cpr-transfer breaks vfio network connectivity to and from the guest, and
the host system log shows:
irq bypass consumer (token 00000000a03c32e5) registration fails: -16
which is EBUSY. This occurs because KVM descriptors are still open in
the old QEMU process. Close them.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/qemu-devel/1751493538-202042-4-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
When there are multiple VFIO containers, vioc->dma_map is restored
multiple times, this made only first container work and remaining
containers using vioc->dma_map restored by first container.
Fix it by save and restore vioc->dma_map locally. saved_dma_map in
VFIOContainerCPR becomes useless and is removed.
Fixes: 7e9f214113 ("vfio/container: restore DMA vaddr")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/qemu-devel/20250627063332.5173-3-zhenzhong.duan@intel.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
CPR overrides then restores dma_map in both outgoing and incoming QEMU, for
different reasons. But it only sets saved_dma_map in the target.
Fix it by always setting saved_dma_map.
Fixes: eba1f657cb ("vfio/container: recover from unmap-all-vaddr failure")
Suggested-by: Steven Sistare <steven.sistare@oracle.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Steve Sistare <steven.sistare@oracle.com>
Link: https://lore.kernel.org/qemu-devel/20250627063332.5173-2-zhenzhong.duan@intel.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
If there are multiple containers and unmap-all fails for some container, we
need to remap vaddr for the other containers for which unmap-all succeeded.
Recover by walking all address ranges of all containers to restore the vaddr
for each. Do so by invoking the vfio listener callback, and passing a new
"remap" flag that tells it to restore a mapping without re-allocating new
userland data structures.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/1749569991-25171-9-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
In new QEMU, do not register the memory listener at device creation time.
Register it later, in the container post_load handler, after all vmstate
that may affect regions and mapping boundaries has been loaded. The
post_load registration will cause the listener to invoke its callback on
each flat section, and the calls will match the mappings remembered by the
kernel.
The listener calls a special dma_map handler that passes the new VA of each
section to the kernel using VFIO_DMA_MAP_FLAG_VADDR. Restore the normal
handler at the end.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/1749569991-25171-7-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
In the container pre_save handler, discard the virtual addresses in DMA
mappings with VFIO_DMA_UNMAP_FLAG_VADDR, because guest RAM will be
remapped at a different VA after in new QEMU. DMA to already-mapped
pages continues.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/1749569991-25171-6-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
At vfio creation time, save the value of vfio container, group, and device
descriptors in CPR state. On qemu restart, vfio_realize() finds and uses
the saved descriptors.
During reuse, device and iommu state is already configured, so operations
in vfio_realize that would modify the configuration, such as vfio ioctl's,
are skipped. The result is that vfio_realize constructs qemu data
structures that reflect the current state of the device.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Link: https://lore.kernel.org/qemu-devel/1749569991-25171-5-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Register a legacy container for cpr-transfer, replacing the generic CPR
register call with a more specific legacy container register call. Add a
blocker if the kernel does not support VFIO_UPDATE_VADDR or VFIO_UNMAP_ALL.
This is mostly boiler plate. The fields to to saved and restored are added
in subsequent patches.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/1749569991-25171-4-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
