| Message ID | 1507124979-8880-3-git-send-email-pmorel@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | Refactoring of AIS support | expand |
On Wed, 4 Oct 2017 15:49:36 +0200 Pierre Morel <pmorel@linux.vnet.ibm.com> wrote: > Testing to use Adapter Interrupt suppression or not depend on AIS > being enabled in the kernel. > To implement AIS emulation we must move this test inside the FLIC > dedicated irq_inject function. > > Furthermore, a test to verify that the adapter is subject to the AIS > must be added. > > Last, there is no need to crash QEMU if the injection failed, the > guest may recover from it. > > Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com> > --- > hw/s390x/css.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/hw/s390x/css.c b/hw/s390x/css.c > index 901dc6a..6e74a5c 100644 > --- a/hw/s390x/css.c > +++ b/hw/s390x/css.c > @@ -672,10 +672,12 @@ void css_adapter_interrupt(CssIoAdapterType type, uint8_t isc) > } > > trace_css_adapter_interrupt(isc); > - if (fs->ais_supported) { > + /* Use standard IRQ injection for adapters not supporting AIS */ I'd move that comment to the else branch. > + if (adapter->flags & S390_ADAPTER_SUPPRESSIBLE) { > + /* Use AIRQ injection for adapters subject to AIS */ > if (fsc->inject_airq(fs, type, isc, adapter->flags)) { > error_report("Failed to inject airq with AIS supported"); > - exit(1); > + /* Report error - guest will handle not receiving interrupts */ I'm not 100% sure that this is the right thing to do. I have always operated under the assumption "if the hardware (host) accepts the I/O, it owes you an interrupt". (Don't the other failed interrupt injection paths do a hard stop as well? Is there any reasonable way for an injection failure to be transient?) > } > } else { > s390_io_interrupt(0, 0, 0, io_int_word);
On 09/10/2017 10:17, Cornelia Huck wrote: > On Wed, 4 Oct 2017 15:49:36 +0200 > Pierre Morel <pmorel@linux.vnet.ibm.com> wrote: > >> Testing to use Adapter Interrupt suppression or not depend on AIS >> being enabled in the kernel. >> To implement AIS emulation we must move this test inside the FLIC >> dedicated irq_inject function. >> >> Furthermore, a test to verify that the adapter is subject to the AIS >> must be added. >> >> Last, there is no need to crash QEMU if the injection failed, the >> guest may recover from it. >> >> Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com> >> --- >> hw/s390x/css.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/hw/s390x/css.c b/hw/s390x/css.c >> index 901dc6a..6e74a5c 100644 >> --- a/hw/s390x/css.c >> +++ b/hw/s390x/css.c >> @@ -672,10 +672,12 @@ void css_adapter_interrupt(CssIoAdapterType type, uint8_t isc) >> } >> >> trace_css_adapter_interrupt(isc); >> - if (fs->ais_supported) { >> + /* Use standard IRQ injection for adapters not supporting AIS */ > > I'd move that comment to the else branch. yes, clear. > >> + if (adapter->flags & S390_ADAPTER_SUPPRESSIBLE) { >> + /* Use AIRQ injection for adapters subject to AIS */ >> if (fsc->inject_airq(fs, type, isc, adapter->flags)) { >> error_report("Failed to inject airq with AIS supported"); >> - exit(1); >> + /* Report error - guest will handle not receiving interrupts */ > > I'm not 100% sure that this is the right thing to do. I have always > operated under the assumption "if the hardware (host) accepts the I/O, > it owes you an interrupt". (Don't the other failed interrupt injection > paths do a hard stop as well? Is there any reasonable way for an > injection failure to be transient?) You are right and it is out of scope. So I will let this untouch. > >> } >> } else { >> s390_io_interrupt(0, 0, 0, io_int_word); >
diff --git a/hw/s390x/css.c b/hw/s390x/css.c index 901dc6a..6e74a5c 100644 --- a/hw/s390x/css.c +++ b/hw/s390x/css.c @@ -672,10 +672,12 @@ void css_adapter_interrupt(CssIoAdapterType type, uint8_t isc) } trace_css_adapter_interrupt(isc); - if (fs->ais_supported) { + /* Use standard IRQ injection for adapters not supporting AIS */ + if (adapter->flags & S390_ADAPTER_SUPPRESSIBLE) { + /* Use AIRQ injection for adapters subject to AIS */ if (fsc->inject_airq(fs, type, isc, adapter->flags)) { error_report("Failed to inject airq with AIS supported"); - exit(1); + /* Report error - guest will handle not receiving interrupts */ } } else { s390_io_interrupt(0, 0, 0, io_int_word);
Testing to use Adapter Interrupt suppression or not depend on AIS being enabled in the kernel. To implement AIS emulation we must move this test inside the FLIC dedicated irq_inject function. Furthermore, a test to verify that the adapter is subject to the AIS must be added. Last, there is no need to crash QEMU if the injection failed, the guest may recover from it. Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com> --- hw/s390x/css.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)