Commit c42767f2 authored by Thomas Huth's avatar Thomas Huth Committed by Cornelia Huck
Browse files

s390x/virtio-ccw: add virtio set-revision call 



Handle the virtio-ccw revision according to what the guest sets.
When revision 1 is selected, we have a virtio-1 standard device
with byteswapping for the virtio rings.

When a channel gets disabled, we have to revert to the legacy behavior
in case the next user of the device does not negotiate the revision 1
anymore (e.g. the boot firmware uses revision 1, but the operating
system only uses the legacy mode).

Note that revisions > 0 are still disabled.

[CH: assure memory accesses are always BE]
Signed-off-by: default avatarThomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 62ac4a52

hw/s390x/virtio-ccw.c

+76 −2
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include "hw/sysbus.h"

#include "qemu/bitops.h"

#include "qemu/error-report.h"

#include "hw/virtio/virtio-access.h"

#include "hw/virtio/virtio-bus.h"

#include "hw/s390x/adapter.h"

#include "hw/s390x/s390_flic.h"
@@ -261,6 +262,12 @@ typedef struct VirtioThinintInfo { 
    uint8_t isc;

} QEMU_PACKED VirtioThinintInfo;



typedef struct VirtioRevInfo {

    uint16_t revision;

    uint16_t length;

    uint8_t data[0];

} QEMU_PACKED VirtioRevInfo;



/* Specify where the virtqueues for the subchannel are in guest memory. */

static int virtio_ccw_set_vqs(SubchDev *sch, uint64_t addr, uint32_t align,

                              uint16_t index, uint16_t num)
@@ -319,6 +326,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw) 
{

    int ret;

    VqInfoBlock info;

    VirtioRevInfo revinfo;

    uint8_t status;

    VirtioFeatDesc features;

    void *config;
@@ -401,7 +409,16 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw) 
                                                MEMTXATTRS_UNSPECIFIED,

                                                NULL);

            if (features.index == 0) {

                features.features = vdev->host_features;

                features.features = (uint32_t)vdev->host_features;

            } else if (features.index == 1) {

                features.features = (uint32_t)(vdev->host_features >> 32);

                /*

                 * Don't offer version 1 to the guest if it did not

                 * negotiate at least revision 1.

                 */

                if (dev->revision <= 0) {

                    features.features &= ~(1 << (VIRTIO_F_VERSION_1 - 32));

                }

            } else {

                /* Return zeroes if the guest supports more feature bits. */

                features.features = 0;
@@ -437,7 +454,20 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw) 
                                                     MEMTXATTRS_UNSPECIFIED,

                                                     NULL);

            if (features.index == 0) {

                virtio_set_features(vdev, features.features);

                virtio_set_features(vdev,

                                    (vdev->guest_features & 0xffffffff00000000ULL) |

                                    features.features);

            } else if (features.index == 1) {

                /*

                 * The guest should not set version 1 if it didn't

                 * negotiate a revision >= 1.

                 */

                if (dev->revision <= 0) {

                    features.features &= ~(1 << (VIRTIO_F_VERSION_1 - 32));

                }

                virtio_set_features(vdev,

                                    (vdev->guest_features & 0x00000000ffffffffULL) |

                                    ((uint64_t)features.features << 32));

            } else {

                /*

                 * If the guest supports more feature bits, assert that it
@@ -658,6 +688,40 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw) 
            }

        }

        break;

    case CCW_CMD_SET_VIRTIO_REV:

        len = sizeof(revinfo);

        if (ccw.count < len) {

            ret = -EINVAL;

            break;

        }

        if (!ccw.cda) {

            ret = -EFAULT;

            break;

        }

        revinfo.revision =

            address_space_lduw_be(&address_space_memory, ccw.cda,

                                  MEMTXATTRS_UNSPECIFIED, NULL);

        revinfo.length =

            address_space_lduw_be(&address_space_memory,

                                  ccw.cda + sizeof(revinfo.revision),

                                  MEMTXATTRS_UNSPECIFIED, NULL);

        if (ccw.count < len + revinfo.length ||

            (check_len && ccw.count > len + revinfo.length)) {

            ret = -EINVAL;

            break;

        }

        /*

         * Once we start to support revisions with additional data, we'll

         * need to fetch it here. Nothing to do for now, though.

         */

        if (dev->revision >= 0 ||

            revinfo.revision > virtio_ccw_rev_max(vdev)) {

            ret = -ENOSYS;

            break;

        }

        ret = 0;

        dev->revision = revinfo.revision;

        break;

    default:

        ret = -ENOSYS;

        break;
@@ -665,6 +729,13 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw) 
    return ret;

}



static void virtio_sch_disable_cb(SubchDev *sch)

{

    VirtioCcwDevice *dev = sch->driver_data;



    dev->revision = -1;

}



static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)

{

    unsigned int cssid = 0;
@@ -784,12 +855,15 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp) 
    css_sch_build_virtual_schib(sch, 0, VIRTIO_CCW_CHPID_TYPE);



    sch->ccw_cb = virtio_ccw_cb;

    sch->disable_cb = virtio_sch_disable_cb;



    /* Build senseid data. */

    memset(&sch->id, 0, sizeof(SenseId));

    sch->id.reserved = 0xff;

    sch->id.cu_type = VIRTIO_CCW_CU_TYPE;



    dev->revision = -1;



    if (k->realize) {

        k->realize(dev, &err);

    }

hw/s390x/virtio-ccw.h

+8 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 
#define CCW_CMD_SET_CONF_IND 0x53

#define CCW_CMD_READ_VQ_CONF 0x32

#define CCW_CMD_SET_IND_ADAPTER 0x73

#define CCW_CMD_SET_VIRTIO_REV 0x83



#define TYPE_VIRTIO_CCW_DEVICE "virtio-ccw-device"

#define VIRTIO_CCW_DEVICE(obj) \
@@ -86,6 +87,7 @@ struct VirtioCcwDevice { 
    DeviceState parent_obj;

    SubchDev *sch;

    char *bus_id;

    int revision;

    VirtioBusState bus;

    bool ioeventfd_started;

    bool ioeventfd_disabled;
@@ -99,6 +101,12 @@ struct VirtioCcwDevice { 
    uint64_t ind_bit;

};



/* The maximum virtio revision we support. */

static inline int virtio_ccw_rev_max(VirtIODevice *vdev)

{

    return 0;

}



/* virtual css bus type */

typedef struct VirtualCssBus {

    BusState parent_obj;