From 3c1b27d5043086a485f8526353ae9fe37bfa1065 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Wed, 23 Sep 2009 22:26:31 -0600 Subject: virtio: make add_buf return capacity remaining This API change means that virtio_net can tell how much capacity remains for buffers. It's necessarily fuzzy, since VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors in one, *if* we can kmalloc. Signed-off-by: Rusty Russell Cc: Dinesh Subhraveti --- include/linux/virtio.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 4fca4f5440b..057a2e01075 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -34,7 +34,7 @@ struct virtqueue { * out_num: the number of sg readable by other side * in_num: the number of sg which are writable (after readable ones) * data: the token identifying the buffer. - * Returns 0 or an error. + * Returns remaining capacity of queue (sg segments) or a negative error. * @kick: update after add_buf * vq: the struct virtqueue * After one or more add_buf calls, invoke this to kick the other side. -- cgit v1.2.3 From 3ca4f5ca73057a617f9444a91022d7127041970a Mon Sep 17 00:00:00 2001 From: Fernando Luis Vazquez Cao Date: Fri, 31 Jul 2009 15:25:56 +0900 Subject: virtio: add virtio IDs file Virtio IDs are spread all over the tree which makes assigning new IDs bothersome. Putting them together should make the process less error-prone. Signed-off-by: Fernando Luis Vazquez Cao Signed-off-by: Rusty Russell --- include/linux/virtio_9p.h | 2 -- include/linux/virtio_balloon.h | 3 --- include/linux/virtio_blk.h | 3 --- include/linux/virtio_console.h | 3 --- include/linux/virtio_ids.h | 17 +++++++++++++++++ include/linux/virtio_net.h | 3 --- include/linux/virtio_rng.h | 3 --- 7 files changed, 17 insertions(+), 17 deletions(-) create mode 100644 include/linux/virtio_ids.h (limited to 'include') diff --git a/include/linux/virtio_9p.h b/include/linux/virtio_9p.h index b3c4a60ceeb..ea7226a45ac 100644 --- a/include/linux/virtio_9p.h +++ b/include/linux/virtio_9p.h @@ -4,8 +4,6 @@ * compatible drivers/servers. */ #include -/* The ID for virtio console */ -#define VIRTIO_ID_9P 9 /* Maximum number of virtio channels per partition (1 for now) */ #define MAX_9P_CHAN 1 diff --git a/include/linux/virtio_balloon.h b/include/linux/virtio_balloon.h index 8726ff77763..09d73008506 100644 --- a/include/linux/virtio_balloon.h +++ b/include/linux/virtio_balloon.h @@ -4,9 +4,6 @@ * compatible drivers/servers. */ #include -/* The ID for virtio_balloon */ -#define VIRTIO_ID_BALLOON 5 - /* The feature bitmap for virtio balloon */ #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */ diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index 8dab9f2b883..25fbabfa90d 100644 --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -5,9 +5,6 @@ #include #include -/* The ID for virtio_block */ -#define VIRTIO_ID_BLOCK 2 - /* Feature bits */ #define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */ #define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */ diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h index dc161115ae3..b5f51980601 100644 --- a/include/linux/virtio_console.h +++ b/include/linux/virtio_console.h @@ -5,9 +5,6 @@ /* This header, excluding the #ifdef __KERNEL__ part, is BSD licensed so * anyone can use the definitions to implement compatible drivers/servers. */ -/* The ID for virtio console */ -#define VIRTIO_ID_CONSOLE 3 - /* Feature bits */ #define VIRTIO_CONSOLE_F_SIZE 0 /* Does host provide console size? */ diff --git a/include/linux/virtio_ids.h b/include/linux/virtio_ids.h new file mode 100644 index 00000000000..06660c0a78d --- /dev/null +++ b/include/linux/virtio_ids.h @@ -0,0 +1,17 @@ +#ifndef _LINUX_VIRTIO_IDS_H +#define _LINUX_VIRTIO_IDS_H +/* + * Virtio IDs + * + * This header is BSD licensed so anyone can use the definitions to implement + * compatible drivers/servers. + */ + +#define VIRTIO_ID_NET 1 /* virtio net */ +#define VIRTIO_ID_BLOCK 2 /* virtio block */ +#define VIRTIO_ID_CONSOLE 3 /* virtio console */ +#define VIRTIO_ID_RNG 4 /* virtio ring */ +#define VIRTIO_ID_BALLOON 5 /* virtio balloon */ +#define VIRTIO_ID_9P 9 /* 9p virtio console */ + +#endif /* _LINUX_VIRTIO_IDS_H */ diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index d8dd539c9f4..1f41734bbb7 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -6,9 +6,6 @@ #include #include -/* The ID for virtio_net */ -#define VIRTIO_ID_NET 1 - /* The feature bitmap for virtio net */ #define VIRTIO_NET_F_CSUM 0 /* Host handles pkts w/ partial csum */ #define VIRTIO_NET_F_GUEST_CSUM 1 /* Guest handles pkts w/ partial csum */ diff --git a/include/linux/virtio_rng.h b/include/linux/virtio_rng.h index 1a85dab8a94..48121c3c434 100644 --- a/include/linux/virtio_rng.h +++ b/include/linux/virtio_rng.h @@ -4,7 +4,4 @@ * compatible drivers/servers. */ #include -/* The ID for virtio_rng */ -#define VIRTIO_ID_RNG 4 - #endif /* _LINUX_VIRTIO_RNG_H */ -- cgit v1.2.3 From f1b0ef062602713c2c7cfa12362d5d90ed01c5f6 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 17 Sep 2009 19:57:42 +0200 Subject: virtio_blk: add support for cache flush Recent qemu has added a VIRTIO_BLK_F_FLUSH flag to advertise that the virtual disk has a volatile write cache that needs to be flushed. In case we see this feature implement tell the Linux block layer about the fact and use the new VIRTIO_BLK_T_FLUSH to flush the cache when required. This allows for an correct and simple implementation of write barriers. Signed-off-by: Christoph Hellwig Signed-off-by: Rusty Russell --- include/linux/virtio_blk.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include') diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index 25fbabfa90d..15cb666581d 100644 --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -14,6 +14,7 @@ #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ #define VIRTIO_BLK_F_IDENTIFY 8 /* ATA IDENTIFY supported */ +#define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */ #define VIRTIO_BLK_ID_BYTES (sizeof(__u16[256])) /* IDENTIFY DATA */ @@ -35,6 +36,17 @@ struct virtio_blk_config { __u8 identify[VIRTIO_BLK_ID_BYTES]; } __attribute__((packed)); +/* + * Command types + * + * Usage is a bit tricky as some bits are used as flags and some are not. + * + * Rules: + * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or + * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own + * and may not be combined with any of the other flags. + */ + /* These two define direction. */ #define VIRTIO_BLK_T_IN 0 #define VIRTIO_BLK_T_OUT 1 @@ -42,6 +54,9 @@ struct virtio_blk_config { /* This bit says it's a scsi command, not an actual read or write. */ #define VIRTIO_BLK_T_SCSI_CMD 2 +/* Cache flush command */ +#define VIRTIO_BLK_T_FLUSH 4 + /* Barrier before this op. */ #define VIRTIO_BLK_T_BARRIER 0x80000000 -- cgit v1.2.3