KVM: s390: Add MEMOP ioctls for reading/writing guest memory
authorThomas Huth <thuth@linux.vnet.ibm.com>
Fri, 6 Feb 2015 14:01:21 +0000 (15:01 +0100)
committerChristian Borntraeger <borntraeger@de.ibm.com>
Tue, 17 Mar 2015 15:26:24 +0000 (16:26 +0100)
commit41408c28f283b49202ae374b1c42bc8e9b33a048
tree4acd40bb4bacc760ad3c65c82b5604145d64d437
parent664b4973537068402954bee6e2959b858f263a6f
KVM: s390: Add MEMOP ioctls for reading/writing guest memory

On s390, we've got to make sure to hold the IPTE lock while accessing
logical memory. So let's add an ioctl for reading and writing logical
memory to provide this feature for userspace, too.
The maximum transfer size of this call is limited to 64kB to prevent
that the guest can trigger huge copy_from/to_user transfers. QEMU
currently only requests up to one or two pages so far, so 16*4kB seems
to be a reasonable limit here.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Documentation/virtual/kvm/api.txt
arch/s390/kvm/gaccess.c
arch/s390/kvm/gaccess.h
arch/s390/kvm/kvm-s390.c
include/uapi/linux/kvm.h