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authorDavid Vrabel <david.vrabel@citrix.com>2013-03-15 10:55:41 +0000
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2014-01-06 10:07:52 -0500
commitbf2bbe07f13846a90d4447521d87566d6f87bc0e (patch)
tree930d312f8d74a5892fb37429969de6016cc3eb6a
parent0dc0064add422bc0ef5165ebe9ece3052bbd457d (diff)
downloadlinux-bf2bbe07f13846a90d4447521d87566d6f87bc0e.tar.bz2
xen/events: Add the hypervisor interface for the FIFO-based event channels
Add the hypercall sub-ops and the structures for the shared data used in the FIFO-based event channel ABI. The design document for this new ABI is available here: http://xenbits.xen.org/people/dvrabel/event-channels-H.pdf In summary, events are reported using a per-domain shared event array of event words. Each event word has PENDING, LINKED and MASKED bits and a LINK field for pointing to the next event in the event queue. There are 16 event queues (with different priorities) per-VCPU. Key advantages of this new ABI include: - Support for over 100,000 events (2^17). - 16 different event priorities. - Improved fairness in event latency through the use of FIFOs. The ABI is available in Xen 4.4 and later. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
-rw-r--r--drivers/xen/events/events_2l.c8
-rw-r--r--include/xen/interface/event_channel.h68
-rw-r--r--include/xen/interface/xen.h6
3 files changed, 72 insertions, 10 deletions
diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c
index ecb402a149e3..d7ff91757307 100644
--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -38,12 +38,12 @@
/* Find the first set bit in a evtchn mask */
#define EVTCHN_FIRST_BIT(w) find_first_bit(BM(&(w)), BITS_PER_EVTCHN_WORD)
-static DEFINE_PER_CPU(xen_ulong_t [NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD],
+static DEFINE_PER_CPU(xen_ulong_t [EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD],
cpu_evtchn_mask);
static unsigned evtchn_2l_max_channels(void)
{
- return NR_EVENT_CHANNELS;
+ return EVTCHN_2L_NR_CHANNELS;
}
static void evtchn_2l_bind_to_cpu(struct irq_info *info, unsigned cpu)
@@ -316,7 +316,7 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
i % 8 == 0 ? "\n " : " ");
printk("\nlocal cpu%d mask:\n ", cpu);
- for (i = (NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD)-1; i >= 0; i--)
+ for (i = (EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD)-1; i >= 0; i--)
printk("%0*"PRI_xen_ulong"%s", (int)(sizeof(cpu_evtchn[0])*2),
cpu_evtchn[i],
i % 8 == 0 ? "\n " : " ");
@@ -332,7 +332,7 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
}
printk("\npending list:\n");
- for (i = 0; i < NR_EVENT_CHANNELS; i++) {
+ for (i = 0; i < EVTCHN_2L_NR_CHANNELS; i++) {
if (sync_test_bit(i, BM(sh->evtchn_pending))) {
int word_idx = i / BITS_PER_EVTCHN_WORD;
printk(" %d: event %d -> irq %d%s%s%s\n",
diff --git a/include/xen/interface/event_channel.h b/include/xen/interface/event_channel.h
index f4942921e202..7e6acef5415b 100644
--- a/include/xen/interface/event_channel.h
+++ b/include/xen/interface/event_channel.h
@@ -190,6 +190,39 @@ struct evtchn_reset {
};
typedef struct evtchn_reset evtchn_reset_t;
+/*
+ * EVTCHNOP_init_control: initialize the control block for the FIFO ABI.
+ */
+#define EVTCHNOP_init_control 11
+struct evtchn_init_control {
+ /* IN parameters. */
+ uint64_t control_gfn;
+ uint32_t offset;
+ uint32_t vcpu;
+ /* OUT parameters. */
+ uint8_t link_bits;
+ uint8_t _pad[7];
+};
+
+/*
+ * EVTCHNOP_expand_array: add an additional page to the event array.
+ */
+#define EVTCHNOP_expand_array 12
+struct evtchn_expand_array {
+ /* IN parameters. */
+ uint64_t array_gfn;
+};
+
+/*
+ * EVTCHNOP_set_priority: set the priority for an event channel.
+ */
+#define EVTCHNOP_set_priority 13
+struct evtchn_set_priority {
+ /* IN parameters. */
+ uint32_t port;
+ uint32_t priority;
+};
+
struct evtchn_op {
uint32_t cmd; /* EVTCHNOP_* */
union {
@@ -207,4 +240,39 @@ struct evtchn_op {
};
DEFINE_GUEST_HANDLE_STRUCT(evtchn_op);
+/*
+ * 2-level ABI
+ */
+
+#define EVTCHN_2L_NR_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64)
+
+/*
+ * FIFO ABI
+ */
+
+/* Events may have priorities from 0 (highest) to 15 (lowest). */
+#define EVTCHN_FIFO_PRIORITY_MAX 0
+#define EVTCHN_FIFO_PRIORITY_DEFAULT 7
+#define EVTCHN_FIFO_PRIORITY_MIN 15
+
+#define EVTCHN_FIFO_MAX_QUEUES (EVTCHN_FIFO_PRIORITY_MIN + 1)
+
+typedef uint32_t event_word_t;
+
+#define EVTCHN_FIFO_PENDING 31
+#define EVTCHN_FIFO_MASKED 30
+#define EVTCHN_FIFO_LINKED 29
+#define EVTCHN_FIFO_BUSY 28
+
+#define EVTCHN_FIFO_LINK_BITS 17
+#define EVTCHN_FIFO_LINK_MASK ((1 << EVTCHN_FIFO_LINK_BITS) - 1)
+
+#define EVTCHN_FIFO_NR_CHANNELS (1 << EVTCHN_FIFO_LINK_BITS)
+
+struct evtchn_fifo_control_block {
+ uint32_t ready;
+ uint32_t _rsvd;
+ event_word_t head[EVTCHN_FIFO_MAX_QUEUES];
+};
+
#endif /* __XEN_PUBLIC_EVENT_CHANNEL_H__ */
diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h
index 53ec4167bd0b..0cd5ca333fac 100644
--- a/include/xen/interface/xen.h
+++ b/include/xen/interface/xen.h
@@ -281,12 +281,6 @@ struct multicall_entry {
};
DEFINE_GUEST_HANDLE_STRUCT(multicall_entry);
-/*
- * Event channel endpoints per domain:
- * 1024 if a long is 32 bits; 4096 if a long is 64 bits.
- */
-#define NR_EVENT_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64)
-
struct vcpu_time_info {
/*
* Updates to the following values are preceded and followed