On Tue, Aug 01, 2023 at 01:31:48AM +0300, Yuri Benditovich wrote:
> USO features of virtio-net device depend on kernel ability
> to support them, for backward compatibility by default the
> features are disabled on 8.0 and earlier.
>
> Signed-off-by: Yuri Benditovich <yuri.benditov...@daynix.com>
> Signed-off-by: Andrew Melnychecnko <and...@daynix.com>
Looks like this patch broke migration when the VM starts on a host that has
USO supported, to another host that doesn't..
Yuri, would it be possible we always keep all the USO* features off by
default (so this feature bit never affects migration ABI), but then:
- only enable them when the user specified ON
- meanwhile, if detecting host feature doesn't support USO*, it could
fail qemu from boot, rather than silently turning it from ON->OFF
?
Silently flipping the bit may cause migration issues like this.
Or any suggestion on how to fix migration?
Thanks,
> ---
> hw/core/machine.c | 4 ++++
> hw/net/virtio-net.c | 31 +++++++++++++++++++++++++++++--
> 2 files changed, 33 insertions(+), 2 deletions(-)
>
> diff --git a/hw/core/machine.c b/hw/core/machine.c
> index f0d35c6401..a725e76738 100644
> --- a/hw/core/machine.c
> +++ b/hw/core/machine.c
> @@ -38,10 +38,14 @@
> #include "exec/confidential-guest-support.h"
> #include "hw/virtio/virtio.h"
> #include "hw/virtio/virtio-pci.h"
> +#include "hw/virtio/virtio-net.h"
>
> GlobalProperty hw_compat_8_0[] = {
> { "migration", "multifd-flush-after-each-section", "on"},
> { TYPE_PCI_DEVICE, "x-pcie-ari-nextfn-1", "on" },
> + { TYPE_VIRTIO_NET, "host_uso", "off"},
> + { TYPE_VIRTIO_NET, "guest_uso4", "off"},
> + { TYPE_VIRTIO_NET, "guest_uso6", "off"},
> };
> const size_t hw_compat_8_0_len = G_N_ELEMENTS(hw_compat_8_0);
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index d2311e7d6e..bd0ead94fe 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -659,6 +659,15 @@ static int peer_has_ufo(VirtIONet *n)
> return n->has_ufo;
> }
>
> +static int peer_has_uso(VirtIONet *n)
> +{
> + if (!peer_has_vnet_hdr(n)) {
> + return 0;
> + }
> +
> + return qemu_has_uso(qemu_get_queue(n->nic)->peer);
> +}
> +
> static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs,
> int version_1, int hash_report)
> {
> @@ -796,6 +805,10 @@ static uint64_t virtio_net_get_features(VirtIODevice
> *vdev, uint64_t features,
> virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_TSO6);
> virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_ECN);
>
> + virtio_clear_feature(&features, VIRTIO_NET_F_HOST_USO);
> + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO4);
> + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO6);
> +
> virtio_clear_feature(&features, VIRTIO_NET_F_HASH_REPORT);
> }
>
> @@ -804,6 +817,12 @@ static uint64_t virtio_net_get_features(VirtIODevice
> *vdev, uint64_t features,
> virtio_clear_feature(&features, VIRTIO_NET_F_HOST_UFO);
> }
>
> + if (!peer_has_uso(n)) {
> + virtio_clear_feature(&features, VIRTIO_NET_F_HOST_USO);
> + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO4);
> + virtio_clear_feature(&features, VIRTIO_NET_F_GUEST_USO6);
> + }
> +
> if (!get_vhost_net(nc->peer)) {
> return features;
> }
> @@ -864,14 +883,16 @@ static void virtio_net_apply_guest_offloads(VirtIONet
> *n)
> !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_USO6)));
> }
>
> -static uint64_t virtio_net_guest_offloads_by_features(uint32_t features)
> +static uint64_t virtio_net_guest_offloads_by_features(uint64_t features)
> {
> static const uint64_t guest_offloads_mask =
> (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
> (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
> (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
> (1ULL << VIRTIO_NET_F_GUEST_ECN) |
> - (1ULL << VIRTIO_NET_F_GUEST_UFO);
> + (1ULL << VIRTIO_NET_F_GUEST_UFO) |
> + (1ULL << VIRTIO_NET_F_GUEST_USO4) |
> + (1ULL << VIRTIO_NET_F_GUEST_USO6);
>
> return guest_offloads_mask & features;
> }
> @@ -3924,6 +3945,12 @@ static Property virtio_net_properties[] = {
> DEFINE_PROP_INT32("speed", VirtIONet, net_conf.speed, SPEED_UNKNOWN),
> DEFINE_PROP_STRING("duplex", VirtIONet, net_conf.duplex_str),
> DEFINE_PROP_BOOL("failover", VirtIONet, failover, false),
> + DEFINE_PROP_BIT64("guest_uso4", VirtIONet, host_features,
> + VIRTIO_NET_F_GUEST_USO4, true),
> + DEFINE_PROP_BIT64("guest_uso6", VirtIONet, host_features,
> + VIRTIO_NET_F_GUEST_USO6, true),
> + DEFINE_PROP_BIT64("host_uso", VirtIONet, host_features,
> + VIRTIO_NET_F_HOST_USO, true),
> DEFINE_PROP_END_OF_LIST(),
> };
>
> --
> 2.34.3
>
>
--
Peter Xu
