| Message ID | 20190130132212.7376-1-cohuck@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | vfio-ccw: support hsch/csch (kernel part) | expand |
On Wed, 30 Jan 2019 14:22:06 +0100 Cornelia Huck <cohuck@redhat.com> wrote: > [This is the Linux kernel part, git tree is available at > https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git vfio-ccw-eagain-caps-v3 I've pushed out the changes I've made so far (patch 1) to vfio-ccw-eagain-caps-v3.5. I'll wait a bit for more comments before sending a new version. > > The companion QEMU patches are available at > https://github.com/cohuck/qemu vfio-ccw-caps > This is the previously posted v2 version, which should continue to work.] I would not mind if somebody looked at those as well :) > > Currently, vfio-ccw only relays START SUBCHANNEL requests to the real > device. This tends to work well for the most common 'good path' scenarios; > however, as we emulate {HALT,CLEAR} SUBCHANNEL in QEMU, things like > clearing pending requests at the device is currently not supported. > This may be a problem for e.g. error recovery. > > This patch series introduces capabilities (similar to what vfio-pci uses) > and exposes a new async region for handling hsch/csch. > > Lightly tested (I can interact with a dasd as before, and reserve/release > seems to work well.) Not sure if there is a better way to test this, ideas > welcome. > > Changes v2->v3: > - Unb0rked patch 1, improved scope > - Split out the new mutex from patch 2 into new patch 3; added missing > locking and hopefully improved description > - Patch 2 now reworks the state handling by splitting the BUSY state > into CP_PROCESSING and CP_PENDING > - Patches 3 and 5 adapted on top of the reworked patches; hsch/csch > are allowed in CP_PENDING, but not in CP_PROCESSING (did not add > any R-b due to that) > - Added missing free in patch 5 > - Probably some small changes I forgot to note down > > Changes v1->v2: > - New patch 1: make it safe to use the cp accessors at any time; this > should avoid problems with unsolicited interrupt handling > - New patch 2: handle concurrent accesses to the io region; the idea is > to return -EAGAIN to userspace more often (so it can simply retry) > - also handle concurrent accesses to the async io region > - change VFIO_REGION_TYPE_CCW > - merge events for halt and clear to a single async event; this turned out > to make the code quite a bit simpler > - probably some small changes I forgot to note down > > Cornelia Huck (6): > vfio-ccw: make it safe to access channel programs > vfio-ccw: rework ssch state handling > vfio-ccw: protect the I/O region > vfio-ccw: add capabilities chain > s390/cio: export hsch to modules > vfio-ccw: add handling for async channel instructions > > drivers/s390/cio/Makefile | 3 +- > drivers/s390/cio/ioasm.c | 1 + > drivers/s390/cio/vfio_ccw_async.c | 88 ++++++++++++ > drivers/s390/cio/vfio_ccw_cp.c | 20 ++- > drivers/s390/cio/vfio_ccw_cp.h | 2 + > drivers/s390/cio/vfio_ccw_drv.c | 57 ++++++-- > drivers/s390/cio/vfio_ccw_fsm.c | 143 ++++++++++++++++++- > drivers/s390/cio/vfio_ccw_ops.c | 210 +++++++++++++++++++++++----- > drivers/s390/cio/vfio_ccw_private.h | 48 ++++++- > include/uapi/linux/vfio.h | 4 + > include/uapi/linux/vfio_ccw.h | 12 ++ > 11 files changed, 531 insertions(+), 57 deletions(-) > create mode 100644 drivers/s390/cio/vfio_ccw_async.c >
On 02/06/2019 09:00 AM, Cornelia Huck wrote: > On Wed, 30 Jan 2019 14:22:06 +0100 > Cornelia Huck <cohuck@redhat.com> wrote: > >> [This is the Linux kernel part, git tree is available at >> https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git vfio-ccw-eagain-caps-v3 > > I've pushed out the changes I've made so far (patch 1) to > vfio-ccw-eagain-caps-v3.5. I'll wait a bit for more comments before > sending a new version. > Thanks for that branch... For patch 1 in v3.5: Reviewed-by: Eric Farman <farman@linux.ibm.com> >> >> The companion QEMU patches are available at >> https://github.com/cohuck/qemu vfio-ccw-caps >> This is the previously posted v2 version, which should continue to work.] > > I would not mind if somebody looked at those as well :) Not precluding anyone else from doing so :) ... I'd planned on looking at them as I get into the meat of patches 4-6 on the kernel side, where the overlap occurs. I'm getting close. :) FWIW, I've been running with both series for the last week or two, along with some host kernel traces to prove things got executed the way I thought, and it's seemed to be working well. So that makes me optimistic for the later patches. - Eric > >> >> Currently, vfio-ccw only relays START SUBCHANNEL requests to the real >> device. This tends to work well for the most common 'good path' scenarios; >> however, as we emulate {HALT,CLEAR} SUBCHANNEL in QEMU, things like >> clearing pending requests at the device is currently not supported. >> This may be a problem for e.g. error recovery. >> >> This patch series introduces capabilities (similar to what vfio-pci uses) >> and exposes a new async region for handling hsch/csch. >> >> Lightly tested (I can interact with a dasd as before, and reserve/release >> seems to work well.) Not sure if there is a better way to test this, ideas >> welcome. >> >> Changes v2->v3: >> - Unb0rked patch 1, improved scope >> - Split out the new mutex from patch 2 into new patch 3; added missing >> locking and hopefully improved description >> - Patch 2 now reworks the state handling by splitting the BUSY state >> into CP_PROCESSING and CP_PENDING >> - Patches 3 and 5 adapted on top of the reworked patches; hsch/csch >> are allowed in CP_PENDING, but not in CP_PROCESSING (did not add >> any R-b due to that) >> - Added missing free in patch 5 >> - Probably some small changes I forgot to note down >> >> Changes v1->v2: >> - New patch 1: make it safe to use the cp accessors at any time; this >> should avoid problems with unsolicited interrupt handling >> - New patch 2: handle concurrent accesses to the io region; the idea is >> to return -EAGAIN to userspace more often (so it can simply retry) >> - also handle concurrent accesses to the async io region >> - change VFIO_REGION_TYPE_CCW >> - merge events for halt and clear to a single async event; this turned out >> to make the code quite a bit simpler >> - probably some small changes I forgot to note down >> >> Cornelia Huck (6): >> vfio-ccw: make it safe to access channel programs >> vfio-ccw: rework ssch state handling >> vfio-ccw: protect the I/O region >> vfio-ccw: add capabilities chain >> s390/cio: export hsch to modules >> vfio-ccw: add handling for async channel instructions >> >> drivers/s390/cio/Makefile | 3 +- >> drivers/s390/cio/ioasm.c | 1 + >> drivers/s390/cio/vfio_ccw_async.c | 88 ++++++++++++ >> drivers/s390/cio/vfio_ccw_cp.c | 20 ++- >> drivers/s390/cio/vfio_ccw_cp.h | 2 + >> drivers/s390/cio/vfio_ccw_drv.c | 57 ++++++-- >> drivers/s390/cio/vfio_ccw_fsm.c | 143 ++++++++++++++++++- >> drivers/s390/cio/vfio_ccw_ops.c | 210 +++++++++++++++++++++++----- >> drivers/s390/cio/vfio_ccw_private.h | 48 ++++++- >> include/uapi/linux/vfio.h | 4 + >> include/uapi/linux/vfio_ccw.h | 12 ++ >> 11 files changed, 531 insertions(+), 57 deletions(-) >> create mode 100644 drivers/s390/cio/vfio_ccw_async.c >> >
On Fri, 8 Feb 2019 16:19:58 -0500 Eric Farman <farman@linux.ibm.com> wrote: > On 02/06/2019 09:00 AM, Cornelia Huck wrote: > > On Wed, 30 Jan 2019 14:22:06 +0100 > > Cornelia Huck <cohuck@redhat.com> wrote: > > > >> [This is the Linux kernel part, git tree is available at > >> https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git vfio-ccw-eagain-caps-v3 > > > > I've pushed out the changes I've made so far (patch 1) to > > vfio-ccw-eagain-caps-v3.5. I'll wait a bit for more comments before > > sending a new version. > > > > Thanks for that branch... For patch 1 in v3.5: > > Reviewed-by: Eric Farman <farman@linux.ibm.com> Thanks! > > >> > >> The companion QEMU patches are available at > >> https://github.com/cohuck/qemu vfio-ccw-caps > >> This is the previously posted v2 version, which should continue to work.] > > > > I would not mind if somebody looked at those as well :) > > Not precluding anyone else from doing so :) ... I'd planned on looking > at them as I get into the meat of patches 4-6 on the kernel side, where > the overlap occurs. I'm getting close. :) Cool :) I'll wait a bit more before resending, then. (I'll probably rebase the QEMU side as well when I do resend.) > > FWIW, I've been running with both series for the last week or two, along > with some host kernel traces to prove things got executed the way I > thought, and it's seemed to be working well. So that makes me > optimistic for the later patches. That's good news, thanks for testing. Do you have a special test load that you run in the guest that you can share?
On 02/11/2019 11:13 AM, Cornelia Huck wrote: > On Fri, 8 Feb 2019 16:19:58 -0500 > Eric Farman <farman@linux.ibm.com> wrote: >> >> FWIW, I've been running with both series for the last week or two, along >> with some host kernel traces to prove things got executed the way I >> thought, and it's seemed to be working well. So that makes me >> optimistic for the later patches. > > That's good news, thanks for testing. Do you have a special test load > that you run in the guest that you can share? > Not really. Lately it's just fio, run via some ancient scripts which randomize the input parameters and distill the output data. If I get some time to make it less hack-y it might be worth sharing, but right now there's more things commented out than actual script. :) - Eric
[This is the Linux kernel part, git tree is available at https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw.git vfio-ccw-eagain-caps-v3 The companion QEMU patches are available at https://github.com/cohuck/qemu vfio-ccw-caps This is the previously posted v2 version, which should continue to work.] Currently, vfio-ccw only relays START SUBCHANNEL requests to the real device. This tends to work well for the most common 'good path' scenarios; however, as we emulate {HALT,CLEAR} SUBCHANNEL in QEMU, things like clearing pending requests at the device is currently not supported. This may be a problem for e.g. error recovery. This patch series introduces capabilities (similar to what vfio-pci uses) and exposes a new async region for handling hsch/csch. Lightly tested (I can interact with a dasd as before, and reserve/release seems to work well.) Not sure if there is a better way to test this, ideas welcome. Changes v2->v3: - Unb0rked patch 1, improved scope - Split out the new mutex from patch 2 into new patch 3; added missing locking and hopefully improved description - Patch 2 now reworks the state handling by splitting the BUSY state into CP_PROCESSING and CP_PENDING - Patches 3 and 5 adapted on top of the reworked patches; hsch/csch are allowed in CP_PENDING, but not in CP_PROCESSING (did not add any R-b due to that) - Added missing free in patch 5 - Probably some small changes I forgot to note down Changes v1->v2: - New patch 1: make it safe to use the cp accessors at any time; this should avoid problems with unsolicited interrupt handling - New patch 2: handle concurrent accesses to the io region; the idea is to return -EAGAIN to userspace more often (so it can simply retry) - also handle concurrent accesses to the async io region - change VFIO_REGION_TYPE_CCW - merge events for halt and clear to a single async event; this turned out to make the code quite a bit simpler - probably some small changes I forgot to note down Cornelia Huck (6): vfio-ccw: make it safe to access channel programs vfio-ccw: rework ssch state handling vfio-ccw: protect the I/O region vfio-ccw: add capabilities chain s390/cio: export hsch to modules vfio-ccw: add handling for async channel instructions drivers/s390/cio/Makefile | 3 +- drivers/s390/cio/ioasm.c | 1 + drivers/s390/cio/vfio_ccw_async.c | 88 ++++++++++++ drivers/s390/cio/vfio_ccw_cp.c | 20 ++- drivers/s390/cio/vfio_ccw_cp.h | 2 + drivers/s390/cio/vfio_ccw_drv.c | 57 ++++++-- drivers/s390/cio/vfio_ccw_fsm.c | 143 ++++++++++++++++++- drivers/s390/cio/vfio_ccw_ops.c | 210 +++++++++++++++++++++++----- drivers/s390/cio/vfio_ccw_private.h | 48 ++++++- include/uapi/linux/vfio.h | 4 + include/uapi/linux/vfio_ccw.h | 12 ++ 11 files changed, 531 insertions(+), 57 deletions(-) create mode 100644 drivers/s390/cio/vfio_ccw_async.c