On Wed, Sep 29, 2010 at 09:59:55PM +0200, Stefan Weil wrote:
> I reviewed the latest sources of Linux, FreeBSD and NetBSD.
> They all reset the multiple IA bit (multi_ia in BSD) to zero,
> but I did not find code which sets this bit to one
> (like it is done by some routers).
>
> Running Windows guests also did not set this bit.
>
> Intel's Open Source Software Developer Manual does not
> give much information on the semantics related to this bit,
> so I had to guess how it works. The guess was good enough
> to make the router emulation work.
>
>
> Related changes in this patch:
> * Update naming and documentation of the internal hash register.
> It is not limited to multicast, but also used for multiple IA.
> * Dump complete configuration register when debug traces are enabled.
> * Debug output when multiple IA bit is set during CmdConfigure.
> * Debug output when frames are received because multiple IA bit is set,
> or when they are ignored although it is set.
>
> Cc: Michael S. Tsirkin <m...@redhat.com>
> Signed-off-by: Stefan Weil <w...@mail.berlios.de>
> ---
> hw/eepro100.c | 30 +++++++++++++++++++++---------
> 1 files changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/hw/eepro100.c b/hw/eepro100.c
> index 2b75c8f..5f6dcb6 100644
> --- a/hw/eepro100.c
> +++ b/hw/eepro100.c
> @@ -219,7 +219,8 @@ typedef enum {
>
> typedef struct {
> PCIDevice dev;
> - uint8_t mult[8]; /* multicast mask array */
> + /* Hash register (multicast mask array, multiple individual addresses).
> */
> + uint8_t mult[8];
Nitpick:
It seems to me like if mult is only used internally. If so, why not
represent the hash filter with an uint64_t?
Then you can replace the current memsets with ->mult = 0 and simplify
the match logic.
> int mmio_index;
> NICState *nic;
> NICConf conf;
> @@ -599,7 +600,7 @@ static void nic_reset(void *opaque)
> {
> EEPRO100State *s = opaque;
> TRACE(OTHER, logout("%p\n", s));
> - /* TODO: Clearing of multicast table for selective reset, too? */
> + /* TODO: Clearing of hash register for selective reset, too? */
> memset(&s->mult[0], 0, sizeof(s->mult));
e.g:
s->mult = 0;
> nic_selective_reset(s);
> }
> @@ -851,7 +852,14 @@ static void action_command(EEPRO100State *s)
> case CmdConfigure:
> cpu_physical_memory_read(s->cb_address + 8, &s->configuration[0],
> sizeof(s->configuration));
> - TRACE(OTHER, logout("configuration: %s\n",
> nic_dump(&s->configuration[0], 16)));
> + TRACE(OTHER, logout("configuration: %s\n",
> + nic_dump(&s->configuration[0], 16)));
> + TRACE(OTHER, logout("configuration: %s\n",
> + nic_dump(&s->configuration[16],
> + ARRAY_SIZE(s->configuration) - 16)));
> + if (s->configuration[20] & BIT(6)) {
> + TRACE(OTHER, logout("Multiple IA bit\n"));
> + }
> break;
> case CmdMulticastList:
> set_multicast_list(s);
> @@ -1647,12 +1655,6 @@ static ssize_t nic_receive(VLANClientState *nc, const
> uint8_t * buf, size_t size
> static const uint8_t broadcast_macaddr[6] =
> { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
>
> - /* TODO: check multiple IA bit. */
> - if (s->configuration[20] & BIT(6)) {
> - missing("Multiple IA bit");
> - return -1;
> - }
> -
> if (s->configuration[8] & 0x80) {
> /* CSMA is disabled. */
> logout("%p received while CSMA is disabled\n", s);
> @@ -1702,6 +1704,16 @@ static ssize_t nic_receive(VLANClientState *nc, const
> uint8_t * buf, size_t size
> /* Promiscuous: receive all. */
> TRACE(RXTX, logout("%p received frame in promiscuous mode,
> len=%zu\n", s, size));
> rfd_status |= 0x0004;
> + } else if (s->configuration[20] & BIT(6)) {
> + /* Multiple IA bit set. */
> + unsigned mcast_idx = compute_mcast_idx(buf);
> + assert(mcast_idx < 64);
> + if (s->mult[mcast_idx >> 3] & (1 << (mcast_idx & 7))) {
e.g:
if (s->mult & (1 << (mcast_idx & 63))) {
Cheers
