This series fixes various bugs observed when saving/restoring the ITS state before the guest writes the ITS registers (on first boot or after reset/reboot). This is a follow up of Wanghaibin's series [1] plus additional patches following additional code review. It also proposes one ITS reset implementation. Currently, the in-kernel emulated ITS is not reset. After a reset/reboot, the ITS register values and caches are left unchanged. Registers may point to some tables in guest memory which do not exist anymore. If an ITS state backup is initiated before the guest re-writes the registers, the save fails because inconsistencies are detected. Also restore of data saved as such moment is failing. Patches [1-5] attempt to fix the migration issues without implementing the reset IOCTL. They are candidate for stable: - handle case where all collection, device and ITT entries are invalid on restore (which is not an error) - Check the GITS_BASER<n> valid bit before attempting the save any table - Check the GITS_BASER<n> and GITS_CBASER are valid before enabling the ITS - save the collection table before device tables Patches [6-10] allow to empty the caches on reset and implement a new ITS reset IOCTL Best Regards Eric Git: complete series available at https://github.com/eauger/linux/tree/v4.14-rc5-its-reset-v5 * Testing: - on Cavium using a virtio-net-pci guest and various sequences of guest shutdown -r now, virsh reset, virsh suspend/resume, virsh reboot, virsh save.restore, virsh shutdown References: [1] [RFC PATCH 0/3] fix migrate failed when vm is in booting https://www.spinics.net/lists/kvm-arm/msg27121.html History: v4 -> v5: - came back to the original version of KVM: arm/arm64: vgic-its: Fix return value for device table restore Rework of error handling will come later - remove [PATCH v4 03/11] KVM: arm/arm64: vgic-its: Improve error reporting on device table save as of now - remove KVM: arm/arm64: vgic-its: Always attempt to save/restore device and collection tables inversing the save order of device/collection tables fixes the same issue - reword ITS IOCTL doc - add mutex lock in vgic_its_free_collection_list - remove vgic_its_unmap_device v3 -> v4: - fixes a bug in indirect mode: in handle_l1_dte, set *valid at the beginning of the function v2 -> v3: - Revisited error handling in restore functions - Added "KVM: arm/arm64: vgic-its: fix vgic_its_restore_collection_table returned value" - Added "KVM: arm/arm64: vgic-its: Check CBASER/BASER validity before enabling the ITS" - Removed KVM: arm/arm64: vgic-its: Always allow clearing GITS_CREADR/CWRITER - Reworded documentation according to Christoffer's comments v1 -> v2: - added KVM: arm/arm64: vgic-its: Always attempt to save/restore device and collection tables PATCH v1 - series including 2 modified patches of Wanghaibin Eric Auger (8): KVM: arm/arm64: vgic-its: Fix vgic_its_restore_collection_table returned value KVM: arm/arm64: vgic-its: Check CBASER/BASER validity before enabling the ITS KVM: arm/arm64: vgic-its: Check GITS_BASER Valid bit before saving tables KVM: arm/arm64: vgic-its: Save the collection table before device tables KVM: arm/arm64: vgic-its: Remove kvm_its_unmap_device KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared KVM: arm/arm64: Document KVM_DEV_ARM_ITS_CTRL_RESET KVM: arm/arm64: vgic-its: Implement KVM_DEV_ARM_ITS_CTRL_RESET wanghaibin (2): KVM: arm/arm64: vgic-its: Fix return value for device table restore KVM: arm/arm64: vgic-its: New helper functions to free the caches Documentation/virtual/kvm/devices/arm-vgic-its.txt | 21 +++ arch/arm/include/uapi/asm/kvm.h | 1 + arch/arm64/include/uapi/asm/kvm.h | 1 + virt/kvm/arm/vgic/vgic-its.c | 205 ++++++++++++++------- 4 files changed, 162 insertions(+), 66 deletions(-) -- 2.5.5
