X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;ds=sidebyside;f=Documentation%2Fkvm%2Fapi.txt;h=baa8fde8bd167f983f9cf9c742c90d82033d2695;hb=647dc49eebad2c30f823cae2bd8204b66c739f9c;hp=6f362356e738c0cba91bae5a2f33d3141a8f9bed;hpb=05b0ab1c0bb526ac1056bab356ee92cfd6daa6fd;p=safe%2Fjmp%2Flinux-2.6

diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt
index 6f36235..baa8fde 100644
--- 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 {