Date: Tue, 15 Jul 2014 00:25:55 +0000 (UTC) From: Peter Grehan <grehan@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r268638 - head/usr.sbin/bhyve Message-ID: <201407150025.s6F0PtQm091786@svn.freebsd.org>
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Author: grehan Date: Tue Jul 15 00:25:54 2014 New Revision: 268638 URL: http://svnweb.freebsd.org/changeset/base/268638 Log: Add a call to synthesize a C/H/S value for block emulations that require it (ahci). The algorithm used is from the VHD specification. Modified: head/usr.sbin/bhyve/block_if.c head/usr.sbin/bhyve/block_if.h Modified: head/usr.sbin/bhyve/block_if.c ============================================================================== --- head/usr.sbin/bhyve/block_if.c Mon Jul 14 23:25:29 2014 (r268637) +++ head/usr.sbin/bhyve/block_if.c Tue Jul 15 00:25:54 2014 (r268638) @@ -390,6 +390,55 @@ blockif_close(struct blockif_ctxt *bc) } /* + * Return virtual C/H/S values for a given block. Use the algorithm + * outlined in the VHD specification to calculate values. + */ +void +blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, uint8_t *s) +{ + off_t sectors; /* total sectors of the block dev */ + off_t hcyl; /* cylinders times heads */ + uint16_t secpt; /* sectors per track */ + uint8_t heads; + + assert(bc->bc_magic == BLOCKIF_SIG); + + sectors = bc->bc_size / bc->bc_sectsz; + + /* Clamp the size to the largest possible with CHS */ + if (sectors > 65535UL*16*255) + sectors = 65535UL*16*255; + + if (sectors >= 65536UL*16*63) { + secpt = 255; + heads = 16; + hcyl = sectors / secpt; + } else { + secpt = 17; + hcyl = sectors / secpt; + heads = (hcyl + 1023) / 1024; + + if (heads < 4) + heads = 4; + + if (hcyl >= (heads * 1024) || heads > 16) { + secpt = 31; + heads = 16; + hcyl = sectors / secpt; + } + if (hcyl >= (heads * 1024)) { + secpt = 63; + heads = 16; + hcyl = sectors / secpt; + } + } + + *c = hcyl / heads; + *h = heads; + *s = secpt; +} + +/* * Accessors */ off_t Modified: head/usr.sbin/bhyve/block_if.h ============================================================================== --- head/usr.sbin/bhyve/block_if.h Mon Jul 14 23:25:29 2014 (r268637) +++ head/usr.sbin/bhyve/block_if.h Tue Jul 15 00:25:54 2014 (r268638) @@ -52,6 +52,8 @@ struct blockif_req { struct blockif_ctxt; struct blockif_ctxt *blockif_open(const char *optstr, const char *ident); off_t blockif_size(struct blockif_ctxt *bc); +void blockif_chs(struct blockif_ctxt *bc, uint16_t *c, uint8_t *h, + uint8_t *s); int blockif_sectsz(struct blockif_ctxt *bc); int blockif_queuesz(struct blockif_ctxt *bc); int blockif_is_ro(struct blockif_ctxt *bc);
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