Because we have potentially-infinite feature bits, it's hard for the device to know when features are finalized.
This adds a new status bit, VIRTIO_CONFIG_S_FEATURES_DONE, which is only set by the modern virtio_pci driver at the moment. Signed-off-by: Rusty Russell <[email protected]> --- drivers/virtio/virtio_pci-common.c | 28 -------------- drivers/virtio/virtio_pci-common.h | 1 - drivers/virtio/virtio_pci.c | 73 ++++++++++++++++++++++++++---------- drivers/virtio/virtio_pci_legacy.c | 27 +++++++++++++ include/uapi/linux/virtio_config.h | 2 + 5 files changed, 83 insertions(+), 48 deletions(-) diff --git a/drivers/virtio/virtio_pci-common.c b/drivers/virtio/virtio_pci-common.c index d4e33ad..d2c78c8 100644 --- a/drivers/virtio/virtio_pci-common.c +++ b/drivers/virtio/virtio_pci-common.c @@ -392,32 +392,4 @@ int virtio_pci_freeze(struct device *dev) pci_disable_device(pci_dev); return ret; } - -int virtio_pci_restore(struct device *dev) -{ - struct pci_dev *pci_dev = to_pci_dev(dev); - struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); - struct virtio_driver *drv; - int ret; - - drv = container_of(vp_dev->vdev.dev.driver, - struct virtio_driver, driver); - - ret = pci_enable_device(pci_dev); - if (ret) - return ret; - - pci_set_master(pci_dev); - vp_dev->vdev.config->finalize_features(&vp_dev->vdev); - - if (drv && drv->restore) - ret = drv->restore(&vp_dev->vdev); - - /* Finally, tell the device we're all set */ - if (!ret) - vp_dev->vdev.config->set_status(&vp_dev->vdev, - vp_dev->saved_status); - - return ret; -} #endif diff --git a/drivers/virtio/virtio_pci-common.h b/drivers/virtio/virtio_pci-common.h index 146c3be..dac434e 100644 --- a/drivers/virtio/virtio_pci-common.h +++ b/drivers/virtio/virtio_pci-common.h @@ -118,5 +118,4 @@ int virtio_pci_set_vq_affinity(struct virtqueue *vq, int cpu); #ifdef CONFIG_PM int virtio_pci_freeze(struct device *dev); -int virtio_pci_restore(struct device *dev); #endif diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 97d9b54..4614a15 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -50,6 +50,21 @@ static u64 ioread64(__le64 *addr) return ioread32(addr) | ((u64)ioread32((__le32 *)addr + 1) << 32); } +/* config->{get,set}_status() implementations */ +static u8 vp_get_status(struct virtio_device *vdev) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + return ioread8(&vp_dev->common->device_status); +} + +static void vp_set_status(struct virtio_device *vdev, u8 status) +{ + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + /* We should never be setting status to 0. */ + BUG_ON(status == 0); + iowrite8(status, &vp_dev->common->device_status); +} + static u64 vp_get_features(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); @@ -62,19 +77,27 @@ static u64 vp_get_features(struct virtio_device *vdev) return features; } -static void vp_finalize_features(struct virtio_device *vdev) +static void write_features(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); - /* Give virtio_ring a chance to accept features. */ - vring_transport_features(vdev); - iowrite32(0, &vp_dev->common->guest_feature_select); iowrite32((u32)vdev->features, &vp_dev->common->guest_feature); iowrite32(1, &vp_dev->common->guest_feature_select); iowrite32(vdev->features >> 32, &vp_dev->common->guest_feature); } +static void vp_finalize_features(struct virtio_device *vdev) +{ + /* Give virtio_ring a chance to accept features. */ + vring_transport_features(vdev); + + write_features(vdev); + + /* Update status to lock it in. */ + vp_set_status(vdev, vp_get_status(vdev)|VIRTIO_CONFIG_S_FEATURES_DONE); +} + /* virtio config is little-endian for virtio_pci (vs guest-endian for legacy) */ static u8 vp_get8(struct virtio_device *vdev, unsigned offset) { @@ -132,21 +155,6 @@ static void vp_set64(struct virtio_device *vdev, unsigned offset, u64 val) iowrite64(val, vp_dev->device + offset); } -/* config->{get,set}_status() implementations */ -static u8 vp_get_status(struct virtio_device *vdev) -{ - struct virtio_pci_device *vp_dev = to_vp_device(vdev); - return ioread8(&vp_dev->common->device_status); -} - -static void vp_set_status(struct virtio_device *vdev, u8 status) -{ - struct virtio_pci_device *vp_dev = to_vp_device(vdev); - /* We should never be setting status to 0. */ - BUG_ON(status == 0); - iowrite8(status, &vp_dev->common->device_status); -} - static void vp_reset(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); @@ -571,6 +579,33 @@ static void virtio_pci_remove(struct pci_dev *pci_dev) } #ifdef CONFIG_PM +static int virtio_pci_restore(struct device *dev) +{ + struct pci_dev *pci_dev = to_pci_dev(dev); + struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); + struct virtio_driver *drv; + int ret; + + drv = container_of(vp_dev->vdev.dev.driver, + struct virtio_driver, driver); + + ret = pci_enable_device(pci_dev); + if (ret) + return ret; + + pci_set_master(pci_dev); + write_features(&vp_dev->vdev); + + if (drv && drv->restore) + ret = drv->restore(&vp_dev->vdev); + + /* Finally, tell the device we're all set */ + if (!ret) + vp_set_status(&vp_dev->vdev, vp_dev->saved_status); + + return ret; +} + static const struct dev_pm_ops virtio_pci_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore) }; diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c index f78a858..cfff009 100644 --- a/drivers/virtio/virtio_pci_legacy.c +++ b/drivers/virtio/virtio_pci_legacy.c @@ -436,6 +436,33 @@ static void virtio_pci_remove(struct pci_dev *pci_dev) } #ifdef CONFIG_PM +static int virtio_pci_restore(struct device *dev) +{ + struct pci_dev *pci_dev = to_pci_dev(dev); + struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); + struct virtio_driver *drv; + int ret; + + drv = container_of(vp_dev->vdev.dev.driver, + struct virtio_driver, driver); + + ret = pci_enable_device(pci_dev); + if (ret) + return ret; + + pci_set_master(pci_dev); + vp_finalize_features(&vp_dev->vdev); + + if (drv && drv->restore) + ret = drv->restore(&vp_dev->vdev); + + /* Finally, tell the device we're all set */ + if (!ret) + vp_set_status(&vp_dev->vdev, vp_dev->saved_status); + + return ret; +} + static const struct dev_pm_ops virtio_pci_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore) }; diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h index b7cda39..83848b7 100644 --- a/include/uapi/linux/virtio_config.h +++ b/include/uapi/linux/virtio_config.h @@ -36,6 +36,8 @@ #define VIRTIO_CONFIG_S_ACKNOWLEDGE 1 /* We have found a driver for the device. */ #define VIRTIO_CONFIG_S_DRIVER 2 +/* Features are finalized (only for new virtio_pci) */ +#define VIRTIO_CONFIG_S_FEATURES_DONE 8 /* Driver has used its parts of the config, and is happy */ #define VIRTIO_CONFIG_S_DRIVER_OK 4 /* We've given up on this device. */ -- 1.7.10.4 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
