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[Qemu-block] [RFC PULL 3/6] virtio-blk: add "discard" and "write-zeroes"
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-block] [RFC PULL 3/6] virtio-blk: add "discard" and "write-zeroes" properties |
Date: |
Tue, 12 Feb 2019 22:03:27 +0800 |
From: Stefano Garzarella <address@hidden>
In order to avoid migration issues, we enable DISCARD and
WRITE_ZEROES features only for machine type >= 4.0
As discussed with Michael S. Tsirkin and Stefan Hajnoczi on the
list [1], DISCARD operation should not have security implications
(eg. page cache attacks), so we can enable it by default.
[1] https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg00504.html
Suggested-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Stefano Garzarella <address@hidden>
Acked-by: Pankaj Gupta <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
hw/block/virtio-blk.c | 4 ++++
hw/core/machine.c | 2 ++
2 files changed, 6 insertions(+)
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 938273c63c..6f2e86264d 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -1026,6 +1026,10 @@ static Property virtio_blk_properties[] = {
DEFINE_PROP_UINT16("queue-size", VirtIOBlock, conf.queue_size, 128),
DEFINE_PROP_LINK("iothread", VirtIOBlock, conf.iothread, TYPE_IOTHREAD,
IOThread *),
+ DEFINE_PROP_BIT64("discard", VirtIOBlock, host_features,
+ VIRTIO_BLK_F_DISCARD, true),
+ DEFINE_PROP_BIT64("write-zeroes", VirtIOBlock, host_features,
+ VIRTIO_BLK_F_WRITE_ZEROES, true),
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/hw/core/machine.c b/hw/core/machine.c
index 077fbd182a..766ca5899d 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -33,6 +33,8 @@ GlobalProperty hw_compat_3_1[] = {
{ "usb-kbd", "serial", "42" },
{ "usb-mouse", "serial", "42" },
{ "usb-kbd", "serial", "42" },
+ { "virtio-blk-device", "discard", "false" },
+ { "virtio-blk-device", "write-zeroes", "false" },
};
const size_t hw_compat_3_1_len = G_N_ELEMENTS(hw_compat_3_1);
--
2.20.1
- [Qemu-block] [RFC PULL 0/6] Block pull request for testing, Stefan Hajnoczi, 2019/02/12
- [Qemu-block] [RFC PULL 1/6] virtio-blk: add acct_failed param to virtio_blk_handle_rw_error(), Stefan Hajnoczi, 2019/02/12
- [Qemu-block] [RFC PULL 2/6] virtio-blk: add host_features field in VirtIOBlock, Stefan Hajnoczi, 2019/02/12
- [Qemu-block] [RFC PULL 5/6] tests/virtio-blk: change assert on data_size in virtio_blk_request(), Stefan Hajnoczi, 2019/02/12
- [Qemu-block] [RFC PULL 3/6] virtio-blk: add "discard" and "write-zeroes" properties,
Stefan Hajnoczi <=
- [Qemu-block] [RFC PULL 4/6] virtio-blk: add DISCARD and WRITE_ZEROES features, Stefan Hajnoczi, 2019/02/12
- [Qemu-block] [RFC PULL 6/6] tests/virtio-blk: add test for WRITE_ZEROES command, Stefan Hajnoczi, 2019/02/12