> > From: Wei Liu <[email protected]> > > hv_compose_msi_msg() sends PCI_CREATE_INTERRUPT carrying > int_desc.vector, and the vPCI backend programs the device with the > address/data it returns for it. > > An affinity change only ran irq_chip_set_affinity_parent(), which re-allocates > the x86 vector and nothing else, and hv_arch_irq_unmask() then issued > MAP_DEVICE_INTERRUPT for the new (VP, vector). Nothing re-composed the > interrupt, so the device kept signalling the vector it was created with and > the > new mapping was never used. This led to loss of interrupts. > > Do the re-target where the vector is known and the interrupt is quiescent. If > the vector changed, re-compose the VMBus interrupt for it, write the > resulting message to the device, and only then map the new (vp, vector); the > old mapping is destroyed as the new message is composed. > > Signed-off-by: Wei Liu <[email protected]> > --- > drivers/pci/controller/pci-hyperv.c | 41 +++++++++++++++++++++++++++-- > 1 file changed, 39 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci- > hyperv.c > index 5a36382742bf..5acb8e41567e 100644 > --- a/drivers/pci/controller/pci-hyperv.c > +++ b/drivers/pci/controller/pci-hyperv.c > @@ -294,6 +294,7 @@ struct tran_int_desc { struct hv_msi_int_entry { > struct tran_int_desc int_desc; > struct hv_interrupt_entry hv_entry; > + unsigned int mapped_vector; > }; > > /* chip_data is passed around as a struct tran_int_desc *, so it must be > first. > */ @@ -742,6 +743,8 @@ static void hv_irq_retarget_interrupt(struct > irq_data *data) > "%s() failed: %#llx", __func__, res); } > > +static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg > +*msg); > + > static void hv_arch_irq_unmask(struct irq_data *data) { > if (hv_root_partition()) { > @@ -752,9 +755,17 @@ static void hv_arch_irq_unmask(struct irq_data > *data) > * RETARGET_INTERRUPT. > * > * Keep the returned entry so the mapping can be removed > again > - * when the interrupt is torn down. > + * when the interrupt is re-targeted or torn down. > + * > + * This is also the re-target point. The core calls us from > + * __irq_move_irq() with the interrupt masked once the new > + * vector has been assigned, so if the vector changed the > vmbus > + * interrupt is re-composed for it first -- > PCI_CREATE_INTERRUPT > + * carries the vector, so the device would otherwise keep > + * signalling the one it was created with. > */ > struct hv_msi_int_entry *ie = data->chip_data; > + unsigned int vec = hv_msi_get_int_vector(data); > > /* > * A NULL chip_data means hv_compose_msi_msg() failed > and the @@ -763,8 +774,29 @@ static void hv_arch_irq_unmask(struct > irq_data *data) > if (!ie) > return; > > - if (hv_map_msi_interrupt(data, &ie->hv_entry)) > + /* Already mapped for this vector, nothing changed. */ > + if (ie->mapped_vector == vec && ie->hv_entry.source) > + return; > + > + if (ie->mapped_vector && ie->mapped_vector != vec) { > + struct msi_msg msg; > + > + hv_compose_msi_msg(data, &msg); > + > + ie = data->chip_data; > + if (!ie) > + return; > + > + if (data->chip->irq_write_msi_msg) > + data->chip->irq_write_msi_msg(data, &msg);
I don't see the function irq_write_msi_msg defined in hv_msi_irq_chip, maybe not looking at the right place. Is this function ever getting called?
