From 3b19f4506901ecce25ff36cf62353a2b4bfe4f2b Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Wed, 4 Oct 2017 12:40:08 +0100 Subject: ide: support reporting of rotation rate 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 Message-Id: <20171004114008.14849-3-berrange@redhat.com> Reviewed-by: John Snow Signed-off-by: Paolo Bonzini --- hw/ide/core.c | 1 + hw/ide/qdev.c | 1 + 2 files changed, 2 insertions(+) (limited to 'hw/ide') diff --git a/hw/ide/core.c b/hw/ide/core.c index 5f1cd3b91f..a04766aee7 100644 --- a/hw/ide/core.c +++ b/hw/ide/core.c @@ -208,6 +208,7 @@ 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 d60ac25be0..a5181b4448 100644 --- a/hw/ide/qdev.c +++ b/hw/ide/qdev.c @@ -299,6 +299,7 @@ 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(), }; -- cgit v1.2.1