svn commit: r280133 - head/usr.sbin/bhyve

[Alexander Motin]

Author: mav
Date: Mon Mar 16 09:15:59 2015
New Revision: 280133
URL: https://svnweb.freebsd.org/changeset/base/280133

Log:
  Increase S/G list size of 32 to 33 entries.
  
  32 entries are not enough for the worst case of misaligned 128KB request,
  that made FreeBSD to chunk large quests in odd pieces.
  
  MFC after:	2 weeks

Modified:
  head/usr.sbin/bhyve/block_if.h
  head/usr.sbin/bhyve/pci_virtio_block.c

Modified: head/usr.sbin/bhyve/block_if.h
==============================================================================
--- head/usr.sbin/bhyve/block_if.h	Mon Mar 16 01:15:08 2015	(r280132)
+++ head/usr.sbin/bhyve/block_if.h	Mon Mar 16 09:15:59 2015	(r280133)
@@ -39,7 +39,7 @@
 #include <sys/uio.h>
 #include <sys/unistd.h>
 
-#define BLOCKIF_IOV_MAX		32	/* not practical to be IOV_MAX */
+#define BLOCKIF_IOV_MAX		33	/* not practical to be IOV_MAX */
 
 struct blockif_req {
 	struct iovec	br_iov[BLOCKIF_IOV_MAX];

Modified: head/usr.sbin/bhyve/pci_virtio_block.c
==============================================================================
--- head/usr.sbin/bhyve/pci_virtio_block.c	Mon Mar 16 01:15:08 2015	(r280132)
+++ head/usr.sbin/bhyve/pci_virtio_block.c	Mon Mar 16 09:15:59 2015	(r280133)
@@ -55,8 +55,6 @@ __FBSDID("$FreeBSD$");
 
 #define VTBLK_RINGSZ	64
 
-#define VTBLK_MAXSEGS	32
-
 #define VTBLK_S_OK	0
 #define VTBLK_S_IOERR	1
 #define	VTBLK_S_UNSUPP	2
@@ -201,10 +199,10 @@ pci_vtblk_proc(struct pci_vtblk_softc *s
 	int iolen;
 	int writeop, type;
 	off_t offset;
-	struct iovec iov[VTBLK_MAXSEGS + 2];
-	uint16_t idx, flags[VTBLK_MAXSEGS + 2];
+	struct iovec iov[BLOCKIF_IOV_MAX + 2];
+	uint16_t idx, flags[BLOCKIF_IOV_MAX + 2];
 
-	n = vq_getchain(vq, &idx, iov, VTBLK_MAXSEGS + 2, flags);
+	n = vq_getchain(vq, &idx, iov, BLOCKIF_IOV_MAX + 2, flags);
 
 	/*
 	 * The first descriptor will be the read-only fixed header,
@@ -214,7 +212,7 @@ pci_vtblk_proc(struct pci_vtblk_softc *s
 	 * XXX - note - this fails on crash dump, which does a
 	 * VIRTIO_BLK_T_FLUSH with a zero transfer length
 	 */
-	assert(n >= 2 && n <= VTBLK_MAXSEGS + 2);
+	assert(n >= 2 && n <= BLOCKIF_IOV_MAX + 2);
 
 	io = &sc->vbsc_ios[idx];
 	assert((flags[0] & VRING_DESC_F_WRITE) == 0);
@@ -347,7 +345,7 @@ pci_vtblk_init(struct vmctx *ctx, struct
 	/* setup virtio block config space */
 	sc->vbsc_cfg.vbc_capacity = size / DEV_BSIZE; /* 512-byte units */
 	sc->vbsc_cfg.vbc_size_max = 0;	/* not negotiated */
-	sc->vbsc_cfg.vbc_seg_max = VTBLK_MAXSEGS;
+	sc->vbsc_cfg.vbc_seg_max = BLOCKIF_IOV_MAX;
 	sc->vbsc_cfg.vbc_geometry.cylinders = 0;	/* no geometry */
 	sc->vbsc_cfg.vbc_geometry.heads = 0;
 	sc->vbsc_cfg.vbc_geometry.sectors = 0;