From 29c4e2b50d95f4a15c3dd62b39f3402f05a34907 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 18 Jul 2013 16:31:25 +0200 Subject: [PATCH] blockdev: Split up 'cache' option The old 'cache' option really encodes three different boolean flags into a cache mode name, without providing all combinations. Make them three separate options instead and translate the old option to the new ones for drive_init(). The specific boolean options take precedence if the old cache option is specified as well, so the following options are equivalent: -drive file=x,cache=none,cache.no-flush=true -drive file=x,cache.writeback=true,cache.direct=true,cache.no-flush=true Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake --- blockdev.c | 57 ++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 47 insertions(+), 10 deletions(-) diff --git a/blockdev.c b/blockdev.c index 3b05e29082..ef55b1a15c 100644 --- a/blockdev.c +++ b/blockdev.c @@ -452,12 +452,15 @@ static DriveInfo *blockdev_init(QemuOpts *all_opts, } } - bdrv_flags |= BDRV_O_CACHE_WB; - if ((buf = qemu_opt_get(opts, "cache")) != NULL) { - if (bdrv_parse_cache_flags(buf, &bdrv_flags) != 0) { - error_report("invalid cache option"); - return NULL; - } + bdrv_flags = 0; + if (qemu_opt_get_bool(opts, "cache.writeback", true)) { + bdrv_flags |= BDRV_O_CACHE_WB; + } + if (qemu_opt_get_bool(opts, "cache.direct", false)) { + bdrv_flags |= BDRV_O_NOCACHE; + } + if (qemu_opt_get_bool(opts, "cache.no-flush", true)) { + bdrv_flags |= BDRV_O_NO_FLUSH; } #ifdef CONFIG_LINUX_AIO @@ -740,6 +743,8 @@ static void qemu_opt_rename(QemuOpts *opts, const char *from, const char *to) DriveInfo *drive_init(QemuOpts *all_opts, BlockInterfaceType block_default_type) { + const char *value; + /* Change legacy command line options into QMP ones */ qemu_opt_rename(all_opts, "iops", "throttling.iops-total"); qemu_opt_rename(all_opts, "iops_rd", "throttling.iops-read"); @@ -751,6 +756,31 @@ DriveInfo *drive_init(QemuOpts *all_opts, BlockInterfaceType block_default_type) qemu_opt_rename(all_opts, "readonly", "read-only"); + value = qemu_opt_get(all_opts, "cache"); + if (value) { + int flags = 0; + + if (bdrv_parse_cache_flags(value, &flags) != 0) { + error_report("invalid cache option"); + return NULL; + } + + /* Specific options take precedence */ + if (!qemu_opt_get(all_opts, "cache.writeback")) { + qemu_opt_set_bool(all_opts, "cache.writeback", + !!(flags & BDRV_O_CACHE_WB)); + } + if (!qemu_opt_get(all_opts, "cache.direct")) { + qemu_opt_set_bool(all_opts, "cache.direct", + !!(flags & BDRV_O_NOCACHE)); + } + if (!qemu_opt_get(all_opts, "cache.no-flush")) { + qemu_opt_set_bool(all_opts, "cache.no-flush", + !!(flags & BDRV_O_NO_FLUSH)); + } + qemu_opt_unset(all_opts, "cache"); + } + return blockdev_init(all_opts, block_default_type); } @@ -1850,10 +1880,17 @@ QemuOptsList qemu_common_drive_opts = { .type = QEMU_OPT_STRING, .help = "discard operation (ignore/off, unmap/on)", },{ - .name = "cache", - .type = QEMU_OPT_STRING, - .help = "host cache usage (none, writeback, writethrough, " - "directsync, unsafe)", + .name = "cache.writeback", + .type = QEMU_OPT_BOOL, + .help = "enables writeback mode for any caches", + },{ + .name = "cache.direct", + .type = QEMU_OPT_BOOL, + .help = "enables use of O_DIRECT (bypass the host page cache)", + },{ + .name = "cache.no-flush", + .type = QEMU_OPT_BOOL, + .help = "ignore any flush requests for the device", },{ .name = "aio", .type = QEMU_OPT_STRING,