 ("virtio_ring: Support DMA APIs") Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Tested-by: Michael Mueller <mimu@linux.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-10-28virtio_ring: fix stalls for packed ringsMarvin Liu
When VIRTIO_F_RING_EVENT_IDX is negotiated, virtio devices can use virtqueue_enable_cb_delayed_packed to reduce the number of device interrupts. At the moment, this is the case for virtio-net when the napi_tx module parameter is set to false. In this case, the virtio driver selects an event offset and expects that the device will send a notification when rolling over the event offset in the ring. However, if this roll-over happens before the event suppression structure update, the notification won't be sent. To address this race condition the driver needs to check wether the device rolled over the offset after updating the event suppression structure. With VIRTIO_F_RING_PACKED, the virtio driver did this by reading the flags field of the descriptor at the specified offset. Unfortunately, checking at the event offset isn't reliable: if descriptors are chained (e.g. when INDIRECT is off) not all descriptors are overwritten by the device, so it's possible that the device skipped the specific descriptor driver is checking when writing out used descriptors. If this happens, the driver won't detect the race condition and will incorrectly expect the device to send a notification. For virtio-net, the result will be a TX queue stall, with the transmission getting blocked forever. With the packed ring, it isn't easy to find a location which is guaranteed to change upon the roll-over, except the next device descriptor, as described in the spec: Writes of device and driver descriptors can generally be reordered, but each side (driver and device) are only required to poll (or test) a single location in memory: the next device descriptor after the one they processed previously, in circular order. while this might be sub-optimal, let's do exactly this for now. Cc: stable@vger.kernel.org Cc: Jason Wang <jasowang@redhat.com> Fixes: f51f982682e2a ("virtio_ring: leverage event idx in packed ring") Signed-off-by: Marvin Liu <yong.liu@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-09-09virtio_ring: fix unmap of indirect descriptorsMatthias Lange
The function virtqueue_add_split() DMA-maps the scatterlist buffers. In case a mapping error occurs the already mapped buffers must be unmapped. This happens by jumping to the 'unmap_release' label. In case of indirect descriptors the release is wrong and may leak kernel memory. Because the implementation assumes that the head descriptor is already mapped it starts iterating over the descriptor list starting from the head descriptor. However for indirect descriptors the head descriptor is never mapped in case of an error. The fix is to initialize the start index with zero in case of indirect descriptors and use the 'desc' pointer directly for iterating over the descriptor chain. Signed-off-by: Matthias Lange <matthias.lange@kernkonzept.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-07-19Merge branch 'work.mount0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs mount updates from Al Viro: "The first part of mount updates. Convert filesystems to use the new mount API" * 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) mnt_init(): call shmem_init() unconditionally constify ksys_mount() string arguments don't bother with registering rootfs init_rootfs(): don't bother with init_ramfs_fs() vfs: Convert smackfs to use the new mount API vfs: Convert selinuxfs to use the new mount API vfs: Convert securityfs to use the new mount API vfs: Convert apparmorfs to use the new mount API vfs: Convert openpromfs to use the new mount API vfs: Convert xenfs to use the new mount API vfs: Convert gadgetfs to use the new mount API vfs: Convert oprofilefs to use the new mount API vfs: Convert ibmasmfs to use the new mount API vfs: Convert qib_fs/ipathfs to use the new mount API vfs: Convert efivarfs to use the new mount API vfs: Convert configfs to use the new mount API vfs: Convert binfmt_misc to use the new mount API convenience helper: get_tree_single() convenience helper get_tree_nodev() vfs: Kill sget_userns() ...
2019-07-18Merge tag 'libnvdimm-for-5.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "Primarily just the virtio_pmem driver: - virtio_pmem The new virtio_pmem facility introduces a paravirtualized persistent memory device that allows a guest VM to use DAX mechanisms to access a host-file with host-page-cache. It arranges for MAP_SYNC to be disabled and instead triggers a host fsync() when a 'write-cache flush' command is sent to the virtual disk device. - Miscellaneous small fixups" * tag 'libnvdimm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: virtio_pmem: fix sparse warning xfs: disable map_sync for async flush ext4: disable map_sync for async flush dax: check synchronous mapping is supported dm: enable synchronous dax libnvdimm: add dax_dev sync flag virtio-pmem: Add virtio pmem driver libnvdimm: nd_region flush callback support libnvdimm, namespace: Drop uuid_t implementation detail
2019-07-11virtio-mmio: add error check for platform_get_irqIhor Matushchak
in vm_find_vqs() irq has a wrong type so, in case of no IRQ resource defined, wrong parameter will be passed to request_irq() Signed-off-by: Ihor Matushchak <ihor.matushchak@foobox.net> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Ivan T. Ivanov <iivanov.xz@gmail.com>
2019-07-05virtio-pmem: Add virtio pmem driverPankaj Gupta
This patch adds virtio-pmem driver for KVM guest. Guest reads the persistent memory range information from Qemu over VIRTIO and registers it on nvdimm_bus. It also creates a nd_region object with the persistent memory range information so that existing 'nvdimm/pmem' driver can reserve this into system memory map. This way 'virtio-pmem' driver uses existing functionality of pmem driver to register persistent memory compatible for DAX capable filesystems. This also provides function to perform guest flush over VIRTIO from 'pmem' driver when userspace performs flush on DAX memory range. Signed-off-by: Pankaj Gupta <pagupta@redhat.com> Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jakub Staron <jstaron@google.com> Tested-by: Jakub Staron <jstaron@google.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-05-27virtio: Fix indentation of VIRTIO_MMIOFabrizio Castro
VIRTIO_MMIO config option block starts with a space, fix that. Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-05-25vfs: Convert virtio_balloon to use the new mount APIDavid Howells
Convert the virtio_balloon filesystem to the new internal mount API as the old one will be obsoleted and removed. This allows greater flexibility in communication of mount parameters between userspace, the VFS and the filesystem. See Documentation/filesystems/mount_api.txt for more information. Signed-off-by: David Howells <dhowells@redhat.com> cc: "Michael S. Tsirkin" <mst@redhat.com> cc: Jason Wang <jasowang@redhat.com> cc: virtualization@lists.linux-foundation.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-25mount_pseudo(): drop 'name' argument, switch to d_make_root()Al Viro
Once upon a time we used to set ->d_name of e.g. pipefs root so that d_path() on pipes would work. These days it's completely pointless - dentries of pipes are not even connected to pipefs root. However, mount_pseudo() had set the root dentry name (passed as the second argument) and callers kept inventing names to pass to it. Including those that didn't *have* any non-root dentries to start with... All of that had been pointless for about 8 years now; it's time to get rid of that cargo-culting... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 102Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 50 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190523091649.499889647@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 78Thomas Gleixner
Based on 1 normalized pattern(s): this work is licensed under the terms of the gnu gpl version 2 or later see the copying file in the top level directory extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 6 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520075210.858783702@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier - Makefile/KconfigThomas Gleixner
Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21treewide: Add SPDX license identifier for more missed filesThomas Gleixner
Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-20balloon: don't bother with dentry_operationsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-12virtio/virtio_ring: do some comment fixesJiang Biao
There are lots of mismatches between comments and codes, this patch do these comment fixes. Signed-off-by: Jiang Biao <benbjiang@tencent.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-05-12virtio_ring: Fix potential mem leak in virtqueue_add_indirect_packedYueHaibing
'desc' should be freed before leaving from err handing path. Fixes: 1ce9e6055fa0 ("virtio_ring: introduce packed ring support") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> stable@vger.kernel.org
2019-04-08virtio: Honour 'may_reduce_num' in vring_create_virtqueueCornelia Huck
vring_create_virtqueue() allows the caller to specify via the may_reduce_num parameter whether the vring code is allowed to allocate a smaller ring than specified. However, the split ring allocation code tries to allocate a smaller ring on allocation failure regardless of what the caller specified. This may cause trouble for e.g. virtio-pci in legacy mode, which does not support ring resizing. (The packed ring code does not resize in any case.) Let's fix this by bailing out immediately in the split ring code if the requested size cannot be allocated and may_reduce_num has not been specified. While at it, fix a typo in the usage instructions. Fixes: 2a2d1382fe9d ("virtio: Add improved queue allocation API") Cc: stable@vger.kernel.org # v4.6+ Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Jens Freimann <jfreimann@redhat.com>
2019-04-08virtio_pci: fix a NULL pointer reference in vp_del_vqsLongpeng
If the msix_affinity_masks is alloced failed, then we'll try to free some resources in vp_free_vectors() that may access it directly. We met the following stack in our production: [ 29.296767] BUG: unable to handle kernel NULL pointer dereference at (null) [ 29.311151] IP: [<ffffffffc04fe35a>] vp_free_vectors+0x6a/0x150 [virtio_pci] [ 29.324787] PGD 0 [ 29.333224] Oops: 0000 [#1] SMP [...] [ 29.425175] RIP: 0010:[<ffffffffc04fe35a>] [<ffffffffc04fe35a>] vp_free_vectors+0x6a/0x150 [virtio_pci] [ 29.441405] RSP: 0018:ffff9a55c2dcfa10 EFLAGS: 00010206 [ 29.453491] RAX: 0000000000000000 RBX: ffff9a55c322c400 RCX: 0000000000000000 [ 29.467488] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9a55c322c400 [ 29.481461] RBP: ffff9a55c2dcfa20 R08: 0000000000000000 R09: ffffc1b6806ff020 [ 29.495427] R10: 0000000000000e95 R11: 0000000000aaaaaa R12: 0000000000000000 [ 29.509414] R13: 0000000000010000 R14: ffff9a55bd2d9e98 R15: ffff9a55c322c400 [ 29.523407] FS: 00007fdcba69f8c0(0000) GS:ffff9a55c2840000(0000) knlGS:0000000000000000 [ 29.538472] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.551621] CR2: 0000000000000000 CR3: 000000003ce52000 CR4: 00000000003607a0 [ 29.565886] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.580055] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.594122] Call Trace: [ 29.603446] [<ffffffffc04fe8a2>] vp_request_msix_vectors+0xe2/0x260 [virtio_pci] [ 29.618017] [<ffffffffc04fedc5>] vp_try_to_find_vqs+0x95/0x3b0 [virtio_pci] [ 29.632152] [<ffffffffc04ff117>] vp_find_vqs+0x37/0xb0 [virtio_pci] [ 29.645582] [<ffffffffc057bf63>] init_vq+0x153/0x260 [virtio_blk] [ 29.658831] [<ffffffffc057c1e8>] virtblk_probe+0xe8/0x87f [virtio_blk] [...] Cc: Gonglei <arei.gonglei@huawei.com> Signed-off-by: Longpeng <longpeng2@huawei.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Gonglei <arei.gonglei@huawei.com>
2019-03-06virtio: hint if callbacks surprisingly might sleepCornelia Huck
A virtio transport is free to implement some of the callbacks in virtio_config_ops in a matter that they cannot be called from atomic context (e.g. virtio-ccw, which maps a lot of the callbacks to channel I/O, which is an inherently asynchronous mechanism). This can be very surprising for developers using the much more common virtio-pci transport, just to find out that things break when used on s390. The documentation for virtio_config_ops now contains a comment explaining this, but it makes sense to add a might_sleep() annotation to various wrapper functions in the virtio core to avoid surprises later. Note that annotations are NOT added to two classes of calls: - direct calls from device drivers (all current callers should be fine, however) - calls which clearly won't be made from atomic context (such as those ultimately coming in via the driver core) Signed-off-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-03-06virtio_balloon: remove the unnecessary 0-initializationWei Wang
We've changed to kzalloc the vb struct, so no need to 0-initialize this field one more time. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2019-03-06virtio-balloon: improve update_balloon_size_funcWei Wang
There is no need to update the balloon actual register when there is no ballooning request. This patch avoids update_balloon_size when diff is 0. Signed-off-by: Wei Wang <wei.w.wang@intel.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Halil Pasic <pasic@linux.ibm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>