Commit 3b2fbb3f authored by Cornelia Huck's avatar Cornelia Huck Committed by Michael S. Tsirkin
Browse files

virtio/s390: deprecate old transport 



There only ever have been two host implementations of the old
s390-virtio (pre-ccw) transport: the experimental kuli userspace,
and qemu. As qemu switched its default to ccw with 2.4 (with most
users having used ccw well before that) and removed the old transport
entirely in 2.6, s390-virtio probably hasn't been in active use for
quite some time and is therefore likely to bitrot.

Let's start the slow march towards removing the code by deprecating
it.

Note that this also deprecates the early virtio console code, which
has been causing trouble in the guest without being wired up in any
relevant hypervisor code.

Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Reviewed-by: default avatarSascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 2ab0d56a

arch/s390/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -871,4 +871,17 @@ config S390_GUEST 
	  Select this option if you want to run the kernel as a guest under

	  the KVM hypervisor.



config S390_GUEST_OLD_TRANSPORT

	def_bool y

	prompt "Guest support for old s390 virtio transport (DEPRECATED)"

	depends on S390_GUEST

	help

	  Enable this option to add support for the old s390-virtio

	  transport (i.e. virtio devices NOT based on virtio-ccw). This

	  type of virtio devices is only available on the experimental

	  kuli userspace or with old (< 2.6) qemu. If you are running

	  with a modern version of qemu (which supports virtio-ccw since

	  1.4 and uses it by default since version 2.4), you probably won't

	  need this.



endmenu

drivers/s390/virtio/Makefile

+5 −1
Original line number Diff line number Diff line
@@ -6,4 +6,8 @@ 
# it under the terms of the GNU General Public License (version 2 only)

# as published by the Free Software Foundation.



obj-$(CONFIG_S390_GUEST) += kvm_virtio.o virtio_ccw.o
 
s390-virtio-objs := virtio_ccw.o

ifdef CONFIG_S390_GUEST_OLD_TRANSPORT

s390-virtio-objs += kvm_virtio.o

endif

obj-$(CONFIG_S390_GUEST) += $(s390-virtio-objs)

drivers/s390/virtio/kvm_virtio.c

+2 −0
Original line number Diff line number Diff line
@@ -458,6 +458,8 @@ static int __init kvm_devices_init(void) 
	if (test_devices_support(total_memory_size) < 0)

		return -ENODEV;



	pr_warn("The s390-virtio transport is deprecated. Please switch to a modern host providing virtio-ccw.\n");



	rc = vmem_add_mapping(total_memory_size, PAGE_SIZE);

	if (rc)

		return rc;

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