Patchwork [35/35] KVM: PPC: Add documentation for magic page enhancements

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Submitter Alexander Graf
Date Aug. 31, 2010, 2:32 a.m.
Message ID <>
Download mbox | patch
Permalink /patch/63182/
State Not Applicable
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Alexander Graf - Aug. 31, 2010, 2:32 a.m.
This documents how to detect additional features inside the magic
page when a guest maps it.

Signed-off-by: Alexander Graf <>
 Documentation/kvm/ppc-pv.txt |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)


diff --git a/Documentation/kvm/ppc-pv.txt b/Documentation/kvm/ppc-pv.txt
index 922cf95..a7f2244 100644
--- a/Documentation/kvm/ppc-pv.txt
+++ b/Documentation/kvm/ppc-pv.txt
@@ -102,6 +102,20 @@  struct kvm_vcpu_arch_shared {
 Additions to the page must only occur at the end. Struct fields are always 32
 or 64 bit aligned, depending on them being 32 or 64 bit wide respectively.
+Magic page features
+When mapping the magic page using the KVM hypercall KVM_HC_PPC_MAP_MAGIC_PAGE,
+a second return value is passed to the guest. This second return value contains
+a bitmap of available features inside the magic page.
+The following enhancements to the magic page are currently available:
+  KVM_MAGIC_FEAT_SR		Maps SR registers r/w in the magic page
+For enhanced features in the magic page, please check for the existence of the
+feature before using them!
 MSR bits