| Message ID | 1350626215-24558-2-git-send-email-dmitry@daynix.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Oct 19, 2012 at 07:56:55AM +0200, Dmitry Fleytman wrote: > Real HW always treats RX ring with RDH == RDT as empty. > Emulation is supposed to behave the same. > > Reported-by: Chris Webb <chris.webb@elastichosts.com> > Reported-by: Richard Davies <richard.davies@elastichosts.com> > Signed-off-by: Dmitry Fleytman <dmitry@daynix.com> > --- > hw/e1000.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) Applied to the net tree: http://github.com/stefanha/qemu/commits/net Thanks for your efforts in squashing this bug! Glad it was possible to drop check_rxov. Stefan
Thanks Stefan, It was my very first idea to drop check_rxov and solve the problem, however for some reason I was sure that it required to emulate real HW behavior. I'm glad we clarified this. Regards, Dmitry Fleytman On Fri, Oct 19, 2012 at 9:52 AM, Stefan Hajnoczi <stefanha@gmail.com> wrote: > On Fri, Oct 19, 2012 at 07:56:55AM +0200, Dmitry Fleytman wrote: >> Real HW always treats RX ring with RDH == RDT as empty. >> Emulation is supposed to behave the same. >> >> Reported-by: Chris Webb <chris.webb@elastichosts.com> >> Reported-by: Richard Davies <richard.davies@elastichosts.com> >> Signed-off-by: Dmitry Fleytman <dmitry@daynix.com> >> --- >> hw/e1000.c | 7 ++----- >> 1 file changed, 2 insertions(+), 5 deletions(-) > > Applied to the net tree: > http://github.com/stefanha/qemu/commits/net > > Thanks for your efforts in squashing this bug! Glad it was possible to > drop check_rxov. > > Stefan
diff --git a/hw/e1000.c b/hw/e1000.c index 63fee10..ab39d47 100644 --- a/hw/e1000.c +++ b/hw/e1000.c @@ -92,7 +92,6 @@ typedef struct E1000State_st { uint32_t rxbuf_size; uint32_t rxbuf_min_shift; - int check_rxov; struct e1000_tx { unsigned char header[256]; unsigned char vlan_header[4]; @@ -741,11 +740,11 @@ static bool e1000_has_rxbufs(E1000State *s, size_t total_size) int bufs; /* Fast-path short packets */ if (total_size <= s->rxbuf_size) { - return s->mac_reg[RDH] != s->mac_reg[RDT] || !s->check_rxov; + return s->mac_reg[RDH] != s->mac_reg[RDT]; } if (s->mac_reg[RDH] < s->mac_reg[RDT]) { bufs = s->mac_reg[RDT] - s->mac_reg[RDH]; - } else if (s->mac_reg[RDH] > s->mac_reg[RDT] || !s->check_rxov) { + } else if (s->mac_reg[RDH] > s->mac_reg[RDT]) { bufs = s->mac_reg[RDLEN] / sizeof(struct e1000_rx_desc) + s->mac_reg[RDT] - s->mac_reg[RDH]; } else { @@ -848,7 +847,6 @@ e1000_receive(NetClientState *nc, const uint8_t *buf, size_t size) if (++s->mac_reg[RDH] * sizeof(desc) >= s->mac_reg[RDLEN]) s->mac_reg[RDH] = 0; - s->check_rxov = 1; /* see comment in start_xmit; same here */ if (s->mac_reg[RDH] == rdh_start) { DBGOUT(RXERR, "RDH wraparound @%x, RDT %x, RDLEN %x\n", @@ -925,7 +923,6 @@ mac_writereg(E1000State *s, int index, uint32_t val) static void set_rdt(E1000State *s, int index, uint32_t val) { - s->check_rxov = 0; s->mac_reg[index] = val & 0xffff; if (e1000_has_rxbufs(s, 1)) { qemu_flush_queued_packets(&s->nic->nc);
Real HW always treats RX ring with RDH == RDT as empty. Emulation is supposed to behave the same. Reported-by: Chris Webb <chris.webb@elastichosts.com> Reported-by: Richard Davies <richard.davies@elastichosts.com> Signed-off-by: Dmitry Fleytman <dmitry@daynix.com> --- hw/e1000.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)