diff options
Diffstat (limited to 'hw/net/spapr_llan.c')
| -rw-r--r-- | hw/net/spapr_llan.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/hw/net/spapr_llan.c b/hw/net/spapr_llan.c index 2d47df6930..23c47d397c 100644 --- a/hw/net/spapr_llan.c +++ b/hw/net/spapr_llan.c @@ -72,7 +72,14 @@ typedef uint64_t vlan_bd_t; #define VLAN_RXQ_BD_OFF 0 #define VLAN_FILTER_BD_OFF 8 #define VLAN_RX_BDS_OFF 16 -#define VLAN_MAX_BUFS ((SPAPR_TCE_PAGE_SIZE - VLAN_RX_BDS_OFF) / 8) +/* + * The final 8 bytes of the buffer list is a counter of frames dropped + * because there was not a buffer in the buffer list capable of holding + * the frame. We must avoid it, or the operating system will report garbage + * for this statistic. + */ +#define VLAN_RX_BDS_LEN (SPAPR_TCE_PAGE_SIZE - VLAN_RX_BDS_OFF - 8) +#define VLAN_MAX_BUFS (VLAN_RX_BDS_LEN / 8) #define TYPE_VIO_SPAPR_VLAN_DEVICE "spapr-vlan" #define VIO_SPAPR_VLAN_DEVICE(obj) \ @@ -119,7 +126,7 @@ static ssize_t spapr_vlan_receive(NetClientState *nc, const uint8_t *buf, do { buf_ptr += 8; - if (buf_ptr >= SPAPR_TCE_PAGE_SIZE) { + if (buf_ptr >= (VLAN_RX_BDS_LEN + VLAN_RX_BDS_OFF)) { buf_ptr = VLAN_RX_BDS_OFF; } @@ -397,7 +404,7 @@ static target_ulong h_add_logical_lan_buffer(PowerPCCPU *cpu, do { dev->add_buf_ptr += 8; - if (dev->add_buf_ptr >= SPAPR_TCE_PAGE_SIZE) { + if (dev->add_buf_ptr >= (VLAN_RX_BDS_LEN + VLAN_RX_BDS_OFF)) { dev->add_buf_ptr = VLAN_RX_BDS_OFF; } |