From c80a420995e721099906607b07c09a24543b31d9 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Thu, 2 Dec 2010 17:55:00 +0000 Subject: [PATCH] xen-blkfront: handle Xen major numbers other than XENVBD This patch makes sure blkfront handles correctly virtual device numbers corresponding to Xen emulated IDE and SCSI disks: in those cases blkfront translates the major number to XENVBD and the minor number to a low xvd minor. Note: this behaviour is different from what old xenlinux PV guests used to do: they used to steal an IDE or SCSI major number and use it instead. Signed-off-by: Stefano Stabellini Acked-by: Jeremy Fitzhardinge --- drivers/block/xen-blkfront.c | 79 +++++++++++++++++++++++++++++++++++++--- include/xen/interface/io/blkif.h | 21 +++++++++++ 2 files changed, 95 insertions(+), 5 deletions(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index d7aa39e..64d9c6d 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -120,6 +120,10 @@ static DEFINE_SPINLOCK(minor_lock); #define EXTENDED (1<feature_flush ? "enabled" : "disabled"); } +static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) +{ + int major; + major = BLKIF_MAJOR(vdevice); + *minor = BLKIF_MINOR(vdevice); + switch (major) { + case XEN_IDE0_MAJOR: + *offset = (*minor / 64) + EMULATED_HD_DISK_NAME_OFFSET; + *minor = ((*minor / 64) * PARTS_PER_DISK) + + EMULATED_HD_DISK_MINOR_OFFSET; + break; + case XEN_IDE1_MAJOR: + *offset = (*minor / 64) + 2 + EMULATED_HD_DISK_NAME_OFFSET; + *minor = (((*minor / 64) + 2) * PARTS_PER_DISK) + + EMULATED_HD_DISK_MINOR_OFFSET; + break; + case XEN_SCSI_DISK0_MAJOR: + *offset = (*minor / PARTS_PER_DISK) + EMULATED_SD_DISK_NAME_OFFSET; + *minor = *minor + EMULATED_SD_DISK_MINOR_OFFSET; + break; + case XEN_SCSI_DISK1_MAJOR: + case XEN_SCSI_DISK2_MAJOR: + case XEN_SCSI_DISK3_MAJOR: + case XEN_SCSI_DISK4_MAJOR: + case XEN_SCSI_DISK5_MAJOR: + case XEN_SCSI_DISK6_MAJOR: + case XEN_SCSI_DISK7_MAJOR: + *offset = (*minor / PARTS_PER_DISK) + + ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16) + + EMULATED_SD_DISK_NAME_OFFSET; + *minor = *minor + + ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16 * PARTS_PER_DISK) + + EMULATED_SD_DISK_MINOR_OFFSET; + break; + case XEN_SCSI_DISK8_MAJOR: + case XEN_SCSI_DISK9_MAJOR: + case XEN_SCSI_DISK10_MAJOR: + case XEN_SCSI_DISK11_MAJOR: + case XEN_SCSI_DISK12_MAJOR: + case XEN_SCSI_DISK13_MAJOR: + case XEN_SCSI_DISK14_MAJOR: + case XEN_SCSI_DISK15_MAJOR: + *offset = (*minor / PARTS_PER_DISK) + + ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16) + + EMULATED_SD_DISK_NAME_OFFSET; + *minor = *minor + + ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16 * PARTS_PER_DISK) + + EMULATED_SD_DISK_MINOR_OFFSET; + break; + case XENVBD_MAJOR: + *offset = *minor / PARTS_PER_DISK; + break; + default: + printk(KERN_WARNING "blkfront: your disk configuration is " + "incorrect, please use an xvd device instead\n"); + return -ENODEV; + } + return 0; +} static int xlvbd_alloc_gendisk(blkif_sector_t capacity, struct blkfront_info *info, @@ -441,7 +504,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, { struct gendisk *gd; int nr_minors = 1; - int err = -ENODEV; + int err; unsigned int offset; int minor; int nr_parts; @@ -456,12 +519,20 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, } if (!VDEV_IS_EXTENDED(info->vdevice)) { - minor = BLKIF_MINOR(info->vdevice); - nr_parts = PARTS_PER_DISK; + err = xen_translate_vdev(info->vdevice, &minor, &offset); + if (err) + return err; + nr_parts = PARTS_PER_DISK; } else { minor = BLKIF_MINOR_EXT(info->vdevice); nr_parts = PARTS_PER_EXT_DISK; + offset = minor / nr_parts; + if (xen_hvm_domain() && offset <= EMULATED_HD_DISK_NAME_OFFSET + 4) + printk(KERN_WARNING "blkfront: vdevice 0x%x might conflict with " + "emulated IDE disks,\n\t choose an xvd device name" + "from xvde on\n", info->vdevice); } + err = -ENODEV; if ((minor % nr_parts) == 0) nr_minors = nr_parts; @@ -475,8 +546,6 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, if (gd == NULL) goto release; - offset = minor / nr_parts; - if (nr_minors > 1) { if (offset < 26) sprintf(gd->disk_name, "%s%c", DEV_NAME, 'a' + offset); diff --git a/include/xen/interface/io/blkif.h b/include/xen/interface/io/blkif.h index c2d1fa4..68dd2b4 100644 --- a/include/xen/interface/io/blkif.h +++ b/include/xen/interface/io/blkif.h @@ -91,4 +91,25 @@ DEFINE_RING_TYPES(blkif, struct blkif_request, struct blkif_response); #define VDISK_REMOVABLE 0x2 #define VDISK_READONLY 0x4 +/* Xen-defined major numbers for virtual disks, they look strangely + * familiar */ +#define XEN_IDE0_MAJOR 3 +#define XEN_IDE1_MAJOR 22 +#define XEN_SCSI_DISK0_MAJOR 8 +#define XEN_SCSI_DISK1_MAJOR 65 +#define XEN_SCSI_DISK2_MAJOR 66 +#define XEN_SCSI_DISK3_MAJOR 67 +#define XEN_SCSI_DISK4_MAJOR 68 +#define XEN_SCSI_DISK5_MAJOR 69 +#define XEN_SCSI_DISK6_MAJOR 70 +#define XEN_SCSI_DISK7_MAJOR 71 +#define XEN_SCSI_DISK8_MAJOR 128 +#define XEN_SCSI_DISK9_MAJOR 129 +#define XEN_SCSI_DISK10_MAJOR 130 +#define XEN_SCSI_DISK11_MAJOR 131 +#define XEN_SCSI_DISK12_MAJOR 132 +#define XEN_SCSI_DISK13_MAJOR 133 +#define XEN_SCSI_DISK14_MAJOR 134 +#define XEN_SCSI_DISK15_MAJOR 135 + #endif /* __XEN_PUBLIC_IO_BLKIF_H__ */ -- 2.7.4