From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57768) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XLWZa-0006HJ-5M for qemu-devel@nongnu.org; Sun, 24 Aug 2014 08:07:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XLWZV-0004w1-41 for qemu-devel@nongnu.org; Sun, 24 Aug 2014 08:07:02 -0400 Message-ID: <53F9D55D.6060804@msgid.tls.msk.ru> Date: Sun, 24 Aug 2014 16:06:53 +0400 From: Michael Tokarev MIME-Version: 1.0 References: <1408537634-3812-1-git-send-email-ben@xrsa.net> In-Reply-To: <1408537634-3812-1-git-send-email-ben@xrsa.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] vmxnet3: Pad short frames to minimum size (60 bytes) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ben Draper , qemu-devel@nongnu.org Cc: qemu-trivial@nongnu.org, Dmitry Fleytman , Yan Vugenfirer , stefanha@redhat.com, Tamir Shomer 20.08.2014 16:27, Ben Draper wrote: > When running VMware ESXi under qemu-kvm the guest discards frames > that are too short. Short ARP Requests will be dropped, this prevents > guests on the same bridge as VMware ESXi from communicating. This patch > simply adds the padding on the network device itself. I'm not sure it is "trivial enough", so to say. Do we have a maintainer for vmxnet? It's been written and updated several times by vmware (Daynix) people, maybe they can comment on this somehow? I mean, if we don't have a maintainer for this device, it is okay to go to -trivial, but maybe it's a good idea to try to reach the author(s) first? (Adding Cc). Especially since this change is only required in certain cases, not generally. Thanks, /mjt > Signed-off-by: Ben Draper > --- > hw/net/vmxnet3.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/hw/net/vmxnet3.c b/hw/net/vmxnet3.c > index 791321f..f246fa1 100644 > --- a/hw/net/vmxnet3.c > +++ b/hw/net/vmxnet3.c > @@ -34,6 +34,7 @@ > > #define PCI_DEVICE_ID_VMWARE_VMXNET3_REVISION 0x1 > #define VMXNET3_MSIX_BAR_SIZE 0x2000 > +#define MIN_BUF_SIZE 60 > > #define VMXNET3_BAR0_IDX (0) > #define VMXNET3_BAR1_IDX (1) > @@ -1871,12 +1872,21 @@ vmxnet3_receive(NetClientState *nc, const uint8_t *buf, size_t size) > { > VMXNET3State *s = qemu_get_nic_opaque(nc); > size_t bytes_indicated; > + uint8_t min_buf[MIN_BUF_SIZE]; > > if (!vmxnet3_can_receive(nc)) { > VMW_PKPRN("Cannot receive now"); > return -1; > } > > + /* Pad to minimum Ethernet frame length */ > + if (size < sizeof(min_buf)) { > + memcpy(min_buf, buf, size); > + memset(&min_buf[size], 0, sizeof(min_buf) - size); > + buf = min_buf; > + size = sizeof(min_buf); > + } > + > if (s->peer_has_vhdr) { > vmxnet_rx_pkt_set_vhdr(s->rx_pkt, (struct virtio_net_hdr *)buf); > buf += sizeof(struct virtio_net_hdr); >