From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=38744 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Pl2JO-0007kQ-Jp for qemu-devel@nongnu.org; Thu, 03 Feb 2011 11:45:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Pl2JN-000482-3p for qemu-devel@nongnu.org; Thu, 03 Feb 2011 11:45:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:21411) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Pl2JM-00047M-Ix for qemu-devel@nongnu.org; Thu, 03 Feb 2011 11:45:37 -0500 Date: Thu, 3 Feb 2011 18:45:16 +0200 From: "Michael S. Tsirkin" Message-ID: <20110203164516.GA10571@redhat.com> References: <20110203153835.GA28388@redhat.com> <1296751017.3125.0.camel@x201> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1296751017.3125.0.camel@x201> Subject: [Qemu-devel] Re: [PATCH] e1000: multi-buffer packet support List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: Jes.Sorensen@redhat.com, stefanha@linux.vnet.ibm.com, qemu-devel@nongnu.org, agraf@suse.de On Thu, Feb 03, 2011 at 09:36:57AM -0700, Alex Williamson wrote: > On Thu, 2011-02-03 at 17:38 +0200, Michael S. Tsirkin wrote: > > e1000 supports multi-buffer packets larger than rxbuf_size. > > > > This fixes the following (on linux): > > - in guest: ifconfig eth1 mtu 16110 > > - in host: ifconfig tap0 mtu 16110 > > ping -s 16082 > > > > Red Hat bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=602205 > > > > Signed-off-by: Michael S. Tsirkin > > --- > > hw/e1000.c | 25 ++++++++++++++++++++----- > > 1 files changed, 20 insertions(+), 5 deletions(-) > > > > diff --git a/hw/e1000.c b/hw/e1000.c > > index af101bd..2c133ab 100644 > > --- a/hw/e1000.c > > +++ b/hw/e1000.c > > @@ -642,6 +642,8 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) > > uint16_t vlan_special = 0; > > uint8_t vlan_status = 0, vlan_offset = 0; > > uint8_t min_buf[MIN_BUF_SIZE]; > > + size_t desc_offset; > > + size_t desc_size; > > > > if (!(s->mac_reg[RCTL] & E1000_RCTL_EN)) > > return -1; > > @@ -654,7 +656,7 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) > > size = sizeof(min_buf); > > } > > > > - if (size > s->rxbuf_size) { > > + if (0 && size > s->rxbuf_size) { > > DBGOUT(RX, "packet too large for buffers (%lu > %d)\n", > > (unsigned long)size, s->rxbuf_size); > > return -1; > > Why are we saving this code if it's unreachable? Just a leftover. > > @@ -672,8 +674,15 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) > > } > > > > rdh_start = s->mac_reg[RDH]; > > + desc_offset = 0; > > do { > > + desc_size = size - desc_offset; > > + if (desc_size > s->rxbuf_size) { > > + desc_size = s->rxbuf_size; > > + } > > if (s->mac_reg[RDH] == s->mac_reg[RDT] && s->check_rxov) { > > + /* Discard all data written so far */ > > + s->mac_reg[RDH] = rdh_start; > > set_ics(s, 0, E1000_ICS_RXO); > > return -1; > > } > > @@ -684,9 +693,15 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) > > desc.status |= (vlan_status | E1000_RXD_STAT_DD); > > if (desc.buffer_addr) { > > cpu_physical_memory_write(le64_to_cpu(desc.buffer_addr), > > - (void *)(buf + vlan_offset), size); > > - desc.length = cpu_to_le16(size + fcs_len(s)); > > - desc.status |= E1000_RXD_STAT_EOP|E1000_RXD_STAT_IXSM; > > + (void *)(buf + desc_offset + vlan_offset), > > + desc_size); > > + desc_offset += desc_size; > > + if (desc_offset >= size) { > > + desc.length = cpu_to_le16(desc_size + fcs_len(s)); > > + desc.status |= E1000_RXD_STAT_EOP | E1000_RXD_STAT_IXSM; > > + } else { > > + desc.length = cpu_to_le16(desc_size); > > + } > > } else { // as per intel docs; skip descriptors with null buf addr > > DBGOUT(RX, "Null RX descriptor!!\n"); > > } > > @@ -702,7 +717,7 @@ e1000_receive(VLANClientState *nc, const uint8_t *buf, size_t size) > > set_ics(s, 0, E1000_ICS_RXO); > > return -1; > > } > > - } while (desc.buffer_addr == 0); > > + } while (desc_offset < size); > > > > s->mac_reg[GPRC]++; > > s->mac_reg[TPR]++; > >