From 0bb526e2aa90f3f9143472da23ae3b64a4e3216d Mon Sep 17 00:00:00 2001
From: "Daniel P. Berrange" <berrange@redhat.com>
Date: Wed, 29 Nov 2017 14:26:05 +0100
Subject: [PATCH 19/21] ide: support reporting of rotation rate

RH-Author: Daniel P. Berrange <berrange@redhat.com>
Message-id: <20171129142606.15965-3-berrange@redhat.com>
Patchwork-id: 77965
O-Subject: [PATCH RHV-7.5 qemu-kvm-rhev 2/3] ide: support reporting of rotation rate
Bugzilla: 1498042
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

The Linux kernel will query the ATA IDENTITY DEVICE data, word 217
to determine the rotations per minute of the disk. If this has
the value 1, it is taken to be an SSD and so Linux sets the
'rotational' flag to 0 for the I/O queue and will stop using that
disk as a source of random entropy. Other operating systems may
also take into account rotation rate when setting up default
behaviour.

Mgmt apps should be able to set the rotation rate for virtualized
block devices, based on characteristics of the host storage in use,
so that the guest OS gets sensible behaviour out of the box. This
patch thus adds a 'rotation-rate' parameter for 'ide-hd' device
types.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <20171004114008.14849-3-berrange@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 3b19f4506901ecce25ff36cf62353a2b4bfe4f2b)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/ide/core.c             | 1 +
 hw/ide/qdev.c             | 1 +
 include/hw/ide/internal.h | 8 ++++++++
 3 files changed, 10 insertions(+)

diff --git a/hw/ide/core.c b/hw/ide/core.c
index bea3953..11986e3 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -191,6 +191,7 @@ static void ide_identify(IDEState *s)
     if (dev && dev->conf.discard_granularity) {
         put_le16(p + 169, 1); /* TRIM support */
     }
+    put_le16(p + 217, dev->rotation_rate); /* Nominal media rotation rate */
 
     ide_identify_size(s);
     s->identify_set = 1;
diff --git a/hw/ide/qdev.c b/hw/ide/qdev.c
index cc2f5bd..a412d6f 100644
--- a/hw/ide/qdev.c
+++ b/hw/ide/qdev.c
@@ -304,6 +304,7 @@ static Property ide_hd_properties[] = {
     DEFINE_BLOCK_CHS_PROPERTIES(IDEDrive, dev.conf),
     DEFINE_PROP_BIOS_CHS_TRANS("bios-chs-trans",
                 IDEDrive, dev.chs_trans, BIOS_ATA_TRANSLATION_AUTO),
+    DEFINE_PROP_UINT16("rotation_rate", IDEDrive, dev.rotation_rate, 0),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/ide/internal.h b/include/hw/ide/internal.h
index 482a951..f1aca72 100644
--- a/include/hw/ide/internal.h
+++ b/include/hw/ide/internal.h
@@ -507,6 +507,14 @@ struct IDEDevice {
     char *serial;
     char *model;
     uint64_t wwn;
+    /*
+     * 0x0000        - rotation rate not reported
+     * 0x0001        - non-rotating medium (SSD)
+     * 0x0002-0x0400 - reserved
+     * 0x0401-0xffe  - rotations per minute
+     * 0xffff        - reserved
+     */
+    uint16_t rotation_rate;
 };
 
 /* These are used for the error_status field of IDEBus */
-- 
1.8.3.1