upstream/opnsense-src
1
0
Fork 0
mirror of https://github.com/opnsense/src.git synced 2026-06-08 16:22:46 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

hyperv/vmbus: Fix the multi-channel revoking on vmbus side.

Browse source 
- Reference count the sub-channel when channel offer message is
  processed, so that immediate rescind message on the same channel
  will not race sub-channel open on driver side.
- Drop the above reference when sub-channel is closed, this closely
  mimics the hypervisor's reaction when primary channel is closed
  on the VM side.  No drivers use sub-channel after primary channel
  is closed.

MFC after:	1 week
Sponsored by:	Microsoft
Differential Revision:	https://reviews.freebsd.org/D8546
This commit is contained in:
Sepherosa Ziehau 2016-11-24 06:01:29 +00:00
parent ea59684977
commit 91955558f5
2 changed files with 50 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

52
sys/dev/hyperv/vmbus/vmbus_chan.c
View file

@ -65,6 +65,7 @@ static void vmbus_chan_cpu_default(struct vmbus_channel *);
static int vmbus_chan_release(struct vmbus_channel *);
static void vmbus_chan_set_chmap(struct vmbus_channel *);
static void vmbus_chan_clear_chmap(struct vmbus_channel *);
static void vmbus_chan_detach(struct vmbus_channel *);
static void vmbus_chan_ins_prilist(struct vmbus_softc *,
struct vmbus_channel *);
@ -627,6 +628,32 @@ vmbus_chan_gpadl_disconnect(struct vmbus_channel *chan, uint32_t gpadl)
return 0;
}
static void
vmbus_chan_detach(struct vmbus_channel *chan)
{
int refs;
KASSERT(chan->ch_refs > 0, ("chan%u: invalid refcnt %d",
chan->ch_id, chan->ch_refs));
refs = atomic_fetchadd_int(&chan->ch_refs, -1);
#ifdef INVARIANTS
if (VMBUS_CHAN_ISPRIMARY(chan)) {
KASSERT(refs == 1, ("chan%u: invalid refcnt %d for prichan",
chan->ch_id, refs + 1));
}
#endif
if (refs == 1) {
/*
* Detach the target channel.
*/
if (bootverbose) {
vmbus_chan_printf(chan, "chan%u detached\n",
chan->ch_id);
}
taskqueue_enqueue(chan->ch_mgmt_tq, &chan->ch_detach_task);
}
}
static void
vmbus_chan_clrchmap_task(void *xchan, int pending __unused)
{
@ -752,8 +779,15 @@ vmbus_chan_close(struct vmbus_channel *chan)
int i;
subchan = vmbus_subchan_get(chan, subchan_cnt);
for (i = 0; i < subchan_cnt; ++i)
for (i = 0; i < subchan_cnt; ++i) {
vmbus_chan_close_internal(subchan[i]);
/*
* This sub-channel is referenced, when it is
* linked to the primary channel; drop that
* reference now.
*/
vmbus_chan_detach(subchan[i]);
}
vmbus_subchan_rel(subchan, subchan_cnt);
}
@ -1114,6 +1148,7 @@ vmbus_chan_alloc(struct vmbus_softc *sc)
return NULL;
}
chan->ch_refs = 1;
chan->ch_vmbus = sc;
mtx_init(&chan->ch_subchan_lock, "vmbus subchan", NULL, MTX_DEF);
sx_init(&chan->ch_orphan_lock, "vmbus chorphan");
@ -1137,6 +1172,8 @@ vmbus_chan_free(struct vmbus_channel *chan)
VMBUS_CHAN_ST_ONLIST)) == 0, ("free busy channel"));
KASSERT(chan->ch_orphan_xact == NULL,
("still has orphan xact installed"));
KASSERT(chan->ch_refs == 0, ("chan%u: invalid refcnt %d",
chan->ch_id, chan->ch_refs));
hyperv_dmamem_free(&chan->ch_monprm_dma, chan->ch_monprm);
mtx_destroy(&chan->ch_subchan_lock);
@ -1213,6 +1250,14 @@ vmbus_chan_add(struct vmbus_channel *newchan)
("new channel is not sub-channel"));
KASSERT(prichan != NULL, ("no primary channel"));
/*
* Reference count this sub-channel; it will be dereferenced
* when this sub-channel is closed.
*/
KASSERT(newchan->ch_refs == 1, ("chan%u: invalid refcnt %d",
newchan->ch_id, newchan->ch_refs));
atomic_add_int(&newchan->ch_refs, 1);
newchan->ch_prichan = prichan;
newchan->ch_dev = prichan->ch_dev;
@ -1359,6 +1404,7 @@ vmbus_chan_msgproc_choffer(struct vmbus_softc *sc,
if (error) {
device_printf(sc->vmbus_dev, "add chan%u failed: %d\n",
chan->ch_id, error);
atomic_subtract_int(&chan->ch_refs, 1);
vmbus_chan_free(chan);
return;
}
@ -1426,9 +1472,7 @@ vmbus_chan_msgproc_chrescind(struct vmbus_softc *sc,
if (bootverbose)
vmbus_chan_printf(chan, "chan%u revoked\n", note->chm_chanid);
/* Detach the target channel. */
taskqueue_enqueue(chan->ch_mgmt_tq, &chan->ch_detach_task);
vmbus_chan_detach(chan);
}
static int

2
sys/dev/hyperv/vmbus/vmbus_chanvar.h
View file

@ -142,6 +142,8 @@ struct vmbus_channel {
struct sx ch_orphan_lock;
struct vmbus_xact_ctx *ch_orphan_xact;
int ch_refs;
struct sysctl_ctx_list ch_sysctl_ctx;
} __aligned(CACHE_LINE_SIZE);