| Message ID | 20241102205653.30476-1-wsh@wshooper.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] net/vmnet: Pad short Ethernet frames | expand |
On Sat, Nov 2, 2024 at 1:56 PM William Hooper <wsh@wshooper.org> wrote: > At least on macOS 12.7.2, vmnet doesn't pad Ethernet frames, such as the > host's ARP replies, to the minimum size (60 bytes before the frame check > sequence) defined in IEEE Std 802.3-2022, so guests' Ethernet device > drivers may drop them with "frame too short" errors. > > This patch calls eth_pad_short_frame() to add padding, as in net/tap.c > and net/slirp.c. Thanks to Bin Meng, Philippe Mathieu-Daudé, and Phil > Dennis-Jordan for reviewing earlier versions. > > Signed-off-by: William Hooper <wsh@wshooper.org> > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2058 > Reviewed-by: Phil Dennis-Jordan <phil@philjordan.eu> > --- > net/vmnet-common.m | 23 ++++++++++++++++++++--- > 1 file changed, 20 insertions(+), 3 deletions(-) > > diff --git a/net/vmnet-common.m b/net/vmnet-common.m > index 30c4e53c13..4b7e330c05 100644 > --- a/net/vmnet-common.m > +++ b/net/vmnet-common.m > @@ -18,6 +18,7 @@ > #include "qemu/error-report.h" > #include "qapi/error.h" > #include "sysemu/runstate.h" > +#include "net/eth.h" > > #include <vmnet/vmnet.h> > #include <dispatch/dispatch.h> > @@ -147,10 +148,26 @@ static int vmnet_read_packets(VmnetState *s) > */ > static void vmnet_write_packets_to_qemu(VmnetState *s) > { > + uint8_t *pkt; > + size_t pktsz; > + uint8_t min_pkt[ETH_ZLEN]; > + size_t min_pktsz; > + ssize_t size; > + > while (s->packets_send_current_pos < s->packets_send_end_pos) { > - ssize_t size = qemu_send_packet_async(&s->nc, > - s->iov_buf[s->packets_send_current_pos].iov_base, > - s->packets_buf[s->packets_send_current_pos].vm_pkt_size, > + pkt = s->iov_buf[s->packets_send_current_pos].iov_base; > + pktsz = s->packets_buf[s->packets_send_current_pos].vm_pkt_size; > + > + if (net_peer_needs_padding(&s->nc)) { > + min_pktsz = sizeof(min_pkt); > + > + if (eth_pad_short_frame(min_pkt, &min_pktsz, pkt, pktsz)) { > + pkt = min_pkt; > + pktsz = min_pktsz; > + } > + } > + > + size = qemu_send_packet_async(&s->nc, pkt, pktsz, > vmnet_send_completed); > > if (size == 0) { Ping? https://patchew.org/QEMU/20241102205653.30476-1-wsh@wshooper.org/
diff --git a/net/vmnet-common.m b/net/vmnet-common.m index 30c4e53c13..4b7e330c05 100644 --- a/net/vmnet-common.m +++ b/net/vmnet-common.m @@ -18,6 +18,7 @@ #include "qemu/error-report.h" #include "qapi/error.h" #include "sysemu/runstate.h" +#include "net/eth.h" #include <vmnet/vmnet.h> #include <dispatch/dispatch.h> @@ -147,10 +148,26 @@ static int vmnet_read_packets(VmnetState *s) */ static void vmnet_write_packets_to_qemu(VmnetState *s) { + uint8_t *pkt; + size_t pktsz; + uint8_t min_pkt[ETH_ZLEN]; + size_t min_pktsz; + ssize_t size; + while (s->packets_send_current_pos < s->packets_send_end_pos) { - ssize_t size = qemu_send_packet_async(&s->nc, - s->iov_buf[s->packets_send_current_pos].iov_base, - s->packets_buf[s->packets_send_current_pos].vm_pkt_size, + pkt = s->iov_buf[s->packets_send_current_pos].iov_base; + pktsz = s->packets_buf[s->packets_send_current_pos].vm_pkt_size; + + if (net_peer_needs_padding(&s->nc)) { + min_pktsz = sizeof(min_pkt); + + if (eth_pad_short_frame(min_pkt, &min_pktsz, pkt, pktsz)) { + pkt = min_pkt; + pktsz = min_pktsz; + } + } + + size = qemu_send_packet_async(&s->nc, pkt, pktsz, vmnet_send_completed); if (size == 0) {