KVM: Document replacements for KVM_EXIT_HYPERCALL

Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: Document replacements for KVM_EXIT_HYPERCALL
Signed-off-by: Avi Kivity <avi@redhat.com>
647dc49e · Avi Kivity · 05b0ab1c · 647dc49e
Commit 647dc49e authored Apr 01, 2010 by Avi Kivity
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Documentation/kvm/api.txt Documentation/kvm/api.txt +3 -1

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--- a/Documentation/kvm/api.txt
+++ b/Documentation/kvm/api.txt
@@ -974,7 +974,9 @@ pending operations.
 			__u32 pad;
 		} hypercall;

-Unused.
+Unused.  This was once used for 'hypercall to userspace'.  To implement
+such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390).
+Note KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO.

 		/* KVM_EXIT_TPR_ACCESS */
 		struct {