Introduce KVM_FEATURE_SPLIT_LOCK_DETECT, for which linux guest running
on KVM can enumerate the avaliablility of feature split lock detection.
Introduce KVM_HINTS_SLD_FATAL, which tells whether host is sld_fatal mode,
i.e., whether split lock detection is forced on for guest vcpu.
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
Documentation/virt/kvm/cpuid.rst | 29 ++++++++++++++++++++--------
arch/x86/include/uapi/asm/kvm_para.h | 8 +++++---
2 files changed, 26 insertions(+), 11 deletions(-)
diff --git a/Documentation/virt/kvm/cpuid.rst b/Documentation/virt/kvm/cpuid.rst
index 01b081f6e7ea..a7e85ac090a8 100644
--- a/Documentation/virt/kvm/cpuid.rst
+++ b/Documentation/virt/kvm/cpuid.rst
@@ -86,6 +86,12 @@ KVM_FEATURE_PV_SCHED_YIELD 13 guest checks this feature bit
before using paravirtualized
sched yield.
+KVM_FEATURE_SPLIT_LOCK_DETECT 14 guest checks this feature bit for
+ available of split lock detection.
+
+ KVM doesn't support enumerating
+ split lock detection via CPU model
+
KVM_FEATURE_CLOCSOURCE_STABLE_BIT 24 host will warn if no guest-side
per-cpu warps are expeced in
kvmclock
@@ -97,11 +103,18 @@ KVM_FEATURE_CLOCSOURCE_STABLE_BIT 24 host will warn if no guest-side
Where ``flag`` here is defined as below:
-================== ============ =================================
-flag value meaning
-================== ============ =================================
-KVM_HINTS_REALTIME 0 guest checks this feature bit to
- determine that vCPUs are never
- preempted for an unlimited time
- allowing optimizations
-================== ============ =================================
+================================ ============ =================================
+flag value meaning
+================================ ============ =================================
+KVM_HINTS_REALTIME 0 guest checks this feature bit to
+ determine that vCPUs are never
+ preempted for an unlimited time
+ allowing optimizations
+
+KVM_HINTS_SLD_FATAL 1 set if split lock detection is
+ forced on in the host, in which
+ case KVM will kill the guest if it
+ generates a split lock #AC with
+ SLD disabled from guest's
+ perspective
+================================ ============ =================================
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index 2a8e0b6b9805..a8fe0221403a 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -31,14 +31,16 @@
#define KVM_FEATURE_PV_SEND_IPI 11
#define KVM_FEATURE_POLL_CONTROL 12
#define KVM_FEATURE_PV_SCHED_YIELD 13
-
-#define KVM_HINTS_REALTIME 0
-
+#define KVM_FEATURE_SPLIT_LOCK_DETECT 14
/* The last 8 bits are used to indicate how to interpret the flags field
* in pvclock structure. If no bits are set, all flags are ignored.
*/
#define KVM_FEATURE_CLOCKSOURCE_STABLE_BIT 24
+/* KVM feature hints in CPUID.0x40000001.EDX */
+#define KVM_HINTS_REALTIME 0
+#define KVM_HINTS_SLD_FATAL 1
+
#define MSR_KVM_WALL_CLOCK 0x11
#define MSR_KVM_SYSTEM_TIME 0x12
--
2.18.2
