From: Thomas Huth <th...@linux.vnet.ibm.com>
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: Thomas Huth <th...@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.h...@de.ibm.com>
---
hw/s390x/virtio-ccw.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++++--
hw/s390x/virtio-ccw.h | 8 ++++++
2 files changed, 85 insertions(+), 2 deletions(-)
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index e32ada9..e9420d5 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -21,9 +21,11 @@
#include "hw/virtio/virtio-net.h"
#include "hw/sysbus.h"
#include "qemu/bitops.h"
+#include "hw/virtio/virtio-access.h"
#include "hw/virtio/virtio-bus.h"
#include "hw/s390x/adapter.h"
#include "hw/s390x/s390_flic.h"
+#include "linux/virtio_config.h"
#include "ioinst.h"
#include "css.h"
@@ -261,6 +263,12 @@ 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)
@@ -300,6 +308,7 @@ static int virtio_ccw_cb(SubchDev *sch, CCW1 ccw)
{
int ret;
VqInfoBlock info;
+ VirtioRevInfo revinfo;
uint8_t status;
VirtioFeatDesc features;
void *config;
@@ -383,7 +392,16 @@ 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;
@@ -419,7 +437,20 @@ 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 &
0xffffffff00000000) |
+ 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 &
0x00000000ffffffff) |
+ ((uint64_t)features.features << 32));
} else {
/*
* If the guest supports more feature bits, assert that it
@@ -640,6 +671,40 @@ 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;
@@ -647,6 +712,13 @@ 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;
@@ -766,12 +838,15 @@ 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);
}
diff --git a/hw/s390x/virtio-ccw.h b/hw/s390x/virtio-ccw.h
index d729263..692ddd7 100644
--- a/hw/s390x/virtio-ccw.h
+++ b/hw/s390x/virtio-ccw.h
@@ -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;
--
2.3.8
