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authorPaul Mackerras <paulus@ozlabs.org>2017-06-21 08:01:27 +0200
committerPaul Mackerras <paulus@ozlabs.org>2017-06-22 03:25:31 +0200
commit2ed4f9dd19c0f76f7fb56c4b201696d29149325c (patch)
treedc386c28edb9885280d62e1fb51fe2dd5b693a94 /Documentation/virtual
parentKVM: PPC: Book3S HV: Exit guest upon MCE when FWNMI capability is enabled (diff)
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KVM: PPC: Book3S HV: Add capability to report possible virtual SMT modes
Now that userspace can set the virtual SMT mode by enabling the KVM_CAP_PPC_SMT capability, it is useful for userspace to be able to query the set of possible virtual SMT modes. This provides a new capability, KVM_CAP_PPC_SMT_POSSIBLE, to provide this information. The return value is a bitmap of possible modes, with bit N set if virtual SMT mode 2^N is available. That is, 1 indicates SMT1 is available, 2 indicates that SMT2 is available, 3 indicates that both SMT1 and SMT2 are available, and so on. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Diffstat (limited to 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/api.txt11
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 1531a3cd548f..63875dbb6ef5 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -4010,6 +4010,8 @@ be 0. A successful call to enable this capability will result in
vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is
subsequently queried for the VM. This capability is only supported by
HV KVM, and can only be set before any VCPUs have been created.
+The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT
+modes are available.
7.12 KVM_CAP_PPC_FWNMI
@@ -4183,3 +4185,12 @@ Currently the following bits are defined for the device_irq_level bitmap:
Future versions of kvm may implement additional events. These will get
indicated by returning a higher number from KVM_CHECK_EXTENSION and will be
listed above.
+
+8.10 KVM_CAP_PPC_SMT_POSSIBLE
+
+Architectures: ppc
+
+Querying this capability returns a bitmap indicating the possible
+virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N
+(counting from the right) is set, then a virtual SMT mode of 2^N is
+available.