From ef41c637feebd279b017838b46dc5cfdb52c1ef6 Mon Sep 17 00:00:00 2001
Message-Id: <ef41c637feebd279b017838b46dc5cfdb52c1ef6.1389014116.git.minovotn@redhat.com>
In-Reply-To: <c8cc35838d42aa286242772d97e3a9be7bb786ba.1389014116.git.minovotn@redhat.com>
References: <c8cc35838d42aa286242772d97e3a9be7bb786ba.1389014116.git.minovotn@redhat.com>
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Mon, 9 Dec 2013 14:09:00 +0100
Subject: [PATCH 12/50] block: add BlockLimits structure to BlockDriverState

RH-Author: Paolo Bonzini <pbonzini@redhat.com>
Message-id: <1386598178-11845-15-git-send-email-pbonzini@redhat.com>
Patchwork-id: 56049
O-Subject: [RHEL 7.0 qemu-kvm PATCH 14/52] block: add BlockLimits structure to BlockDriverState
Bugzilla: 1007815
RH-Acked-by: Jeffrey Cody <jcody@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

From: Peter Lieven <pl@kamp.de>

this patch adds BlockLimits which introduces discard and write_zeroes
limits and alignment information to the BlockDriverState.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit fe81c2cca6dc69a5e423f6d8b235606b7f3ca7b7)
---
 include/block/block_int.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

Signed-off-by: Michal Novotny <minovotn@redhat.com>
---
 include/block/block_int.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/block/block_int.h b/include/block/block_int.h
index 236c0c2..ab98c07 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -219,6 +219,20 @@ struct BlockDriver {
     QLIST_ENTRY(BlockDriver) list;
 };
 
+typedef struct BlockLimits {
+    /* maximum number of sectors that can be discarded at once */
+    int max_discard;
+
+    /* optimal alignment for discard requests in sectors */
+    int64_t discard_alignment;
+
+    /* maximum number of sectors that can zeroized at once */
+    int max_write_zeroes;
+
+    /* optimal alignment for write zeroes requests in sectors */
+    int64_t write_zeroes_alignment;
+} BlockLimits;
+
 /*
  * Note: the function bdrv_append() copies and swaps contents of
  * BlockDriverStates, so if you add new fields to this struct, please
@@ -273,6 +287,9 @@ struct BlockDriverState {
     uint64_t total_time_ns[BDRV_MAX_IOTYPE];
     uint64_t wr_highest_sector;
 
+    /* I/O Limits */
+    BlockLimits bl;
+
     /* Whether the disk can expand beyond total_sectors */
     int growable;
 
-- 
1.7.11.7