Extend the features configuration space to 128 bits, and allow the
common read/write operation to access all of it.
On migration, save the 128 bit version of the features only if the
upper bits are non zero. Relay reset to clear all the feature
space before load.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
v2 -> v3:
- drop the pre_load/post_load trickery and relay on reset zeroing
the features instead.
- avoid union usage, just increase guest_features size and use
SUB_ARRAY.
- drop unneeded '!!'
- _array -> _ex
v1 -> v2:
- use separate VMStateDescription and pre/post load to avoid breaking
migration
- clear proxy features on device reset
---
hw/virtio/virtio-pci.c | 54 +++++++++++++++++++++++++++++-----
include/hw/virtio/virtio-pci.h | 2 +-
2 files changed, 48 insertions(+), 8 deletions(-)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 767216d795..6800c80eed 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -109,6 +109,29 @@ static const VMStateDescription vmstate_virtio_pci_modern_queue_state = {
}
};
+static bool virtio_pci_modern_state_features128_needed(void *opaque)
+{
+ VirtIOPCIProxy *proxy = opaque;
+ uint32_t features = 0;
+ int i;
+
+ for (i = 2; i < ARRAY_SIZE(proxy->guest_features); ++i) {
+ features |= proxy->guest_features[i];
+ }
+ return features;
+}
+
+static const VMStateDescription vmstate_virtio_pci_modern_state_features128 = {
+ .name = "virtio_pci/modern_state/features128",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = &virtio_pci_modern_state_features128_needed,
+ .fields = (const VMStateField[]) {
+ VMSTATE_UINT32_SUB_ARRAY(guest_features, VirtIOPCIProxy, 2, 2),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
static bool virtio_pci_modern_state_needed(void *opaque)
{
VirtIOPCIProxy *proxy = opaque;
@@ -124,11 +147,15 @@ static const VMStateDescription vmstate_virtio_pci_modern_state_sub = {
.fields = (const VMStateField[]) {
VMSTATE_UINT32(dfselect, VirtIOPCIProxy),
VMSTATE_UINT32(gfselect, VirtIOPCIProxy),
- VMSTATE_UINT32_ARRAY(guest_features, VirtIOPCIProxy, 2),
+ VMSTATE_UINT32_SUB_ARRAY(guest_features, VirtIOPCIProxy, 0, 2),
VMSTATE_STRUCT_ARRAY(vqs, VirtIOPCIProxy, VIRTIO_QUEUE_MAX, 0,
vmstate_virtio_pci_modern_queue_state,
VirtIOPCIQueue),
VMSTATE_END_OF_LIST()
+ },
+ .subsections = (const VMStateDescription * const []) {
+ &vmstate_virtio_pci_modern_state_features128,
+ NULL
}
};
@@ -1494,11 +1521,14 @@ static uint64_t virtio_pci_common_read(void *opaque, hwaddr addr,
val = proxy->dfselect;
break;
case VIRTIO_PCI_COMMON_DF:
- if (proxy->dfselect <= 1) {
+ if (proxy->dfselect < VIRTIO_FEATURES_WORDS) {
VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
- val = (vdev->host_features & ~vdc->legacy_features) >>
- (32 * proxy->dfselect);
+ val = vdev->host_features_ex[proxy->dfselect >> 1] >>
+ (32 * (proxy->dfselect & 1));
+ if (proxy->dfselect <= 1) {
+ val &= (~vdc->legacy_features) >> (32 * proxy->dfselect);
+ }
}
break;
case VIRTIO_PCI_COMMON_GFSELECT:
@@ -1589,10 +1619,17 @@ static void virtio_pci_common_write(void *opaque, hwaddr addr,
break;
case VIRTIO_PCI_COMMON_GF:
if (proxy->gfselect < ARRAY_SIZE(proxy->guest_features)) {
+ uint64_t features[VIRTIO_FEATURES_DWORDS];
+ int i;
+
proxy->guest_features[proxy->gfselect] = val;
- virtio_set_features(vdev,
- (((uint64_t)proxy->guest_features[1]) << 32) |
- proxy->guest_features[0]);
+ virtio_features_clear(features);
+ for (i = 0; i < ARRAY_SIZE(proxy->guest_features); ++i) {
+ uint64_t cur = proxy->guest_features[i];
+
+ features[i >> 1] |= cur << ((i & 1) * 32);
+ }
+ virtio_set_features_ex(vdev, features);
}
break;
case VIRTIO_PCI_COMMON_MSIX:
@@ -2311,6 +2348,9 @@ static void virtio_pci_reset(DeviceState *qdev)
virtio_bus_reset(bus);
msix_unuse_all_vectors(&proxy->pci_dev);
+ QEMU_BUILD_BUG_ON(ARRAY_SIZE(proxy->guest_features) != 4);
+ memset(proxy->guest_features, 0, sizeof(proxy->guest_features));
+
for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
proxy->vqs[i].enabled = 0;
proxy->vqs[i].reset = 0;
diff --git a/include/hw/virtio/virtio-pci.h b/include/hw/virtio/virtio-pci.h
index eab5394898..eae0fcdec3 100644
--- a/include/hw/virtio/virtio-pci.h
+++ b/include/hw/virtio/virtio-pci.h
@@ -158,7 +158,7 @@ struct VirtIOPCIProxy {
uint32_t nvectors;
uint32_t dfselect;
uint32_t gfselect;
- uint32_t guest_features[2];
+ uint32_t guest_features[4];
VirtIOPCIQueue vqs[VIRTIO_QUEUE_MAX];
VirtIOIRQFD *vector_irqfd;
--
2.50.0