On Sat, Dec 09, 2017 at 09:43:22AM +0100, Cédric Le Goater wrote: > Each XIVE interrupt source is associated with a two bit state machine > called an Event State Buffer (ESB) : the first bit "P" means that an > interrupt is "pending" and waiting for an EOI and the bit "Q" (queued) > means a new interrupt was triggered while another was still pending. > > When an event is triggered, the associated interrupt state bits are > fetched and modified and forwarded to the virtualization engine of the > controller doing the routing. These can also be controlled by MMIO, to > trigger events or turn off the sources for instance. See code for more > details on the states and transitions. > > The MMIO space for the ESBs is 512GB large on the bare-metal system > (PowerNV) and the BAR depends on the chip id. In our model for the > sPAPR machine, we choose to only map the sub-region for the > provisioned IRQ numbers and to use the mapping address of chip 0 of a > real system.
I think we probably want a device property to make the virtualized base address arbitrary. It's fine for it to default to the chip 0 base, but that'll make it easier to adapt if we need to later on. As noted in the followup messages, I think you're going to want to move this stuff from the current xive object into a "block of sources" object. Apart from that this looks pretty sound. > In the real world, each source may have different characteristics > depending on the revision of a controller or the CPU. Early systems > had two different MMIO pages for trigger and for EOI. We choose to use > the same characteristics for all sources to simplify the model. The > minimum CPU level for XIVE exploitation mode will be DD2.X as it has > full support. > > The OS will obtain the address of the MMIO page of the ESB entry > associated with a source and its characteristic using the > H_INT_GET_SOURCE_INFO hcall. This will be addressed in the patch > introducing the hcalls. > > The spapr_xive_irq() routine in charge of triggering the CPU interrupt > line will be filled later on. > > Signed-off-by: Cédric Le Goater <c...@kaod.org> > --- > > Changes since v1: > > - merged in the same patch the qemu_irq handlers > - reworked the event notification logic of the qemu_irq handlers. > - introduced XIVE_ESB_STORE_EOI support > - removed 'esb_shift' field > - removed a useless check on the validity of the IVE in the memory > region handlers. > - fixed spapr_xive_pq_trigger() to return true when XIVE_ESB_QUEUED > is set > - removed the overall ESB memory region. We now have only one region > for the provisioned sources. > - improved 'info pic' output > > hw/intc/spapr_xive.c | 254 > +++++++++++++++++++++++++++++++++++++++++++- > hw/intc/xive-internal.h | 10 ++ > include/hw/ppc/spapr_xive.h | 9 ++ > 3 files changed, 271 insertions(+), 2 deletions(-) > > diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c > index e6e8841add17..43df6814619d 100644 > --- a/hw/intc/spapr_xive.c > +++ b/hw/intc/spapr_xive.c > @@ -18,23 +18,252 @@ > > #include "xive-internal.h" > > +static void spapr_xive_irq(sPAPRXive *xive, int lisn) > +{ > + > +} > + > /* > - * Main XIVE object > + * XIVE Interrupt Source > + */ > + > +/* > + * "magic" Event State Buffer (ESB) MMIO offsets. > + * > + * Each interrupt source has a 2-bit state machine called ESB > + * which can be controlled by MMIO. It's made of 2 bits, P and > + * Q. P indicates that an interrupt is pending (has been sent > + * to a queue and is waiting for an EOI). Q indicates that the > + * interrupt has been triggered while pending. > + * > + * This acts as a coalescing mechanism in order to guarantee > + * that a given interrupt only occurs at most once in a queue. > + * > + * When doing an EOI, the Q bit will indicate if the interrupt > + * needs to be re-triggered. > + * > + * The following offsets into the ESB MMIO allow to read or > + * manipulate the PQ bits. They must be used with an 8-bytes > + * load instruction. They all return the previous state of the > + * interrupt (atomically). > + * > + * Additionally, some ESB pages support doing an EOI via a > + * store at 0 and some ESBs support doing a trigger via a > + * separate trigger page. > + */ > +#define XIVE_ESB_STORE_EOI 0x400 /* Store */ > +#define XIVE_ESB_LOAD_EOI 0x000 /* Load */ > +#define XIVE_ESB_GET 0x800 /* Load */ > +#define XIVE_ESB_SET_PQ_00 0xc00 /* Load */ > +#define XIVE_ESB_SET_PQ_01 0xd00 /* Load */ > +#define XIVE_ESB_SET_PQ_10 0xe00 /* Load */ > +#define XIVE_ESB_SET_PQ_11 0xf00 /* Load */ > + > +#define XIVE_ESB_VAL_P 0x2 > +#define XIVE_ESB_VAL_Q 0x1 > + > +#define XIVE_ESB_RESET 0x0 > +#define XIVE_ESB_PENDING XIVE_ESB_VAL_P > +#define XIVE_ESB_QUEUED (XIVE_ESB_VAL_P | XIVE_ESB_VAL_Q) > +#define XIVE_ESB_OFF XIVE_ESB_VAL_Q > + > +static uint8_t spapr_xive_pq_get(sPAPRXive *xive, uint32_t lisn) > +{ > + uint32_t byte = lisn / 4; > + uint32_t bit = (lisn % 4) * 2; > + > + assert(byte < xive->sbe_size); > + > + return (xive->sbe[byte] >> bit) & 0x3; > +} > + > +static uint8_t spapr_xive_pq_set(sPAPRXive *xive, uint32_t lisn, uint8_t pq) > +{ > + uint32_t byte = lisn / 4; > + uint32_t bit = (lisn % 4) * 2; > + uint8_t old, new; > + > + assert(byte < xive->sbe_size); > + > + old = xive->sbe[byte]; > + > + new = xive->sbe[byte] & ~(0x3 << bit); > + new |= (pq & 0x3) << bit; > + > + xive->sbe[byte] = new; > + > + return (old >> bit) & 0x3; > +} > + > +static bool spapr_xive_pq_eoi(sPAPRXive *xive, uint32_t lisn) > +{ > + uint8_t old_pq = spapr_xive_pq_get(xive, lisn); > + > + switch (old_pq) { > + case XIVE_ESB_RESET: > + spapr_xive_pq_set(xive, lisn, XIVE_ESB_RESET); > + return false; > + case XIVE_ESB_PENDING: > + spapr_xive_pq_set(xive, lisn, XIVE_ESB_RESET); > + return false; > + case XIVE_ESB_QUEUED: > + spapr_xive_pq_set(xive, lisn, XIVE_ESB_PENDING); > + return true; > + case XIVE_ESB_OFF: > + spapr_xive_pq_set(xive, lisn, XIVE_ESB_OFF); > + return false; > + default: > + g_assert_not_reached(); > + } > +} > + > +/* > + * Returns whether the event notification should be forwarded to the > + * IVE for routing. > */ > +static bool spapr_xive_pq_trigger(sPAPRXive *xive, uint32_t lisn) > +{ > + uint8_t old_pq = spapr_xive_pq_get(xive, lisn); > > + switch (old_pq) { > + case XIVE_ESB_RESET: > + spapr_xive_pq_set(xive, lisn, XIVE_ESB_PENDING); > + return true; > + case XIVE_ESB_PENDING: > + spapr_xive_pq_set(xive, lisn, XIVE_ESB_QUEUED); > + return false; > + case XIVE_ESB_QUEUED: > + spapr_xive_pq_set(xive, lisn, XIVE_ESB_QUEUED); > + return false; > + case XIVE_ESB_OFF: > + spapr_xive_pq_set(xive, lisn, XIVE_ESB_OFF); > + return false; > + default: > + g_assert_not_reached(); > + } > +} > + > +/* > + * XIVE Interrupt Source MMIOs > + */ > + > +/* > + * Some HW use a separate page for trigger. We only support the case > + * in which the trigger can be done in the same page as the EOI. > + */ > +static uint64_t spapr_xive_esb_read(void *opaque, hwaddr addr, unsigned size) > +{ > + sPAPRXive *xive = SPAPR_XIVE(opaque); > + uint32_t offset = addr & 0xF00; > + uint32_t lisn = addr >> ESB_SHIFT; > + uint64_t ret = -1; > + > + switch (offset) { > + case XIVE_ESB_LOAD_EOI: > + /* > + * EOI on load is not used anymore as we now advertise > + * XIVE_ESB_STORE_EOI support for the interrupt sources > + */ > + ret = spapr_xive_pq_eoi(xive, lisn); > + break; > + > + case XIVE_ESB_GET: > + ret = spapr_xive_pq_get(xive, lisn); > + break; > + > + case XIVE_ESB_SET_PQ_00: > + case XIVE_ESB_SET_PQ_01: > + case XIVE_ESB_SET_PQ_10: > + case XIVE_ESB_SET_PQ_11: > + ret = spapr_xive_pq_set(xive, lisn, (offset >> 8) & 0x3); > + break; > + default: > + qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid ESB addr %d\n", > offset); > + } > + > + return ret; > +} > + > +static void spapr_xive_esb_write(void *opaque, hwaddr addr, > + uint64_t value, unsigned size) > +{ > + sPAPRXive *xive = SPAPR_XIVE(opaque); > + uint32_t offset = addr & 0xF00; > + uint32_t lisn = addr >> ESB_SHIFT; > + bool notify = false; > + > + switch (offset) { > + case 0: > + notify = spapr_xive_pq_trigger(xive, lisn); > + break; > + case XIVE_ESB_STORE_EOI: > + /* If the Q bit is set, we should forward a new source event > + * notification > + */ > + notify = spapr_xive_pq_eoi(xive, lisn); > + break; > + default: > + qemu_log_mask(LOG_GUEST_ERROR, "XIVE: invalid ESB write addr %d\n", > + offset); > + return; > + } > + > + /* Forward the source event notification for routing */ > + if (notify) { > + spapr_xive_irq(xive, lisn); > + } > +} > + > +static const MemoryRegionOps spapr_xive_esb_ops = { > + .read = spapr_xive_esb_read, > + .write = spapr_xive_esb_write, > + .endianness = DEVICE_BIG_ENDIAN, > + .valid = { > + .min_access_size = 8, > + .max_access_size = 8, > + }, > + .impl = { > + .min_access_size = 8, > + .max_access_size = 8, > + }, > +}; > + > +static void spapr_xive_source_set_irq(void *opaque, int lisn, int val) > +{ > + sPAPRXive *xive = SPAPR_XIVE(opaque); > + bool notify = false; > + > + if (val) { > + notify = spapr_xive_pq_trigger(xive, lisn); > + } > + > + /* Forward the source event notification for routing */ > + if (notify) { > + spapr_xive_irq(xive, lisn); > + } > +} > + > +/* > + * Main XIVE object > + */ > void spapr_xive_pic_print_info(sPAPRXive *xive, Monitor *mon) > { > int i; > > for (i = 0; i < xive->nr_irqs; i++) { > XiveIVE *ive = &xive->ivt[i]; > + uint8_t pq; > > if (!(ive->w & IVE_VALID)) { > continue; > } > > - monitor_printf(mon, " %4x %s %08x %08x\n", i, > + pq = spapr_xive_pq_get(xive, i); > + > + monitor_printf(mon, " %4x %s %c%c %08x %08x\n", i, > ive->w & IVE_MASKED ? "M" : " ", > + pq & XIVE_ESB_VAL_P ? 'P' : '-', > + pq & XIVE_ESB_VAL_Q ? 'Q' : '-', > (int) GETFIELD(IVE_EQ_INDEX, ive->w), > (int) GETFIELD(IVE_EQ_DATA, ive->w)); > } > @@ -52,6 +281,9 @@ static void spapr_xive_reset(DeviceState *dev) > ive->w |= IVE_MASKED; > } > } > + > + /* SBEs are initialized to 0b01 which corresponds to "ints off" */ > + memset(xive->sbe, 0x55, xive->sbe_size); > } > > static void spapr_xive_realize(DeviceState *dev, Error **errp) > @@ -65,6 +297,23 @@ static void spapr_xive_realize(DeviceState *dev, Error > **errp) > > /* Allocate the IVT (Interrupt Virtualization Table) */ > xive->ivt = g_new0(XiveIVE, xive->nr_irqs); > + > + /* QEMU IRQs */ > + xive->qirqs = qemu_allocate_irqs(spapr_xive_source_set_irq, xive, > + xive->nr_irqs); > + > + /* Allocate SBEs (State Bit Entry). 2 bits, so 4 entries per byte */ > + xive->sbe_size = DIV_ROUND_UP(xive->nr_irqs, 4); > + xive->sbe = g_malloc0(xive->sbe_size); > + > + /* VC BAR. Use address of chip 0 to install the ESB memory region > + * for *all* interrupt sources */ > + xive->esb_base = (P9_MMIO_BASE | VC_BAR_DEFAULT); > + > + memory_region_init_io(&xive->esb_iomem, OBJECT(xive), > + &spapr_xive_esb_ops, xive, "xive.esb", > + (1ull << ESB_SHIFT) * xive->nr_irqs); > + sysbus_init_mmio(SYS_BUS_DEVICE(dev), &xive->esb_iomem); > } > > static const VMStateDescription vmstate_spapr_xive_ive = { > @@ -92,6 +341,7 @@ static const VMStateDescription vmstate_spapr_xive = { > VMSTATE_UINT32_EQUAL(nr_irqs, sPAPRXive, NULL), > VMSTATE_STRUCT_VARRAY_UINT32(ivt, sPAPRXive, nr_irqs, 1, > vmstate_spapr_xive_ive, XiveIVE), > + VMSTATE_VBUFFER_UINT32(sbe, sPAPRXive, 1, NULL, sbe_size), > VMSTATE_END_OF_LIST() > }, > }; > diff --git a/hw/intc/xive-internal.h b/hw/intc/xive-internal.h > index 132b71a6daf0..872648dd96a2 100644 > --- a/hw/intc/xive-internal.h > +++ b/hw/intc/xive-internal.h > @@ -16,6 +16,16 @@ > #define SETFIELD(m, v, val) \ > (((v) & ~(m)) | ((((typeof(v))(val)) << MASK_TO_LSH(m)) & (m))) > > +/* > + * XIVE MMIO regions > + */ > +#define P9_MMIO_BASE 0x006000000000000ull > + > +/* VC BAR contains set translations for the ESBs and the EQs. */ > +#define VC_BAR_DEFAULT 0x10000000000ull > +#define VC_BAR_SIZE 0x08000000000ull > +#define ESB_SHIFT 16 /* One 64k page. OPAL has two */ > + > /* IVE/EAS > * > * One per interrupt source. Targets that interrupt to a given EQ > diff --git a/include/hw/ppc/spapr_xive.h b/include/hw/ppc/spapr_xive.h > index 5b1f78e06a1e..ecc15d889b74 100644 > --- a/include/hw/ppc/spapr_xive.h > +++ b/include/hw/ppc/spapr_xive.h > @@ -24,8 +24,17 @@ struct sPAPRXive { > /* Properties */ > uint32_t nr_irqs; > > + /* IRQ */ > + qemu_irq *qirqs; > + > /* XIVE internal tables */ > XiveIVE *ivt; > + uint8_t *sbe; > + uint32_t sbe_size; > + > + /* ESB memory region */ > + hwaddr esb_base; > + MemoryRegion esb_iomem; > }; > > bool spapr_xive_irq_enable(sPAPRXive *xive, uint32_t lisn); -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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