KVM: s390: Allocate and save/restore vector registers
authorEric Farman <farman@linux.vnet.ibm.com>
Mon, 9 Jun 2014 14:57:26 +0000 (10:57 -0400)
committerChristian Borntraeger <borntraeger@de.ibm.com>
Fri, 6 Mar 2015 12:49:33 +0000 (13:49 +0100)
commit68c557501b008515cb86c9a36c75f4e82e14a819
tree43ae3a7fcfe7296550f0c95e72407a55a0901ad7
parent1f289a8429022f112be9817a81ff07308eb78a9c
KVM: s390: Allocate and save/restore vector registers

Define and allocate space for both the host and guest views of
the vector registers for a given vcpu.  The 32 vector registers
occupy 128 bits each (512 bytes total), but architecturally are
paired with 512 additional bytes of reserved space for future
expansion.

The kvm_sync_regs structs containing the registers are union'ed
with 1024 bytes of padding in the common kvm_run struct.  The
addition of 1024 bytes of new register information clearly exceeds
the existing union, so an expansion of that padding is required.

When changing environments, we need to appropriately save and
restore the vector registers viewed by both the host and guest,
into and out of the sync_regs space.

The floating point registers overlay the upper half of vector
registers 0-15, so there's a bit of data duplication here that
needs to be carefully avoided.

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