Currently offloads disabled by guest via the VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET
command are not preserved on VM migration.
Instead all offloads reported by guest features (via VIRTIO_PCI_GUEST_FEATURES)
get enabled.
What happens is: first the VirtIONet::curr_guest_offloads gets restored and
offloads
are getting set correctly:
#0 qemu_set_offload (nc=0x555556a11400, csum=1, tso4=0, tso6=0, ecn=0, ufo=0)
at net/net.c:474
#1 virtio_net_apply_guest_offloads (n=0x555557701ca0) at
hw/net/virtio-net.c:720
#2 virtio_net_post_load_device (opaque=0x555557701ca0, version_id=11) at
hw/net/virtio-net.c:2334
#3 vmstate_load_state (f=0x5555569dc010, vmsd=0x555556577c80
<vmstate_virtio_net_device>, opaque=0x555557701ca0, version_id=11)
at migration/vmstate.c:168
#4 virtio_load (vdev=0x555557701ca0, f=0x5555569dc010, version_id=11) at
hw/virtio/virtio.c:2197
#5 virtio_device_get (f=0x5555569dc010, opaque=0x555557701ca0, size=0,
field=0x55555668cd00 <__compound_literal.5>) at hw/virtio/virtio.c:2036
#6 vmstate_load_state (f=0x5555569dc010, vmsd=0x555556577ce0
<vmstate_virtio_net>, opaque=0x555557701ca0, version_id=11) at
migration/vmstate.c:143
#7 vmstate_load (f=0x5555569dc010, se=0x5555578189e0) at
migration/savevm.c:829
#8 qemu_loadvm_section_start_full (f=0x5555569dc010, mis=0x5555569eee20) at
migration/savevm.c:2211
#9 qemu_loadvm_state_main (f=0x5555569dc010, mis=0x5555569eee20) at
migration/savevm.c:2395
#10 qemu_loadvm_state (f=0x5555569dc010) at migration/savevm.c:2467
#11 process_incoming_migration_co (opaque=0x0) at migration/migration.c:449
However later on the features are getting restored, and offloads get reset to
everything supported by features:
#0 qemu_set_offload (nc=0x555556a11400, csum=1, tso4=1, tso6=1, ecn=0, ufo=0)
at net/net.c:474
#1 virtio_net_apply_guest_offloads (n=0x555557701ca0) at
hw/net/virtio-net.c:720
#2 virtio_net_set_features (vdev=0x555557701ca0, features=5104441767) at
hw/net/virtio-net.c:773
#3 virtio_set_features_nocheck (vdev=0x555557701ca0, val=5104441767) at
hw/virtio/virtio.c:2052
#4 virtio_load (vdev=0x555557701ca0, f=0x5555569dc010, version_id=11) at
hw/virtio/virtio.c:2220
#5 virtio_device_get (f=0x5555569dc010, opaque=0x555557701ca0, size=0,
field=0x55555668cd00 <__compound_literal.5>) at hw/virtio/virtio.c:2036
#6 vmstate_load_state (f=0x5555569dc010, vmsd=0x555556577ce0
<vmstate_virtio_net>, opaque=0x555557701ca0, version_id=11) at
migration/vmstate.c:143
#7 vmstate_load (f=0x5555569dc010, se=0x5555578189e0) at
migration/savevm.c:829
#8 qemu_loadvm_section_start_full (f=0x5555569dc010, mis=0x5555569eee20) at
migration/savevm.c:2211
#9 qemu_loadvm_state_main (f=0x5555569dc010, mis=0x5555569eee20) at
migration/savevm.c:2395
#10 qemu_loadvm_state (f=0x5555569dc010) at migration/savevm.c:2467
#11 process_incoming_migration_co (opaque=0x0) at migration/migration.c:449
This patch fixes this by adding an extra argument to the set_features callback,
specifying whether the offloads are to be reset, and setting it to false
for the migration case.
Signed-off-by: Mikhail Sennikovsky <mikhail.sennikovs...@cloud.ionos.com>
---
hw/display/virtio-gpu-base.c | 3 ++-
hw/net/virtio-net.c | 5 +++--
hw/virtio/virtio.c | 10 +++++-----
include/hw/virtio/virtio.h | 2 +-
4 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/hw/display/virtio-gpu-base.c b/hw/display/virtio-gpu-base.c
index 55e0799..04d8a23 100644
--- a/hw/display/virtio-gpu-base.c
+++ b/hw/display/virtio-gpu-base.c
@@ -193,7 +193,8 @@ virtio_gpu_base_get_features(VirtIODevice *vdev, uint64_t
features,
}
static void
-virtio_gpu_base_set_features(VirtIODevice *vdev, uint64_t features)
+virtio_gpu_base_set_features(VirtIODevice *vdev, uint64_t features,
+ bool reset_offloads)
{
static const uint32_t virgl = (1 << VIRTIO_GPU_F_VIRGL);
VirtIOGPUBase *g = VIRTIO_GPU_BASE(vdev);
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index b9e1cd7..5d108e5 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -743,7 +743,8 @@ static inline uint64_t
virtio_net_supported_guest_offloads(VirtIONet *n)
return virtio_net_guest_offloads_by_features(vdev->guest_features);
}
-static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features)
+static void virtio_net_set_features(VirtIODevice *vdev, uint64_t features,
+ bool reset_offloads)
{
VirtIONet *n = VIRTIO_NET(vdev);
int i;
@@ -767,7 +768,7 @@ static void virtio_net_set_features(VirtIODevice *vdev,
uint64_t features)
n->rsc6_enabled = virtio_has_feature(features, VIRTIO_NET_F_RSC_EXT) &&
virtio_has_feature(features, VIRTIO_NET_F_GUEST_TSO6);
- if (n->has_vnet_hdr) {
+ if (reset_offloads && n->has_vnet_hdr) {
n->curr_guest_offloads =
virtio_net_guest_offloads_by_features(features);
virtio_net_apply_guest_offloads(n);
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index a94ea18..b89f7b0 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2042,14 +2042,14 @@ const VMStateInfo virtio_vmstate_info = {
.put = virtio_device_put,
};
-static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val)
+static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val, bool
reset_offloads)
{
VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
bool bad = (val & ~(vdev->host_features)) != 0;
val &= vdev->host_features;
if (k->set_features) {
- k->set_features(vdev, val);
+ k->set_features(vdev, val, reset_offloads);
}
vdev->guest_features = val;
return bad ? -1 : 0;
@@ -2065,7 +2065,7 @@ int virtio_set_features(VirtIODevice *vdev, uint64_t val)
if (vdev->status & VIRTIO_CONFIG_S_FEATURES_OK) {
return -EINVAL;
}
- ret = virtio_set_features_nocheck(vdev, val);
+ ret = virtio_set_features_nocheck(vdev, val, true);
if (!ret) {
if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
/* VIRTIO_RING_F_EVENT_IDX changes the size of the caches. */
@@ -2217,14 +2217,14 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int
version_id)
* host_features.
*/
uint64_t features64 = vdev->guest_features;
- if (virtio_set_features_nocheck(vdev, features64) < 0) {
+ if (virtio_set_features_nocheck(vdev, features64, false) < 0) {
error_report("Features 0x%" PRIx64 " unsupported. "
"Allowed features: 0x%" PRIx64,
features64, vdev->host_features);
return -1;
}
} else {
- if (virtio_set_features_nocheck(vdev, features) < 0) {
+ if (virtio_set_features_nocheck(vdev, features, false) < 0) {
error_report("Features 0x%x unsupported. "
"Allowed features: 0x%" PRIx64,
features, vdev->host_features);
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index b189788..fd8cac5 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -128,7 +128,7 @@ typedef struct VirtioDeviceClass {
uint64_t requested_features,
Error **errp);
uint64_t (*bad_features)(VirtIODevice *vdev);
- void (*set_features)(VirtIODevice *vdev, uint64_t val);
+ void (*set_features)(VirtIODevice *vdev, uint64_t val, bool
reset_offloads);
int (*validate_features)(VirtIODevice *vdev);
void (*get_config)(VirtIODevice *vdev, uint8_t *config);
void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
--
2.7.4
