| Message ID | 20240827164304.88876-3-nifan.cxl@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | QEMU DCD emulation support fix | expand |
On Tue, 27 Aug 2024 09:40:05 -0700 nifan.cxl@gmail.com wrote: > From: Fan Ni <fan.ni@samsung.com> > > When inserting multiple dynamic capacity event records grouped via More flag, > we should only trigger interrupt after the last record is inserted into the > event log. Achieving the goal by letting cxl_event_insert return true only > for the insertion of the last dynamic capacity event record in the sequence. I'm not sure this one is accurate. We might well have a slow system provisioning capacity one extent at time (and interrupting). The event buffer might also not be large enough to hold all records so the device might 'wait' before figuring out the next extent for there to be somewhere to put the record. Overall I think we can interrupt on each one and it should 'work' as should interrupt only once there are lots of them or every (n). Interrupt only fires on a 0 to >= 1 transition anyway, not on repeats after that unless the log has been cleared. It's up to OS to keep clearing records until it at least momentarily hits 0 if it wants to get any more interrupts. Jonathan > > Signed-off-by: Fan Ni <fan.ni@samsung.com> > --- > hw/cxl/cxl-events.c | 8 ++++++++ > include/hw/cxl/cxl_events.h | 1 + > 2 files changed, 9 insertions(+) > > diff --git a/hw/cxl/cxl-events.c b/hw/cxl/cxl-events.c > index 12dee2e467..90536c0e68 100644 > --- a/hw/cxl/cxl-events.c > +++ b/hw/cxl/cxl-events.c > @@ -135,6 +135,14 @@ bool cxl_event_insert(CXLDeviceState *cxlds, CXLEventLogType log_type, > QSIMPLEQ_INSERT_TAIL(&log->events, entry, node); > cxl_event_set_status(cxlds, log_type, true); > > + /* > + * For dynamic capacity event records grouped via More flag, > + * Only raise interrupt after inserting the last record in the log. > + */ > + if (log_type == CXL_EVENT_TYPE_DYNAMIC_CAP) { > + CXLEventDynamicCapacity *dCap = (CXLEventDynamicCapacity *)event; > + return (dCap->flags & MORE_FLAG) ? false : true; > + } > /* Count went from 0 to 1 */ > return cxl_event_count(log) == 1; If there are multiple this will fail I think as cxl_event_count(log) will go from 0 to X not 1. > } > diff --git a/include/hw/cxl/cxl_events.h b/include/hw/cxl/cxl_events.h > index 38cadaa0f3..b0e5cc89c0 100644 > --- a/include/hw/cxl/cxl_events.h > +++ b/include/hw/cxl/cxl_events.h > @@ -170,6 +170,7 @@ typedef struct CXLEventMemoryModule { > * CXL r3.1 section Table 8-50: Dynamic Capacity Event Record > * All fields little endian. > */ > +#define MORE_FLAG BIT_MASK(0) > typedef struct CXLEventDynamicCapacity { > CXLEventRecordHdr hdr; > uint8_t type;
Jonathan Cameron wrote: > On Tue, 27 Aug 2024 09:40:05 -0700 > nifan.cxl@gmail.com wrote: > > > From: Fan Ni <fan.ni@samsung.com> > > > > When inserting multiple dynamic capacity event records grouped via More flag, > > we should only trigger interrupt after the last record is inserted into the > > event log. Achieving the goal by letting cxl_event_insert return true only > > for the insertion of the last dynamic capacity event record in the sequence. > > I'm not sure this one is accurate. We might well have a slow > system provisioning capacity one extent at time (and interrupting). > > The event buffer might also not be large enough to hold all records so > the device might 'wait' before figuring out the next extent for there > to be somewhere to put the record. > > Overall I think we can interrupt on each one and it should 'work' > as should interrupt only once there are lots of them or > every (n). Indeed I think it should work. But you won't see any extents as they will be pending in the memdev. Did this fail in some way? I'm sorry I did not try and use qemu to test the more bit. Rather I used cxl_test for that. Ira > > Interrupt only fires on a 0 to >= 1 transition anyway, not > on repeats after that unless the log has been cleared. > It's up to OS to keep clearing records until it at least > momentarily hits 0 if it wants to get any more interrupts. > > Jonathan > > > > > > Signed-off-by: Fan Ni <fan.ni@samsung.com> > > --- > > hw/cxl/cxl-events.c | 8 ++++++++ > > include/hw/cxl/cxl_events.h | 1 + > > 2 files changed, 9 insertions(+) > > > > diff --git a/hw/cxl/cxl-events.c b/hw/cxl/cxl-events.c > > index 12dee2e467..90536c0e68 100644 > > --- a/hw/cxl/cxl-events.c > > +++ b/hw/cxl/cxl-events.c > > @@ -135,6 +135,14 @@ bool cxl_event_insert(CXLDeviceState *cxlds, CXLEventLogType log_type, > > QSIMPLEQ_INSERT_TAIL(&log->events, entry, node); > > cxl_event_set_status(cxlds, log_type, true); > > > > + /* > > + * For dynamic capacity event records grouped via More flag, > > + * Only raise interrupt after inserting the last record in the log. > > + */ > > + if (log_type == CXL_EVENT_TYPE_DYNAMIC_CAP) { > > + CXLEventDynamicCapacity *dCap = (CXLEventDynamicCapacity *)event; > > + return (dCap->flags & MORE_FLAG) ? false : true; > > + } > > /* Count went from 0 to 1 */ > > return cxl_event_count(log) == 1; > > If there are multiple this will fail I think as cxl_event_count(log) will go from 0 > to X not 1. > > > } > > diff --git a/include/hw/cxl/cxl_events.h b/include/hw/cxl/cxl_events.h > > index 38cadaa0f3..b0e5cc89c0 100644 > > --- a/include/hw/cxl/cxl_events.h > > +++ b/include/hw/cxl/cxl_events.h > > @@ -170,6 +170,7 @@ typedef struct CXLEventMemoryModule { > > * CXL r3.1 section Table 8-50: Dynamic Capacity Event Record > > * All fields little endian. > > */ > > +#define MORE_FLAG BIT_MASK(0) > > typedef struct CXLEventDynamicCapacity { > > CXLEventRecordHdr hdr; > > uint8_t type; >
On Wed, Sep 04, 2024 at 11:37:33AM -0500, Ira Weiny wrote: > Jonathan Cameron wrote: > > On Tue, 27 Aug 2024 09:40:05 -0700 > > nifan.cxl@gmail.com wrote: > > > > > From: Fan Ni <fan.ni@samsung.com> > > > > > > When inserting multiple dynamic capacity event records grouped via More flag, > > > we should only trigger interrupt after the last record is inserted into the > > > event log. Achieving the goal by letting cxl_event_insert return true only > > > for the insertion of the last dynamic capacity event record in the sequence. > > > > I'm not sure this one is accurate. We might well have a slow > > system provisioning capacity one extent at time (and interrupting). > > > > The event buffer might also not be large enough to hold all records so > > the device might 'wait' before figuring out the next extent for there > > to be somewhere to put the record. > > > > Overall I think we can interrupt on each one and it should 'work' > > as should interrupt only once there are lots of them or > > every (n). > > Indeed I think it should work. But you won't see any extents as they will > be pending in the memdev. > > Did this fail in some way? I'm sorry I did not try and use qemu to test > the more bit. Rather I used cxl_test for that. > > Ira It works with or without this fix in my test. Until the last extent is notified to the OS, the extents will be pending as you mentioned. Fan > > > > > Interrupt only fires on a 0 to >= 1 transition anyway, not > > on repeats after that unless the log has been cleared. > > It's up to OS to keep clearing records until it at least > > momentarily hits 0 if it wants to get any more interrupts. > > > > Jonathan > > > > > > > > > > Signed-off-by: Fan Ni <fan.ni@samsung.com> > > > --- > > > hw/cxl/cxl-events.c | 8 ++++++++ > > > include/hw/cxl/cxl_events.h | 1 + > > > 2 files changed, 9 insertions(+) > > > > > > diff --git a/hw/cxl/cxl-events.c b/hw/cxl/cxl-events.c > > > index 12dee2e467..90536c0e68 100644 > > > --- a/hw/cxl/cxl-events.c > > > +++ b/hw/cxl/cxl-events.c > > > @@ -135,6 +135,14 @@ bool cxl_event_insert(CXLDeviceState *cxlds, CXLEventLogType log_type, > > > QSIMPLEQ_INSERT_TAIL(&log->events, entry, node); > > > cxl_event_set_status(cxlds, log_type, true); > > > > > > + /* > > > + * For dynamic capacity event records grouped via More flag, > > > + * Only raise interrupt after inserting the last record in the log. > > > + */ > > > + if (log_type == CXL_EVENT_TYPE_DYNAMIC_CAP) { > > > + CXLEventDynamicCapacity *dCap = (CXLEventDynamicCapacity *)event; > > > + return (dCap->flags & MORE_FLAG) ? false : true; > > > + } > > > /* Count went from 0 to 1 */ > > > return cxl_event_count(log) == 1; > > > > If there are multiple this will fail I think as cxl_event_count(log) will go from 0 > > to X not 1. > > > > > } > > > diff --git a/include/hw/cxl/cxl_events.h b/include/hw/cxl/cxl_events.h > > > index 38cadaa0f3..b0e5cc89c0 100644 > > > --- a/include/hw/cxl/cxl_events.h > > > +++ b/include/hw/cxl/cxl_events.h > > > @@ -170,6 +170,7 @@ typedef struct CXLEventMemoryModule { > > > * CXL r3.1 section Table 8-50: Dynamic Capacity Event Record > > > * All fields little endian. > > > */ > > > +#define MORE_FLAG BIT_MASK(0) > > > typedef struct CXLEventDynamicCapacity { > > > CXLEventRecordHdr hdr; > > > uint8_t type; > > > >
diff --git a/hw/cxl/cxl-events.c b/hw/cxl/cxl-events.c index 12dee2e467..90536c0e68 100644 --- a/hw/cxl/cxl-events.c +++ b/hw/cxl/cxl-events.c @@ -135,6 +135,14 @@ bool cxl_event_insert(CXLDeviceState *cxlds, CXLEventLogType log_type, QSIMPLEQ_INSERT_TAIL(&log->events, entry, node); cxl_event_set_status(cxlds, log_type, true); + /* + * For dynamic capacity event records grouped via More flag, + * Only raise interrupt after inserting the last record in the log. + */ + if (log_type == CXL_EVENT_TYPE_DYNAMIC_CAP) { + CXLEventDynamicCapacity *dCap = (CXLEventDynamicCapacity *)event; + return (dCap->flags & MORE_FLAG) ? false : true; + } /* Count went from 0 to 1 */ return cxl_event_count(log) == 1; } diff --git a/include/hw/cxl/cxl_events.h b/include/hw/cxl/cxl_events.h index 38cadaa0f3..b0e5cc89c0 100644 --- a/include/hw/cxl/cxl_events.h +++ b/include/hw/cxl/cxl_events.h @@ -170,6 +170,7 @@ typedef struct CXLEventMemoryModule { * CXL r3.1 section Table 8-50: Dynamic Capacity Event Record * All fields little endian. */ +#define MORE_FLAG BIT_MASK(0) typedef struct CXLEventDynamicCapacity { CXLEventRecordHdr hdr; uint8_t type;