Re: [Qemu-devel] [PATCH 17/33] spapr_drc: initial implementation of sPAPRDRConnector device

[Alexander Graf <agraf@suse.de>]

On 07.05.15 07:33, David Gibson wrote:
> From: Michael Roth <mdroth@linux.vnet.ibm.com>
> 
> This device emulates a firmware abstraction used by pSeries guests to
> manage hotplug/dynamic-reconfiguration of host-bridges, PCI devices,
> memory, and CPUs. It is conceptually similar to an SHPC device,
> complete with LED indicators to identify individual slots to physical
> physical users and indicate when it is safe to remove a device. In
> some cases it is also used to manage virtualized resources, such a
> memory, CPUs, and physical-host bridges, which in the case of pSeries
> guests are virtualized resources where the physical components are
> managed by the host.
> 
> Guests communicate with these DR Connectors using RTAS calls,
> generally by addressing the unique DRC index associated with a
> particular connector for a particular resource. For introspection
> purposes we expose this state initially as QOM properties, and
> in subsequent patches will introduce the RTAS calls that make use of
> it. This constitutes to the 'guest' interface.
> 
> On the QEMU side we provide an attach/detach interface to associate
> or cleanup a DeviceState with a particular sPAPRDRConnector in
> response to hotplug/unplug, respectively. This constitutes the
> 'physical' interface to the DR Connector.
> 
> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  hw/ppc/Makefile.objs       |   2 +-
>  hw/ppc/spapr_drc.c         | 588 +++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/ppc/spapr_drc.h | 199 +++++++++++++++
>  3 files changed, 788 insertions(+), 1 deletion(-)
>  create mode 100644 hw/ppc/spapr_drc.c
>  create mode 100644 include/hw/ppc/spapr_drc.h
> 
> diff --git a/hw/ppc/Makefile.objs b/hw/ppc/Makefile.objs
> index 437955d..c8ab06e 100644
> --- a/hw/ppc/Makefile.objs
> +++ b/hw/ppc/Makefile.objs
> @@ -3,7 +3,7 @@ obj-y += ppc.o ppc_booke.o
>  # IBM pSeries (sPAPR)
>  obj-$(CONFIG_PSERIES) += spapr.o spapr_vio.o spapr_events.o
>  obj-$(CONFIG_PSERIES) += spapr_hcall.o spapr_iommu.o spapr_rtas.o
> -obj-$(CONFIG_PSERIES) += spapr_pci.o spapr_rtc.o
> +obj-$(CONFIG_PSERIES) += spapr_pci.o spapr_rtc.o spapr_drc.o
>  ifeq ($(CONFIG_PCI)$(CONFIG_PSERIES)$(CONFIG_LINUX), yyy)
>  obj-y += spapr_pci_vfio.o
>  endif
> diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
> new file mode 100644
> index 0000000..047c6c7
> --- /dev/null
> +++ b/hw/ppc/spapr_drc.c
> @@ -0,0 +1,588 @@
> +/*
> + * QEMU SPAPR Dynamic Reconfiguration Connector Implementation
> + *
> + * Copyright IBM Corp. 2014
> + *
> + * Authors:
> + *  Michael Roth      <mdroth@linux.vnet.ibm.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "hw/ppc/spapr_drc.h"
> +#include "qom/object.h"
> +#include "hw/qdev.h"
> +#include "qapi/visitor.h"
> +#include "qemu/error-report.h"
> +
> +/* #define DEBUG_SPAPR_DRC */
> +
> +#ifdef DEBUG_SPAPR_DRC
> +#define DPRINTF(fmt, ...) \
> +    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
> +#define DPRINTFN(fmt, ...) \
> +    do { DPRINTF(fmt, ## __VA_ARGS__); fprintf(stderr, "\n"); } while (0)
> +#else
> +#define DPRINTF(fmt, ...) \
> +    do { } while (0)
> +#define DPRINTFN(fmt, ...) \
> +    do { } while (0)
> +#endif
> +
> +#define DRC_CONTAINER_PATH "/dr-connector"
> +#define DRC_INDEX_TYPE_SHIFT 28
> +#define DRC_INDEX_ID_MASK (~(~0 << DRC_INDEX_TYPE_SHIFT))
> +
> +static sPAPRDRConnectorTypeShift get_type_shift(sPAPRDRConnectorType type)
> +{
> +    uint32_t shift = 0;
> +
> +    /* make sure this isn't SPAPR_DR_CONNECTOR_TYPE_ANY, or some
> +     * other wonky value.
> +     */
> +    g_assert(is_power_of_2(type));
> +
> +    while (type != (1 << shift)) {
> +        shift++;
> +    }
> +    return shift;
> +}
> +
> +static uint32_t get_index(sPAPRDRConnector *drc)
> +{
> +    /* no set format for a drc index: it only needs to be globally
> +     * unique. this is how we encode the DRC type on bare-metal
> +     * however, so might as well do that here
> +     */
> +    return (get_type_shift(drc->type) << DRC_INDEX_TYPE_SHIFT) |
> +            (drc->id & DRC_INDEX_ID_MASK);
> +}
> +
> +static int set_isolation_state(sPAPRDRConnector *drc,
> +                               sPAPRDRIsolationState state)
> +{
> +    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> +
> +    DPRINTFN("drc: %x, set_isolation_state: %x", get_index(drc), state);
> +
> +    drc->isolation_state = state;
> +
> +    if (drc->isolation_state == SPAPR_DR_ISOLATION_STATE_ISOLATED) {
> +        /* if we're awaiting release, but still in an unconfigured state,
> +         * it's likely the guest is still in the process of configuring
> +         * the device and is transitioning the devices to an ISOLATED
> +         * state as a part of that process. so we only complete the
> +         * removal when this transition happens for a device in a
> +         * configured state, as suggested by the state diagram from
> +         * PAPR+ 2.7, 13.4
> +         */
> +        if (drc->awaiting_release) {
> +            if (drc->configured) {
> +                DPRINTFN("finalizing device removal");
> +                drck->detach(drc, DEVICE(drc->dev), drc->detach_cb,
> +                             drc->detach_cb_opaque, NULL);
> +            } else {
> +                DPRINTFN("deferring device removal on unconfigured device\n");
> +            }
> +        }
> +        drc->configured = false;
> +    }
> +
> +    return 0;
> +}
> +
> +static int set_indicator_state(sPAPRDRConnector *drc,
> +                               sPAPRDRIndicatorState state)
> +{
> +    DPRINTFN("drc: %x, set_indicator_state: %x", get_index(drc), state);
> +    drc->indicator_state = state;
> +    return 0;
> +}
> +
> +static int set_allocation_state(sPAPRDRConnector *drc,
> +                                sPAPRDRAllocationState state)
> +{
> +    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> +
> +    DPRINTFN("drc: %x, set_allocation_state: %x", get_index(drc), state);
> +
> +    if (drc->type != SPAPR_DR_CONNECTOR_TYPE_PCI) {
> +        drc->allocation_state = state;
> +        if (drc->awaiting_release &&
> +            drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
> +            DPRINTFN("finalizing device removal");
> +            drck->detach(drc, DEVICE(drc->dev), drc->detach_cb,
> +                         drc->detach_cb_opaque, NULL);
> +        }
> +    }
> +    return 0;
> +}
> +
> +static uint32_t get_type(sPAPRDRConnector *drc)
> +{
> +    return drc->type;
> +}
> +
> +static const char *get_name(sPAPRDRConnector *drc)
> +{
> +    return drc->name;
> +}
> +
> +static const void *get_fdt(sPAPRDRConnector *drc, int *fdt_start_offset)
> +{
> +    if (fdt_start_offset) {
> +        *fdt_start_offset = drc->fdt_start_offset;
> +    }
> +    return drc->fdt;
> +}
> +
> +static void set_configured(sPAPRDRConnector *drc)
> +{
> +    DPRINTFN("drc: %x, set_configured", get_index(drc));
> +
> +    if (drc->isolation_state != SPAPR_DR_ISOLATION_STATE_UNISOLATED) {
> +        /* guest should be not configuring an isolated device */
> +        DPRINTFN("drc: %x, set_configured: skipping isolated device",
> +                 get_index(drc));
> +        return;
> +    }
> +    drc->configured = true;
> +}
> +
> +/*
> + * dr-entity-sense sensor value
> + * returned via get-sensor-state RTAS calls
> + * as expected by state diagram in PAPR+ 2.7, 13.4
> + * based on the current allocation/indicator/power states
> + * for the DR connector.
> + */
> +static sPAPRDREntitySense entity_sense(sPAPRDRConnector *drc)
> +{
> +    sPAPRDREntitySense state;
> +
> +    if (drc->dev) {
> +        if (drc->type != SPAPR_DR_CONNECTOR_TYPE_PCI &&
> +            drc->allocation_state == SPAPR_DR_ALLOCATION_STATE_UNUSABLE) {
> +            /* for logical DR, we return a state of UNUSABLE
> +             * iff the allocation state UNUSABLE.
> +             * Otherwise, report the state as USABLE/PRESENT,
> +             * as we would for PCI.
> +             */
> +            state = SPAPR_DR_ENTITY_SENSE_UNUSABLE;
> +        } else {
> +            /* this assumes all PCI devices are assigned to
> +             * a 'live insertion' power domain, where QEMU
> +             * manages power state automatically as opposed
> +             * to the guest. present, non-PCI resources are
> +             * unaffected by power state.
> +             */
> +            state = SPAPR_DR_ENTITY_SENSE_PRESENT;
> +        }
> +    } else {
> +        if (drc->type == SPAPR_DR_CONNECTOR_TYPE_PCI) {
> +            /* PCI devices, and only PCI devices, use EMPTY
> +             * in cases where we'd otherwise use UNUSABLE
> +             */
> +            state = SPAPR_DR_ENTITY_SENSE_EMPTY;
> +        } else {
> +            state = SPAPR_DR_ENTITY_SENSE_UNUSABLE;
> +        }
> +    }
> +
> +    DPRINTFN("drc: %x, entity_sense: %x", get_index(drc), state);
> +    return state;
> +}
> +
> +static void prop_get_index(Object *obj, Visitor *v, void *opaque,
> +                                  const char *name, Error **errp)
> +{
> +    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
> +    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> +    uint32_t value = (uint32_t)drck->get_index(drc);
> +    visit_type_uint32(v, &value, name, errp);
> +}
> +
> +static void prop_get_type(Object *obj, Visitor *v, void *opaque,
> +                          const char *name, Error **errp)
> +{
> +    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
> +    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> +    uint32_t value = (uint32_t)drck->get_type(drc);
> +    visit_type_uint32(v, &value, name, errp);
> +}
> +
> +static char *prop_get_name(Object *obj, Error **errp)
> +{
> +    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
> +    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> +    return g_strdup(drck->get_name(drc));
> +}
> +
> +static void prop_get_entity_sense(Object *obj, Visitor *v, void *opaque,
> +                                  const char *name, Error **errp)
> +{
> +    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
> +    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
> +    uint32_t value = (uint32_t)drck->entity_sense(drc);
> +    visit_type_uint32(v, &value, name, errp);
> +}
> +
> +static void prop_get_fdt(Object *obj, Visitor *v, void *opaque,
> +                        const char *name, Error **errp)
> +{
> +    sPAPRDRConnector *drc = SPAPR_DR_CONNECTOR(obj);
> +    int fdt_offset_next, fdt_offset, fdt_depth;
> +    void *fdt;
> +
> +    if (!drc->fdt) {
> +        return;
> +    }
> +
> +    fdt = drc->fdt;
> +    fdt_offset = drc->fdt_start_offset;
> +    fdt_depth = 0;
> +
> +    do {
> +        const char *name = NULL;
> +        const struct fdt_property *prop = NULL;
> +        int prop_len = 0, name_len = 0;
> +        uint32_t tag;
> +
> +        tag = fdt_next_tag(fdt, fdt_offset, &fdt_offset_next);
> +        switch (tag) {
> +        case FDT_BEGIN_NODE:
> +            fdt_depth++;
> +            name = fdt_get_name(fdt, fdt_offset, &name_len);
> +            visit_start_struct(v, NULL, NULL, name, 0, NULL);
> +            break;
> +        case FDT_END_NODE:
> +            /* shouldn't ever see an FDT_END_NODE before FDT_BEGIN_NODE */
> +            g_assert(fdt_depth > 0);
> +            visit_end_struct(v, NULL);
> +            fdt_depth--;
> +            break;
> +        case FDT_PROP: {
> +            int i;
> +            prop = fdt_get_property_by_offset(fdt, fdt_offset, &prop_len);

Did this fdt function only get introduced recently? My test system has
1.3.0 installed which doesn't contain it apparently.

Please add a configure check to verify it actually exists if it's really
necessary.


Alex