On Fri, 6 Jul 2018 11:07:11 +0200 Cédric Le Goater <c...@kaod.org> wrote:
> This proposal introduces a new IRQ number space layout using static > numbers for all devices, depending on a device index, and a bitmap > allocator for the MSI IRQ numbers which are negotiated by the guest at > runtime. > > As the VIO device model does not have a device index but a "reg" > property, we introduce a formula to compute an IRQ number from a "reg" > value. It should minimize most of the collisions. > > The previous layout is kept in pre-3.0 machines raising the > 'legacy_irq_allocation' machine class flag. > > Signed-off-by: Cédric Le Goater <c...@kaod.org> > --- > The new XICS layout will only be activated when a new pseries-3.1 > machine is introduced. > > include/hw/ppc/spapr.h | 5 ++++ > include/hw/ppc/spapr_irq.h | 32 ++++++++++++++++++++++ > hw/ppc/spapr.c | 32 +++++++++++++++++++++- > hw/ppc/spapr_events.c | 12 ++++++-- > hw/ppc/spapr_irq.c | 56 ++++++++++++++++++++++++++++++++++++++ > hw/ppc/spapr_pci.c | 29 ++++++++++++++++---- > hw/ppc/spapr_vio.c | 47 ++++++++++++++++++++++++++++---- > hw/ppc/Makefile.objs | 2 +- > 8 files changed, 199 insertions(+), 16 deletions(-) > create mode 100644 include/hw/ppc/spapr_irq.h > create mode 100644 hw/ppc/spapr_irq.c > > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > index 7e5de1a6fd42..73067f5ee8aa 100644 > --- a/include/hw/ppc/spapr.h > +++ b/include/hw/ppc/spapr.h > @@ -8,6 +8,7 @@ > #include "hw/ppc/spapr_drc.h" > #include "hw/mem/pc-dimm.h" > #include "hw/ppc/spapr_ovec.h" > +#include "hw/ppc/spapr_irq.h" > > struct VIOsPAPRBus; > struct sPAPRPHBState; > @@ -101,6 +102,8 @@ struct sPAPRMachineClass { > bool dr_lmb_enabled; /* enable dynamic-reconfig/hotplug of LMBs */ > bool use_ohci_by_default; /* use USB-OHCI instead of XHCI */ > bool pre_2_10_has_unused_icps; > + bool legacy_irq_allocation; > + > void (*phb_placement)(sPAPRMachineState *spapr, uint32_t index, > uint64_t *buid, hwaddr *pio, > hwaddr *mmio32, hwaddr *mmio64, > @@ -167,6 +170,8 @@ struct sPAPRMachineState { > char *kvm_type; > > const char *icp_type; > + int32_t irq_map_nr; > + unsigned long *irq_map; > > bool cmd_line_caps[SPAPR_CAP_NUM]; > sPAPRCapabilities def, eff, mig; > diff --git a/include/hw/ppc/spapr_irq.h b/include/hw/ppc/spapr_irq.h > new file mode 100644 > index 000000000000..6f7f50548809 > --- /dev/null > +++ b/include/hw/ppc/spapr_irq.h > @@ -0,0 +1,32 @@ > +/* > + * QEMU PowerPC sPAPR IRQ backend definitions > + * > + * Copyright (c) 2018, IBM Corporation. > + * > + * This code is licensed under the GPL version 2 or later. See the > + * COPYING file in the top-level directory. > + */ > + > +#ifndef HW_SPAPR_IRQ_H > +#define HW_SPAPR_IRQ_H > + > +/* > + * IRQ range offsets per device type > + */ > +#define SPAPR_IRQ_EPOW 0x1000 /* XICS_IRQ_BASE offset */ > +#define SPAPR_IRQ_HOTPLUG 0x1001 > +#define SPAPR_IRQ_VIO 0x1100 /* 256 VIO devices */ > +#define SPAPR_IRQ_PCI_LSI 0x1200 /* 32+ PHBs devices */ > + > +#define SPAPR_IRQ_MSI 0x1300 /* Offset of the dynamic range covered > + * by the bitmap allocator */ > + > +typedef struct sPAPRMachineState sPAPRMachineState; > + > +void spapr_irq_msi_init(sPAPRMachineState *spapr, uint32_t nr_msis); > +int spapr_irq_msi_alloc(sPAPRMachineState *spapr, uint32_t num, bool align, > + Error **errp); > +void spapr_irq_msi_free(sPAPRMachineState *spapr, int irq, uint32_t num); > +void spapr_irq_msi_reset(sPAPRMachineState *spapr); > + > +#endif > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 3f5e1d3ec21a..7bc9a48abf04 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -189,6 +189,11 @@ static void xics_system_init(MachineState *machine, int > nr_irqs, Error **errp) > sPAPRMachineState *spapr = SPAPR_MACHINE(machine); > Error *local_err = NULL; > > + /* Initialize the MSI IRQ allocator. */ > + if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > + spapr_irq_msi_init(spapr, XICS_IRQ_BASE + nr_irqs - SPAPR_IRQ_MSI); > + } > + > if (kvm_enabled()) { > if (machine_kernel_irqchip_allowed(machine) && > !xics_kvm_init(spapr, &local_err)) { > @@ -1636,6 +1641,10 @@ static void spapr_machine_reset(void) > ppc_set_compat(first_ppc_cpu, spapr->max_compat_pvr, &error_fatal); > } > > + if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > + spapr_irq_msi_reset(spapr); > + } > + > qemu_devices_reset(); > > /* DRC reset may cause a device to be unplugged. This will cause troubles > @@ -1910,6 +1919,24 @@ static const VMStateDescription > vmstate_spapr_patb_entry = { > }, > }; > > +static bool spapr_irq_map_needed(void *opaque) > +{ > + sPAPRMachineState *spapr = opaque; > + > + return spapr->irq_map && !bitmap_empty(spapr->irq_map, > spapr->irq_map_nr); > +} > + > +static const VMStateDescription vmstate_spapr_irq_map = { > + .name = "spapr_irq_map", > + .version_id = 1, > + .minimum_version_id = 1, > + .needed = spapr_irq_map_needed, > + .fields = (VMStateField[]) { > + VMSTATE_BITMAP(irq_map, sPAPRMachineState, 0, irq_map_nr), > + VMSTATE_END_OF_LIST() > + }, > +}; > + > static const VMStateDescription vmstate_spapr = { > .name = "spapr", > .version_id = 3, > @@ -1937,6 +1964,7 @@ static const VMStateDescription vmstate_spapr = { > &vmstate_spapr_cap_cfpc, > &vmstate_spapr_cap_sbbc, > &vmstate_spapr_cap_ibs, > + &vmstate_spapr_irq_map, > NULL > } > }; > @@ -4067,7 +4095,9 @@ static void > spapr_machine_3_0_instance_options(MachineState *machine) > > static void spapr_machine_3_0_class_options(MachineClass *mc) > { > - /* Defaults for the latest behaviour inherited from the base class */ > + sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc); > + > + smc->legacy_irq_allocation = true; > } > > DEFINE_SPAPR_MACHINE(3_0, "3.0", true); > diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c > index e4f5946a2188..cab950d33446 100644 > --- a/hw/ppc/spapr_events.c > +++ b/hw/ppc/spapr_events.c > @@ -709,7 +709,11 @@ void spapr_events_init(sPAPRMachineState *spapr) > { > int epow_irq; > > - epow_irq = spapr_irq_findone(spapr, &error_fatal); > + if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > + epow_irq = spapr_irq_findone(spapr, &error_fatal); > + } else { > + epow_irq = SPAPR_IRQ_EPOW; > + } > > spapr_irq_claim(spapr, epow_irq, false, &error_fatal); > > @@ -731,7 +735,11 @@ void spapr_events_init(sPAPRMachineState *spapr) > if (spapr->use_hotplug_event_source) { > int hp_irq; > > - hp_irq = spapr_irq_findone(spapr, &error_fatal); > + if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > + hp_irq = spapr_irq_findone(spapr, &error_fatal); > + } else { > + hp_irq = SPAPR_IRQ_HOTPLUG; > + } > > spapr_irq_claim(spapr, hp_irq, false, &error_fatal); > > diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c > new file mode 100644 > index 000000000000..24e9c1d4433c > --- /dev/null > +++ b/hw/ppc/spapr_irq.c > @@ -0,0 +1,56 @@ > +/* > + * QEMU PowerPC sPAPR IRQ interface > + * > + * Copyright (c) 2018, IBM Corporation. > + * > + * This code is licensed under the GPL version 2 or later. See the > + * COPYING file in the top-level directory. > + */ > + > +#include "qemu/osdep.h" > +#include "qemu/log.h" > +#include "qemu/error-report.h" > +#include "qapi/error.h" > +#include "hw/ppc/spapr.h" > +#include "hw/ppc/xics.h" > + > +void spapr_irq_msi_init(sPAPRMachineState *spapr, uint32_t nr_msis) > +{ > + spapr->irq_map_nr = nr_msis; > + spapr->irq_map = bitmap_new(spapr->irq_map_nr); > +} > + > +int spapr_irq_msi_alloc(sPAPRMachineState *spapr, uint32_t num, bool align, > + Error **errp) > +{ > + int irq; > + > + /* > + * The 'align_mask' parameter of bitmap_find_next_zero_area() > + * should be one less than a power of 2; 0 means no > + * alignment. Adapt the 'align' value of the former allocator > + * to fit the requirements of bitmap_find_next_zero_area() > + */ > + align -= 1; > + > + irq = bitmap_find_next_zero_area(spapr->irq_map, spapr->irq_map_nr, 0, > num, > + align); > + if (irq == spapr->irq_map_nr) { > + error_setg(errp, "can't find a free %d-IRQ block", num); > + return -1; > + } > + > + bitmap_set(spapr->irq_map, irq, num); > + > + return irq + SPAPR_IRQ_MSI; > +} > + > +void spapr_irq_msi_free(sPAPRMachineState *spapr, int irq, uint32_t num) > +{ > + bitmap_clear(spapr->irq_map, irq - SPAPR_IRQ_MSI, num); > +} > + > +void spapr_irq_msi_reset(sPAPRMachineState *spapr) > +{ > + bitmap_clear(spapr->irq_map, 0, spapr->irq_map_nr); > +} > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c > index 497b896c7d24..cba5340f4bad 100644 > --- a/hw/ppc/spapr_pci.c > +++ b/hw/ppc/spapr_pci.c > @@ -334,6 +334,9 @@ static void rtas_ibm_change_msi(PowerPCCPU *cpu, > sPAPRMachineState *spapr, > return; > } > > + if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > + spapr_irq_msi_free(spapr, msi->first_irq, msi->num); > + } > spapr_irq_free(spapr, msi->first_irq, msi->num); > if (msi_present(pdev)) { > spapr_msi_setmsg(pdev, 0, false, 0, 0); > @@ -372,7 +375,13 @@ static void rtas_ibm_change_msi(PowerPCCPU *cpu, > sPAPRMachineState *spapr, > } > > /* Allocate MSIs */ > - irq = spapr_irq_find(spapr, req_num, ret_intr_type == RTAS_TYPE_MSI, > &err); > + if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > + irq = spapr_irq_find(spapr, req_num, ret_intr_type == RTAS_TYPE_MSI, > + &err); > + } else { > + irq = spapr_irq_msi_alloc(spapr, req_num, > + ret_intr_type == RTAS_TYPE_MSI, &err); > + } > if (err) { > error_reportf_err(err, "Can't allocate MSIs for device %x: ", > config_addr); > @@ -392,6 +401,9 @@ static void rtas_ibm_change_msi(PowerPCCPU *cpu, > sPAPRMachineState *spapr, > > /* Release previous MSIs */ > if (msi) { > + if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > + spapr_irq_msi_free(spapr, msi->first_irq, msi->num); > + } > spapr_irq_free(spapr, msi->first_irq, msi->num); > g_hash_table_remove(phb->msi, &config_addr); > } > @@ -1708,11 +1720,15 @@ static void spapr_phb_realize(DeviceState *dev, Error > **errp) > uint32_t irq; > Error *local_err = NULL; > > - irq = spapr_irq_findone(spapr, &local_err); > - if (local_err) { > - error_propagate(errp, local_err); > - error_prepend(errp, "can't allocate LSIs: "); > - return; > + if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > + irq = spapr_irq_findone(spapr, &local_err); > + if (local_err) { > + error_propagate(errp, local_err); > + error_prepend(errp, "can't allocate LSIs: "); > + return; > + } > + } else { > + irq = SPAPR_IRQ_PCI_LSI + sphb->index * PCI_NUM_PINS + i; > } > > spapr_irq_claim(spapr, irq, true, &local_err); > @@ -2123,6 +2139,7 @@ int spapr_populate_pci_dt(sPAPRPHBState *phb, > _FDT(fdt_setprop(fdt, bus_off, "ranges", &ranges, sizeof_ranges)); > _FDT(fdt_setprop(fdt, bus_off, "reg", &bus_reg, sizeof(bus_reg))); > _FDT(fdt_setprop_cell(fdt, bus_off, "ibm,pci-config-space-type", 0x1)); > + /* TODO: fine tune the total count of allocatable MSIs per PHB */ > _FDT(fdt_setprop_cell(fdt, bus_off, "ibm,pe-total-#msi", > XICS_IRQS_SPAPR)); > > /* Dynamic DMA window */ > diff --git a/hw/ppc/spapr_vio.c b/hw/ppc/spapr_vio.c > index be9af71437cc..a0695200f348 100644 > --- a/hw/ppc/spapr_vio.c > +++ b/hw/ppc/spapr_vio.c > @@ -37,12 +37,13 @@ > > #include "hw/ppc/spapr.h" > #include "hw/ppc/spapr_vio.h" > -#include "hw/ppc/xics.h" > #include "hw/ppc/fdt.h" > #include "trace.h" > > #include <libfdt.h> > > +#define SPAPR_VIO_REG_BASE 0x71000000 > + > static void spapr_vio_get_irq(Object *obj, Visitor *v, const char *name, > void *opaque, Error **errp) > { > @@ -445,6 +446,32 @@ static void spapr_vio_busdev_reset(DeviceState *qdev) > } > } > > +/* > + * The register property of a VIO device is defined in livirt using a > + * base number + 0x1000 increment and in QEMU by incrementing the base > + * register number 0x71000000. > + * > + * The formula below tries to compute a unique index number from the > + * register value that will be used to define the IRQ number of the > + * VIO device. A maximum of 256 (0x100) VIO devices is covered. > + * > + * To minimize collisions, we define two distinct ranges depending on > + * the "reg" value definition: > + * > + * [0x00 - 0x7f] user/libvirt > + * [0x80 - 0xff] QEMU VIO model > + * > + * Collisions will be detected when the IRQ is claimed. > + */ > +static inline uint32_t spapr_vio_reg_to_irq(uint32_t reg) > +{ > + if (reg >= SPAPR_VIO_REG_BASE) { > + return SPAPR_IRQ_VIO | (reg & 0x7f) | 0x80; > + } else { > + return SPAPR_IRQ_VIO | ((reg & 0x7f) ^ ((reg >> 12) & 0x7f)); Hmm... if you put a VIO net and two VIO vty in the domain XML, libvirt will generate reg == 0x1000 for the VIO net and reg == 0x30001000 for the second VIO vty... this will necessarily collide, won't it ? With a 256 VIO devices limit, libvirt can only add 255 devices since the nvram is created by QEMU by default (libvirt can only change its reg using -global). As David mentioned in another mail: VIO net devices start at reg=0x1000 VIO scsi devices start at reg=0x2000 VIO nvram devices start at reg=0x3000 VIO vty devices start at reg=0x30000000 and increment by 0x1000 each type The values for net, scsi and nvram overlap... which makes me wonder why do we even care to have per-type base value !?! Anyway, I don't think it's important for what you're trying to achieve. Basically libvirt can generate regs in two distinct ranges: - one for scsi/net/nvram: smallest possible reg: 0x1000 largest possible reg: 0x2000 + 254 * 0x1000 = 0x100000 ie, 254 scsi devices starting at 0x2000 and 1 nvram - one for vty smallest possible reg: 0x30000000 largest possible reg: 0x30000000 + 253 * 0x1000 = 0x300fd000 ie, 254 vty devices Thinking about the bit shifting magic that is needed to convert reg into a usable index makes my brain hurt, but I'll happily review anything you propose :) > + } > +} > + > static void spapr_vio_busdev_realize(DeviceState *qdev, Error **errp) > { > sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine()); > @@ -485,10 +512,18 @@ static void spapr_vio_busdev_realize(DeviceState *qdev, > Error **errp) > } > > if (!dev->irq) { > - dev->irq = spapr_irq_findone(spapr, &local_err); > - if (local_err) { > - error_propagate(errp, local_err); > - return; > + if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) { > + dev->irq = spapr_irq_findone(spapr, &local_err); > + if (local_err) { > + error_propagate(errp, local_err); > + return; > + } > + } else { > + dev->irq = spapr_vio_reg_to_irq(dev->reg); > + if (dev->irq == SPAPR_IRQ_PCI_LSI) { > + error_setg(errp, "Too many VIO devices"); > + return; > + } > } > } > > @@ -557,7 +592,7 @@ VIOsPAPRBus *spapr_vio_bus_init(void) > /* Create bus on bridge device */ > qbus = qbus_create(TYPE_SPAPR_VIO_BUS, dev, "spapr-vio"); > bus = SPAPR_VIO_BUS(qbus); > - bus->next_reg = 0x71000000; > + bus->next_reg = SPAPR_VIO_REG_BASE; > > /* hcall-vio */ > spapr_register_hypercall(H_VIO_SIGNAL, h_vio_signal); > diff --git a/hw/ppc/Makefile.objs b/hw/ppc/Makefile.objs > index bcab6323b7ed..4ab556467289 100644 > --- a/hw/ppc/Makefile.objs > +++ b/hw/ppc/Makefile.objs > @@ -4,7 +4,7 @@ obj-y += ppc.o ppc_booke.o fdt.o > obj-$(CONFIG_PSERIES) += spapr.o spapr_caps.o spapr_vio.o spapr_events.o > obj-$(CONFIG_PSERIES) += spapr_hcall.o spapr_iommu.o spapr_rtas.o > obj-$(CONFIG_PSERIES) += spapr_pci.o spapr_rtc.o spapr_drc.o spapr_rng.o > -obj-$(CONFIG_PSERIES) += spapr_cpu_core.o spapr_ovec.o > +obj-$(CONFIG_PSERIES) += spapr_cpu_core.o spapr_ovec.o spapr_irq.o > # IBM PowerNV > obj-$(CONFIG_POWERNV) += pnv.o pnv_xscom.o pnv_core.o pnv_lpc.o pnv_psi.o > pnv_occ.o pnv_bmc.o > ifeq ($(CONFIG_PCI)$(CONFIG_PSERIES)$(CONFIG_LINUX), yyy)