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-rw-r--r--sys/dev/pv/xen.c248
-rw-r--r--sys/dev/pv/xenvar.h7
2 files changed, 159 insertions, 96 deletions
diff --git a/sys/dev/pv/xen.c b/sys/dev/pv/xen.c
index c7c5ad661ac..22e5072af17 100644
--- a/sys/dev/pv/xen.c
+++ b/sys/dev/pv/xen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: xen.c,v 1.42 2016/01/27 15:29:00 mikeb Exp $ */
+/* $OpenBSD: xen.c,v 1.43 2016/01/27 15:34:50 mikeb Exp $ */
/*
* Copyright (c) 2015 Mike Belopuhov
@@ -58,7 +58,7 @@ struct xen_gntent *
xen_grant_table_grow(struct xen_softc *);
int xen_grant_table_alloc(struct xen_softc *, grant_ref_t *);
void xen_grant_table_free(struct xen_softc *, grant_ref_t);
-int xen_grant_table_enter(struct xen_softc *, grant_ref_t, paddr_t, int);
+void xen_grant_table_enter(struct xen_softc *, grant_ref_t, paddr_t, int);
void xen_grant_table_remove(struct xen_softc *, grant_ref_t);
void xen_disable_emulated_devices(struct xen_softc *);
@@ -775,7 +775,6 @@ xen_init_grant_tables(struct xen_softc *sc)
struct gnttab_query_size gqs;
struct gnttab_get_version ggv;
struct gnttab_set_version gsv;
- int i;
gqs.dom = DOMID_SELF;
if (xen_hypercall(sc, XC_GNTTAB, 3, GNTTABOP_query_size, &gqs, 1)) {
@@ -797,13 +796,24 @@ xen_init_grant_tables(struct xen_softc *sc)
return (-1);
}
- SLIST_INIT(&sc->sc_gnts);
+ sc->sc_gntmax = gqs.max_nr_frames;
- for (i = 0; i < gqs.max_nr_frames; i++)
- if (xen_grant_table_grow(sc) == NULL)
- break;
+ sc->sc_gnt = mallocarray(sc->sc_gntmax + 1, sizeof(struct xen_gntent),
+ M_DEVBUF, M_ZERO | M_NOWAIT);
+ if (sc->sc_gnt == NULL) {
+ printf(": failed to allocate grant table lookup table\n");
+ return (-1);
+ }
- printf(", %u grant table frames", sc->sc_gntcnt);
+ mtx_init(&sc->sc_gntmtx, IPL_NET);
+
+ if (xen_grant_table_grow(sc) == NULL) {
+ free(sc->sc_gnt, M_DEVBUF, sc->sc_gntmax *
+ sizeof(struct xen_gntent));
+ return (-1);
+ }
+
+ printf(", %u grant table frames", sc->sc_gntmax);
xen_bus_dma_tag._cookie = sc;
@@ -817,15 +827,19 @@ xen_grant_table_grow(struct xen_softc *sc)
struct xen_gntent *ge;
paddr_t pa;
- ge = malloc(sizeof(*ge), M_DEVBUF, M_ZERO | M_NOWAIT);
- if (ge == NULL) {
- printf("%s: failed to allocate a grant table entry\n",
+ if (sc->sc_gntcnt == sc->sc_gntmax) {
+ printf("%s: grant table frame allotment limit reached\n",
sc->sc_dev.dv_xname);
return (NULL);
}
+
+ mtx_enter(&sc->sc_gntmtx);
+
+ ge = &sc->sc_gnt[sc->sc_gntcnt];
ge->ge_table = km_alloc(PAGE_SIZE, &kv_any, &kp_zero, &kd_nowait);
if (ge->ge_table == NULL) {
free(ge, M_DEVBUF, sizeof(*ge));
+ mtx_leave(&sc->sc_gntmtx);
return (NULL);
}
if (!pmap_extract(pmap_kernel(), (vaddr_t)ge->ge_table, &pa)) {
@@ -833,6 +847,7 @@ xen_grant_table_grow(struct xen_softc *sc)
sc->sc_dev.dv_xname);
km_free(ge->ge_table, PAGE_SIZE, &kv_any, &kp_zero);
free(ge, M_DEVBUF, sizeof(*ge));
+ mtx_leave(&sc->sc_gntmtx);
return (NULL);
}
xatp.domid = DOMID_SELF;
@@ -844,6 +859,7 @@ xen_grant_table_grow(struct xen_softc *sc)
sc->sc_dev.dv_xname);
km_free(ge->ge_table, PAGE_SIZE, &kv_any, &kp_zero);
free(ge, M_DEVBUF, sizeof(*ge));
+ mtx_leave(&sc->sc_gntmtx);
return (NULL);
}
ge->ge_start = sc->sc_gntcnt * GNTTAB_NEPG;
@@ -852,9 +868,9 @@ xen_grant_table_grow(struct xen_softc *sc)
ge->ge_free = GNTTAB_NEPG - ge->ge_reserved;
ge->ge_next = ge->ge_reserved ? ge->ge_reserved + 1 : 0;
mtx_init(&ge->ge_mtx, IPL_NET);
- SLIST_INSERT_HEAD(&sc->sc_gnts, ge, ge_entry);
sc->sc_gntcnt++;
+ mtx_leave(&sc->sc_gntmtx);
return (ge);
}
@@ -865,34 +881,63 @@ xen_grant_table_alloc(struct xen_softc *sc, grant_ref_t *ref)
struct xen_gntent *ge;
int i;
- SLIST_FOREACH(ge, &sc->sc_gnts, ge_entry) {
- if (!ge->ge_free)
+ /* Start with a previously allocated table page */
+ ge = &sc->sc_gnt[sc->sc_gntcnt - 1];
+ if (ge->ge_free > 0) {
+ mtx_enter(&ge->ge_mtx);
+ if (ge->ge_free > 0)
+ goto search;
+ mtx_leave(&ge->ge_mtx);
+ }
+
+ /* Try other existing table pages */
+ for (i = 0; i < sc->sc_gntcnt; i++) {
+ ge = &sc->sc_gnt[i];
+ if (ge->ge_free == 0)
continue;
mtx_enter(&ge->ge_mtx);
- for (i = ge->ge_next;
- /* Math works here because GNTTAB_NEPG is a power of 2 */
- i != ((ge->ge_next + GNTTAB_NEPG - 1) & (GNTTAB_NEPG - 1));
- i++) {
- if (i == GNTTAB_NEPG)
- i = 0;
- if (ge->ge_reserved && i < ge->ge_reserved)
- continue;
- if (ge->ge_table[i].flags != GTF_invalid &&
- ge->ge_table[i].frame != 0)
- continue;
- *ref = ge->ge_start + i;
- /* XXX Mark as taken */
- ge->ge_table[i].frame = 0xffffffff;
- if ((ge->ge_next = i + 1) == GNTTAB_NEPG)
- ge->ge_next = ge->ge_reserved + 1;
- ge->ge_free--;
- mtx_leave(&ge->ge_mtx);
- return (0);
- }
+ if (ge->ge_free > 0)
+ goto search;
mtx_leave(&ge->ge_mtx);
}
- /* We're out of entries */
+ alloc:
+ /* Allocate a new table page */
+ if ((ge = xen_grant_table_grow(sc)) == NULL)
+ return (-1);
+
+ mtx_enter(&ge->ge_mtx);
+ if (ge->ge_free == 0) {
+ /* We were not fast enough... */
+ mtx_leave(&ge->ge_mtx);
+ goto alloc;
+ }
+
+ search:
+ for (i = ge->ge_next;
+ /* Math works here because GNTTAB_NEPG is a power of 2 */
+ i != ((ge->ge_next + GNTTAB_NEPG - 1) & (GNTTAB_NEPG - 1));
+ i++) {
+ if (i == GNTTAB_NEPG)
+ i = 0;
+ if (ge->ge_reserved && i < ge->ge_reserved)
+ continue;
+ if (ge->ge_table[i].flags != GTF_invalid &&
+ ge->ge_table[i].frame != 0)
+ continue;
+ *ref = ge->ge_start + i;
+ /* XXX Mark as taken */
+ ge->ge_table[i].frame = 0xffffffff;
+ if ((ge->ge_next = i + 1) == GNTTAB_NEPG)
+ ge->ge_next = ge->ge_reserved + 1;
+ ge->ge_free--;
+ mtx_leave(&ge->ge_mtx);
+ return (0);
+ }
+ mtx_leave(&ge->ge_mtx);
+
+ panic("page full, sc %p gnts %p (%d) ge %p", sc, sc->sc_gnt,
+ sc->sc_gntcnt, ge);
return (-1);
}
@@ -901,40 +946,61 @@ xen_grant_table_free(struct xen_softc *sc, grant_ref_t ref)
{
struct xen_gntent *ge;
- SLIST_FOREACH(ge, &sc->sc_gnts, ge_entry) {
- if (ref < ge->ge_start || ref > ge->ge_start + GNTTAB_NEPG)
- continue;
- ref -= ge->ge_start;
- mtx_enter(&ge->ge_mtx);
- if (ge->ge_table[ref].flags != GTF_invalid) {
- mtx_leave(&ge->ge_mtx);
- return;
- }
- ge->ge_table[ref].frame = 0;
- ge->ge_next = ref;
- ge->ge_free++;
+#ifdef XEN_DEBUG
+ if (ref > sc->sc_gntcnt * GNTTAB_NEPG)
+ panic("unmanaged ref %u sc %p gnt %p (%d)", ref, sc,
+ sc->sc_gnt, sc->sc_gntcnt);
+#endif
+ ge = &sc->sc_gnt[ref / GNTTAB_NEPG];
+ mtx_enter(&ge->ge_mtx);
+#ifdef XEN_DEBUG
+ if (ref < ge->ge_start || ref > ge->ge_start + GNTTAB_NEPG) {
mtx_leave(&ge->ge_mtx);
+ panic("out of bounds ref %u ge %p start %u sc %p gtt %p",
+ ref, ge, ge->ge_start, sc, sc->sc_gnt);
}
+#endif
+ ref -= ge->ge_start;
+ if (ge->ge_table[ref].flags != GTF_invalid) {
+ mtx_leave(&ge->ge_mtx);
+#ifdef XEN_DEBUG
+ panic("ref %u is still in use, sc %p gnt %p", ref,
+ sc, sc->sc_gnt);
+#else
+ printf("%s: reference %u is still in use\n",
+ sc->sc_dev.dv_xname, ref);
+#endif
+ }
+ ge->ge_table[ref].frame = 0;
+ ge->ge_next = ref;
+ ge->ge_free++;
+ mtx_leave(&ge->ge_mtx);
}
-int
+void
xen_grant_table_enter(struct xen_softc *sc, grant_ref_t ref, paddr_t pa,
int flags)
{
struct xen_gntent *ge;
- SLIST_FOREACH(ge, &sc->sc_gnts, ge_entry) {
- if (ref < ge->ge_start || ref > ge->ge_start + GNTTAB_NEPG)
- continue;
- ref -= ge->ge_start;
- ge->ge_table[ref].frame = atop(pa);
- ge->ge_table[ref].domid = 0;
- virtio_membar_sync();
- ge->ge_table[ref].flags = GTF_permit_access | flags;
- virtio_membar_sync();
- return (0);
+#ifdef XEN_DEBUG
+ if (ref > sc->sc_gntcnt * GNTTAB_NEPG)
+ panic("unmanaged ref %u sc %p gnt %p (%d)", ref, sc,
+ sc->sc_gnt, sc->sc_gntcnt);
+#endif
+ ge = &sc->sc_gnt[ref / GNTTAB_NEPG];
+#ifdef XEN_DEBUG
+ if (ref < ge->ge_start || ref > ge->ge_start + GNTTAB_NEPG) {
+ panic("out of bounds ref %u ge %p start %u sc %p gtt %p",
+ ref, ge, ge->ge_start, sc, sc->sc_gnt);
}
- return (ENOBUFS);
+#endif
+ ref -= ge->ge_start;
+ ge->ge_table[ref].frame = atop(pa);
+ ge->ge_table[ref].domid = 0;
+ virtio_membar_sync();
+ ge->ge_table[ref].flags = GTF_permit_access | flags;
+ virtio_membar_sync();
}
void
@@ -944,28 +1010,34 @@ xen_grant_table_remove(struct xen_softc *sc, grant_ref_t ref)
uint32_t flags, *ptr;
int loop;
- SLIST_FOREACH(ge, &sc->sc_gnts, ge_entry) {
- if (ref < ge->ge_start || ref > ge->ge_start + GNTTAB_NEPG)
- continue;
- ref -= ge->ge_start;
-
- /* Invalidate the grant reference */
- virtio_membar_sync();
- ptr = (uint32_t *)&ge->ge_table[ref];
- flags = (ge->ge_table[ref].flags & ~(GTF_reading|GTF_writing));
- loop = 0;
- while (atomic_cas_uint(ptr, flags, GTF_invalid) != flags) {
- if (loop++ > 10000000) {
- printf("%s: grant table reference %u is held "
- "by domain %d\n", sc->sc_dev.dv_xname, ref +
- ge->ge_start, ge->ge_table[ref].domid);
- return;
- }
- CPU_BUSY_CYCLE();
+#ifdef XEN_DEBUG
+ if (ref > sc->sc_gntcnt * GNTTAB_NEPG)
+ panic("unmanaged ref %u sc %p gnts %p (%d)", ref, sc,
+ sc->sc_gnt, sc->sc_gntcnt);
+#endif
+ ge = &sc->sc_gnt[ref / GNTTAB_NEPG];
+#ifdef XEN_DEBUG
+ if (ref < ge->ge_start || ref > ge->ge_start + GNTTAB_NEPG) {
+ panic("out of bounds ref %u ge %p start %u sc %p gtt %p",
+ ref, ge, ge->ge_start, sc, sc->sc_gnt);
+ }
+#endif
+ ref -= ge->ge_start;
+ /* Invalidate the grant reference */
+ virtio_membar_sync();
+ ptr = (uint32_t *)&ge->ge_table[ref];
+ flags = (ge->ge_table[ref].flags & ~(GTF_reading|GTF_writing));
+ loop = 0;
+ while (atomic_cas_uint(ptr, flags, GTF_invalid) != flags) {
+ if (loop++ > 10000000) {
+ printf("%s: grant table reference %u is held "
+ "by domain %d\n", sc->sc_dev.dv_xname, ref +
+ ge->ge_start, ge->ge_table[ref].domid);
+ return;
}
- ge->ge_table[ref].frame = 0xffffffff;
- break;
+ CPU_BUSY_CYCLE();
}
+ ge->ge_table[ref].frame = 0xffffffff;
}
int
@@ -1034,13 +1106,8 @@ xen_bus_dmamap_load(bus_dma_tag_t t, bus_dmamap_t map, void *buf,
if (error)
return (error);
for (i = 0; i < map->dm_nsegs; i++) {
- error = xen_grant_table_enter(sc, gm[i].gm_ref,
- map->dm_segs[i].ds_addr, flags & BUS_DMA_WRITE ?
- GTF_readonly : 0);
- if (error) {
- xen_bus_dmamap_unload(t, map);
- return (error);
- }
+ xen_grant_table_enter(sc, gm[i].gm_ref, map->dm_segs[i].ds_addr,
+ flags & BUS_DMA_WRITE ? GTF_readonly : 0);
gm[i].gm_paddr = map->dm_segs[i].ds_addr;
map->dm_segs[i].ds_offset = map->dm_segs[i].ds_addr &
PAGE_MASK;
@@ -1063,13 +1130,8 @@ xen_bus_dmamap_load_mbuf(bus_dma_tag_t t, bus_dmamap_t map, struct mbuf *m0,
if (error)
return (error);
for (i = 0; i < map->dm_nsegs; i++) {
- error = xen_grant_table_enter(sc, gm[i].gm_ref,
- map->dm_segs[i].ds_addr, flags & BUS_DMA_WRITE ?
- GTF_readonly : 0);
- if (error) {
- xen_bus_dmamap_unload(t, map);
- return (error);
- }
+ xen_grant_table_enter(sc, gm[i].gm_ref, map->dm_segs[i].ds_addr,
+ flags & BUS_DMA_WRITE ? GTF_readonly : 0);
gm[i].gm_paddr = map->dm_segs[i].ds_addr;
map->dm_segs[i].ds_offset = map->dm_segs[i].ds_addr &
PAGE_MASK;
diff --git a/sys/dev/pv/xenvar.h b/sys/dev/pv/xenvar.h
index 3042e5b00e9..89426c86feb 100644
--- a/sys/dev/pv/xenvar.h
+++ b/sys/dev/pv/xenvar.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: xenvar.h,v 1.24 2016/01/27 09:04:19 reyk Exp $ */
+/* $OpenBSD: xenvar.h,v 1.25 2016/01/27 15:34:50 mikeb Exp $ */
/*
* Copyright (c) 2015 Mike Belopuhov
@@ -38,7 +38,6 @@ struct xen_intsrc {
};
struct xen_gntent {
- SLIST_ENTRY(xen_gntent) ge_entry;
grant_entry_t *ge_table;
grant_ref_t ge_start;
short ge_reserved;
@@ -70,8 +69,10 @@ struct xen_softc {
uint64_t sc_irq; /* IDT vector number */
SLIST_HEAD(, xen_intsrc) sc_intrs;
- SLIST_HEAD(, xen_gntent) sc_gnts; /* grant table entries */
+ struct xen_gntent *sc_gnt; /* grant table entries */
+ struct mutex sc_gntmtx;
int sc_gntcnt; /* number of allocated frames */
+ int sc_gntmax; /* number of allotted frames */
/*
* Xenstore
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-18 12:53:33 +0000