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Re: [Qemu-devel] [PATCH v6 2/4] spapr: introduce a fixed IRQ number spac
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From: |
Greg Kurz |
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Subject: |
Re: [Qemu-devel] [PATCH v6 2/4] spapr: introduce a fixed IRQ number space |
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Date: |
Tue, 31 Jul 2018 19:39:45 +0200 |
On Mon, 30 Jul 2018 16:11:32 +0200
Cédric Le Goater <address@hidden> 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-3.1 machines raising the
> 'legacy_irq_allocation' machine class flag.
>
> Signed-off-by: Cédric Le Goater <address@hidden>
> ---
> 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 | 66 ++++++++++++++++++++++++++++++++++----
> hw/ppc/Makefile.objs | 2 +-
> 8 files changed, 216 insertions(+), 18 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;
> +
Old compilers (GCC < 4.6) might complain about 'redefinition of typedef' if
some file, say hw/ppc/spapr.c, includes both this header and "hw/ppc/xics.h".
We had several build breaks detected by 'make address@hidden'...
The correct way to address this would be to move the typedef to the
"qemu/typedefs.h" header.
This being said, address@hidden vanished with commit e7b3af81597,
so I guess we don't support such old distros anymore, and we can live with
duplicate typedefs.
> +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 3c72173c7e0f..792e24453d8b 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
> }
> };
> @@ -4085,8 +4113,12 @@ static void
> spapr_machine_3_0_instance_options(MachineState *machine)
>
> static void spapr_machine_3_0_class_options(MachineClass *mc)
> {
> + sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc);
> +
> spapr_machine_3_1_class_options(mc);
> SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_3_0);
> +
> + smc->legacy_irq_allocation = true;
> }
>
> DEFINE_SPAPR_MACHINE(3_0, "3.0", false);
> diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
> index e4f5946a2188..32719a1b72d0 100644
> --- a/hw/ppc/spapr_events.c
> +++ b/hw/ppc/spapr_events.c
> @@ -707,9 +707,11 @@ void spapr_clear_pending_events(sPAPRMachineState *spapr)
>
> void spapr_events_init(sPAPRMachineState *spapr)
> {
> - int epow_irq;
> + int epow_irq = SPAPR_IRQ_EPOW;
>
> - 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);
> + }
>
> spapr_irq_claim(spapr, epow_irq, false, &error_fatal);
>
> @@ -729,9 +731,11 @@ void spapr_events_init(sPAPRMachineState *spapr)
> * checking that it's enabled.
> */
> if (spapr->use_hotplug_event_source) {
> - int hp_irq;
> + int hp_irq = SPAPR_IRQ_HOTPLUG;
>
> - 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);
> + }
>
> 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..3791ced6c536 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_MACHINE_GET_CLASS() does all the recursive type checking, and you
call it three times. Even if this isn't a hot path, maybe cache this in
an smc variable at the beginning of the function as we do pretty much
everywhere else. Also this would give prettier code IMHO.
> spapr_irq_free(spapr, msi->first_irq, msi->num);
> g_hash_table_remove(phb->msi, &config_addr);
> }
> @@ -1705,14 +1717,16 @@ static void spapr_phb_realize(DeviceState *dev, Error
> **errp)
>
> /* Initialize the LSI table */
> for (i = 0; i < PCI_NUM_PINS; i++) {
> - uint32_t irq;
> + uint32_t irq = SPAPR_IRQ_PCI_LSI + sphb->index * PCI_NUM_PINS + i;
> 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) {
Same remark. There's another SPAPR_MACHINE_GET_CLASS() user in this
function.
> + irq = spapr_irq_findone(spapr, &local_err);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + error_prepend(errp, "can't allocate LSIs: ");
> + return;
> + }
> }
>
> spapr_irq_claim(spapr, irq, true, &local_err);
> @@ -2123,6 +2137,7 @@ 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..840d4a3c451c 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 +446,55 @@ static void spapr_vio_busdev_reset(DeviceState *qdev)
> }
> }
>
> +/*
> + * The register property of a VIO device is defined in livirt using
> + * 0x1000 as a base register number plus a 0x1000 increment. For the
> + * VIO tty device, the base number is changed to 0x30000000. QEMU uses
> + * a base register number of 0x71000000 and then a simple increment.
> + *
> + * 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 VIO devices is covered. Collisions are possible
> + * but they will be detected when the IRQ is claimed.
> + */
> +static inline uint32_t spapr_vio_reg_to_irq(uint32_t reg)
> +{
> + uint32_t irq;
> +
> + if (reg >= SPAPR_VIO_REG_BASE) {
> + /*
> + * VIO device register values when allocated by QEMU. For
> + * these, we simply mask the high bits to fit the overall
> + * range: [0x00 - 0xff].
> + *
> + * The nvram VIO device (reg=0x71000000) is a static device of
> + * the pseries machine and so is always allocated by QEMU. Its
> + * IRQ number is 0x0.
> + */
> + irq = reg & 0xff;
> +
> + } else if (reg >= 0x30000000) {
> + /*
> + * VIO tty devices register values, when allocated by livirt,
> + * are mapped in range [0xf0 - 0xff], gives us a maximum of 16
> + * vtys.
> + */
> + irq = 0xf0 | ((reg >> 12) & 0xf);
> +
> + } else {
> + /*
> + * Other VIO devices register values, when allocated by
> + * livirt, should be mapped in range [0x00 - 0xef]. Conflicts
> + * will be detected when IRQ is claimed.
> + */
> + irq = (reg >> 12) & 0xff;
> + }
> +
Nice formula :)
The patch looks quite good to me, and my remarks about SPAPR_MACHINE_GET_CLASS()
can be addressed in a followup, so:
Reviewed-by: Greg Kurz <address@hidden>
> + return SPAPR_IRQ_VIO | irq;
> +}
> +
> static void spapr_vio_busdev_realize(DeviceState *qdev, Error **errp)
> {
> sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> @@ -485,10 +535,14 @@ 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;
> + dev->irq = spapr_vio_reg_to_irq(dev->reg);
> +
> + 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;
> + }
> }
> }
>
> @@ -557,7 +611,7 @@ 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)