add virtio-scsi driver

virtio-scsi is a simple HBA that talks to the host via a single
vring.  The implementation looks like a hybrid of usb-msc and
virtio-blk.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 178 insertions, 0 deletions

diff --git a/src/virtio-scsi.c b/src/virtio-scsi.c
new file mode 100644
index 0000000..3c59438
--- /dev/null
+++ b/src/virtio-scsi.c
@@ -0,0 +1,178 @@
+// Virtio SCSI boot support.
+//
+// Copyright (C) 2012 Red Hat Inc.
+//
+// Authors:
+//  Paolo Bonzini <pbonzini@redhat.com>
+//
+// This file may be distributed under the terms of the GNU LGPLv3 license.
+
+#include "util.h" // dprintf
+#include "pci.h" // foreachpci
+#include "config.h" // CONFIG_*
+#include "biosvar.h" // GET_GLOBAL
+#include "pci_ids.h" // PCI_DEVICE_ID_VIRTIO_BLK
+#include "pci_regs.h" // PCI_VENDOR_ID
+#include "boot.h" // bootprio_find_scsi_device
+#include "blockcmd.h" // scsi_init_drive
+#include "virtio-pci.h"
+#include "virtio-ring.h"
+#include "virtio-scsi.h"
+#include "disk.h"
+
+struct virtio_lun_s {
+    struct drive_s drive;
+    struct pci_device *pci;
+    struct vring_virtqueue *vq;
+    u16 ioaddr;
+    u16 target;
+    u16 lun;
+};
+
+static int
+virtio_scsi_cmd(u16 ioaddr, struct vring_virtqueue *vq, struct disk_op_s *op,
+                void *cdbcmd, u16 target, u16 lun, u32 len)
+{
+    struct virtio_scsi_req_cmd req;
+    struct virtio_scsi_resp_cmd resp;
+    struct vring_list sg[3];
+
+    memset(&req, 0, sizeof(req));
+    req.lun[0] = 1;
+    req.lun[1] = target;
+    req.lun[2] = (lun >> 8) | 0x40;
+    req.lun[3] = (lun & 0xff);
+    memcpy(req.cdb, cdbcmd, 16);
+
+    int datain = (req.cdb[0] != CDB_CMD_WRITE_10);
+    int data_idx = (datain ? 2 : 1);
+    int out_num = (datain ? 1 : 2);
+    int in_num = (len ? 3 : 2) - out_num;
+
+    sg[0].addr   = MAKE_FLATPTR(GET_SEG(SS), &req);
+    sg[0].length = sizeof(req);
+
+    sg[out_num].addr   = MAKE_FLATPTR(GET_SEG(SS), &resp);
+    sg[out_num].length = sizeof(resp);
+
+    sg[data_idx].addr   = op->buf_fl;
+    sg[data_idx].length = len;
+
+    /* Add to virtqueue and kick host */
+    vring_add_buf(vq, sg, out_num, in_num, 0, 0);
+    vring_kick(ioaddr, vq, 1);
+
+    /* Wait for reply */
+    while (!vring_more_used(vq))
+        usleep(5);
+
+    /* Reclaim virtqueue element */
+    vring_get_buf(vq, NULL);
+
+    /* Clear interrupt status register.  Avoid leaving interrupts stuck if
+     * VRING_AVAIL_F_NO_INTERRUPT was ignored and interrupts were raised.
+     */
+    vp_get_isr(ioaddr);
+
+    if (resp.response == VIRTIO_SCSI_S_OK && resp.status == 0) {
+        return DISK_RET_SUCCESS;
+    }
+    return DISK_RET_EBADTRACK;
+}
+
+int
+virtio_scsi_cmd_data(struct disk_op_s *op, void *cdbcmd, u16 blocksize)
+{
+    struct virtio_lun_s *vlun =
+        container_of(op->drive_g, struct virtio_lun_s, drive);
+
+    return virtio_scsi_cmd(GET_GLOBAL(vlun->ioaddr),
+                           GET_GLOBAL(vlun->vq), op, cdbcmd,
+                           GET_GLOBAL(vlun->target), GET_GLOBAL(vlun->lun),
+                           blocksize * op->count);
+}
+
+static int
+virtio_scsi_add_lun(struct pci_device *pci, u16 ioaddr,
+                    struct vring_virtqueue *vq, u16 target, u16 lun)
+{
+    struct virtio_lun_s *vlun = malloc_fseg(sizeof(*vlun));
+    if (!vlun) {
+        warn_noalloc();
+        return -1;
+    }
+    memset(vlun, 0, sizeof(*vlun));
+    vlun->drive.type = DTYPE_VIRTIO_SCSI;
+    vlun->drive.cntl_id = pci->bdf;
+    vlun->pci = pci;
+    vlun->ioaddr = ioaddr;
+    vlun->vq = vq;
+    vlun->target = target;
+    vlun->lun = lun;
+
+    int prio = bootprio_find_scsi_device(pci, target, lun);
+    int ret = scsi_init_drive(&vlun->drive, "virtio-scsi", prio);
+    if (ret)
+        goto fail;
+    return 0;
+
+fail:
+    free(vlun);
+    return -1;
+}
+
+static int
+virtio_scsi_scan_target(struct pci_device *pci, u16 ioaddr,
+                        struct vring_virtqueue *vq, u16 target)
+{
+    /* TODO: send REPORT LUNS.  For now, only LUN 0 is recognized.  */
+    int ret = virtio_scsi_add_lun(pci, ioaddr, vq, target, 0);
+    return ret < 0 ? 0 : 1;
+}
+
+static void
+init_virtio_scsi(struct pci_device *pci)
+{
+    u16 bdf = pci->bdf;
+    dprintf(1, "found virtio-scsi at %x:%x\n", pci_bdf_to_bus(bdf),
+            pci_bdf_to_dev(bdf));
+    struct vring_virtqueue *vq = NULL;
+    u16 ioaddr = vp_init_simple(bdf);
+    if (vp_find_vq(ioaddr, 2, &vq) < 0 ) {
+        dprintf(1, "fail to find vq for virtio-scsi %x:%x\n",
+                pci_bdf_to_bus(bdf), pci_bdf_to_dev(bdf));
+        goto fail;
+    }
+
+    int i, tot;
+    for (tot = 0, i = 0; i < 256; i++)
+        tot += virtio_scsi_scan_target(pci, ioaddr, vq, i);
+
+    if (!tot)
+        goto fail;
+
+    vp_set_status(ioaddr, VIRTIO_CONFIG_S_ACKNOWLEDGE |
+                  VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK);
+    return;
+
+fail:
+    free(vq);
+}
+
+void
+virtio_scsi_setup(void)
+{
+    ASSERT32FLAT();
+    if (! CONFIG_VIRTIO_SCSI || CONFIG_COREBOOT)
+        return;
+
+    dprintf(3, "init virtio-scsi\n");
+
+    struct pci_device *pci;
+    foreachpci(pci) {
+        if (pci->vendor != PCI_VENDOR_ID_REDHAT_QUMRANET
+            || pci->device != PCI_DEVICE_ID_VIRTIO_SCSI)
+            continue;
+        init_virtio_scsi(pci);
+    }
+}