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authorRadim Krčmář <rkrcmar@redhat.com>2016-07-21 12:20:42 (GMT)
committerRadim Krčmář <rkrcmar@redhat.com>2016-07-21 12:20:42 (GMT)
commit61f5dea179653558562ba9a5dd71eb29d91a383e (patch)
tree09be280e5bd85517b176060e4cdb3b4fa5a34c3d /Documentation/virtual/kvm
parentaf1bae5497b98cb99d6b0492e6981f060420a00c (diff)
parent9acc317b183fdd3ed3bca218271875c0e808daae (diff)
downloadlinux-61f5dea179653558562ba9a5dd71eb29d91a383e.tar.xz
Merge tag 'kvm-s390-next-4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into next
KVM: s390: : Feature and fix for kvm/next (4.8) part 4 1. Provide an exit to userspace for the invalid opcode 0 (used for software breakpoints) 2. "Fix" (by returning condition code 3) some unhandled PTFF subcodes
Diffstat (limited to 'Documentation/virtual/kvm')
-rw-r--r--Documentation/virtual/kvm/api.txt13
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index c4d2fb0..299306d 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -3857,6 +3857,19 @@ as a broadcast even in x2APIC mode in order to support physical x2APIC
without interrupt remapping. This is undesirable in logical mode,
where 0xff represents CPUs 0-7 in cluster 0.
+7.8 KVM_CAP_S390_USER_INSTR0
+
+Architectures: s390
+Parameters: none
+
+With this capability enabled, all illegal instructions 0x0000 (2 bytes) will
+be intercepted and forwarded to user space. User space can use this
+mechanism e.g. to realize 2-byte software breakpoints. The kernel will
+not inject an operating exception for these instructions, user space has
+to take care of that.
+
+This capability can be enabled dynamically even if VCPUs were already
+created and are running.
8. Other capabilities.
----------------------