| Message ID | 1520435434-24471-1-git-send-email-imbrenda@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v5,1/1] s390x/sclp: extend SCLP event masks to 64 bits | expand |
On Wed, 7 Mar 2018 16:10:34 +0100 Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> wrote: > Extend the SCLP event masks to 64 bits. > > Notice that using any of the new bits results in a state that cannot be > migrated to an older version. > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> > --- > hw/s390x/event-facility.c | 49 ++++++++++++++++++++++++++++++++------- > include/hw/s390x/event-facility.h | 2 +- > 2 files changed, 41 insertions(+), 10 deletions(-) > > @@ -376,6 +387,21 @@ static bool vmstate_event_facility_mask_length_needed(void *opaque) > return ef->allow_all_mask_sizes; > } > > +static const VMStateDescription vmstate_event_facility_mask64 = { > + .name = "vmstate-event-facility/mask64", Should that really be called 'mask64' - you're just transferring the missing part of the mask here, aren't you? > + .version_id = 0, > + .minimum_version_id = 0, > + .needed = vmstate_event_facility_mask64_needed, > + .fields = (VMStateField[]) { > +#ifdef HOST_WORDS_BIGENDIAN > + VMSTATE_UINT32(receive_mask_pieces[1], SCLPEventFacility), > +#else > + VMSTATE_UINT32(receive_mask_pieces[0], SCLPEventFacility), > +#endif That #ifdef is kind of ugly, and a bit confusing, I think. What about doing something like /* we need to save 32 bit chunks for compatibility */ #ifdef HOST_WORDS_BIGENDIAN #define RECV_MASK_LOWER 0 #define RECV_MASK_UPPER 1 #else /* little endian host */ #define RECV_MASK_LOWER 1 #define RECV_MASK_UPPER 0 #endif and transfer receive_mask_pieces[RECV_MASK_UPPER] here... > + VMSTATE_END_OF_LIST() > + } > +}; > + > static const VMStateDescription vmstate_event_facility_mask_length = { > .name = "vmstate-event-facility/mask_length", > .version_id = 0, > @@ -392,10 +418,15 @@ static const VMStateDescription vmstate_event_facility = { > .version_id = 0, > .minimum_version_id = 0, > .fields = (VMStateField[]) { > - VMSTATE_UINT32(receive_mask, SCLPEventFacility), > +#ifdef HOST_WORDS_BIGENDIAN > + VMSTATE_UINT32(receive_mask_pieces[0], SCLPEventFacility), > +#else > + VMSTATE_UINT32(receive_mask_pieces[1], SCLPEventFacility), > +#endif ...and receive_mask_pieces[REV_MASK_LOWER] here? (And I guess 64bit receive masks should be enough for everybody? IOW, we don't expect a similar dance in the near future?) > VMSTATE_END_OF_LIST() > }, > .subsections = (const VMStateDescription * []) { > + &vmstate_event_facility_mask64, > &vmstate_event_facility_mask_length, > NULL > }
On Wed, 7 Mar 2018 16:55:48 +0100 Cornelia Huck <cohuck@redhat.com> wrote: > On Wed, 7 Mar 2018 16:10:34 +0100 > Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> wrote: > > > Extend the SCLP event masks to 64 bits. > > > > Notice that using any of the new bits results in a state that > > cannot be migrated to an older version. > > > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> > > --- > > hw/s390x/event-facility.c | 49 > > ++++++++++++++++++++++++++++++++------- > > include/hw/s390x/event-facility.h | 2 +- 2 files changed, 41 > > insertions(+), 10 deletions(-) > > > @@ -376,6 +387,21 @@ static bool > > vmstate_event_facility_mask_length_needed(void *opaque) return > > ef->allow_all_mask_sizes; } > > > > +static const VMStateDescription vmstate_event_facility_mask64 = { > > + .name = "vmstate-event-facility/mask64", > > Should that really be called 'mask64' - you're just transferring the > missing part of the mask here, aren't you? > > > + .version_id = 0, > > + .minimum_version_id = 0, > > + .needed = vmstate_event_facility_mask64_needed, > > + .fields = (VMStateField[]) { > > +#ifdef HOST_WORDS_BIGENDIAN > > + VMSTATE_UINT32(receive_mask_pieces[1], SCLPEventFacility), > > +#else > > + VMSTATE_UINT32(receive_mask_pieces[0], SCLPEventFacility), > > +#endif > > That #ifdef is kind of ugly, and a bit confusing, I think. > > What about doing something like > > /* we need to save 32 bit chunks for compatibility */ > #ifdef HOST_WORDS_BIGENDIAN > #define RECV_MASK_LOWER 0 > #define RECV_MASK_UPPER 1 > #else /* little endian host */ > #define RECV_MASK_LOWER 1 > #define RECV_MASK_UPPER 0 > #endif > > and transfer receive_mask_pieces[RECV_MASK_UPPER] here... yes, this is better, I'll respin > > + VMSTATE_END_OF_LIST() > > + } > > +}; > > + > > static const VMStateDescription vmstate_event_facility_mask_length > > = { .name = "vmstate-event-facility/mask_length", > > .version_id = 0, > > @@ -392,10 +418,15 @@ static const VMStateDescription > > vmstate_event_facility = { .version_id = 0, > > .minimum_version_id = 0, > > .fields = (VMStateField[]) { > > - VMSTATE_UINT32(receive_mask, SCLPEventFacility), > > +#ifdef HOST_WORDS_BIGENDIAN > > + VMSTATE_UINT32(receive_mask_pieces[0], SCLPEventFacility), > > +#else > > + VMSTATE_UINT32(receive_mask_pieces[1], SCLPEventFacility), > > +#endif > > ...and receive_mask_pieces[REV_MASK_LOWER] here? > > (And I guess 64bit receive masks should be enough for everybody? IOW, > we don't expect a similar dance in the near future?) well, by then we'll need proper bitfields, so everything will need to be rewritten anyway :) > > VMSTATE_END_OF_LIST() > > }, > > .subsections = (const VMStateDescription * []) { > > + &vmstate_event_facility_mask64, > > &vmstate_event_facility_mask_length, > > NULL > > } >
On 03/07/2018 04:10 PM, Claudio Imbrenda wrote: > Extend the SCLP event masks to 64 bits. > > Notice that using any of the new bits results in a state that cannot be > migrated to an older version. > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> > --- > hw/s390x/event-facility.c | 49 ++++++++++++++++++++++++++++++++------- > include/hw/s390x/event-facility.h | 2 +- > 2 files changed, 41 insertions(+), 10 deletions(-) > > diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c > index e04ed9f..c166e0a 100644 > --- a/hw/s390x/event-facility.c > +++ b/hw/s390x/event-facility.c > @@ -30,7 +30,10 @@ struct SCLPEventFacility { > SysBusDevice parent_obj; > SCLPEventsBus sbus; > /* guest's receive mask */ > - sccb_mask_t receive_mask; > + union { > + uint32_t receive_mask_pieces[2]; > + sccb_mask_t receive_mask; > + }; Would it work to make sccb_mask_t a union instead?
On Thu, 8 Mar 2018 08:41:47 +0100 Christian Borntraeger <borntraeger@de.ibm.com> wrote: > On 03/07/2018 04:10 PM, Claudio Imbrenda wrote: > > Extend the SCLP event masks to 64 bits. > > > > Notice that using any of the new bits results in a state that > > cannot be migrated to an older version. > > > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> > > --- > > hw/s390x/event-facility.c | 49 > > ++++++++++++++++++++++++++++++++------- > > include/hw/s390x/event-facility.h | 2 +- 2 files changed, 41 > > insertions(+), 10 deletions(-) > > > > diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c > > index e04ed9f..c166e0a 100644 > > --- a/hw/s390x/event-facility.c > > +++ b/hw/s390x/event-facility.c > > @@ -30,7 +30,10 @@ struct SCLPEventFacility { > > SysBusDevice parent_obj; > > SCLPEventsBus sbus; > > /* guest's receive mask */ > > - sccb_mask_t receive_mask; > > + union { > > + uint32_t receive_mask_pieces[2]; > > + sccb_mask_t receive_mask; > > + }; > > Would it work to make sccb_mask_t a union instead? yes, but then a lot of other code should be changed: we use sccb_mask_t as scalar everywhere. also, we only need the pieces when migrating the state, never during normal operation
On 03/08/2018 11:02 AM, Claudio Imbrenda wrote: > On Thu, 8 Mar 2018 08:41:47 +0100 > Christian Borntraeger <borntraeger@de.ibm.com> wrote: > >> On 03/07/2018 04:10 PM, Claudio Imbrenda wrote: >>> Extend the SCLP event masks to 64 bits. >>> >>> Notice that using any of the new bits results in a state that >>> cannot be migrated to an older version. >>> >>> Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> >>> --- >>> hw/s390x/event-facility.c | 49 >>> ++++++++++++++++++++++++++++++++------- >>> include/hw/s390x/event-facility.h | 2 +- 2 files changed, 41 >>> insertions(+), 10 deletions(-) >>> >>> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c >>> index e04ed9f..c166e0a 100644 >>> --- a/hw/s390x/event-facility.c >>> +++ b/hw/s390x/event-facility.c >>> @@ -30,7 +30,10 @@ struct SCLPEventFacility { >>> SysBusDevice parent_obj; >>> SCLPEventsBus sbus; >>> /* guest's receive mask */ >>> - sccb_mask_t receive_mask; >>> + union { >>> + uint32_t receive_mask_pieces[2]; >>> + sccb_mask_t receive_mask; >>> + }; >> >> Would it work to make sccb_mask_t a union instead? > > yes, but then a lot of other code should be changed: we use sccb_mask_t > as scalar everywhere. > > also, we only need the pieces when migrating the state, never during > normal operation ok, makes sense.
diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c index e04ed9f..c166e0a 100644 --- a/hw/s390x/event-facility.c +++ b/hw/s390x/event-facility.c @@ -30,7 +30,10 @@ struct SCLPEventFacility { SysBusDevice parent_obj; SCLPEventsBus sbus; /* guest's receive mask */ - sccb_mask_t receive_mask; + union { + uint32_t receive_mask_pieces[2]; + sccb_mask_t receive_mask; + }; /* * when false, we keep the same broken, backwards compatible behaviour as * before, allowing only masks of size exactly 4; when true, we implement @@ -262,7 +265,7 @@ static void read_event_data(SCLPEventFacility *ef, SCCB *sccb) case SCLP_SELECTIVE_READ: copy_mask((uint8_t *)&sclp_active_selection_mask, (uint8_t *)&red->mask, sizeof(sclp_active_selection_mask), ef->mask_length); - sclp_active_selection_mask = be32_to_cpu(sclp_active_selection_mask); + sclp_active_selection_mask = be64_to_cpu(sclp_active_selection_mask); if (!sclp_cp_receive_mask || (sclp_active_selection_mask & ~sclp_cp_receive_mask)) { sccb->h.response_code = @@ -294,21 +297,22 @@ static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb) } /* - * Note: We currently only support masks up to 4 byte length; - * the remainder is filled up with zeroes. Linux uses - * a 4 byte mask length. + * Note: We currently only support masks up to 8 byte length; + * the remainder is filled up with zeroes. Older Linux + * kernels use a 4 byte mask length, newer ones can use both + * 8 or 4 depending on what is available on the host. */ /* keep track of the guest's capability masks */ copy_mask((uint8_t *)&tmp_mask, WEM_CP_RECEIVE_MASK(we_mask, mask_length), sizeof(tmp_mask), mask_length); - ef->receive_mask = be32_to_cpu(tmp_mask); + ef->receive_mask = be64_to_cpu(tmp_mask); /* return the SCLP's capability masks to the guest */ - tmp_mask = cpu_to_be32(get_host_receive_mask(ef)); + tmp_mask = cpu_to_be64(get_host_receive_mask(ef)); copy_mask(WEM_RECEIVE_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask, mask_length, sizeof(tmp_mask)); - tmp_mask = cpu_to_be32(get_host_send_mask(ef)); + tmp_mask = cpu_to_be64(get_host_send_mask(ef)); copy_mask(WEM_SEND_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask, mask_length, sizeof(tmp_mask)); @@ -369,6 +373,13 @@ static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code) } } +static bool vmstate_event_facility_mask64_needed(void *opaque) +{ + SCLPEventFacility *ef = opaque; + + return (ef->receive_mask & 0xFFFFFFFF) != 0; +} + static bool vmstate_event_facility_mask_length_needed(void *opaque) { SCLPEventFacility *ef = opaque; @@ -376,6 +387,21 @@ static bool vmstate_event_facility_mask_length_needed(void *opaque) return ef->allow_all_mask_sizes; } +static const VMStateDescription vmstate_event_facility_mask64 = { + .name = "vmstate-event-facility/mask64", + .version_id = 0, + .minimum_version_id = 0, + .needed = vmstate_event_facility_mask64_needed, + .fields = (VMStateField[]) { +#ifdef HOST_WORDS_BIGENDIAN + VMSTATE_UINT32(receive_mask_pieces[1], SCLPEventFacility), +#else + VMSTATE_UINT32(receive_mask_pieces[0], SCLPEventFacility), +#endif + VMSTATE_END_OF_LIST() + } +}; + static const VMStateDescription vmstate_event_facility_mask_length = { .name = "vmstate-event-facility/mask_length", .version_id = 0, @@ -392,10 +418,15 @@ static const VMStateDescription vmstate_event_facility = { .version_id = 0, .minimum_version_id = 0, .fields = (VMStateField[]) { - VMSTATE_UINT32(receive_mask, SCLPEventFacility), +#ifdef HOST_WORDS_BIGENDIAN + VMSTATE_UINT32(receive_mask_pieces[0], SCLPEventFacility), +#else + VMSTATE_UINT32(receive_mask_pieces[1], SCLPEventFacility), +#endif VMSTATE_END_OF_LIST() }, .subsections = (const VMStateDescription * []) { + &vmstate_event_facility_mask64, &vmstate_event_facility_mask_length, NULL } diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h index 0e2b761..06ba4ea 100644 --- a/include/hw/s390x/event-facility.h +++ b/include/hw/s390x/event-facility.h @@ -73,7 +73,7 @@ typedef struct WriteEventMask { #define WEM_RECEIVE_MASK(wem, mask_len) ((wem)->masks + 2 * (mask_len)) #define WEM_SEND_MASK(wem, mask_len) ((wem)->masks + 3 * (mask_len)) -typedef uint32_t sccb_mask_t; +typedef uint64_t sccb_mask_t; typedef struct EventBufferHeader { uint16_t length;
Extend the SCLP event masks to 64 bits. Notice that using any of the new bits results in a state that cannot be migrated to an older version. Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> --- hw/s390x/event-facility.c | 49 ++++++++++++++++++++++++++++++++------- include/hw/s390x/event-facility.h | 2 +- 2 files changed, 41 insertions(+), 10 deletions(-)