kernel/drivers/virtio/virtio_ring.c, branch linux-4.16.y

virtio_ring: fix num_free handling in error case

2018-03-01T16:53:38Z

The vq->vq.num_free hasn't been changed when error happens, so it shouldn't be changed when handling the error. Fixes: 780bc7903a32 ("virtio_ring: Support DMA APIs") Cc: Andy Lutomirski Cc: Michael S. Tsirkin Cc: stable@vger.kernel.org Signed-off-by: Tiwei Bie Signed-off-by: Michael S. Tsirkin

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2017-09-08T04:11:05Z

Pull SCSI updates from James Bottomley: "This is mostly updates of the usual suspects: lpfc, qla2xxx, hisi_sas, megaraid_sas, zfcp and a host of minor updates. The major driver change here is the elimination of the block based cciss driver in favour of the SCSI based hpsa driver (which now drives all the legacy cases cciss used to be required for). Plus a reset handler clean up and the redo of the SAS SMP handler to use bsg lib" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (279 commits) scsi: scsi-mq: Always unprepare before requeuing a request scsi: Show .retries and .jiffies_at_alloc in debugfs scsi: Improve requeuing behavior scsi: Call scsi_initialize_rq() for filesystem requests scsi: qla2xxx: Reset the logo flag, after target re-login. scsi: qla2xxx: Fix slow mem alloc behind lock scsi: qla2xxx: Clear fc4f_nvme flag scsi: qla2xxx: add missing includes for qla_isr scsi: qla2xxx: Fix an integer overflow in sysfs code scsi: aacraid: report -ENOMEM to upper layer from aac_convert_sgraw2() scsi: aacraid: get rid of one level of indentation scsi: aacraid: fix indentation errors scsi: storvsc: fix memory leak on ring buffer busy scsi: scsi_transport_sas: switch to bsg-lib for SMP passthrough scsi: smartpqi: remove the smp_handler stub scsi: hpsa: remove the smp_handler stub scsi: bsg-lib: pass the release callback through bsg_setup_queue scsi: Rework handling of scsi_device.vpd_pg8[03] scsi: Rework the code for caching Vital Product Data (VPD) scsi: rcu: Introduce rcu_swap_protected() ...

scsi: virtio: Reduce BUG if total_sg > virtqueue size to WARN.

2017-08-25T02:28:51Z

If using indirect descriptors, you can make the total_sg as large as you want. If not, BUG is too serious because the function later returns -ENOSPC. Signed-off-by: Richard W.M. Jones Reviewed-by: Paolo Bonzini Signed-off-by: Martin K. Petersen

virtio_ring: allow to store zero as the ctx

2017-07-24T20:37:00Z

Allow zero to be store as a ctx, with this we could store e.g zero value which could be meaningful for the case of storing headroom through ctx. Signed-off-by: Jason Wang Signed-off-by: David S. Miller

virtio: allow extra context per descriptor

2017-05-02T20:41:43Z

Allow extra context per descriptor. To avoid slow down for data path, this disables use of indirect descriptors for this vq. Signed-off-by: Michael S. Tsirkin

virtio: add context flag to find vqs

2017-05-02T20:41:43Z

Allows maintaining extra context per vq. For ease of use, passing in NULL is legal and disables the feature for all vqs. Includes fixes by Christian for s390, acked by Cornelia. Signed-off-by: Christian Borntraeger Acked-by: Cornelia Huck Signed-off-by: Michael S. Tsirkin

Revert "vring: Force use of DMA API for ARM-based systems with legacy devices"

2017-02-03T21:38:50Z

This reverts commit c7070619f3408d9a0dffbed9149e6f00479cf43b. This has been shown to regress on some ARM systems: by forcing on DMA API usage for ARM systems, we have inadvertently kicked open a hornets' nest in terms of cache-coherency. Namely that unless the virtio device is explicitly described as capable of coherent DMA by firmware, the DMA APIs on ARM and other DT-based platforms will assume it is non-coherent. This turns out to cause a big problem for the likes of QEMU and kvmtool, which generate virtio-mmio devices in their guest DTs but neglect to add the often-overlooked "dma-coherent" property; as a result, we end up with the guest making non-cacheable accesses to the vring, the host doing so cacheably, both talking past each other and things going horribly wrong. We are working on a safer work-around. Fixes: c7070619f340 ("vring: Force use of DMA API for ARM-based systems with legacy devices") Reported-by: Robin Murphy Cc: Signed-off-by: Will Deacon Signed-off-by: Michael S. Tsirkin Acked-by: Marc Zyngier

vring: Force use of DMA API for ARM-based systems with legacy devices

2017-01-24T22:33:11Z

Booting Linux on an ARM fastmodel containing an SMMU emulation results in an unexpected I/O page fault from the legacy virtio-blk PCI device: [ 1.211721] arm-smmu-v3 2b400000.smmu: event 0x10 received: [ 1.211800] arm-smmu-v3 2b400000.smmu: 0x00000000fffff010 [ 1.211880] arm-smmu-v3 2b400000.smmu: 0x0000020800000000 [ 1.211959] arm-smmu-v3 2b400000.smmu: 0x00000008fa081002 [ 1.212075] arm-smmu-v3 2b400000.smmu: 0x0000000000000000 [ 1.212155] arm-smmu-v3 2b400000.smmu: event 0x10 received: [ 1.212234] arm-smmu-v3 2b400000.smmu: 0x00000000fffff010 [ 1.212314] arm-smmu-v3 2b400000.smmu: 0x0000020800000000 [ 1.212394] arm-smmu-v3 2b400000.smmu: 0x00000008fa081000 [ 1.212471] arm-smmu-v3 2b400000.smmu: 0x0000000000000000 This is because the legacy virtio-blk device is behind an SMMU, so we have consequently swizzled its DMA ops and configured the SMMU to translate accesses. This then requires the vring code to use the DMA API to establish translations, otherwise all transactions will result in fatal faults and termination. Given that ARM-based systems only see an SMMU if one is really present (the topology is all described by firmware tables such as device-tree or IORT), then we can safely use the DMA API for all legacy virtio devices. Modern devices can advertise the prescense of an IOMMU using the VIRTIO_F_IOMMU_PLATFORM feature flag. Cc: Andy Lutomirski Cc: Michael S. Tsirkin Cc: Fixes: 876945dbf649 ("arm64: Hook up IOMMU dma_ops") Signed-off-by: Will Deacon Signed-off-by: Michael S. Tsirkin Acked-by: Marc Zyngier

virtio_ring: fix description of virtqueue_get_buf

2016-12-15T22:13:38Z

The device (not the driver) populates the used ring and includes the len of how much data was written. Signed-off-by: Felipe Franciosi Signed-off-by: Michael S. Tsirkin

virtio_ring: fix complaint by sparse

2016-12-15T04:39:47Z

# make C=2 CF="-D__CHECK_ENDIAN__" ./drivers/virtio/ drivers/virtio/virtio_ring.c:423:19: warning: incorrect type in assignment (different base types) drivers/virtio/virtio_ring.c:423:19: expected unsigned int [unsigned] [assigned] i drivers/virtio/virtio_ring.c:423:19: got restricted __virtio16 [usertype] next drivers/virtio/virtio_ring.c:423:19: warning: incorrect type in assignment (different base types) drivers/virtio/virtio_ring.c:423:19: expected unsigned int [unsigned] [assigned] i drivers/virtio/virtio_ring.c:423:19: got restricted __virtio16 [usertype] next drivers/virtio/virtio_ring.c:423:19: warning: incorrect type in assignment (different base types) drivers/virtio/virtio_ring.c:423:19: expected unsigned int [unsigned] [assigned] i drivers/virtio/virtio_ring.c:423:19: got restricted __virtio16 [usertype] next drivers/virtio/virtio_ring.c:604:39: warning: incorrect type in initializer (different base types) drivers/virtio/virtio_ring.c:604:39: expected unsigned short [unsigned] [usertype] nextflag drivers/virtio/virtio_ring.c:604:39: got restricted __virtio16 drivers/virtio/virtio_ring.c:612:33: warning: restricted __virtio16 degrades to integer Signed-off-by: Gonglei Signed-off-by: Michael S. Tsirkin