[PATCH v1 4/7] pc-bios/s390-ccw: Add support for virtio-net-pci IPL

[Zhuoying Cai <zycai@linux.ibm.com>]

Enable network booting via virtio-net-pci by implementing PCI transport
support for virtio-net.

This patch also adds endianness handling for virtio PCI ring operations in
little-endian to ensure correct behavior on s390x.

Signed-off-by: Zhuoying Cai <zycai@linux.ibm.com>
---
 pc-bios/s390-ccw/main.c       |  1 +
 pc-bios/s390-ccw/virtio-net.c | 37 +++++++++++++++++++++++-------
 pc-bios/s390-ccw/virtio-pci.c | 43 +++++++++++++++++++++++++++++++++++
 pc-bios/s390-ccw/virtio-pci.h |  2 ++
 4 files changed, 75 insertions(+), 8 deletions(-)

diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
index 8bc6e8eaa3..0eeb53a2bf 100644
--- a/pc-bios/s390-ccw/main.c
+++ b/pc-bios/s390-ccw/main.c
@@ -328,6 +328,7 @@ static void ipl_pci_device(void)
     }
 
     switch (vdev->dev_type) {
+    case VIRTIO_ID_NET:
     case VIRTIO_ID_BLOCK:
         if (virtio_setup() == 0) {
             zipl_load(); /* only return on error */
diff --git a/pc-bios/s390-ccw/virtio-net.c b/pc-bios/s390-ccw/virtio-net.c
index 3a9ae789cf..209f98a0e3 100644
--- a/pc-bios/s390-ccw/virtio-net.c
+++ b/pc-bios/s390-ccw/virtio-net.c
@@ -62,7 +62,16 @@ int virtio_net_init(void *mac_addr)
     rx_last_idx = 0;
 
     vdev->guest_features[0] = VIRTIO_NET_F_MAC_BIT;
-    virtio_ccw_setup(vdev);
+    switch (virtio_get_device()->ipl_type) {
+    case S390_IPL_TYPE_CCW:
+        virtio_ccw_setup(vdev);
+        break;
+    case S390_IPL_TYPE_PCI:
+        virtio_pci_setup(vdev);
+        break;
+    default:
+        return -1;
+    }
 
     if (!(vdev->guest_features[0] & VIRTIO_NET_F_MAC_BIT)) {
         puts("virtio-net device does not support the MAC address feature");
@@ -115,22 +124,30 @@ int recv(int fd, void *buf, int maxlen, int flags)
     VRing *rxvq = &vdev->vrings[VQ_RX];
     int len, id;
     uint8_t *pkt;
+    uint16_t rx_used_idx, rx_avail_idx;
+    uint32_t rx_used_len, rx_used_id;
+    uint64_t rx_desc_addr;
 
-    if (rx_last_idx == rxvq->used->idx) {
+    rx_used_idx = virtio_tswap16(rxvq->used->idx);
+    if (rx_last_idx == rx_used_idx) {
         return 0;
     }
 
-    len = rxvq->used->ring[rx_last_idx % rxvq->num].len - virtio_net_hdr_size;
+    rx_used_len = virtio_tswap32(rxvq->used->ring[rx_last_idx % rxvq->num].len);
+    rx_used_id = virtio_tswap32(rxvq->used->ring[rx_last_idx % rxvq->num].id);
+
+    len = rx_used_len - virtio_net_hdr_size;
     if (len > maxlen) {
         puts("virtio-net: Receive buffer too small");
         len = maxlen;
     }
-    id = rxvq->used->ring[rx_last_idx % rxvq->num].id % rxvq->num;
-    pkt = (uint8_t *)(rxvq->desc[id].addr + virtio_net_hdr_size);
+    id = rx_used_id % rxvq->num;
+    rx_desc_addr = virtio_tswap64(rxvq->desc[id].addr);
+    pkt = (uint8_t *)(rx_desc_addr + virtio_net_hdr_size);
 
 #if DEBUG_VIRTIO_NET   /* Dump packet */
     int i;
-    printf("\nbuf %p: len=%i\n", (void *)rxvq->desc[id].addr, len);
+    printf("\nbuf %p: len=%i\n", (void *)rx_desc_addr, len);
     for (i = 0; i < 64; i++) {
         printf(" %02x", pkt[i]);
         if ((i % 16) == 15) {
@@ -144,8 +161,10 @@ int recv(int fd, void *buf, int maxlen, int flags)
     memcpy(buf, pkt, len);
 
     /* Mark buffer as available to the host again */
-    rxvq->avail->ring[rxvq->avail->idx % rxvq->num] = id;
-    rxvq->avail->idx = rxvq->avail->idx + 1;
+    rx_avail_idx = virtio_tswap16(rxvq->avail->idx);
+    rxvq->avail->ring[rx_avail_idx % rxvq->num] = virtio_tswap16(id);
+    rx_avail_idx++;
+    rxvq->avail->idx = virtio_tswap16(rx_avail_idx);
     vring_notify(rxvq);
 
     /* Move index to next entry */
@@ -164,6 +183,8 @@ bool virtio_net_setup(void)
     switch (virtio_get_device()->ipl_type) {
     case S390_IPL_TYPE_CCW:
         return virtio_ccw_net_setup();
+    case S390_IPL_TYPE_PCI:
+        return virtio_pci_net_setup();
     default:
         return false;
     }
diff --git a/pc-bios/s390-ccw/virtio-pci.c b/pc-bios/s390-ccw/virtio-pci.c
index f501252c81..c7d62766b8 100644
--- a/pc-bios/s390-ccw/virtio-pci.c
+++ b/pc-bios/s390-ccw/virtio-pci.c
@@ -52,6 +52,10 @@ void virtio_pci_id2type(VDev *vdev, uint16_t device_id)
     case 0x1001:
         vdev->dev_type = VIRTIO_ID_BLOCK;
         break;
+    case 0x1041:
+    case 0x1000:
+        vdev->dev_type = VIRTIO_ID_NET;
+        break;
     default:
         vdev->dev_type = 0;
     }
@@ -199,6 +203,14 @@ static int virtio_pci_get_blk_config(void)
     return rc;
 }
 
+static int virtio_pci_get_net_config(void)
+{
+    VirtioNetConfig *cfg = &virtio_get_device()->config.net;
+    int rc = vpci_read_flex(d_cap.off, d_cap.bar, cfg, sizeof(VirtioNetConfig));
+
+    return rc;
+}
+
 static int virtio_pci_negotiate(void)
 {
     int i, rc;
@@ -330,6 +342,7 @@ bool virtio_pci_is_supported(VDev *vdev)
     if (vdev->vendor_id == PCI_VENDOR_VIRTIO) {
         switch (vdev->dev_type) {
         case VIRTIO_ID_BLOCK:
+        case VIRTIO_ID_NET:
             return true;
         default:
             return false;
@@ -384,6 +397,11 @@ int virtio_pci_setup(VDev *vdev)
         vdev->cmd_vr_idx = 0;
         virtio_pci_get_blk_config();
         break;
+    case VIRTIO_ID_NET:
+        vdev->nr_vqs = 2;
+        vdev->cmd_vr_idx = 0;
+        virtio_pci_get_net_config();
+        break;
     default:
         puts("Unsupported virtio device");
         return -ENODEV;
@@ -458,3 +476,28 @@ int virtio_pci_setup_device(void)
 
     return 0;
 }
+
+static bool find_pci_net_dev(void)
+{
+    if (!virtio_is_supported(virtio_get_device())) {
+        return false;
+    }
+
+    if (virtio_get_device_type() != VIRTIO_ID_NET) {
+        return false;
+    }
+
+    return true;
+}
+
+bool virtio_pci_net_setup(void)
+{
+    bool found = false;
+
+    if (have_iplb || store_iplb(&iplb)) {
+        IPL_assert(iplb.pbt == S390_IPL_TYPE_PCI, "IPL_TYPE_PCI expected");
+        found = find_pci_net_dev();
+    }
+
+    return found;
+}
diff --git a/pc-bios/s390-ccw/virtio-pci.h b/pc-bios/s390-ccw/virtio-pci.h
index 33b683bd92..2c3136fd05 100644
--- a/pc-bios/s390-ccw/virtio-pci.h
+++ b/pc-bios/s390-ccw/virtio-pci.h
@@ -70,6 +70,8 @@ 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);
+bool virtio_pci_is_supported(VDev *vdev);
+bool virtio_pci_net_setup(void);
 
 int vpci_read_flex(uint64_t offset, uint8_t pcias, void *buf, int len);
 int vpci_read_bswap64(uint64_t offset, uint8_t pcias, uint64_t *buf);
-- 
2.55.0