similar to: [PATCH] virtio_console: fix uninitialized variable use

when multiport is off, virtio console invokes config access from irq context, config access is blocking on s390. Fix this up by scheduling work from config irq - similar to what we do for multiport configs. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Applies on top of "virtio_console: init work unconditionally" that I sent previously. drivers/char/virtio_console.c

when multiport is off, virtio console invokes config access from irq context, config access is blocking on s390. Fix this up by scheduling work from config irq - similar to what we do for multiport configs. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- Applies on top of "virtio_console: init work unconditionally" that I sent previously. drivers/char/virtio_console.c

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add a virtio remoteproc serial driver: VIRTIO_ID_RPROC_SERIAL (0xB) for communicating with a remote processor in an asymmetric multi-processing configuration. The virtio remoteproc serial driver reuses the existing virtio_console implementation, and adds support for DMA allocation of data buffers but disables support for tty

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add a virtio remoteproc serial driver: VIRTIO_ID_RPROC_SERIAL (0xB) for communicating with a remote processor in an asymmetric multi-processing configuration. The virtio remoteproc serial driver reuses the existing virtio_console implementation, and adds support for DMA allocation of data buffers but disables support for tty

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add a simple serial connection driver called VIRTIO_ID_RPROC_SERIAL (11) for communicating with a remote processor in an asymmetric multi-processing configuration. This implementation reuses the existing virtio_console implementation, and adds support for DMA allocation of data buffers and disables use of tty console and the virtio

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add a simple serial connection driver called VIRTIO_ID_RPROC_SERIAL (11) for communicating with a remote processor in an asymmetric multi-processing configuration. This implementation reuses the existing virtio_console implementation, and adds support for DMA allocation of data buffers and disables use of tty console and the virtio

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add a simple serial connection driver called VIRTIO_ID_RPROC_SERIAL (0xB) for communicating with a remote processor in an asymmetric multi-processing configuration. This implementation reuses the existing virtio_console implementation, and adds support for DMA allocation of data buffers and disables use of tty console and the virtio

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add a simple serial connection driver called VIRTIO_ID_RPROC_SERIAL (0xB) for communicating with a remote processor in an asymmetric multi-processing configuration. This implementation reuses the existing virtio_console implementation, and adds support for DMA allocation of data buffers and disables use of tty console and the virtio

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add feature VIRTIO_CONSOLE_F_DMA_MEM. If the architecture has DMA support and this feature bit is set, the virtio data buffers will be allocated from DMA memory. This is needed for using virtio_console from the remoteproc framework. Signed-off-by: Sjur Br?ndeland <sjur.brandeland at stericsson.com> cc: Rusty Russell <rusty

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add feature VIRTIO_CONSOLE_F_DMA_MEM. If the architecture has DMA support and this feature bit is set, the virtio data buffers will be allocated from DMA memory. This is needed for using virtio_console from the remoteproc framework. Signed-off-by: Sjur Br?ndeland <sjur.brandeland at stericsson.com> cc: Rusty Russell <rusty

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add feature VIRTIO_CONSOLE_F_DMA_MEM. If the architecture has DMA support and this feature bit is set, the virtio data buffers will be allocated from DMA memory. If the device requests the feature VIRTIO_CONSOLE_F_DMA_MEM, but the architecture don't support DMA the driver's probe function will fail. This is needed for using

From: Sjur Br?ndeland <sjur.brandeland at stericsson.com> Add feature VIRTIO_CONSOLE_F_DMA_MEM. If the architecture has DMA support and this feature bit is set, the virtio data buffers will be allocated from DMA memory. If the device requests the feature VIRTIO_CONSOLE_F_DMA_MEM, but the architecture don't support DMA the driver's probe function will fail. This is needed for using

when multiport is off, we don't initialize config work, but we then cancel uninitialized control_work on freeze. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/char/virtio_console.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index fae2dbb..def736d 100644 ---

when multiport is off, we don't initialize config work, but we then cancel uninitialized control_work on freeze. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/char/virtio_console.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index fae2dbb..def736d 100644 ---

On Wed, Nov 13, 2019 at 04:00:56PM +0100, Laurent Vivier wrote: > When we hot unplug a virtserialport and then try to hot plug again, > it fails: > > (qemu) chardev-add socket,id=serial0,path=/tmp/serial0,server,nowait > (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ > chardev=serial0,id=serial0,name=serial0 > (qemu) device_del serial0 >

On Thu, 2019-11-14 at 13:25 +0100, Laurent Vivier wrote: > When we hot unplug a virtserialport and then try to hot plug again, > it fails: > > (qemu) chardev-add socket,id=serial0,path=/tmp/serial0,server,nowait > (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ > chardev=serial0,id=serial0,name=serial0 > (qemu) device_del serial0 > (qemu)

We currently allow multiple instances of the control work handler to run in parallel. This isn't expected to work; serialise access by disabling interrupts on new packets from the Host and enable them when all the existing ones are consumed. --- drivers/char/virtio_console.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/drivers/char/virtio_console.c

We currently allow multiple instances of the control work handler to run in parallel. This isn't expected to work; serialise access by disabling interrupts on new packets from the Host and enable them when all the existing ones are consumed. --- drivers/char/virtio_console.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/drivers/char/virtio_console.c

virtio_console uses a small DMA buffer for control requests. Move that buffer into heap memory. Doing virtio DMA on the stack is normally okay on non-DMA-API virtio systems (which is currently most of them), but it breaks completely if the stack is virtually mapped. Tested by typing both directions using picocom aimed at /dev/hvc0. Signed-off-by: Andy Lutomirski <luto at kernel.org> ---

virtio_console uses a small DMA buffer for control requests. Move that buffer into heap memory. Doing virtio DMA on the stack is normally okay on non-DMA-API virtio systems (which is currently most of them), but it breaks completely if the stack is virtually mapped. Tested by typing both directions using picocom aimed at /dev/hvc0. Signed-off-by: Andy Lutomirski <luto at kernel.org> ---