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MFC r256389

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Implement the virtio block 'get-ident' operation. This eliminates the
  annoying verbose boot error of the form

     g_handleattr: vtbd0 bio_length 24 len 28 -> EFAULT

  The ident returned by bhyve is a text string 'BHYVE-XXXX-XXXX', where
  the X's are the first bytes of the md5 hash of the backing filename.

Approved by:	re (gjb)
This commit is contained in:
grehan 2013-10-12 19:41:35 +00:00
parent 2a63615074
commit c1abbfde2d
1 changed files with 47 additions and 5 deletions
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52
usr.sbin/bhyve/pci_virtio_block.c
View File

@ -46,17 +46,25 @@ __FBSDID("$FreeBSD$");
#include <unistd.h>
#include <assert.h>
#include <pthread.h>
#include <md5.h>
#include "bhyverun.h"
#include "pci_emul.h"
#include "virtio.h"
#ifndef min
#define min(a, b) ((a) < (b) ? (a) : (b))
#endif
#define VTBLK_RINGSZ 64
#define VTBLK_MAXSEGS 32
#define VTBLK_S_OK 0
#define VTBLK_S_IOERR 1
#define VTBLK_S_UNSUPP 2
#define VTBLK_BLK_ID_BYTES 20
/*
* Host capabilities
@ -85,6 +93,7 @@ struct vtblk_config {
struct virtio_blk_hdr {
#define VBH_OP_READ 0
#define VBH_OP_WRITE 1
#define VBH_OP_IDENT 8
#define VBH_FLAG_BARRIER 0x80000000 /* OR'ed into vbh_type */
uint32_t vbh_type;
uint32_t vbh_ioprio;
@ -106,6 +115,7 @@ struct pci_vtblk_softc {
struct vqueue_info vbsc_vq;
int vbsc_fd;
struct vtblk_config vbsc_cfg;
char vbsc_ident[VTBLK_BLK_ID_BYTES];
};
static void pci_vtblk_reset(void *);
@ -180,7 +190,7 @@ pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
for (i = 1; i < n; i++) {
/*
* - write op implies read-only descriptor,
* - read op implies write-only descriptor,
* - read/ident op implies write-only descriptor,
* therefore test the inverse of the descriptor bit
* to the op.
*/
@ -189,14 +199,34 @@ pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
}
DPRINTF(("virtio-block: %s op, %d bytes, %d segs, offset %ld\n\r",
writeop ? "write" : "read", iolen, i - 1, offset));
writeop ? "write" : "read/ident", iolen, i - 1, offset));
if (writeop)
switch (type) {
case VBH_OP_WRITE:
err = pwritev(sc->vbsc_fd, iov + 1, i - 1, offset);
else
break;
case VBH_OP_READ:
err = preadv(sc->vbsc_fd, iov + 1, i - 1, offset);
break;
case VBH_OP_IDENT:
/* Assume a single buffer */
strlcpy(iov[1].iov_base, sc->vbsc_ident,
min(iov[1].iov_len, sizeof(sc->vbsc_ident)));
err = 0;
break;
default:
err = -ENOSYS;
break;
}
*status = err < 0 ? VTBLK_S_IOERR : VTBLK_S_OK;
/* convert errno into a virtio block error return */
if (err < 0) {
if (err == -ENOSYS)
*status = VTBLK_S_UNSUPP;
else
*status = VTBLK_S_IOERR;
} else
*status = VTBLK_S_OK;
/*
* Return the descriptor back to the host.
@ -220,6 +250,8 @@ static int
pci_vtblk_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
{
struct stat sbuf;
MD5_CTX mdctx;
u_char digest[16];
struct pci_vtblk_softc *sc;
off_t size;
int fd;
@ -274,6 +306,16 @@ pci_vtblk_init(struct vmctx *ctx, struct pci_devinst *pi, char *opts)
sc->vbsc_vq.vq_qsize = VTBLK_RINGSZ;
/* sc->vbsc_vq.vq_notify = we have no per-queue notify */
/*
* Create an identifier for the backing file. Use parts of the
* md5 sum of the filename
*/
MD5Init(&mdctx);
MD5Update(&mdctx, opts, strlen(opts));
MD5Final(digest, &mdctx);
sprintf(sc->vbsc_ident, "BHYVE-%02X%02X-%02X%02X-%02X%02X",
digest[0], digest[1], digest[2], digest[3], digest[4], digest[5]);
/* setup virtio block config space */
sc->vbsc_cfg.vbc_capacity = size / sectsz;
sc->vbsc_cfg.vbc_seg_max = VTBLK_MAXSEGS;