On Thu, 23 May 2019 18:22:04 +0200 Michael Mueller <[email protected]> wrote:
> From: Halil Pasic <[email protected]> > > As virtio-ccw devices are channel devices, we need to use the dma area > for any communication with the hypervisor. > > It handles neither QDIO in the common code, nor any device type specific > stuff (like channel programs constructed by the DASD driver). > > An interesting side effect is that virtio structures are now going to > get allocated in 31 bit addressable storage. > > Signed-off-by: Halil Pasic <[email protected]> [Side note: you really should add your s-o-b if you send someone else's patches... if Halil ends up committing them, it's fine, though.] > --- > arch/s390/include/asm/ccwdev.h | 4 +++ > drivers/s390/cio/ccwreq.c | 9 +++--- > drivers/s390/cio/device.c | 64 > +++++++++++++++++++++++++++++++++------- > drivers/s390/cio/device_fsm.c | 53 ++++++++++++++++++++------------- > drivers/s390/cio/device_id.c | 20 +++++++------ > drivers/s390/cio/device_ops.c | 21 +++++++++++-- > drivers/s390/cio/device_pgid.c | 22 +++++++------- > drivers/s390/cio/device_status.c | 24 +++++++-------- > drivers/s390/cio/io_sch.h | 20 +++++++++---- > drivers/s390/virtio/virtio_ccw.c | 10 ------- > 10 files changed, 164 insertions(+), 83 deletions(-) > (...) > @@ -1593,20 +1622,31 @@ struct ccw_device * __init > ccw_device_create_console(struct ccw_driver *drv) > return ERR_CAST(sch); > > io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA); > - if (!io_priv) { > - put_device(&sch->dev); > - return ERR_PTR(-ENOMEM); > - } > + if (!io_priv) > + goto err_priv; > + io_priv->dma_area = dma_alloc_coherent(&sch->dev, > + sizeof(*io_priv->dma_area), > + &io_priv->dma_area_dma, GFP_KERNEL); Even though we'll only end up here for 3215 or 3270 consoles, this sent me looking. This code is invoked via console_init(). A few lines down in start_kernel(), we have /* * This needs to be called before any devices perform DMA * operations that might use the SWIOTLB bounce buffers. It will * mark the bounce buffers as decrypted so that their usage will * not cause "plain-text" data to be decrypted when accessed. */ mem_encrypt_init(); So, I'm wondering if creating the console device interacts in any way with the memory encryption interface? [Does basic recognition work if you start a protected virt guest with a 3270 console? I realize that the console is unlikely to work, but that should at least exercise this code path.] > + if (!io_priv->dma_area) > + goto err_dma_area; > set_io_private(sch, io_priv); > cdev = io_subchannel_create_ccwdev(sch); > if (IS_ERR(cdev)) { > put_device(&sch->dev); > + dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area), > + io_priv->dma_area, io_priv->dma_area_dma); > kfree(io_priv); > return cdev; > } > cdev->drv = drv; > ccw_device_set_int_class(cdev); > return cdev; > + > +err_dma_area: > + kfree(io_priv); > +err_priv: > + put_device(&sch->dev); > + return ERR_PTR(-ENOMEM); > } > > void __init ccw_device_destroy_console(struct ccw_device *cdev) _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
