[PATCH v2 4/6] pc-bios/s390-ccw: Verify virtio support when booting from virtio PCI device on s390x

[jrossi@linux.ibm.com]

From: Jared Rossi <jrossi@linux.ibm.com>

The virtio specification requires that each PCI device has a vendor ID of
0x1af4.  Verify this value before continuing with boot process.

Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
---
 pc-bios/s390-ccw/main.c       |  1 +
 pc-bios/s390-ccw/virtio-pci.c | 19 +++++++++++++++++++
 pc-bios/s390-ccw/virtio-pci.h |  3 +++
 pc-bios/s390-ccw/virtio.c     |  2 ++
 pc-bios/s390-ccw/virtio.h     |  1 +
 5 files changed, 26 insertions(+)

diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
index 26287cfd81..fb47d29bb1 100644
--- a/pc-bios/s390-ccw/main.c
+++ b/pc-bios/s390-ccw/main.c
@@ -163,6 +163,7 @@ static bool find_fid(uint32_t fid)
     }
 
     vdev->pci_fh = entry.fh;
+    vdev->vendor_id = entry.vendor_id;
     virtio_pci_id2type(vdev, entry.device_id);
 
     return vdev->dev_type != 0;
diff --git a/pc-bios/s390-ccw/virtio-pci.c b/pc-bios/s390-ccw/virtio-pci.c
index 2c83ec4f13..f501252c81 100644
--- a/pc-bios/s390-ccw/virtio-pci.c
+++ b/pc-bios/s390-ccw/virtio-pci.c
@@ -325,6 +325,20 @@ static int enable_pci_bus_master(void)
     return 0;
 }
 
+bool virtio_pci_is_supported(VDev *vdev)
+{
+    if (vdev->vendor_id == PCI_VENDOR_VIRTIO) {
+        switch (vdev->dev_type) {
+        case VIRTIO_ID_BLOCK:
+            return true;
+        default:
+            return false;
+        }
+    }
+
+    return false;
+}
+
 int virtio_pci_setup(VDev *vdev)
 {
     VRing *vr;
@@ -335,6 +349,11 @@ int virtio_pci_setup(VDev *vdev)
     vdev->guessed_disk_nature = VIRTIO_GDN_NONE;
     vdev->cmd_vr_idx = 0;
 
+    if (!virtio_pci_is_supported(vdev)) {
+        puts("Virtio PCI unsupported for this device ID");
+        return -ENODEV;
+    }
+
     if (virtio_pci_read_pci_cap_config()) {
         puts("Invalid virtio PCI capabilities");
         return -EIO;
diff --git a/pc-bios/s390-ccw/virtio-pci.h b/pc-bios/s390-ccw/virtio-pci.h
index 2494df1619..33b683bd92 100644
--- a/pc-bios/s390-ccw/virtio-pci.h
+++ b/pc-bios/s390-ccw/virtio-pci.h
@@ -56,6 +56,8 @@
 
 #define VIRTIO_F_VERSION_1          1   /* Feature bit 32 */
 
+#define PCI_VENDOR_VIRTIO           0x1af4
+
 struct VirtioPciCap {
     uint8_t bar;     /* Which PCIAS it's in */
     uint32_t off;    /* Offset within bar */
@@ -65,6 +67,7 @@ typedef struct VirtioPciCap  VirtioPciCap;
 void virtio_pci_id2type(VDev *vdev, uint16_t device_id);
 int virtio_pci_reset(VDev *vdev);
 long virtio_pci_notify(VRing *vr);
+bool virtio_pci_is_supported(VDev *vdev);
 int virtio_pci_setup(VDev *vdev);
 int virtio_pci_setup_device(void);
 
diff --git a/pc-bios/s390-ccw/virtio.c b/pc-bios/s390-ccw/virtio.c
index df04479aa6..a0d249db24 100644
--- a/pc-bios/s390-ccw/virtio.c
+++ b/pc-bios/s390-ccw/virtio.c
@@ -247,6 +247,8 @@ bool virtio_is_supported(VDev *vdev)
     case S390_IPL_TYPE_QEMU_SCSI:
     case S390_IPL_TYPE_CCW:
         return virtio_ccw_is_supported(vdev);
+    case S390_IPL_TYPE_PCI:
+        return virtio_pci_is_supported(vdev);
     default:
         return false;
     }
diff --git a/pc-bios/s390-ccw/virtio.h b/pc-bios/s390-ccw/virtio.h
index 75ae5bdbc2..aa307025e0 100644
--- a/pc-bios/s390-ccw/virtio.h
+++ b/pc-bios/s390-ccw/virtio.h
@@ -259,6 +259,7 @@ struct VDev {
     bool scsi_device_selected;
     ScsiDevice selected_scsi_device;
     uint32_t pci_fh;
+    uint16_t vendor_id;
     uint32_t max_transfer;
     uint32_t guest_features[2];
 };
-- 
2.54.0