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authorLinus Torvalds <torvalds@linux-foundation.org>2020-09-21 08:53:48 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-09-21 08:53:48 -0700
commitbeaeb4f39bc31d5a5eb6d05465a86af4fe147732 (patch)
treea9f3e96b08e2063571f38abb90693eb548d8c290 /Documentation
parenta31128384dfd9ca11f15ef4ea73df25e394846d1 (diff)
parent32251b07d532174d66941488c112ec046f646157 (diff)
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini: "ARM: - fix fault on page table writes during instruction fetch s390: - doc improvement x86: - The obvious patches are always the ones that turn out to be completely broken. /me hangs his head in shame" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: Revert "KVM: Check the allocation of pv cpu mask" KVM: arm64: Remove S1PTW check from kvm_vcpu_dabt_iswrite() KVM: arm64: Assume write fault on S1PTW permission fault on instruction fetch docs: kvm: add documentation for KVM_CAP_S390_DIAG318
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/virt/kvm/api.rst20
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index d2b733dc7892..51191b56e61c 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6173,3 +6173,23 @@ specific interfaces must be consistent, i.e. if one says the feature
is supported, than the other should as well and vice versa. For arm64
see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL".
For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME".
+
+8.25 KVM_CAP_S390_DIAG318
+-------------------------
+
+:Architectures: s390
+
+This capability enables a guest to set information about its control program
+(i.e. guest kernel type and version). The information is helpful during
+system/firmware service events, providing additional data about the guest
+environments running on the machine.
+
+The information is associated with the DIAGNOSE 0x318 instruction, which sets
+an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and
+a 7-byte Control Program Version Code (CPVC). The CPNC determines what
+environment the control program is running in (e.g. Linux, z/VM...), and the
+CPVC is used for information specific to OS (e.g. Linux version, Linux
+distribution...)
+
+If this capability is available, then the CPNC and CPVC can be synchronized
+between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318).