On Fri, 5 Apr 2019 01:16:15 +0200 Halil Pasic <[email protected]> wrote:
> Virtio-ccw relies on cio mechanisms for bootstrapping the ccw device. Well, a ccw device is, by definition, using cio mechanisms ;) Better say: "As virtio-ccw devices are channel devices, we need to use the dma area for any communication with the hypervisor." Or something like that. > Thus we need to make sure any memory that is used for communication with > the hypervisor is shared. In this context, does 'hypervisor' always mean 'QEMU/KVM'? If Other Hypervisors implement protected virtualization, we probably need to make sure that all common I/O layer control blocks are in the dma area (including e.g. QDIO), not just what virtio-ccw devices use. > > Signed-off-by: Halil Pasic <[email protected]> > --- > drivers/s390/cio/ccwreq.c | 8 +++---- > drivers/s390/cio/device.c | 46 > +++++++++++++++++++++++++++++++--------- > drivers/s390/cio/device_fsm.c | 40 +++++++++++++++++----------------- > drivers/s390/cio/device_id.c | 18 ++++++++-------- > drivers/s390/cio/device_ops.c | 4 ++-- > drivers/s390/cio/device_pgid.c | 20 ++++++++--------- > drivers/s390/cio/device_status.c | 24 ++++++++++----------- > drivers/s390/cio/io_sch.h | 19 ++++++++++++----- > 8 files changed, 107 insertions(+), 72 deletions(-) > (...) (just looking at which fields are moved for now) > diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h > index 90e4e3a7841b..fc3220fede0f 100644 > --- a/drivers/s390/cio/io_sch.h > +++ b/drivers/s390/cio/io_sch.h > @@ -9,15 +9,20 @@ > #include "css.h" > #include "orb.h" > > + > +struct io_subchannel_dma_area { > + struct ccw1 sense_ccw; /* static ccw for sense command */ The ccw makes sense. > +}; > + > struct io_subchannel_private { > union orb orb; /* operation request block */ > - struct ccw1 sense_ccw; /* static ccw for sense command */ > struct ccw_device *cdev;/* pointer to the child ccw device */ > struct { > unsigned int suspend:1; /* allow suspend */ > unsigned int prefetch:1;/* deny prefetch */ > unsigned int inter:1; /* suppress intermediate interrupts */ > } __packed options; > + struct io_subchannel_dma_area *dma_area; > } __aligned(8); > > #define to_io_private(n) ((struct io_subchannel_private *) \ > @@ -115,6 +120,13 @@ enum cdev_todo { > #define FAKE_CMD_IRB 1 > #define FAKE_TM_IRB 2 > > +struct ccw_device_dma_area { > + struct senseid senseid; /* SenseID info */ > + struct ccw1 iccws[2]; /* ccws for SNID/SID/SPGID commands */ > + struct irb irb; /* device status */ > + struct pgid pgid[8]; /* path group IDs per chpid*/ Again, ccws, and blocks that will be written by the hypervisor, which makes sense as well. > +}; > + > struct ccw_device_private { > struct ccw_device *cdev; > struct subchannel *sch; > @@ -156,11 +168,7 @@ struct ccw_device_private { > } __attribute__((packed)) flags; > unsigned long intparm; /* user interruption parameter */ > struct qdio_irq *qdio_data; > - struct irb irb; /* device status */ > int async_kill_io_rc; > - struct senseid senseid; /* SenseID info */ > - struct pgid pgid[8]; /* path group IDs per chpid*/ > - struct ccw1 iccws[2]; /* ccws for SNID/SID/SPGID commands */ > struct work_struct todo_work; > enum cdev_todo todo; > wait_queue_head_t wait_q; > @@ -169,6 +177,7 @@ struct ccw_device_private { > struct list_head cmb_list; /* list of measured devices */ > u64 cmb_start_time; /* clock value of cmb reset */ > void *cmb_wait; /* deferred cmb enable/disable */ > + struct ccw_device_dma_area *dma_area; > enum interruption_class int_class; > }; > So, this leaves some things I'm not sure about, especially as I do not know the architecture of this new feature. - This applies only to asynchronously handled things, it seems? So things like control blocks modified by stsch/msch/etc does not need special treatment? - What about channel measurements? Or are they not supported? - What about CHSCs? Or would only asynchronous commands (which we currently don't implement in QEMU) need special treatment? _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
