@@ -44,6 +44,8 @@ typedef unsigned long long __u64;
((b) == 0 ? (a) : (MIN(a, b))))
#endif
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
+
#include "cio.h"
#include "iplb.h"
@@ -12,6 +12,7 @@
#include "s390-ccw.h"
#include "virtio.h"
#include "virtio-scsi.h"
+#include "bswap.h"
#define VRING_WAIT_REPLY_TIMEOUT 3
@@ -249,8 +250,12 @@ int virtio_run(VDev *vdev, int vqid, VirtioCmd *cmd)
void virtio_setup_ccw(VDev *vdev)
{
- int i, cfg_size = 0;
+ int i, rc, cfg_size = 0;
unsigned char status = VIRTIO_CONFIG_S_DRIVER_OK;
+ struct VirtioFeatureDesc {
+ uint32_t features;
+ uint8_t index;
+ } __attribute__((packed)) feats;
IPL_assert(virtio_is_supported(vdev->schid), "PE");
/* device ID has been established now */
@@ -277,11 +282,17 @@ void virtio_setup_ccw(VDev *vdev)
IPL_assert(run_ccw(vdev, CCW_CMD_READ_CONF, &vdev->config, cfg_size) == 0,
"Could not get block device configuration");
- /*
- * Skipping CCW_CMD_READ_FEAT. We're not doing anything fancy, and
- * we'll just stop dead anyway if anything does not work like we
- * expect it.
- */
+ /* Feature negotiation */
+ for (i = 0; i < ARRAY_SIZE(vdev->guest_features); i++) {
+ feats.features = 0;
+ feats.index = i;
+ rc = run_ccw(vdev, CCW_CMD_READ_FEAT, &feats, sizeof(feats));
+ IPL_assert(rc == 0, "Could not get features bits");
+ vdev->guest_features[i] &= bswap32(feats.features);
+ feats.features = bswap32(vdev->guest_features[i]);
+ rc = run_ccw(vdev, CCW_CMD_WRITE_FEAT, &feats, sizeof(feats));
+ IPL_assert(rc == 0, "Could not set features bits");
+ }
for (i = 0; i < vdev->nr_vqs; i++) {
VqInfo info = {
@@ -251,6 +251,7 @@ struct VDev {
ScsiDevice selected_scsi_device;
uint64_t netboot_start_addr;
uint32_t max_transfer;
+ uint32_t guest_features[2];
};
typedef struct VDev VDev;