Allow Xen to use backing store devices with 4K-byte sectors.

Problem reported and much testing by Christian Kujau. Thanks!

Roughly equivalent to bouyer@NetBSD changes prompted by
Christian.

ok mlarkin@ dlg@

diff --git a/sys/dev/pv/xbf.c b/sys/dev/pv/xbf.c
index 63b9002..08c285d 100644 (file)
--- a/sys/dev/pv/xbf.c
+++ b/sys/dev/pv/xbf.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: xbf.c,v 1.52 2022/04/16 19:19:59 naddy Exp $  */
+/*     $OpenBSD: xbf.c,v 1.53 2023/11/08 12:01:21 krw Exp $    */
 
 /*
  * Copyright (c) 2016, 2017 Mike Belopuhov
@@ -57,6 +57,7 @@
 #define XBF_MAX_ISGE           8
 
 #define XBF_SEC_SHIFT          9
+#define XBF_SEC_SIZE           (1 << XBF_SEC_SHIFT)
 
 #define XBF_CDROM              1
 #define XBF_REMOVABLE          2
@@ -662,6 +663,10 @@ xbf_submit_cmd(struct scsi_xfer *xs)
                nblk = _4btol(rw16->length);
        }
 
+       /* SCSI lba/nblk are sc_block_size. ccb's need XBF_SEC_SIZE. */
+       lba *= sc->sc_block_size / XBF_SEC_SIZE;
+       nblk *= sc->sc_block_size / XBF_SEC_SIZE;
+
        ccb->ccb_want = ccb->ccb_seen = 0;
 
        do {
@@ -856,7 +861,8 @@ xbf_scsi_capacity(struct scsi_xfer *xs)
 
        bzero(&rcd, sizeof(rcd));
 
-       capacity = sc->sc_disk_size - 1;
+       /* [addr|length] are sc_block_size. sc->sc_disk_size is XBF_SEC_SIZE. */
+       capacity = (sc->sc_disk_size * XBF_SEC_SIZE) / sc->sc_block_size - 1;
        if (capacity > 0xffffffff)
                capacity = 0xffffffff;
 
@@ -873,10 +879,13 @@ xbf_scsi_capacity16(struct scsi_xfer *xs)
 {
        struct xbf_softc *sc = xs->sc_link->bus->sb_adapter_softc;
        struct scsi_read_cap_data_16 rcd;
+       uint64_t capacity;
 
        bzero(&rcd, sizeof(rcd));
 
-       _lto8b(sc->sc_disk_size - 1, rcd.addr);
+       /* [addr|length] are sc_block_size. sc->sc_disk_size is XBF_SEC_SIZE. */
+       capacity = (sc->sc_disk_size * XBF_SEC_SIZE) / sc->sc_block_size - 1;
+       _lto8b(capacity, rcd.addr);
        _lto4b(sc->sc_block_size, rcd.length);
 
        bcopy(&rcd, xs->data, MIN(sizeof(rcd), xs->datalen));