git: 3fc8a816d9a3 - stable/13 - bhyve: change vq_getchain to return iovecs in both directions
Ka Ho Ng
khng at FreeBSD.org
Thu Aug 12 06:45:25 UTC 2021
The branch stable/13 has been updated by khng:
URL: https://cgit.FreeBSD.org/src/commit/?id=3fc8a816d9a34462b473b1db3ccdd073efa91cd0
commit 3fc8a816d9a34462b473b1db3ccdd073efa91cd0
Author: Ka Ho Ng <khng at FreeBSD.org>
AuthorDate: 2021-03-30 08:43:24 +0000
Commit: Ka Ho Ng <khng at FreeBSD.org>
CommitDate: 2021-08-12 06:45:01 +0000
bhyve: change vq_getchain to return iovecs in both directions
The old prototype requires callers to inspect flags of each descriptors
to get the starting position of host-writable iovecs.
vq_getchain() is changed to return a virtio request with the number of
host-readable iovecs and host-writable iovecs instead. Callers can avoid
boilerplate code of getting the start offset of host-writable iovecs.
Sponsored by: The FreeBSD Foundation
Reviewed by: afedorov
Approved by: philip (mentor)
Differential Revision: https://reviews.freebsd.org/D29433
(cherry picked from commit b013912772ec9e135b52aaec5f70bc92a191ebdb)
---
usr.sbin/bhyve/pci_virtio_9p.c | 22 +++++++---------------
usr.sbin/bhyve/pci_virtio_block.c | 25 +++++++++++++------------
usr.sbin/bhyve/pci_virtio_console.c | 20 ++++++++++----------
usr.sbin/bhyve/pci_virtio_net.c | 12 +++++++-----
usr.sbin/bhyve/pci_virtio_rnd.c | 6 +++---
usr.sbin/bhyve/pci_virtio_scsi.c | 34 +++++++++++++---------------------
usr.sbin/bhyve/virtio.c | 36 +++++++++++++++++++++---------------
usr.sbin/bhyve/virtio.h | 16 ++++++++++++++--
8 files changed, 88 insertions(+), 83 deletions(-)
diff --git a/usr.sbin/bhyve/pci_virtio_9p.c b/usr.sbin/bhyve/pci_virtio_9p.c
index 830e13878a71..f96d53858225 100644
--- a/usr.sbin/bhyve/pci_virtio_9p.c
+++ b/usr.sbin/bhyve/pci_virtio_9p.c
@@ -197,32 +197,24 @@ pci_vt9p_notify(void *vsc, struct vqueue_info *vq)
struct iovec iov[VT9P_MAX_IOV];
struct pci_vt9p_softc *sc;
struct pci_vt9p_request *preq;
- uint16_t idx, n, i;
- uint16_t flags[VT9P_MAX_IOV];
+ struct vi_req req;
+ uint16_t n;
sc = vsc;
while (vq_has_descs(vq)) {
- n = vq_getchain(vq, &idx, iov, VT9P_MAX_IOV, flags);
+ n = vq_getchain(vq, iov, VT9P_MAX_IOV, &req);
preq = calloc(1, sizeof(struct pci_vt9p_request));
preq->vsr_sc = sc;
- preq->vsr_idx = idx;
+ preq->vsr_idx = req.idx;
preq->vsr_iov = iov;
preq->vsr_niov = n;
- preq->vsr_respidx = 0;
-
- /* Count readable descriptors */
- for (i = 0; i < n; i++) {
- if (flags[i] & VRING_DESC_F_WRITE)
- break;
-
- preq->vsr_respidx++;
- }
+ preq->vsr_respidx = req.readable;
for (int i = 0; i < n; i++) {
DPRINTF(("vt9p: vt9p_notify(): desc%d base=%p, "
- "len=%zu, flags=0x%04x\r\n", i, iov[i].iov_base,
- iov[i].iov_len, flags[i]));
+ "len=%zu\r\n", i, iov[i].iov_base,
+ iov[i].iov_len));
}
l9p_connection_recv(sc->vsc_conn, iov, preq->vsr_respidx, preq);
diff --git a/usr.sbin/bhyve/pci_virtio_block.c b/usr.sbin/bhyve/pci_virtio_block.c
index 0dc58e49594b..8a172c54eda7 100644
--- a/usr.sbin/bhyve/pci_virtio_block.c
+++ b/usr.sbin/bhyve/pci_virtio_block.c
@@ -308,11 +308,11 @@ pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
int err;
ssize_t iolen;
int writeop, type;
+ struct vi_req req;
struct iovec iov[BLOCKIF_IOV_MAX + 2];
- uint16_t idx, flags[BLOCKIF_IOV_MAX + 2];
struct virtio_blk_discard_write_zeroes *discard;
- n = vq_getchain(vq, &idx, iov, BLOCKIF_IOV_MAX + 2, flags);
+ n = vq_getchain(vq, iov, BLOCKIF_IOV_MAX + 2, &req);
/*
* The first descriptor will be the read-only fixed header,
@@ -324,16 +324,16 @@ pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
*/
assert(n >= 2 && n <= BLOCKIF_IOV_MAX + 2);
- io = &sc->vbsc_ios[idx];
- assert((flags[0] & VRING_DESC_F_WRITE) == 0);
+ io = &sc->vbsc_ios[req.idx];
+ assert(req.readable != 0);
assert(iov[0].iov_len == sizeof(struct virtio_blk_hdr));
vbh = (struct virtio_blk_hdr *)iov[0].iov_base;
memcpy(&io->io_req.br_iov, &iov[1], sizeof(struct iovec) * (n - 2));
io->io_req.br_iovcnt = n - 2;
io->io_req.br_offset = vbh->vbh_sector * VTBLK_BSIZE;
io->io_status = (uint8_t *)iov[--n].iov_base;
+ assert(req.writable != 0);
assert(iov[n].iov_len == 1);
- assert(flags[n] & VRING_DESC_F_WRITE);
/*
* XXX
@@ -342,16 +342,17 @@ pci_vtblk_proc(struct pci_vtblk_softc *sc, struct vqueue_info *vq)
*/
type = vbh->vbh_type & ~VBH_FLAG_BARRIER;
writeop = (type == VBH_OP_WRITE || type == VBH_OP_DISCARD);
+ /*
+ * - Write op implies read-only descriptor
+ * - Read/ident op implies write-only descriptor
+ *
+ * By taking away either the read-only fixed header or the write-only
+ * status iovec, the following condition should hold true.
+ */
+ assert(n == (writeop ? req.readable : req.writable));
iolen = 0;
for (i = 1; i < n; i++) {
- /*
- * - write op implies read-only descriptor,
- * - read/ident op implies write-only descriptor,
- * therefore test the inverse of the descriptor bit
- * to the op.
- */
- assert(((flags[i] & VRING_DESC_F_WRITE) == 0) == writeop);
iolen += iov[i].iov_len;
}
io->io_req.br_resid = iolen;
diff --git a/usr.sbin/bhyve/pci_virtio_console.c b/usr.sbin/bhyve/pci_virtio_console.c
index 88d6c37f582e..6832a3f92774 100644
--- a/usr.sbin/bhyve/pci_virtio_console.c
+++ b/usr.sbin/bhyve/pci_virtio_console.c
@@ -415,10 +415,10 @@ pci_vtcon_sock_rx(int fd __unused, enum ev_type t __unused, void *arg)
struct pci_vtcon_port *port;
struct pci_vtcon_sock *sock = (struct pci_vtcon_sock *)arg;
struct vqueue_info *vq;
+ struct vi_req req;
struct iovec iov;
static char dummybuf[2048];
int len, n;
- uint16_t idx;
port = sock->vss_port;
vq = pci_vtcon_port_to_vq(port, true);
@@ -441,7 +441,7 @@ pci_vtcon_sock_rx(int fd __unused, enum ev_type t __unused, void *arg)
}
do {
- n = vq_getchain(vq, &idx, &iov, 1, NULL);
+ n = vq_getchain(vq, &iov, 1, &req);
len = readv(sock->vss_conn_fd, &iov, n);
if (len == 0 || (len < 0 && errno == EWOULDBLOCK)) {
@@ -453,7 +453,7 @@ pci_vtcon_sock_rx(int fd __unused, enum ev_type t __unused, void *arg)
return;
}
- vq_relchain(vq, idx, len);
+ vq_relchain(vq, req.idx, len);
} while (vq_has_descs(vq));
vq_endchains(vq, 1);
@@ -572,8 +572,8 @@ pci_vtcon_control_send(struct pci_vtcon_softc *sc,
struct pci_vtcon_control *ctrl, const void *payload, size_t len)
{
struct vqueue_info *vq;
+ struct vi_req req;
struct iovec iov;
- uint16_t idx;
int n;
vq = pci_vtcon_port_to_vq(&sc->vsc_control_port, true);
@@ -581,7 +581,7 @@ pci_vtcon_control_send(struct pci_vtcon_softc *sc,
if (!vq_has_descs(vq))
return;
- n = vq_getchain(vq, &idx, &iov, 1, NULL);
+ n = vq_getchain(vq, &iov, 1, &req);
assert(n == 1);
@@ -590,7 +590,7 @@ pci_vtcon_control_send(struct pci_vtcon_softc *sc,
memcpy(iov.iov_base + sizeof(struct pci_vtcon_control),
payload, len);
- vq_relchain(vq, idx, sizeof(struct pci_vtcon_control) + len);
+ vq_relchain(vq, req.idx, sizeof(struct pci_vtcon_control) + len);
vq_endchains(vq, 1);
}
@@ -601,14 +601,14 @@ pci_vtcon_notify_tx(void *vsc, struct vqueue_info *vq)
struct pci_vtcon_softc *sc;
struct pci_vtcon_port *port;
struct iovec iov[1];
- uint16_t idx, n;
- uint16_t flags[8];
+ struct vi_req req;
+ uint16_t n;
sc = vsc;
port = pci_vtcon_vq_to_port(sc, vq);
while (vq_has_descs(vq)) {
- n = vq_getchain(vq, &idx, iov, 1, flags);
+ n = vq_getchain(vq, iov, 1, &req);
assert(n >= 1);
if (port != NULL)
port->vsp_cb(port, port->vsp_arg, iov, 1);
@@ -616,7 +616,7 @@ pci_vtcon_notify_tx(void *vsc, struct vqueue_info *vq)
/*
* Release this chain and handle more
*/
- vq_relchain(vq, idx, 0);
+ vq_relchain(vq, req.idx, 0);
}
vq_endchains(vq, 1); /* Generate interrupt if appropriate. */
}
diff --git a/usr.sbin/bhyve/pci_virtio_net.c b/usr.sbin/bhyve/pci_virtio_net.c
index 0ea470a71b56..d253b081d13a 100644
--- a/usr.sbin/bhyve/pci_virtio_net.c
+++ b/usr.sbin/bhyve/pci_virtio_net.c
@@ -248,6 +248,7 @@ pci_vtnet_rx(struct pci_vtnet_softc *sc)
struct virtio_mrg_rxbuf_info info[VTNET_MAXSEGS];
struct iovec iov[VTNET_MAXSEGS + 1];
struct vqueue_info *vq;
+ struct vi_req req;
vq = &sc->vsc_queues[VTNET_RXQ];
@@ -288,8 +289,9 @@ pci_vtnet_rx(struct pci_vtnet_softc *sc)
riov = iov;
n_chains = 0;
do {
- int n = vq_getchain(vq, &info[n_chains].idx, riov,
- VTNET_MAXSEGS - riov_len, NULL);
+ int n = vq_getchain(vq, riov, VTNET_MAXSEGS - riov_len,
+ &req);
+ info[n_chains].idx = req.idx;
if (n == 0) {
/*
@@ -435,7 +437,7 @@ pci_vtnet_proctx(struct pci_vtnet_softc *sc, struct vqueue_info *vq)
{
struct iovec iov[VTNET_MAXSEGS + 1];
struct iovec *siov = iov;
- uint16_t idx;
+ struct vi_req req;
ssize_t len;
int n;
@@ -443,7 +445,7 @@ pci_vtnet_proctx(struct pci_vtnet_softc *sc, struct vqueue_info *vq)
* Obtain chain of descriptors. The first descriptor also
* contains the virtio-net header.
*/
- n = vq_getchain(vq, &idx, iov, VTNET_MAXSEGS, NULL);
+ n = vq_getchain(vq, iov, VTNET_MAXSEGS, &req);
assert(n >= 1 && n <= VTNET_MAXSEGS);
if (sc->vhdrlen != sc->be_vhdrlen) {
@@ -473,7 +475,7 @@ pci_vtnet_proctx(struct pci_vtnet_softc *sc, struct vqueue_info *vq)
* Return the processed chain to the guest, reporting
* the number of bytes that we read.
*/
- vq_relchain(vq, idx, len);
+ vq_relchain(vq, req.idx, len);
}
/* Called on TX kick. */
diff --git a/usr.sbin/bhyve/pci_virtio_rnd.c b/usr.sbin/bhyve/pci_virtio_rnd.c
index d51301b32534..1d2d6144f949 100644
--- a/usr.sbin/bhyve/pci_virtio_rnd.c
+++ b/usr.sbin/bhyve/pci_virtio_rnd.c
@@ -113,8 +113,8 @@ pci_vtrnd_notify(void *vsc, struct vqueue_info *vq)
{
struct iovec iov;
struct pci_vtrnd_softc *sc;
+ struct vi_req req;
int len;
- uint16_t idx;
sc = vsc;
@@ -124,7 +124,7 @@ pci_vtrnd_notify(void *vsc, struct vqueue_info *vq)
}
while (vq_has_descs(vq)) {
- vq_getchain(vq, &idx, &iov, 1, NULL);
+ vq_getchain(vq, &iov, 1, &req);
len = read(sc->vrsc_fd, iov.iov_base, iov.iov_len);
@@ -136,7 +136,7 @@ pci_vtrnd_notify(void *vsc, struct vqueue_info *vq)
/*
* Release this chain and handle more
*/
- vq_relchain(vq, idx, len);
+ vq_relchain(vq, req.idx, len);
}
vq_endchains(vq, 1); /* Generate interrupt if appropriate. */
}
diff --git a/usr.sbin/bhyve/pci_virtio_scsi.c b/usr.sbin/bhyve/pci_virtio_scsi.c
index e17c3002bc54..e8124b9b3441 100644
--- a/usr.sbin/bhyve/pci_virtio_scsi.c
+++ b/usr.sbin/bhyve/pci_virtio_scsi.c
@@ -558,7 +558,8 @@ pci_vtscsi_controlq_notify(void *vsc, struct vqueue_info *vq)
{
struct pci_vtscsi_softc *sc;
struct iovec iov[VTSCSI_MAXSEG];
- uint16_t idx, n;
+ struct vi_req req;
+ uint16_t n;
void *buf = NULL;
size_t bufsize;
int iolen;
@@ -566,7 +567,7 @@ pci_vtscsi_controlq_notify(void *vsc, struct vqueue_info *vq)
sc = vsc;
while (vq_has_descs(vq)) {
- n = vq_getchain(vq, &idx, iov, VTSCSI_MAXSEG, NULL);
+ n = vq_getchain(vq, iov, VTSCSI_MAXSEG, &req);
bufsize = iov_to_buf(iov, n, &buf);
iolen = pci_vtscsi_control_handle(sc, buf, bufsize);
buf_to_iov(buf + bufsize - iolen, iolen, iov, n,
@@ -575,7 +576,7 @@ pci_vtscsi_controlq_notify(void *vsc, struct vqueue_info *vq)
/*
* Release this chain and handle more
*/
- vq_relchain(vq, idx, iolen);
+ vq_relchain(vq, req.idx, iolen);
}
vq_endchains(vq, 1); /* Generate interrupt if appropriate. */
free(buf);
@@ -595,33 +596,23 @@ pci_vtscsi_requestq_notify(void *vsc, struct vqueue_info *vq)
struct pci_vtscsi_queue *q;
struct pci_vtscsi_request *req;
struct iovec iov[VTSCSI_MAXSEG];
- uint16_t flags[VTSCSI_MAXSEG];
- uint16_t idx, n, i;
- int readable;
+ struct vi_req vireq;
+ uint16_t n;
sc = vsc;
q = &sc->vss_queues[vq->vq_num - 2];
while (vq_has_descs(vq)) {
- readable = 0;
- n = vq_getchain(vq, &idx, iov, VTSCSI_MAXSEG, flags);
-
- /* Count readable descriptors */
- for (i = 0; i < n; i++) {
- if (flags[i] & VRING_DESC_F_WRITE)
- break;
-
- readable++;
- }
+ n = vq_getchain(vq, iov, VTSCSI_MAXSEG, &vireq);
req = calloc(1, sizeof(struct pci_vtscsi_request));
- req->vsr_idx = idx;
+ req->vsr_idx = vireq.idx;
req->vsr_queue = q;
- req->vsr_niov_in = readable;
- req->vsr_niov_out = n - readable;
+ req->vsr_niov_in = vireq.readable;
+ req->vsr_niov_out = vireq.writable;
memcpy(req->vsr_iov_in, iov,
req->vsr_niov_in * sizeof(struct iovec));
- memcpy(req->vsr_iov_out, iov + readable,
+ memcpy(req->vsr_iov_out, iov + vireq.readable,
req->vsr_niov_out * sizeof(struct iovec));
pthread_mutex_lock(&q->vsq_mtx);
@@ -629,7 +620,8 @@ pci_vtscsi_requestq_notify(void *vsc, struct vqueue_info *vq)
pthread_cond_signal(&q->vsq_cv);
pthread_mutex_unlock(&q->vsq_mtx);
- DPRINTF(("virtio-scsi: request <idx=%d> enqueued", idx));
+ DPRINTF(("virtio-scsi: request <idx=%d> enqueued",
+ vireq.idx));
}
}
diff --git a/usr.sbin/bhyve/virtio.c b/usr.sbin/bhyve/virtio.c
index 078a74b759df..7f0485cbb826 100644
--- a/usr.sbin/bhyve/virtio.c
+++ b/usr.sbin/bhyve/virtio.c
@@ -40,6 +40,7 @@ __FBSDID("$FreeBSD$");
#include <stdio.h>
#include <stdint.h>
+#include <string.h>
#include <pthread.h>
#include <pthread_np.h>
@@ -213,15 +214,18 @@ vi_vq_init(struct virtio_softc *vs, uint32_t pfn)
* descriptor.
*/
static inline void
-_vq_record(int i, volatile struct vring_desc *vd, struct vmctx *ctx,
- struct iovec *iov, int n_iov, uint16_t *flags) {
+_vq_record(int i, volatile struct vring_desc *vd,
+ struct vmctx *ctx, struct iovec *iov, int n_iov,
+ struct vi_req *reqp) {
if (i >= n_iov)
return;
iov[i].iov_base = paddr_guest2host(ctx, vd->addr, vd->len);
iov[i].iov_len = vd->len;
- if (flags != NULL)
- flags[i] = vd->flags;
+ if ((vd->flags & VRING_DESC_F_WRITE) == 0)
+ reqp->readable++;
+ else
+ reqp->writable++;
}
#define VQ_MAX_DESCRIPTORS 512 /* see below */
@@ -253,11 +257,6 @@ _vq_record(int i, volatile struct vring_desc *vd, struct vmctx *ctx,
* a larger iov array if needed, or supply a zero length to find
* out how much space is needed).
*
- * If you want to verify the WRITE flag on each descriptor, pass a
- * non-NULL "flags" pointer to an array of "uint16_t" of the same size
- * as n_iov and we'll copy each "flags" field after unwinding any
- * indirects.
- *
* If some descriptor(s) are invalid, this prints a diagnostic message
* and returns -1. If no descriptors are ready now it simply returns 0.
*
@@ -265,12 +264,13 @@ _vq_record(int i, volatile struct vring_desc *vd, struct vmctx *ctx,
* that vq_has_descs() does one).
*/
int
-vq_getchain(struct vqueue_info *vq, uint16_t *pidx,
- struct iovec *iov, int n_iov, uint16_t *flags)
+vq_getchain(struct vqueue_info *vq, struct iovec *iov, int niov,
+ struct vi_req *reqp)
{
int i;
u_int ndesc, n_indir;
u_int idx, next;
+ struct vi_req req;
volatile struct vring_desc *vdir, *vindir, *vp;
struct vmctx *ctx;
struct virtio_softc *vs;
@@ -278,6 +278,7 @@ vq_getchain(struct vqueue_info *vq, uint16_t *pidx,
vs = vq->vq_vs;
name = vs->vs_vc->vc_name;
+ memset(&req, 0, sizeof(req));
/*
* Note: it's the responsibility of the guest not to
@@ -313,7 +314,7 @@ vq_getchain(struct vqueue_info *vq, uint16_t *pidx,
* index, but we just abort if the count gets excessive.
*/
ctx = vs->vs_pi->pi_vmctx;
- *pidx = next = vq->vq_avail->ring[idx & (vq->vq_qsize - 1)];
+ req.idx = next = vq->vq_avail->ring[idx & (vq->vq_qsize - 1)];
vq->vq_last_avail++;
for (i = 0; i < VQ_MAX_DESCRIPTORS; next = vdir->next) {
if (next >= vq->vq_qsize) {
@@ -325,7 +326,7 @@ vq_getchain(struct vqueue_info *vq, uint16_t *pidx,
}
vdir = &vq->vq_desc[next];
if ((vdir->flags & VRING_DESC_F_INDIRECT) == 0) {
- _vq_record(i, vdir, ctx, iov, n_iov, flags);
+ _vq_record(i, vdir, ctx, iov, niov, &req);
i++;
} else if ((vs->vs_vc->vc_hv_caps &
VIRTIO_RING_F_INDIRECT_DESC) == 0) {
@@ -362,7 +363,7 @@ vq_getchain(struct vqueue_info *vq, uint16_t *pidx,
name);
return (-1);
}
- _vq_record(i, vp, ctx, iov, n_iov, flags);
+ _vq_record(i, vp, ctx, iov, niov, &req);
if (++i > VQ_MAX_DESCRIPTORS)
goto loopy;
if ((vp->flags & VRING_DESC_F_NEXT) == 0)
@@ -378,13 +379,18 @@ vq_getchain(struct vqueue_info *vq, uint16_t *pidx,
}
}
if ((vdir->flags & VRING_DESC_F_NEXT) == 0)
- return (i);
+ goto done;
}
+
loopy:
EPRINTLN(
"%s: descriptor loop? count > %d - driver confused?",
name, i);
return (-1);
+
+done:
+ *reqp = req;
+ return (i);
}
/*
diff --git a/usr.sbin/bhyve/virtio.h b/usr.sbin/bhyve/virtio.h
index c5730f71000e..e03fd5f710d1 100644
--- a/usr.sbin/bhyve/virtio.h
+++ b/usr.sbin/bhyve/virtio.h
@@ -371,6 +371,18 @@ vq_kick_disable(struct vqueue_info *vq)
}
struct iovec;
+
+/*
+ * Request description returned by vq_getchain.
+ *
+ * Writable iovecs start at iov[req.readable].
+ */
+struct vi_req {
+ int readable; /* num of readable iovecs */
+ int writable; /* num of writable iovecs */
+ unsigned int idx; /* ring index */
+};
+
void vi_softc_linkup(struct virtio_softc *vs, struct virtio_consts *vc,
void *dev_softc, struct pci_devinst *pi,
struct vqueue_info *queues);
@@ -378,8 +390,8 @@ int vi_intr_init(struct virtio_softc *vs, int barnum, int use_msix);
void vi_reset_dev(struct virtio_softc *);
void vi_set_io_bar(struct virtio_softc *, int);
-int vq_getchain(struct vqueue_info *vq, uint16_t *pidx,
- struct iovec *iov, int n_iov, uint16_t *flags);
+int vq_getchain(struct vqueue_info *vq, struct iovec *iov, int niov,
+ struct vi_req *reqp);
void vq_retchains(struct vqueue_info *vq, uint16_t n_chains);
void vq_relchain_prepare(struct vqueue_info *vq, uint16_t idx,
uint32_t iolen);
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