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Christian Borntraeger e1788bb995 KVM: s390: handle floating point registers in the run ioctl not in vcpu_put/load 
Right now we switch the host fprs/vrs in kvm_arch_vcpu_load and switch
back in kvm_arch_vcpu_put. This process is already optimized
since commit 9977e886cb ("s390/kernel: lazy restore fpu registers")
avoiding double save/restores on schedule. We still reload the pointers
and test the guest fpc on each context switch, though.

We can minimize the cost of vcpu_load/put by doing the test in the
VCPU_RUN ioctl itself. As most VCPU threads almost never exit to
userspace in the common fast path, this allows to avoid this overhead
for the common case (eventfd driven I/O, all exits including sleep
handled in the kernel) - making kvm_arch_vcpu_load/put basically
disappear in perf top.

Also adapt the fpu get/set ioctls.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
 		2016-11-22 19:32:35 +01:00
..
appldata s390: Remove deprecated create_singlethread_workqueue 2016-09-06 10:59:57 +02:00
boot s390: enable UBSAN 2016-09-20 14:26:23 +02:00
configs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2016-10-04 14:05:52 -07:00
crypto s390/crypto: avoid returning garbage value 2016-09-06 11:00:00 +02:00
hypfs s390/hypfs: Use get_free_page() instead of kmalloc to ensure page alignment 2016-10-28 10:08:58 +02:00
include s390/dumpstack: get rid of return_address again 2016-10-17 14:44:33 +02:00
kernel mm: kmemleak: scan .data.ro_after_init 2016-11-11 08:12:37 -08:00
kvm KVM: s390: handle floating point registers in the run ioctl not in vcpu_put/load 2016-11-22 19:32:35 +01:00
lib Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
mm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2016-10-27 14:16:30 -07:00
net s390/bpf: fix recache skb->data/hlen for skb_vlan_push/pop 2016-05-19 09:14:27 +02:00
numa s390/numa: only set possible nodes within node_possible_map 2016-07-31 05:28:00 -04:00
oprofile s390/dumpstack: restore reliable indicator for call traces 2016-10-17 14:44:30 +02:00
pci s390: pci: don't print uninitialized data for debugging 2016-11-11 08:45:08 -08:00
tools s390/facilities: do not generate DWORDS define anymore 2016-07-31 05:27:59 -04:00
Kbuild s390/numa: add core infrastructure 2015-08-03 18:40:25 +02:00
Kconfig atomic64: no need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 2016-10-07 18:46:30 -07:00
Kconfig.debug arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug 2016-01-09 06:30:49 -08:00
Makefile s390: add assembler include path for vx-insn.h 2016-09-06 11:00:04 +02:00
defconfig mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS 2016-08-30 10:10:21 -07:00