From 2788cd4e327f3b6e63da52e6a59bf8927abfe4bb Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 24 Mar 2014 10:49:19 +0100 Subject: [PATCH] sysctl: annotate struct pm_cx_stat's pc[]/cc[] Suggested-by: Ian Jackson Signed-off-by: Jan Beulich Acked-by: Ian Campbell Acked-by: Keir Fraser --- xen/include/public/sysctl.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h index 8ae6870b40..35886985e9 100644 --- a/xen/include/public/sysctl.h +++ b/xen/include/public/sysctl.h @@ -228,8 +228,15 @@ struct pm_cx_stat { XEN_GUEST_HANDLE_64(uint64) residencies; /* Cx residencies */ uint32_t nr_pc; /* entry nr in pc[] */ uint32_t nr_cc; /* entry nr in cc[] */ - XEN_GUEST_HANDLE_64(uint64) pc; /* 1-biased indexing */ - XEN_GUEST_HANDLE_64(uint64) cc; /* 1-biased indexing */ + /* + * These two arrays may (and generally will) have unused slots; slots not + * having a corresponding hardware register will not be written by the + * hypervisor. It is therefore up to the caller to put a suitable sentinel + * into all slots before invoking the function. + * Indexing is 1-biased (PC1/CC1 being at index 0). + */ + XEN_GUEST_HANDLE_64(uint64) pc; + XEN_GUEST_HANDLE_64(uint64) cc; }; struct xen_sysctl_get_pmstat { -- 2.30.2