The virtio-net device used a fixed header size that did not account for the num_buffers field used in VirtIO 1.0 or for the mergeable receive buffers feature.
Use dynamic header sizing: 10 bytes for legacy mode and 12 bytes for VirtIO 1.0 or when VIRTIO_NET_F_MRG_RXBUF is enabled. This ensures correct packet handling across different VirtIO configurations. Signed-off-by: Zhuoying Cai <[email protected]> --- pc-bios/s390-ccw/virtio-net.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/pc-bios/s390-ccw/virtio-net.c b/pc-bios/s390-ccw/virtio-net.c index 0ee51653ab..3a9ae789cf 100644 --- a/pc-bios/s390-ccw/virtio-net.c +++ b/pc-bios/s390-ccw/virtio-net.c @@ -20,6 +20,7 @@ #include "s390-ccw.h" #include "virtio.h" #include "virtio-ccw.h" +#include "virtio-pci.h" #include "s390-time.h" #include "helper.h" @@ -28,10 +29,15 @@ #endif #define VIRTIO_NET_F_MAC_BIT (1 << 5) +#define VIRTIO_NET_F_MRG_RXBUF_BIT (1 << 15) #define VQ_RX 0 /* Receive queue */ #define VQ_TX 1 /* Transmit queue */ +/* Header sizes for different modes */ +#define VIRTIO_NET_HDR_SIZE_LEGACY 10 /* Without num_buffers */ +#define VIRTIO_NET_HDR_SIZE_V1 12 /* With num_buffers */ + struct VirtioNetHdr { uint8_t flags; uint8_t gso_type; @@ -39,11 +45,12 @@ struct VirtioNetHdr { uint16_t gso_size; uint16_t csum_start; uint16_t csum_offset; - /*uint16_t num_buffers;*/ /* Only with VIRTIO_NET_F_MRG_RXBUF or VIRTIO1 */ + uint16_t num_buffers; /* Only with VIRTIO_NET_F_MRG_RXBUF or VIRTIO1 */ }; typedef struct VirtioNetHdr VirtioNetHdr; static uint16_t rx_last_idx; /* Last index in receive queue "used" ring */ +static int virtio_net_hdr_size; int virtio_net_init(void *mac_addr) { @@ -62,12 +69,17 @@ int virtio_net_init(void *mac_addr) return -1; } + virtio_net_hdr_size = ((vdev->guest_features[1] & VIRTIO_F_VERSION_1) || + (vdev->guest_features[0] & VIRTIO_NET_F_MRG_RXBUF_BIT)) + ? VIRTIO_NET_HDR_SIZE_V1 + : VIRTIO_NET_HDR_SIZE_LEGACY; + memcpy(mac_addr, vdev->config.net.mac, ETH_ALEN); for (i = 0; i < 64; i++) { - buf = malloc(ETH_MTU_SIZE + sizeof(VirtioNetHdr)); + buf = malloc(ETH_MTU_SIZE + virtio_net_hdr_size); IPL_assert(buf != NULL, "Can not allocate memory for receive buffers"); - vring_send_buf(rxvq, buf, ETH_MTU_SIZE + sizeof(VirtioNetHdr), + vring_send_buf(rxvq, buf, ETH_MTU_SIZE + virtio_net_hdr_size, VRING_DESC_F_WRITE); } vring_notify(rxvq); @@ -82,9 +94,9 @@ int send(int fd, const void *buf, int len, int flags) VRing *txvq = &vdev->vrings[VQ_TX]; /* Set up header - we do not use anything special, so simply clear it */ - memset(&tx_hdr, 0, sizeof(tx_hdr)); + memset(&tx_hdr, 0, virtio_net_hdr_size); - vring_send_buf(txvq, &tx_hdr, sizeof(tx_hdr), VRING_DESC_F_NEXT); + vring_send_buf(txvq, &tx_hdr, virtio_net_hdr_size, VRING_DESC_F_NEXT); vring_send_buf(txvq, (void *)buf, len, VRING_HIDDEN_IS_CHAIN); while (!vr_poll(txvq)) { yield(); @@ -108,13 +120,13 @@ int recv(int fd, void *buf, int maxlen, int flags) return 0; } - len = rxvq->used->ring[rx_last_idx % rxvq->num].len - sizeof(VirtioNetHdr); + len = rxvq->used->ring[rx_last_idx % rxvq->num].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 + sizeof(VirtioNetHdr)); + pkt = (uint8_t *)(rxvq->desc[id].addr + virtio_net_hdr_size); #if DEBUG_VIRTIO_NET /* Dump packet */ int i; -- 2.55.0
