Kirti? Migration experts? Thanks,
Alex On Mon, 11 Jan 2021 15:34:39 +0800 Keqian Zhu <zhukeqi...@huawei.com> wrote: > For now the switch of vfio dirty page tracking is integrated into > the vfio_save_handler, it causes some problems [1]. > > The object of dirty tracking is guest memory, but the object of > the vfio_save_handler is device state. This mixed logic produces > unnecessary coupling and conflicts: > > 1. Coupling: Their saving granule is different (perVM vs perDevice). > vfio will enable dirty_page_tracking for each devices, actually > once is enough. > 2. Conflicts: The ram_save_setup() traverses all memory_listeners > to execute their log_start() and log_sync() hooks to get the > first round dirty bitmap, which is used by the bulk stage of > ram saving. However, it can't get dirty bitmap from vfio, as > @savevm_ram_handlers is registered before @vfio_save_handler. > > Move the switch of vfio dirty_page_tracking into vfio_memory_listener > can solve above problems. Besides, Do not require devices in SAVING > state for vfio_sync_dirty_bitmap(). > > [1] https://www.spinics.net/lists/kvm/msg229967.html > > Reported-by: Zenghui Yu <yuzeng...@huawei.com> > Signed-off-by: Keqian Zhu <zhukeqi...@huawei.com> > --- > hw/vfio/common.c | 53 +++++++++++++++++++++++++++++++++++++-------- > hw/vfio/migration.c | 35 ------------------------------ > 2 files changed, 44 insertions(+), 44 deletions(-) > > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index 6ff1daa763..9128cd7ee1 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -311,7 +311,7 @@ bool vfio_mig_active(void) > return true; > } > > -static bool vfio_devices_all_saving(VFIOContainer *container) > +static bool vfio_devices_all_dirty_tracking(VFIOContainer *container) > { > VFIOGroup *group; > VFIODevice *vbasedev; > @@ -329,13 +329,8 @@ static bool vfio_devices_all_saving(VFIOContainer > *container) > return false; > } > > - if (migration->device_state & VFIO_DEVICE_STATE_SAVING) { > - if ((vbasedev->pre_copy_dirty_page_tracking == > ON_OFF_AUTO_OFF) > - && (migration->device_state & > VFIO_DEVICE_STATE_RUNNING)) { > - return false; > - } > - continue; > - } else { > + if ((vbasedev->pre_copy_dirty_page_tracking == ON_OFF_AUTO_OFF) > + && (migration->device_state & VFIO_DEVICE_STATE_RUNNING)) { > return false; > } > } > @@ -987,6 +982,44 @@ static void vfio_listener_region_del(MemoryListener > *listener, > } > } > > +static void vfio_set_dirty_page_tracking(VFIOContainer *container, bool > start) > +{ > + int ret; > + struct vfio_iommu_type1_dirty_bitmap dirty = { > + .argsz = sizeof(dirty), > + }; > + > + if (start) { > + dirty.flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_START; > + } else { > + dirty.flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP; > + } > + > + ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, &dirty); > + if (ret) { > + error_report("Failed to set dirty tracking flag 0x%x errno: %d", > + dirty.flags, errno); > + } > +} > + > +static void vfio_listener_log_start(MemoryListener *listener, > + MemoryRegionSection *section, > + int old, int new) > +{ > + VFIOContainer *container = container_of(listener, VFIOContainer, > listener); > + > + vfio_set_dirty_page_tracking(container, true); > +} > + > +static void vfio_listener_log_stop(MemoryListener *listener, > + MemoryRegionSection *section, > + int old, int new) > +{ > + VFIOContainer *container = container_of(listener, VFIOContainer, > listener); > + > + vfio_set_dirty_page_tracking(container, false); > +} > + > static int vfio_get_dirty_bitmap(VFIOContainer *container, uint64_t iova, > uint64_t size, ram_addr_t ram_addr) > { > @@ -1128,7 +1161,7 @@ static void vfio_listerner_log_sync(MemoryListener > *listener, > return; > } > > - if (vfio_devices_all_saving(container)) { > + if (vfio_devices_all_dirty_tracking(container)) { > vfio_sync_dirty_bitmap(container, section); > } > } > @@ -1136,6 +1169,8 @@ static void vfio_listerner_log_sync(MemoryListener > *listener, > static const MemoryListener vfio_memory_listener = { > .region_add = vfio_listener_region_add, > .region_del = vfio_listener_region_del, > + .log_start = vfio_listener_log_start, > + .log_stop = vfio_listener_log_stop, > .log_sync = vfio_listerner_log_sync, > }; > > diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c > index 00daa50ed8..c0f646823a 100644 > --- a/hw/vfio/migration.c > +++ b/hw/vfio/migration.c > @@ -395,40 +395,10 @@ static int vfio_load_device_config_state(QEMUFile *f, > void *opaque) > return qemu_file_get_error(f); > } > > -static int vfio_set_dirty_page_tracking(VFIODevice *vbasedev, bool start) > -{ > - int ret; > - VFIOMigration *migration = vbasedev->migration; > - VFIOContainer *container = vbasedev->group->container; > - struct vfio_iommu_type1_dirty_bitmap dirty = { > - .argsz = sizeof(dirty), > - }; > - > - if (start) { > - if (migration->device_state & VFIO_DEVICE_STATE_SAVING) { > - dirty.flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_START; > - } else { > - return -EINVAL; > - } > - } else { > - dirty.flags = VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP; > - } > - > - ret = ioctl(container->fd, VFIO_IOMMU_DIRTY_PAGES, &dirty); > - if (ret) { > - error_report("Failed to set dirty tracking flag 0x%x errno: %d", > - dirty.flags, errno); > - return -errno; > - } > - return ret; > -} > - > static void vfio_migration_cleanup(VFIODevice *vbasedev) > { > VFIOMigration *migration = vbasedev->migration; > > - vfio_set_dirty_page_tracking(vbasedev, false); > - > if (migration->region.mmaps) { > vfio_region_unmap(&migration->region); > } > @@ -469,11 +439,6 @@ static int vfio_save_setup(QEMUFile *f, void *opaque) > return ret; > } > > - ret = vfio_set_dirty_page_tracking(vbasedev, true); > - if (ret) { > - return ret; > - } > - > qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); > > ret = qemu_file_get_error(f);
