From 215e47b9ea2cd7926333b7dc683024aa00e0c386 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 8 Feb 2013 14:06:14 +0100 Subject: blockdev: enable discard by default Because discard is now a host parameter, we can always fake it as enabled in the guest. This is an extension of the current choice to ignore "not supported" errors from the host when discard_granularity is set to nonzero. The default granularity is set to the logical block size or 4k, whichever is largest, because cluster sizes below 4k are rarely used and 4K is a typical block size for files. Signed-off-by: Paolo Bonzini Signed-off-by: Kevin Wolf --- hw/scsi-disk.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'hw/scsi-disk.c') diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c index 28e75bbf5b..d41158693e 100644 --- a/hw/scsi-disk.c +++ b/hw/scsi-disk.c @@ -41,9 +41,11 @@ do { printf("scsi-disk: " fmt , ## __VA_ARGS__); } while (0) #include #endif -#define SCSI_DMA_BUF_SIZE 131072 -#define SCSI_MAX_INQUIRY_LEN 256 -#define SCSI_MAX_MODE_LEN 256 +#define SCSI_DMA_BUF_SIZE 131072 +#define SCSI_MAX_INQUIRY_LEN 256 +#define SCSI_MAX_MODE_LEN 256 + +#define DEFAULT_DISCARD_GRANULARITY 4096 typedef struct SCSIDiskState SCSIDiskState; @@ -2059,6 +2061,11 @@ static int scsi_initfn(SCSIDevice *dev) return -1; } + if (s->qdev.conf.discard_granularity == -1) { + s->qdev.conf.discard_granularity = + MAX(s->qdev.conf.logical_block_size, DEFAULT_DISCARD_GRANULARITY); + } + if (!s->version) { s->version = g_strdup(qemu_get_version()); } -- cgit v1.2.3