From: Roman Kagan <rvkagan@yandex-team.ru>
To: qemu-devel@nongnu.org
Cc: "Fam Zheng" <fam@euphon.net>, "Kevin Wolf" <kwolf@redhat.com>,
"Stefano Stabellini" <sstabellini@kernel.org>,
"Daniel P. Berrangé" <berrange@redhat.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
qemu-block@nongnu.org, "Paul Durrant" <paul@xen.org>,
"John Snow" <jsnow@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Laurent Vivier" <laurent@vivier.eu>,
"Max Reitz" <mreitz@redhat.com>,
"Keith Busch" <kbusch@kernel.org>,
"Gerd Hoffmann" <kraxel@redhat.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Anthony Perard" <anthony.perard@citrix.com>,
xen-devel@lists.xenproject.org,
"Philippe Mathieu-Daudé" <philmd@redhat.com>
Subject: [PATCH v8 8/8] block: lift blocksize property limit to 2 MiB
Date: Fri, 29 May 2020 01:55:16 +0300 [thread overview]
Message-ID: <20200528225516.1676602-9-rvkagan@yandex-team.ru> (raw)
In-Reply-To: <20200528225516.1676602-1-rvkagan@yandex-team.ru>
Logical and physical block sizes in QEMU are limited to 32 KiB.
This appears unnecessarily tight, and we've seen bigger block sizes
handy at times.
Lift the limitation up to 2 MiB which appears to be good enough for
everybody, and matches the qcow2 cluster size limit.
Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
hw/core/qdev-properties.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 63d48db70c..ead35d7ffd 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -784,9 +784,12 @@ const PropertyInfo qdev_prop_size32 = {
/* lower limit is sector size */
#define MIN_BLOCK_SIZE 512
#define MIN_BLOCK_SIZE_STR "512 B"
-/* upper limit is the max power of 2 that fits in uint16_t */
-#define MAX_BLOCK_SIZE (32 * KiB)
-#define MAX_BLOCK_SIZE_STR "32 KiB"
+/*
+ * upper limit is arbitrary, 2 MiB looks sufficient for all sensible uses, and
+ * matches qcow2 cluster size limit
+ */
+#define MAX_BLOCK_SIZE (2 * MiB)
+#define MAX_BLOCK_SIZE_STR "2 MiB"
static void set_blocksize(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
--
2.26.2
WARNING: multiple messages have this Message-ID (diff)
From: Roman Kagan <rvkagan@yandex-team.ru>
To: qemu-devel@nongnu.org
Cc: "Fam Zheng" <fam@euphon.net>, "Kevin Wolf" <kwolf@redhat.com>,
"Stefano Stabellini" <sstabellini@kernel.org>,
"Daniel P. Berrangé" <berrange@redhat.com>,
"Eduardo Habkost" <ehabkost@redhat.com>,
qemu-block@nongnu.org, "Paul Durrant" <paul@xen.org>,
"John Snow" <jsnow@redhat.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
"Laurent Vivier" <laurent@vivier.eu>,
"Eric Blake" <eblake@redhat.com>, "Max Reitz" <mreitz@redhat.com>,
"Keith Busch" <kbusch@kernel.org>,
"Gerd Hoffmann" <kraxel@redhat.com>,
"Stefan Hajnoczi" <stefanha@redhat.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Anthony Perard" <anthony.perard@citrix.com>,
xen-devel@lists.xenproject.org,
"Philippe Mathieu-Daudé" <philmd@redhat.com>
Subject: [PATCH v8 8/8] block: lift blocksize property limit to 2 MiB
Date: Fri, 29 May 2020 01:55:16 +0300 [thread overview]
Message-ID: <20200528225516.1676602-9-rvkagan@yandex-team.ru> (raw)
In-Reply-To: <20200528225516.1676602-1-rvkagan@yandex-team.ru>
Logical and physical block sizes in QEMU are limited to 32 KiB.
This appears unnecessarily tight, and we've seen bigger block sizes
handy at times.
Lift the limitation up to 2 MiB which appears to be good enough for
everybody, and matches the qcow2 cluster size limit.
Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
hw/core/qdev-properties.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 63d48db70c..ead35d7ffd 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -784,9 +784,12 @@ const PropertyInfo qdev_prop_size32 = {
/* lower limit is sector size */
#define MIN_BLOCK_SIZE 512
#define MIN_BLOCK_SIZE_STR "512 B"
-/* upper limit is the max power of 2 that fits in uint16_t */
-#define MAX_BLOCK_SIZE (32 * KiB)
-#define MAX_BLOCK_SIZE_STR "32 KiB"
+/*
+ * upper limit is arbitrary, 2 MiB looks sufficient for all sensible uses, and
+ * matches qcow2 cluster size limit
+ */
+#define MAX_BLOCK_SIZE (2 * MiB)
+#define MAX_BLOCK_SIZE_STR "2 MiB"
static void set_blocksize(Object *obj, Visitor *v, const char *name,
void *opaque, Error **errp)
--
2.26.2
next prev parent reply other threads:[~2020-05-28 23:02 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-28 22:55 [PATCH v8 0/8] block: enhance handling of size-related BlockConf properties Roman Kagan
2020-05-28 22:55 ` Roman Kagan
2020-05-28 22:55 ` [PATCH v8 1/8] virtio-blk: store opt_io_size with correct size Roman Kagan
2020-05-28 22:55 ` Roman Kagan
2020-05-28 22:55 ` [PATCH v8 2/8] block: consolidate blocksize properties consistency checks Roman Kagan
2020-05-28 22:55 ` Roman Kagan
2020-05-29 9:53 ` Markus Armbruster
2020-05-29 10:56 ` Roman Kagan
2020-06-02 11:42 ` Kevin Wolf
2020-05-28 22:55 ` [PATCH v8 3/8] qdev-properties: blocksize: use same limits in code and description Roman Kagan
2020-05-28 22:55 ` Roman Kagan
2020-05-28 22:55 ` [PATCH v8 4/8] qdev-properties: add size32 property type Roman Kagan
2020-05-28 22:55 ` Roman Kagan
2020-05-28 22:55 ` [PATCH v8 5/8] qdev-properties: make blocksize accept size suffixes Roman Kagan
2020-05-28 22:55 ` Roman Kagan
2020-06-02 12:06 ` Philippe Mathieu-Daudé
2020-06-02 12:06 ` Philippe Mathieu-Daudé
2020-05-28 22:55 ` [PATCH v8 6/8] block: make BlockConf size props 32bit and " Roman Kagan
2020-05-28 22:55 ` Roman Kagan
2020-05-28 22:55 ` [PATCH v8 7/8] qdev-properties: add getter for size32 and blocksize Roman Kagan
2020-05-28 22:55 ` Roman Kagan
2020-05-28 22:55 ` Roman Kagan [this message]
2020-05-28 22:55 ` [PATCH v8 8/8] block: lift blocksize property limit to 2 MiB Roman Kagan
2020-06-15 18:05 ` [PATCH v8 0/8] block: enhance handling of size-related BlockConf properties Roman Kagan
2020-06-16 16:09 ` Kevin Wolf
2020-06-16 16:09 ` Kevin Wolf
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