KVM: arm64: vgic-its: Clear DTE when MAPD unmaps a device

commit e9649129d33dca561305fc590a7c4ba8c3e5675a upstream.

vgic_its_save_device_tables will traverse its->device_list to
save DTE for each device. vgic_its_restore_device_tables will
traverse each entry of device table and check if it is valid.
Restore if valid.

But when MAPD unmaps a device, it does not invalidate the
corresponding DTE. In the scenario of continuous saves
and restores, there may be a situation where a device's DTE
is not saved but is restored. This is unreasonable and may
cause restore to fail. This patch clears the corresponding
DTE when MAPD unmaps a device.

Cc: stable@vger.kernel.org
Fixes: 57a9a117 ("KVM: arm64: vgic-its: Device table save/restore")
Co-developed-by: Shusen Li <lishusen2@huawei.com>
Signed-off-by: Shusen Li <lishusen2@huawei.com>
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
[Jing: Update with entry write helper]
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20241107214137.428439-5-jingzhangos@google.com


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>