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

diff --git a/usr.sbin/bhyve/block_if.h b/usr.sbin/bhyve/block_if.h
index 4e2c1b4e55e629853755377dd618aa11fecb362f..1cb7c8048688e7af157bf2ecd855037942ea1fa7 100644 (file)
--- a/usr.sbin/bhyve/block_if.h
+++ b/usr.sbin/bhyve/block_if.h
@@ -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];

diff --git a/usr.sbin/bhyve/pci_virtio_block.c b/usr.sbin/bhyve/pci_virtio_block.c
index b0d3830217a822acb647d51560e11cee7cda7caf..163fa0640e6a74cffad2d7b449d8f39432bde407 100644 (file)
--- a/usr.sbin/bhyve/pci_virtio_block.c
+++ b/usr.sbin/bhyve/pci_virtio_block.c
@@ -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 *sc, struct vqueue_info *vq)
        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 *sc, struct vqueue_info *vq)
         * 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 pci_devinst *pi, char *opts)
        /* 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;