Merge tag 'for-linus-5.10b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull more xen updates from Juergen Gross:
- A single patch to fix the Xen security issue XSA-331 (malicious
guests can DoS dom0 by triggering NULL-pointer dereferences or access
to stale data).
- A larger series to fix the Xen security issue XSA-332 (malicious
guests can DoS dom0 by sending events at high frequency leading to
dom0's vcpus being busy in IRQ handling for elongated times).
* tag 'for-linus-5.10b-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/events: block rogue events for some time
xen/events: defer eoi in case of excessive number of events
xen/events: use a common cpu hotplug hook for event channels
xen/events: switch user event channels to lateeoi model
xen/pciback: use lateeoi irq binding
xen/pvcallsback: use lateeoi irq binding
xen/scsiback: use lateeoi irq binding
xen/netback: use lateeoi irq binding
xen/blkback: use lateeoi irq binding
xen/events: add a new "late EOI" evtchn framework
xen/events: fix race in evtchn_fifo_unmask()
xen/events: add a proper barrier to 2-level uevent unmasking
xen/events: avoid removing an event channel while handling it
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index f1eeba7..02d4adb 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -5970,6 +5970,14 @@
improve timer resolution at the expense of processing
more timer interrupts.
+ xen.event_eoi_delay= [XEN]
+ How long to delay EOI handling in case of event
+ storms (jiffies). Default is 10.
+
+ xen.event_loop_timeout= [XEN]
+ After which time (jiffies) the event handling loop
+ should start to delay EOI handling. Default is 2.
+
nopv= [X86,XEN,KVM,HYPER_V,VMWARE]
Disables the PV optimizations forcing the guest to run
as generic guest with no PV drivers. Currently support
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index adfc935..501e9da 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -201,7 +201,7 @@ static inline void shrink_free_pagepool(struct xen_blkif_ring *ring, int num)
#define vaddr(page) ((unsigned long)pfn_to_kaddr(page_to_pfn(page)))
-static int do_block_io_op(struct xen_blkif_ring *ring);
+static int do_block_io_op(struct xen_blkif_ring *ring, unsigned int *eoi_flags);
static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
struct blkif_request *req,
struct pending_req *pending_req);
@@ -612,6 +612,8 @@ int xen_blkif_schedule(void *arg)
struct xen_vbd *vbd = &blkif->vbd;
unsigned long timeout;
int ret;
+ bool do_eoi;
+ unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
set_freezable();
while (!kthread_should_stop()) {
@@ -636,16 +638,23 @@ int xen_blkif_schedule(void *arg)
if (timeout == 0)
goto purge_gnt_list;
+ do_eoi = ring->waiting_reqs;
+
ring->waiting_reqs = 0;
smp_mb(); /* clear flag *before* checking for work */
- ret = do_block_io_op(ring);
+ ret = do_block_io_op(ring, &eoi_flags);
if (ret > 0)
ring->waiting_reqs = 1;
if (ret == -EACCES)
wait_event_interruptible(ring->shutdown_wq,
kthread_should_stop());
+ if (do_eoi && !ring->waiting_reqs) {
+ xen_irq_lateeoi(ring->irq, eoi_flags);
+ eoi_flags |= XEN_EOI_FLAG_SPURIOUS;
+ }
+
purge_gnt_list:
if (blkif->vbd.feature_gnt_persistent &&
time_after(jiffies, ring->next_lru)) {
@@ -1121,7 +1130,7 @@ static void end_block_io_op(struct bio *bio)
* and transmute it to the block API to hand it over to the proper block disk.
*/
static int
-__do_block_io_op(struct xen_blkif_ring *ring)
+__do_block_io_op(struct xen_blkif_ring *ring, unsigned int *eoi_flags)
{
union blkif_back_rings *blk_rings = &ring->blk_rings;
struct blkif_request req;
@@ -1144,6 +1153,9 @@ __do_block_io_op(struct xen_blkif_ring *ring)
if (RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, rc))
break;
+ /* We've seen a request, so clear spurious eoi flag. */
+ *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
+
if (kthread_should_stop()) {
more_to_do = 1;
break;
@@ -1202,13 +1214,13 @@ __do_block_io_op(struct xen_blkif_ring *ring)
}
static int
-do_block_io_op(struct xen_blkif_ring *ring)
+do_block_io_op(struct xen_blkif_ring *ring, unsigned int *eoi_flags)
{
union blkif_back_rings *blk_rings = &ring->blk_rings;
int more_to_do;
do {
- more_to_do = __do_block_io_op(ring);
+ more_to_do = __do_block_io_op(ring, eoi_flags);
if (more_to_do)
break;
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index b9aa5d1..5e7c36d 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -246,9 +246,8 @@ static int xen_blkif_map(struct xen_blkif_ring *ring, grant_ref_t *gref,
if (req_prod - rsp_prod > size)
goto fail;
- err = bind_interdomain_evtchn_to_irqhandler(blkif->domid, evtchn,
- xen_blkif_be_int, 0,
- "blkif-backend", ring);
+ err = bind_interdomain_evtchn_to_irqhandler_lateeoi(blkif->domid,
+ evtchn, xen_blkif_be_int, 0, "blkif-backend", ring);
if (err < 0)
goto fail;
ring->irq = err;
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h
index ae477f7..8ee24e3 100644
--- a/drivers/net/xen-netback/common.h
+++ b/drivers/net/xen-netback/common.h
@@ -140,6 +140,20 @@ struct xenvif_queue { /* Per-queue data for xenvif */
char name[QUEUE_NAME_SIZE]; /* DEVNAME-qN */
struct xenvif *vif; /* Parent VIF */
+ /*
+ * TX/RX common EOI handling.
+ * When feature-split-event-channels = 0, interrupt handler sets
+ * NETBK_COMMON_EOI, otherwise NETBK_RX_EOI and NETBK_TX_EOI are set
+ * by the RX and TX interrupt handlers.
+ * RX and TX handler threads will issue an EOI when either
+ * NETBK_COMMON_EOI or their specific bits (NETBK_RX_EOI or
+ * NETBK_TX_EOI) are set and they will reset those bits.
+ */
+ atomic_t eoi_pending;
+#define NETBK_RX_EOI 0x01
+#define NETBK_TX_EOI 0x02
+#define NETBK_COMMON_EOI 0x04
+
/* Use NAPI for guest TX */
struct napi_struct napi;
/* When feature-split-event-channels = 0, tx_irq = rx_irq. */
@@ -378,6 +392,7 @@ int xenvif_dealloc_kthread(void *data);
irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data);
+bool xenvif_have_rx_work(struct xenvif_queue *queue, bool test_kthread);
void xenvif_rx_action(struct xenvif_queue *queue);
void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index 8af49728..acb786d 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -77,12 +77,28 @@ int xenvif_schedulable(struct xenvif *vif)
!vif->disabled;
}
+static bool xenvif_handle_tx_interrupt(struct xenvif_queue *queue)
+{
+ bool rc;
+
+ rc = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx);
+ if (rc)
+ napi_schedule(&queue->napi);
+ return rc;
+}
+
static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
{
struct xenvif_queue *queue = dev_id;
+ int old;
- if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))
- napi_schedule(&queue->napi);
+ old = atomic_fetch_or(NETBK_TX_EOI, &queue->eoi_pending);
+ WARN(old & NETBK_TX_EOI, "Interrupt while EOI pending\n");
+
+ if (!xenvif_handle_tx_interrupt(queue)) {
+ atomic_andnot(NETBK_TX_EOI, &queue->eoi_pending);
+ xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS);
+ }
return IRQ_HANDLED;
}
@@ -116,19 +132,46 @@ static int xenvif_poll(struct napi_struct *napi, int budget)
return work_done;
}
+static bool xenvif_handle_rx_interrupt(struct xenvif_queue *queue)
+{
+ bool rc;
+
+ rc = xenvif_have_rx_work(queue, false);
+ if (rc)
+ xenvif_kick_thread(queue);
+ return rc;
+}
+
static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
{
struct xenvif_queue *queue = dev_id;
+ int old;
- xenvif_kick_thread(queue);
+ old = atomic_fetch_or(NETBK_RX_EOI, &queue->eoi_pending);
+ WARN(old & NETBK_RX_EOI, "Interrupt while EOI pending\n");
+
+ if (!xenvif_handle_rx_interrupt(queue)) {
+ atomic_andnot(NETBK_RX_EOI, &queue->eoi_pending);
+ xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS);
+ }
return IRQ_HANDLED;
}
irqreturn_t xenvif_interrupt(int irq, void *dev_id)
{
- xenvif_tx_interrupt(irq, dev_id);
- xenvif_rx_interrupt(irq, dev_id);
+ struct xenvif_queue *queue = dev_id;
+ int old;
+
+ old = atomic_fetch_or(NETBK_COMMON_EOI, &queue->eoi_pending);
+ WARN(old, "Interrupt while EOI pending\n");
+
+ /* Use bitwise or as we need to call both functions. */
+ if ((!xenvif_handle_tx_interrupt(queue) |
+ !xenvif_handle_rx_interrupt(queue))) {
+ atomic_andnot(NETBK_COMMON_EOI, &queue->eoi_pending);
+ xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS);
+ }
return IRQ_HANDLED;
}
@@ -605,7 +648,7 @@ int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
if (req_prod - rsp_prod > RING_SIZE(&vif->ctrl))
goto err_unmap;
- err = bind_interdomain_evtchn_to_irq(vif->domid, evtchn);
+ err = bind_interdomain_evtchn_to_irq_lateeoi(vif->domid, evtchn);
if (err < 0)
goto err_unmap;
@@ -709,7 +752,7 @@ int xenvif_connect_data(struct xenvif_queue *queue,
if (tx_evtchn == rx_evtchn) {
/* feature-split-event-channels == 0 */
- err = bind_interdomain_evtchn_to_irqhandler(
+ err = bind_interdomain_evtchn_to_irqhandler_lateeoi(
queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,
queue->name, queue);
if (err < 0)
@@ -720,7 +763,7 @@ int xenvif_connect_data(struct xenvif_queue *queue,
/* feature-split-event-channels == 1 */
snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
"%s-tx", queue->name);
- err = bind_interdomain_evtchn_to_irqhandler(
+ err = bind_interdomain_evtchn_to_irqhandler_lateeoi(
queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
queue->tx_irq_name, queue);
if (err < 0)
@@ -730,7 +773,7 @@ int xenvif_connect_data(struct xenvif_queue *queue,
snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
"%s-rx", queue->name);
- err = bind_interdomain_evtchn_to_irqhandler(
+ err = bind_interdomain_evtchn_to_irqhandler_lateeoi(
queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
queue->rx_irq_name, queue);
if (err < 0)
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 6dfca72..bc3421d 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -169,6 +169,10 @@ void xenvif_napi_schedule_or_enable_events(struct xenvif_queue *queue)
if (more_to_do)
napi_schedule(&queue->napi);
+ else if (atomic_fetch_andnot(NETBK_TX_EOI | NETBK_COMMON_EOI,
+ &queue->eoi_pending) &
+ (NETBK_TX_EOI | NETBK_COMMON_EOI))
+ xen_irq_lateeoi(queue->tx_irq, 0);
}
static void tx_add_credit(struct xenvif_queue *queue)
@@ -1643,9 +1647,14 @@ static bool xenvif_ctrl_work_todo(struct xenvif *vif)
irqreturn_t xenvif_ctrl_irq_fn(int irq, void *data)
{
struct xenvif *vif = data;
+ unsigned int eoi_flag = XEN_EOI_FLAG_SPURIOUS;
- while (xenvif_ctrl_work_todo(vif))
+ while (xenvif_ctrl_work_todo(vif)) {
xenvif_ctrl_action(vif);
+ eoi_flag = 0;
+ }
+
+ xen_irq_lateeoi(irq, eoi_flag);
return IRQ_HANDLED;
}
diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c
index ac034f6..b8febe1 100644
--- a/drivers/net/xen-netback/rx.c
+++ b/drivers/net/xen-netback/rx.c
@@ -503,13 +503,13 @@ static bool xenvif_rx_queue_ready(struct xenvif_queue *queue)
return queue->stalled && prod - cons >= 1;
}
-static bool xenvif_have_rx_work(struct xenvif_queue *queue)
+bool xenvif_have_rx_work(struct xenvif_queue *queue, bool test_kthread)
{
return xenvif_rx_ring_slots_available(queue) ||
(queue->vif->stall_timeout &&
(xenvif_rx_queue_stalled(queue) ||
xenvif_rx_queue_ready(queue))) ||
- kthread_should_stop() ||
+ (test_kthread && kthread_should_stop()) ||
queue->vif->disabled;
}
@@ -540,15 +540,20 @@ static void xenvif_wait_for_rx_work(struct xenvif_queue *queue)
{
DEFINE_WAIT(wait);
- if (xenvif_have_rx_work(queue))
+ if (xenvif_have_rx_work(queue, true))
return;
for (;;) {
long ret;
prepare_to_wait(&queue->wq, &wait, TASK_INTERRUPTIBLE);
- if (xenvif_have_rx_work(queue))
+ if (xenvif_have_rx_work(queue, true))
break;
+ if (atomic_fetch_andnot(NETBK_RX_EOI | NETBK_COMMON_EOI,
+ &queue->eoi_pending) &
+ (NETBK_RX_EOI | NETBK_COMMON_EOI))
+ xen_irq_lateeoi(queue->rx_irq, 0);
+
ret = schedule_timeout(xenvif_rx_queue_timeout(queue));
if (!ret)
break;
diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c
index 64df919..fe5ad0e 100644
--- a/drivers/xen/events/events_2l.c
+++ b/drivers/xen/events/events_2l.c
@@ -91,6 +91,8 @@ static void evtchn_2l_unmask(evtchn_port_t port)
BUG_ON(!irqs_disabled());
+ smp_wmb(); /* All writes before unmask must be visible. */
+
if (unlikely((cpu != cpu_from_evtchn(port))))
do_hypercall = 1;
else {
@@ -159,7 +161,7 @@ static inline xen_ulong_t active_evtchns(unsigned int cpu,
* a bitset of words which contain pending event bits. The second
* level is a bitset of pending events themselves.
*/
-static void evtchn_2l_handle_events(unsigned cpu)
+static void evtchn_2l_handle_events(unsigned cpu, struct evtchn_loop_ctrl *ctrl)
{
int irq;
xen_ulong_t pending_words;
@@ -240,10 +242,7 @@ static void evtchn_2l_handle_events(unsigned cpu)
/* Process port. */
port = (word_idx * BITS_PER_EVTCHN_WORD) + bit_idx;
- irq = get_evtchn_to_irq(port);
-
- if (irq != -1)
- generic_handle_irq(irq);
+ handle_irq_for_port(port, ctrl);
bit_idx = (bit_idx + 1) % BITS_PER_EVTCHN_WORD;
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 6f02c18..cc31773 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -33,6 +33,10 @@
#include <linux/slab.h>
#include <linux/irqnr.h>
#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/cpuhotplug.h>
+#include <linux/atomic.h>
+#include <linux/ktime.h>
#ifdef CONFIG_X86
#include <asm/desc.h>
@@ -63,6 +67,15 @@
#include "events_internal.h"
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "xen."
+
+static uint __read_mostly event_loop_timeout = 2;
+module_param(event_loop_timeout, uint, 0644);
+
+static uint __read_mostly event_eoi_delay = 10;
+module_param(event_eoi_delay, uint, 0644);
+
const struct evtchn_ops *evtchn_ops;
/*
@@ -71,6 +84,24 @@ const struct evtchn_ops *evtchn_ops;
*/
static DEFINE_MUTEX(irq_mapping_update_lock);
+/*
+ * Lock protecting event handling loop against removing event channels.
+ * Adding of event channels is no issue as the associated IRQ becomes active
+ * only after everything is setup (before request_[threaded_]irq() the handler
+ * can't be entered for an event, as the event channel will be unmasked only
+ * then).
+ */
+static DEFINE_RWLOCK(evtchn_rwlock);
+
+/*
+ * Lock hierarchy:
+ *
+ * irq_mapping_update_lock
+ * evtchn_rwlock
+ * IRQ-desc lock
+ * percpu eoi_list_lock
+ */
+
static LIST_HEAD(xen_irq_list_head);
/* IRQ <-> VIRQ mapping. */
@@ -95,17 +126,20 @@ static bool (*pirq_needs_eoi)(unsigned irq);
static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY];
static struct irq_chip xen_dynamic_chip;
+static struct irq_chip xen_lateeoi_chip;
static struct irq_chip xen_percpu_chip;
static struct irq_chip xen_pirq_chip;
static void enable_dynirq(struct irq_data *data);
static void disable_dynirq(struct irq_data *data);
+static DEFINE_PER_CPU(unsigned int, irq_epoch);
+
static void clear_evtchn_to_irq_row(unsigned row)
{
unsigned col;
for (col = 0; col < EVTCHN_PER_ROW; col++)
- evtchn_to_irq[row][col] = -1;
+ WRITE_ONCE(evtchn_to_irq[row][col], -1);
}
static void clear_evtchn_to_irq_all(void)
@@ -142,7 +176,7 @@ static int set_evtchn_to_irq(evtchn_port_t evtchn, unsigned int irq)
clear_evtchn_to_irq_row(row);
}
- evtchn_to_irq[row][col] = irq;
+ WRITE_ONCE(evtchn_to_irq[row][col], irq);
return 0;
}
@@ -152,7 +186,7 @@ int get_evtchn_to_irq(evtchn_port_t evtchn)
return -1;
if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
return -1;
- return evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)];
+ return READ_ONCE(evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)]);
}
/* Get info for IRQ */
@@ -261,10 +295,14 @@ static void xen_irq_info_cleanup(struct irq_info *info)
*/
evtchn_port_t evtchn_from_irq(unsigned irq)
{
- if (WARN(irq >= nr_irqs, "Invalid irq %d!\n", irq))
+ const struct irq_info *info = NULL;
+
+ if (likely(irq < nr_irqs))
+ info = info_for_irq(irq);
+ if (!info)
return 0;
- return info_for_irq(irq)->evtchn;
+ return info->evtchn;
}
unsigned int irq_from_evtchn(evtchn_port_t evtchn)
@@ -375,9 +413,157 @@ void notify_remote_via_irq(int irq)
}
EXPORT_SYMBOL_GPL(notify_remote_via_irq);
+struct lateeoi_work {
+ struct delayed_work delayed;
+ spinlock_t eoi_list_lock;
+ struct list_head eoi_list;
+};
+
+static DEFINE_PER_CPU(struct lateeoi_work, lateeoi);
+
+static void lateeoi_list_del(struct irq_info *info)
+{
+ struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu);
+ unsigned long flags;
+
+ spin_lock_irqsave(&eoi->eoi_list_lock, flags);
+ list_del_init(&info->eoi_list);
+ spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
+}
+
+static void lateeoi_list_add(struct irq_info *info)
+{
+ struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu);
+ struct irq_info *elem;
+ u64 now = get_jiffies_64();
+ unsigned long delay;
+ unsigned long flags;
+
+ if (now < info->eoi_time)
+ delay = info->eoi_time - now;
+ else
+ delay = 1;
+
+ spin_lock_irqsave(&eoi->eoi_list_lock, flags);
+
+ if (list_empty(&eoi->eoi_list)) {
+ list_add(&info->eoi_list, &eoi->eoi_list);
+ mod_delayed_work_on(info->eoi_cpu, system_wq,
+ &eoi->delayed, delay);
+ } else {
+ list_for_each_entry_reverse(elem, &eoi->eoi_list, eoi_list) {
+ if (elem->eoi_time <= info->eoi_time)
+ break;
+ }
+ list_add(&info->eoi_list, &elem->eoi_list);
+ }
+
+ spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
+}
+
+static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious)
+{
+ evtchn_port_t evtchn;
+ unsigned int cpu;
+ unsigned int delay = 0;
+
+ evtchn = info->evtchn;
+ if (!VALID_EVTCHN(evtchn) || !list_empty(&info->eoi_list))
+ return;
+
+ if (spurious) {
+ if ((1 << info->spurious_cnt) < (HZ << 2))
+ info->spurious_cnt++;
+ if (info->spurious_cnt > 1) {
+ delay = 1 << (info->spurious_cnt - 2);
+ if (delay > HZ)
+ delay = HZ;
+ if (!info->eoi_time)
+ info->eoi_cpu = smp_processor_id();
+ info->eoi_time = get_jiffies_64() + delay;
+ }
+ } else {
+ info->spurious_cnt = 0;
+ }
+
+ cpu = info->eoi_cpu;
+ if (info->eoi_time &&
+ (info->irq_epoch == per_cpu(irq_epoch, cpu) || delay)) {
+ lateeoi_list_add(info);
+ return;
+ }
+
+ info->eoi_time = 0;
+ unmask_evtchn(evtchn);
+}
+
+static void xen_irq_lateeoi_worker(struct work_struct *work)
+{
+ struct lateeoi_work *eoi;
+ struct irq_info *info;
+ u64 now = get_jiffies_64();
+ unsigned long flags;
+
+ eoi = container_of(to_delayed_work(work), struct lateeoi_work, delayed);
+
+ read_lock_irqsave(&evtchn_rwlock, flags);
+
+ while (true) {
+ spin_lock(&eoi->eoi_list_lock);
+
+ info = list_first_entry_or_null(&eoi->eoi_list, struct irq_info,
+ eoi_list);
+
+ if (info == NULL || now < info->eoi_time) {
+ spin_unlock(&eoi->eoi_list_lock);
+ break;
+ }
+
+ list_del_init(&info->eoi_list);
+
+ spin_unlock(&eoi->eoi_list_lock);
+
+ info->eoi_time = 0;
+
+ xen_irq_lateeoi_locked(info, false);
+ }
+
+ if (info)
+ mod_delayed_work_on(info->eoi_cpu, system_wq,
+ &eoi->delayed, info->eoi_time - now);
+
+ read_unlock_irqrestore(&evtchn_rwlock, flags);
+}
+
+static void xen_cpu_init_eoi(unsigned int cpu)
+{
+ struct lateeoi_work *eoi = &per_cpu(lateeoi, cpu);
+
+ INIT_DELAYED_WORK(&eoi->delayed, xen_irq_lateeoi_worker);
+ spin_lock_init(&eoi->eoi_list_lock);
+ INIT_LIST_HEAD(&eoi->eoi_list);
+}
+
+void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags)
+{
+ struct irq_info *info;
+ unsigned long flags;
+
+ read_lock_irqsave(&evtchn_rwlock, flags);
+
+ info = info_for_irq(irq);
+
+ if (info)
+ xen_irq_lateeoi_locked(info, eoi_flags & XEN_EOI_FLAG_SPURIOUS);
+
+ read_unlock_irqrestore(&evtchn_rwlock, flags);
+}
+EXPORT_SYMBOL_GPL(xen_irq_lateeoi);
+
static void xen_irq_init(unsigned irq)
{
struct irq_info *info;
+
#ifdef CONFIG_SMP
/* By default all event channels notify CPU#0. */
cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(0));
@@ -392,6 +578,7 @@ static void xen_irq_init(unsigned irq)
set_info_for_irq(irq, info);
+ INIT_LIST_HEAD(&info->eoi_list);
list_add_tail(&info->list, &xen_irq_list_head);
}
@@ -440,16 +627,24 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi)
static void xen_free_irq(unsigned irq)
{
struct irq_info *info = info_for_irq(irq);
+ unsigned long flags;
if (WARN_ON(!info))
return;
+ write_lock_irqsave(&evtchn_rwlock, flags);
+
+ if (!list_empty(&info->eoi_list))
+ lateeoi_list_del(info);
+
list_del(&info->list);
set_info_for_irq(irq, NULL);
WARN_ON(info->refcnt > 0);
+ write_unlock_irqrestore(&evtchn_rwlock, flags);
+
kfree(info);
/* Legacy IRQ descriptors are managed by the arch. */
@@ -841,7 +1036,7 @@ int xen_pirq_from_irq(unsigned irq)
}
EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
-int bind_evtchn_to_irq(evtchn_port_t evtchn)
+static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip)
{
int irq;
int ret;
@@ -858,7 +1053,7 @@ int bind_evtchn_to_irq(evtchn_port_t evtchn)
if (irq < 0)
goto out;
- irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
+ irq_set_chip_and_handler_name(irq, chip,
handle_edge_irq, "event");
ret = xen_irq_info_evtchn_setup(irq, evtchn);
@@ -879,8 +1074,19 @@ int bind_evtchn_to_irq(evtchn_port_t evtchn)
return irq;
}
+
+int bind_evtchn_to_irq(evtchn_port_t evtchn)
+{
+ return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip);
+}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
+int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn)
+{
+ return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi);
+
static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
{
struct evtchn_bind_ipi bind_ipi;
@@ -922,8 +1128,9 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
return irq;
}
-int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
- evtchn_port_t remote_port)
+static int bind_interdomain_evtchn_to_irq_chip(unsigned int remote_domain,
+ evtchn_port_t remote_port,
+ struct irq_chip *chip)
{
struct evtchn_bind_interdomain bind_interdomain;
int err;
@@ -934,10 +1141,26 @@ int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
&bind_interdomain);
- return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
+ return err ? : bind_evtchn_to_irq_chip(bind_interdomain.local_port,
+ chip);
+}
+
+int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
+ evtchn_port_t remote_port)
+{
+ return bind_interdomain_evtchn_to_irq_chip(remote_domain, remote_port,
+ &xen_dynamic_chip);
}
EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq);
+int bind_interdomain_evtchn_to_irq_lateeoi(unsigned int remote_domain,
+ evtchn_port_t remote_port)
+{
+ return bind_interdomain_evtchn_to_irq_chip(remote_domain, remote_port,
+ &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq_lateeoi);
+
static int find_virq(unsigned int virq, unsigned int cpu, evtchn_port_t *evtchn)
{
struct evtchn_status status;
@@ -1034,14 +1257,15 @@ static void unbind_from_irq(unsigned int irq)
mutex_unlock(&irq_mapping_update_lock);
}
-int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
- irq_handler_t handler,
- unsigned long irqflags,
- const char *devname, void *dev_id)
+static int bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname, void *dev_id,
+ struct irq_chip *chip)
{
int irq, retval;
- irq = bind_evtchn_to_irq(evtchn);
+ irq = bind_evtchn_to_irq_chip(evtchn, chip);
if (irq < 0)
return irq;
retval = request_irq(irq, handler, irqflags, devname, dev_id);
@@ -1052,8 +1276,50 @@ int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
return irq;
}
+
+int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname, void *dev_id)
+{
+ return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
+ devname, dev_id,
+ &xen_dynamic_chip);
+}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
+int bind_evtchn_to_irqhandler_lateeoi(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname, void *dev_id)
+{
+ return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
+ devname, dev_id,
+ &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler_lateeoi);
+
+static int bind_interdomain_evtchn_to_irqhandler_chip(
+ unsigned int remote_domain, evtchn_port_t remote_port,
+ irq_handler_t handler, unsigned long irqflags,
+ const char *devname, void *dev_id, struct irq_chip *chip)
+{
+ int irq, retval;
+
+ irq = bind_interdomain_evtchn_to_irq_chip(remote_domain, remote_port,
+ chip);
+ if (irq < 0)
+ return irq;
+
+ retval = request_irq(irq, handler, irqflags, devname, dev_id);
+ if (retval != 0) {
+ unbind_from_irq(irq);
+ return retval;
+ }
+
+ return irq;
+}
+
int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
evtchn_port_t remote_port,
irq_handler_t handler,
@@ -1061,22 +1327,25 @@ int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
const char *devname,
void *dev_id)
{
- int irq, retval;
-
- irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
- if (irq < 0)
- return irq;
-
- retval = request_irq(irq, handler, irqflags, devname, dev_id);
- if (retval != 0) {
- unbind_from_irq(irq);
- return retval;
- }
-
- return irq;
+ return bind_interdomain_evtchn_to_irqhandler_chip(remote_domain,
+ remote_port, handler, irqflags, devname,
+ dev_id, &xen_dynamic_chip);
}
EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
+int bind_interdomain_evtchn_to_irqhandler_lateeoi(unsigned int remote_domain,
+ evtchn_port_t remote_port,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname,
+ void *dev_id)
+{
+ return bind_interdomain_evtchn_to_irqhandler_chip(remote_domain,
+ remote_port, handler, irqflags, devname,
+ dev_id, &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler_lateeoi);
+
int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
irq_handler_t handler,
unsigned long irqflags, const char *devname, void *dev_id)
@@ -1189,7 +1458,7 @@ int evtchn_get(evtchn_port_t evtchn)
goto done;
err = -EINVAL;
- if (info->refcnt <= 0)
+ if (info->refcnt <= 0 || info->refcnt == SHRT_MAX)
goto done;
info->refcnt++;
@@ -1228,21 +1497,81 @@ void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
notify_remote_via_irq(irq);
}
+struct evtchn_loop_ctrl {
+ ktime_t timeout;
+ unsigned count;
+ bool defer_eoi;
+};
+
+void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
+{
+ int irq;
+ struct irq_info *info;
+
+ irq = get_evtchn_to_irq(port);
+ if (irq == -1)
+ return;
+
+ /*
+ * Check for timeout every 256 events.
+ * We are setting the timeout value only after the first 256
+ * events in order to not hurt the common case of few loop
+ * iterations. The 256 is basically an arbitrary value.
+ *
+ * In case we are hitting the timeout we need to defer all further
+ * EOIs in order to ensure to leave the event handling loop rather
+ * sooner than later.
+ */
+ if (!ctrl->defer_eoi && !(++ctrl->count & 0xff)) {
+ ktime_t kt = ktime_get();
+
+ if (!ctrl->timeout) {
+ kt = ktime_add_ms(kt,
+ jiffies_to_msecs(event_loop_timeout));
+ ctrl->timeout = kt;
+ } else if (kt > ctrl->timeout) {
+ ctrl->defer_eoi = true;
+ }
+ }
+
+ info = info_for_irq(irq);
+
+ if (ctrl->defer_eoi) {
+ info->eoi_cpu = smp_processor_id();
+ info->irq_epoch = __this_cpu_read(irq_epoch);
+ info->eoi_time = get_jiffies_64() + event_eoi_delay;
+ }
+
+ generic_handle_irq(irq);
+}
+
static void __xen_evtchn_do_upcall(void)
{
struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
int cpu = smp_processor_id();
+ struct evtchn_loop_ctrl ctrl = { 0 };
+
+ read_lock(&evtchn_rwlock);
do {
vcpu_info->evtchn_upcall_pending = 0;
- xen_evtchn_handle_events(cpu);
+ xen_evtchn_handle_events(cpu, &ctrl);
BUG_ON(!irqs_disabled());
virt_rmb(); /* Hypervisor can set upcall pending. */
} while (vcpu_info->evtchn_upcall_pending);
+
+ read_unlock(&evtchn_rwlock);
+
+ /*
+ * Increment irq_epoch only now to defer EOIs only for
+ * xen_irq_lateeoi() invocations occurring from inside the loop
+ * above.
+ */
+ __this_cpu_inc(irq_epoch);
}
void xen_evtchn_do_upcall(struct pt_regs *regs)
@@ -1606,6 +1935,21 @@ static struct irq_chip xen_dynamic_chip __read_mostly = {
.irq_retrigger = retrigger_dynirq,
};
+static struct irq_chip xen_lateeoi_chip __read_mostly = {
+ /* The chip name needs to contain "xen-dyn" for irqbalance to work. */
+ .name = "xen-dyn-lateeoi",
+
+ .irq_disable = disable_dynirq,
+ .irq_mask = disable_dynirq,
+ .irq_unmask = enable_dynirq,
+
+ .irq_ack = mask_ack_dynirq,
+ .irq_mask_ack = mask_ack_dynirq,
+
+ .irq_set_affinity = set_affinity_irq,
+ .irq_retrigger = retrigger_dynirq,
+};
+
static struct irq_chip xen_pirq_chip __read_mostly = {
.name = "xen-pirq",
@@ -1676,12 +2020,31 @@ void xen_setup_callback_vector(void) {}
static inline void xen_alloc_callback_vector(void) {}
#endif
-#undef MODULE_PARAM_PREFIX
-#define MODULE_PARAM_PREFIX "xen."
-
static bool fifo_events = true;
module_param(fifo_events, bool, 0);
+static int xen_evtchn_cpu_prepare(unsigned int cpu)
+{
+ int ret = 0;
+
+ xen_cpu_init_eoi(cpu);
+
+ if (evtchn_ops->percpu_init)
+ ret = evtchn_ops->percpu_init(cpu);
+
+ return ret;
+}
+
+static int xen_evtchn_cpu_dead(unsigned int cpu)
+{
+ int ret = 0;
+
+ if (evtchn_ops->percpu_deinit)
+ ret = evtchn_ops->percpu_deinit(cpu);
+
+ return ret;
+}
+
void __init xen_init_IRQ(void)
{
int ret = -EINVAL;
@@ -1692,6 +2055,12 @@ void __init xen_init_IRQ(void)
if (ret < 0)
xen_evtchn_2l_init();
+ xen_cpu_init_eoi(smp_processor_id());
+
+ cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
+ "xen/evtchn:prepare",
+ xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
+
evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
sizeof(*evtchn_to_irq), GFP_KERNEL);
BUG_ON(!evtchn_to_irq);
diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c
index c60ee04..6085a80 100644
--- a/drivers/xen/events/events_fifo.c
+++ b/drivers/xen/events/events_fifo.c
@@ -227,19 +227,25 @@ static bool evtchn_fifo_is_masked(evtchn_port_t port)
return sync_test_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
}
/*
- * Clear MASKED, spinning if BUSY is set.
+ * Clear MASKED if not PENDING, spinning if BUSY is set.
+ * Return true if mask was cleared.
*/
-static void clear_masked(volatile event_word_t *word)
+static bool clear_masked_cond(volatile event_word_t *word)
{
event_word_t new, old, w;
w = *word;
do {
+ if (w & (1 << EVTCHN_FIFO_PENDING))
+ return false;
+
old = w & ~(1 << EVTCHN_FIFO_BUSY);
new = old & ~(1 << EVTCHN_FIFO_MASKED);
w = sync_cmpxchg(word, old, new);
} while (w != old);
+
+ return true;
}
static void evtchn_fifo_unmask(evtchn_port_t port)
@@ -248,8 +254,7 @@ static void evtchn_fifo_unmask(evtchn_port_t port)
BUG_ON(!irqs_disabled());
- clear_masked(word);
- if (evtchn_fifo_is_pending(port)) {
+ if (!clear_masked_cond(word)) {
struct evtchn_unmask unmask = { .port = port };
(void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
}
@@ -270,19 +275,9 @@ static uint32_t clear_linked(volatile event_word_t *word)
return w & EVTCHN_FIFO_LINK_MASK;
}
-static void handle_irq_for_port(evtchn_port_t port)
-{
- int irq;
-
- irq = get_evtchn_to_irq(port);
- if (irq != -1)
- generic_handle_irq(irq);
-}
-
-static void consume_one_event(unsigned cpu,
+static void consume_one_event(unsigned cpu, struct evtchn_loop_ctrl *ctrl,
struct evtchn_fifo_control_block *control_block,
- unsigned priority, unsigned long *ready,
- bool drop)
+ unsigned priority, unsigned long *ready)
{
struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu);
uint32_t head;
@@ -315,16 +310,17 @@ static void consume_one_event(unsigned cpu,
clear_bit(priority, ready);
if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port)) {
- if (unlikely(drop))
+ if (unlikely(!ctrl))
pr_warn("Dropping pending event for port %u\n", port);
else
- handle_irq_for_port(port);
+ handle_irq_for_port(port, ctrl);
}
q->head[priority] = head;
}
-static void __evtchn_fifo_handle_events(unsigned cpu, bool drop)
+static void __evtchn_fifo_handle_events(unsigned cpu,
+ struct evtchn_loop_ctrl *ctrl)
{
struct evtchn_fifo_control_block *control_block;
unsigned long ready;
@@ -336,14 +332,15 @@ static void __evtchn_fifo_handle_events(unsigned cpu, bool drop)
while (ready) {
q = find_first_bit(&ready, EVTCHN_FIFO_MAX_QUEUES);
- consume_one_event(cpu, control_block, q, &ready, drop);
+ consume_one_event(cpu, ctrl, control_block, q, &ready);
ready |= xchg(&control_block->ready, 0);
}
}
-static void evtchn_fifo_handle_events(unsigned cpu)
+static void evtchn_fifo_handle_events(unsigned cpu,
+ struct evtchn_loop_ctrl *ctrl)
{
- __evtchn_fifo_handle_events(cpu, false);
+ __evtchn_fifo_handle_events(cpu, ctrl);
}
static void evtchn_fifo_resume(void)
@@ -380,21 +377,6 @@ static void evtchn_fifo_resume(void)
event_array_pages = 0;
}
-static const struct evtchn_ops evtchn_ops_fifo = {
- .max_channels = evtchn_fifo_max_channels,
- .nr_channels = evtchn_fifo_nr_channels,
- .setup = evtchn_fifo_setup,
- .bind_to_cpu = evtchn_fifo_bind_to_cpu,
- .clear_pending = evtchn_fifo_clear_pending,
- .set_pending = evtchn_fifo_set_pending,
- .is_pending = evtchn_fifo_is_pending,
- .test_and_set_mask = evtchn_fifo_test_and_set_mask,
- .mask = evtchn_fifo_mask,
- .unmask = evtchn_fifo_unmask,
- .handle_events = evtchn_fifo_handle_events,
- .resume = evtchn_fifo_resume,
-};
-
static int evtchn_fifo_alloc_control_block(unsigned cpu)
{
void *control_block = NULL;
@@ -417,19 +399,36 @@ static int evtchn_fifo_alloc_control_block(unsigned cpu)
return ret;
}
-static int xen_evtchn_cpu_prepare(unsigned int cpu)
+static int evtchn_fifo_percpu_init(unsigned int cpu)
{
if (!per_cpu(cpu_control_block, cpu))
return evtchn_fifo_alloc_control_block(cpu);
return 0;
}
-static int xen_evtchn_cpu_dead(unsigned int cpu)
+static int evtchn_fifo_percpu_deinit(unsigned int cpu)
{
- __evtchn_fifo_handle_events(cpu, true);
+ __evtchn_fifo_handle_events(cpu, NULL);
return 0;
}
+static const struct evtchn_ops evtchn_ops_fifo = {
+ .max_channels = evtchn_fifo_max_channels,
+ .nr_channels = evtchn_fifo_nr_channels,
+ .setup = evtchn_fifo_setup,
+ .bind_to_cpu = evtchn_fifo_bind_to_cpu,
+ .clear_pending = evtchn_fifo_clear_pending,
+ .set_pending = evtchn_fifo_set_pending,
+ .is_pending = evtchn_fifo_is_pending,
+ .test_and_set_mask = evtchn_fifo_test_and_set_mask,
+ .mask = evtchn_fifo_mask,
+ .unmask = evtchn_fifo_unmask,
+ .handle_events = evtchn_fifo_handle_events,
+ .resume = evtchn_fifo_resume,
+ .percpu_init = evtchn_fifo_percpu_init,
+ .percpu_deinit = evtchn_fifo_percpu_deinit,
+};
+
int __init xen_evtchn_fifo_init(void)
{
int cpu = smp_processor_id();
@@ -443,9 +442,5 @@ int __init xen_evtchn_fifo_init(void)
evtchn_ops = &evtchn_ops_fifo;
- cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
- "xen/evtchn:prepare",
- xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
-
return ret;
}
diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h
index 10684fe..82937d9 100644
--- a/drivers/xen/events/events_internal.h
+++ b/drivers/xen/events/events_internal.h
@@ -30,11 +30,16 @@ enum xen_irq_type {
*/
struct irq_info {
struct list_head list;
- int refcnt;
+ struct list_head eoi_list;
+ short refcnt;
+ short spurious_cnt;
enum xen_irq_type type; /* type */
unsigned irq;
evtchn_port_t evtchn; /* event channel */
unsigned short cpu; /* cpu bound */
+ unsigned short eoi_cpu; /* EOI must happen on this cpu */
+ unsigned int irq_epoch; /* If eoi_cpu valid: irq_epoch of event */
+ u64 eoi_time; /* Time in jiffies when to EOI. */
union {
unsigned short virq;
@@ -53,6 +58,8 @@ struct irq_info {
#define PIRQ_SHAREABLE (1 << 1)
#define PIRQ_MSI_GROUP (1 << 2)
+struct evtchn_loop_ctrl;
+
struct evtchn_ops {
unsigned (*max_channels)(void);
unsigned (*nr_channels)(void);
@@ -67,14 +74,18 @@ struct evtchn_ops {
void (*mask)(evtchn_port_t port);
void (*unmask)(evtchn_port_t port);
- void (*handle_events)(unsigned cpu);
+ void (*handle_events)(unsigned cpu, struct evtchn_loop_ctrl *ctrl);
void (*resume)(void);
+
+ int (*percpu_init)(unsigned int cpu);
+ int (*percpu_deinit)(unsigned int cpu);
};
extern const struct evtchn_ops *evtchn_ops;
extern int **evtchn_to_irq;
int get_evtchn_to_irq(evtchn_port_t evtchn);
+void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl);
struct irq_info *info_for_irq(unsigned irq);
unsigned cpu_from_irq(unsigned irq);
@@ -132,9 +143,10 @@ static inline void unmask_evtchn(evtchn_port_t port)
return evtchn_ops->unmask(port);
}
-static inline void xen_evtchn_handle_events(unsigned cpu)
+static inline void xen_evtchn_handle_events(unsigned cpu,
+ struct evtchn_loop_ctrl *ctrl)
{
- return evtchn_ops->handle_events(cpu);
+ return evtchn_ops->handle_events(cpu, ctrl);
}
static inline void xen_evtchn_resume(void)
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index 6e0b1dd..5dc016d 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -167,7 +167,6 @@ static irqreturn_t evtchn_interrupt(int irq, void *data)
"Interrupt for port %u, but apparently not enabled; per-user %p\n",
evtchn->port, u);
- disable_irq_nosync(irq);
evtchn->enabled = false;
spin_lock(&u->ring_prod_lock);
@@ -293,7 +292,7 @@ static ssize_t evtchn_write(struct file *file, const char __user *buf,
evtchn = find_evtchn(u, port);
if (evtchn && !evtchn->enabled) {
evtchn->enabled = true;
- enable_irq(irq_from_evtchn(port));
+ xen_irq_lateeoi(irq_from_evtchn(port), 0);
}
}
@@ -393,8 +392,8 @@ static int evtchn_bind_to_user(struct per_user_data *u, evtchn_port_t port)
if (rc < 0)
goto err;
- rc = bind_evtchn_to_irqhandler(port, evtchn_interrupt, 0,
- u->name, evtchn);
+ rc = bind_evtchn_to_irqhandler_lateeoi(port, evtchn_interrupt, 0,
+ u->name, evtchn);
if (rc < 0)
goto err;
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
index 9eae1fc..a7d293f 100644
--- a/drivers/xen/pvcalls-back.c
+++ b/drivers/xen/pvcalls-back.c
@@ -66,6 +66,7 @@ struct sock_mapping {
atomic_t write;
atomic_t io;
atomic_t release;
+ atomic_t eoi;
void (*saved_data_ready)(struct sock *sk);
struct pvcalls_ioworker ioworker;
};
@@ -87,7 +88,7 @@ static int pvcalls_back_release_active(struct xenbus_device *dev,
struct pvcalls_fedata *fedata,
struct sock_mapping *map);
-static void pvcalls_conn_back_read(void *opaque)
+static bool pvcalls_conn_back_read(void *opaque)
{
struct sock_mapping *map = (struct sock_mapping *)opaque;
struct msghdr msg;
@@ -107,17 +108,17 @@ static void pvcalls_conn_back_read(void *opaque)
virt_mb();
if (error)
- return;
+ return false;
size = pvcalls_queued(prod, cons, array_size);
if (size >= array_size)
- return;
+ return false;
spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
if (skb_queue_empty(&map->sock->sk->sk_receive_queue)) {
atomic_set(&map->read, 0);
spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock,
flags);
- return;
+ return true;
}
spin_unlock_irqrestore(&map->sock->sk->sk_receive_queue.lock, flags);
wanted = array_size - size;
@@ -141,7 +142,7 @@ static void pvcalls_conn_back_read(void *opaque)
ret = inet_recvmsg(map->sock, &msg, wanted, MSG_DONTWAIT);
WARN_ON(ret > wanted);
if (ret == -EAGAIN) /* shouldn't happen */
- return;
+ return true;
if (!ret)
ret = -ENOTCONN;
spin_lock_irqsave(&map->sock->sk->sk_receive_queue.lock, flags);
@@ -160,10 +161,10 @@ static void pvcalls_conn_back_read(void *opaque)
virt_wmb();
notify_remote_via_irq(map->irq);
- return;
+ return true;
}
-static void pvcalls_conn_back_write(struct sock_mapping *map)
+static bool pvcalls_conn_back_write(struct sock_mapping *map)
{
struct pvcalls_data_intf *intf = map->ring;
struct pvcalls_data *data = &map->data;
@@ -180,7 +181,7 @@ static void pvcalls_conn_back_write(struct sock_mapping *map)
array_size = XEN_FLEX_RING_SIZE(map->ring_order);
size = pvcalls_queued(prod, cons, array_size);
if (size == 0)
- return;
+ return false;
memset(&msg, 0, sizeof(msg));
msg.msg_flags |= MSG_DONTWAIT;
@@ -198,12 +199,11 @@ static void pvcalls_conn_back_write(struct sock_mapping *map)
atomic_set(&map->write, 0);
ret = inet_sendmsg(map->sock, &msg, size);
- if (ret == -EAGAIN || (ret >= 0 && ret < size)) {
+ if (ret == -EAGAIN) {
atomic_inc(&map->write);
atomic_inc(&map->io);
+ return true;
}
- if (ret == -EAGAIN)
- return;
/* write the data, then update the indexes */
virt_wmb();
@@ -216,9 +216,13 @@ static void pvcalls_conn_back_write(struct sock_mapping *map)
}
/* update the indexes, then notify the other end */
virt_wmb();
- if (prod != cons + ret)
+ if (prod != cons + ret) {
atomic_inc(&map->write);
+ atomic_inc(&map->io);
+ }
notify_remote_via_irq(map->irq);
+
+ return true;
}
static void pvcalls_back_ioworker(struct work_struct *work)
@@ -227,6 +231,7 @@ static void pvcalls_back_ioworker(struct work_struct *work)
struct pvcalls_ioworker, register_work);
struct sock_mapping *map = container_of(ioworker, struct sock_mapping,
ioworker);
+ unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
while (atomic_read(&map->io) > 0) {
if (atomic_read(&map->release) > 0) {
@@ -234,10 +239,18 @@ static void pvcalls_back_ioworker(struct work_struct *work)
return;
}
- if (atomic_read(&map->read) > 0)
- pvcalls_conn_back_read(map);
- if (atomic_read(&map->write) > 0)
- pvcalls_conn_back_write(map);
+ if (atomic_read(&map->read) > 0 &&
+ pvcalls_conn_back_read(map))
+ eoi_flags = 0;
+ if (atomic_read(&map->write) > 0 &&
+ pvcalls_conn_back_write(map))
+ eoi_flags = 0;
+
+ if (atomic_read(&map->eoi) > 0 && !atomic_read(&map->write)) {
+ atomic_set(&map->eoi, 0);
+ xen_irq_lateeoi(map->irq, eoi_flags);
+ eoi_flags = XEN_EOI_FLAG_SPURIOUS;
+ }
atomic_dec(&map->io);
}
@@ -334,12 +347,9 @@ static struct sock_mapping *pvcalls_new_active_socket(
goto out;
map->bytes = page;
- ret = bind_interdomain_evtchn_to_irqhandler(fedata->dev->otherend_id,
- evtchn,
- pvcalls_back_conn_event,
- 0,
- "pvcalls-backend",
- map);
+ ret = bind_interdomain_evtchn_to_irqhandler_lateeoi(
+ fedata->dev->otherend_id, evtchn,
+ pvcalls_back_conn_event, 0, "pvcalls-backend", map);
if (ret < 0)
goto out;
map->irq = ret;
@@ -873,15 +883,18 @@ static irqreturn_t pvcalls_back_event(int irq, void *dev_id)
{
struct xenbus_device *dev = dev_id;
struct pvcalls_fedata *fedata = NULL;
+ unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
- if (dev == NULL)
- return IRQ_HANDLED;
+ if (dev) {
+ fedata = dev_get_drvdata(&dev->dev);
+ if (fedata) {
+ pvcalls_back_work(fedata);
+ eoi_flags = 0;
+ }
+ }
- fedata = dev_get_drvdata(&dev->dev);
- if (fedata == NULL)
- return IRQ_HANDLED;
+ xen_irq_lateeoi(irq, eoi_flags);
- pvcalls_back_work(fedata);
return IRQ_HANDLED;
}
@@ -891,12 +904,15 @@ static irqreturn_t pvcalls_back_conn_event(int irq, void *sock_map)
struct pvcalls_ioworker *iow;
if (map == NULL || map->sock == NULL || map->sock->sk == NULL ||
- map->sock->sk->sk_user_data != map)
+ map->sock->sk->sk_user_data != map) {
+ xen_irq_lateeoi(irq, 0);
return IRQ_HANDLED;
+ }
iow = &map->ioworker;
atomic_inc(&map->write);
+ atomic_inc(&map->eoi);
atomic_inc(&map->io);
queue_work(iow->wq, &iow->register_work);
@@ -932,7 +948,7 @@ static int backend_connect(struct xenbus_device *dev)
goto error;
}
- err = bind_interdomain_evtchn_to_irq(dev->otherend_id, evtchn);
+ err = bind_interdomain_evtchn_to_irq_lateeoi(dev->otherend_id, evtchn);
if (err < 0)
goto error;
fedata->irq = err;
diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index e876c3d..cb904ac 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -734,10 +734,17 @@ static pci_ers_result_t common_process(struct pcistub_device *psdev,
wmb();
notify_remote_via_irq(pdev->evtchn_irq);
+ /* Enable IRQ to signal "request done". */
+ xen_pcibk_lateeoi(pdev, 0);
+
ret = wait_event_timeout(xen_pcibk_aer_wait_queue,
!(test_bit(_XEN_PCIB_active, (unsigned long *)
&sh_info->flags)), 300*HZ);
+ /* Enable IRQ for pcifront request if not already active. */
+ if (!test_bit(_PDEVF_op_active, &pdev->flags))
+ xen_pcibk_lateeoi(pdev, 0);
+
if (!ret) {
if (test_bit(_XEN_PCIB_active,
(unsigned long *)&sh_info->flags)) {
@@ -751,12 +758,6 @@ static pci_ers_result_t common_process(struct pcistub_device *psdev,
}
clear_bit(_PCIB_op_pending, (unsigned long *)&pdev->flags);
- if (test_bit(_XEN_PCIF_active,
- (unsigned long *)&sh_info->flags)) {
- dev_dbg(&psdev->dev->dev, "schedule pci_conf service\n");
- xen_pcibk_test_and_schedule_op(psdev->pdev);
- }
-
res = (pci_ers_result_t)aer_op->err;
return res;
}
diff --git a/drivers/xen/xen-pciback/pciback.h b/drivers/xen/xen-pciback/pciback.h
index f1ed2db..95e28ee 100644
--- a/drivers/xen/xen-pciback/pciback.h
+++ b/drivers/xen/xen-pciback/pciback.h
@@ -14,6 +14,7 @@
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/atomic.h>
+#include <xen/events.h>
#include <xen/interface/io/pciif.h>
#define DRV_NAME "xen-pciback"
@@ -27,6 +28,8 @@ struct pci_dev_entry {
#define PDEVF_op_active (1<<(_PDEVF_op_active))
#define _PCIB_op_pending (1)
#define PCIB_op_pending (1<<(_PCIB_op_pending))
+#define _EOI_pending (2)
+#define EOI_pending (1<<(_EOI_pending))
struct xen_pcibk_device {
void *pci_dev_data;
@@ -183,10 +186,15 @@ static inline void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id);
void xen_pcibk_do_op(struct work_struct *data);
+static inline void xen_pcibk_lateeoi(struct xen_pcibk_device *pdev,
+ unsigned int eoi_flag)
+{
+ if (test_and_clear_bit(_EOI_pending, &pdev->flags))
+ xen_irq_lateeoi(pdev->evtchn_irq, eoi_flag);
+}
+
int xen_pcibk_xenbus_register(void);
void xen_pcibk_xenbus_unregister(void);
-
-void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev);
#endif
/* Handles shared IRQs that can to device domain and control domain. */
diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c
index e11a743..3fbc214 100644
--- a/drivers/xen/xen-pciback/pciback_ops.c
+++ b/drivers/xen/xen-pciback/pciback_ops.c
@@ -276,26 +276,41 @@ int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
return 0;
}
#endif
+
+static inline bool xen_pcibk_test_op_pending(struct xen_pcibk_device *pdev)
+{
+ return test_bit(_XEN_PCIF_active,
+ (unsigned long *)&pdev->sh_info->flags) &&
+ !test_and_set_bit(_PDEVF_op_active, &pdev->flags);
+}
+
/*
* Now the same evtchn is used for both pcifront conf_read_write request
* as well as pcie aer front end ack. We use a new work_queue to schedule
* xen_pcibk conf_read_write service for avoiding confict with aer_core
* do_recovery job which also use the system default work_queue
*/
-void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
+static void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
{
+ bool eoi = true;
+
/* Check that frontend is requesting an operation and that we are not
* already processing a request */
- if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
- && !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
+ if (xen_pcibk_test_op_pending(pdev)) {
schedule_work(&pdev->op_work);
+ eoi = false;
}
/*_XEN_PCIB_active should have been cleared by pcifront. And also make
sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
&& test_bit(_PCIB_op_pending, &pdev->flags)) {
wake_up(&xen_pcibk_aer_wait_queue);
+ eoi = false;
}
+
+ /* EOI if there was nothing to do. */
+ if (eoi)
+ xen_pcibk_lateeoi(pdev, XEN_EOI_FLAG_SPURIOUS);
}
/* Performing the configuration space reads/writes must not be done in atomic
@@ -303,10 +318,8 @@ void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
* use of semaphores). This function is intended to be called from a work
* queue in process context taking a struct xen_pcibk_device as a parameter */
-void xen_pcibk_do_op(struct work_struct *data)
+static void xen_pcibk_do_one_op(struct xen_pcibk_device *pdev)
{
- struct xen_pcibk_device *pdev =
- container_of(data, struct xen_pcibk_device, op_work);
struct pci_dev *dev;
struct xen_pcibk_dev_data *dev_data = NULL;
struct xen_pci_op *op = &pdev->op;
@@ -379,16 +392,31 @@ void xen_pcibk_do_op(struct work_struct *data)
smp_mb__before_atomic(); /* /after/ clearing PCIF_active */
clear_bit(_PDEVF_op_active, &pdev->flags);
smp_mb__after_atomic(); /* /before/ final check for work */
+}
- /* Check to see if the driver domain tried to start another request in
- * between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
- */
- xen_pcibk_test_and_schedule_op(pdev);
+void xen_pcibk_do_op(struct work_struct *data)
+{
+ struct xen_pcibk_device *pdev =
+ container_of(data, struct xen_pcibk_device, op_work);
+
+ do {
+ xen_pcibk_do_one_op(pdev);
+ } while (xen_pcibk_test_op_pending(pdev));
+
+ xen_pcibk_lateeoi(pdev, 0);
}
irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
{
struct xen_pcibk_device *pdev = dev_id;
+ bool eoi;
+
+ /* IRQs might come in before pdev->evtchn_irq is written. */
+ if (unlikely(pdev->evtchn_irq != irq))
+ pdev->evtchn_irq = irq;
+
+ eoi = test_and_set_bit(_EOI_pending, &pdev->flags);
+ WARN(eoi, "IRQ while EOI pending\n");
xen_pcibk_test_and_schedule_op(pdev);
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index b500466..4b99ec3 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -123,7 +123,7 @@ static int xen_pcibk_do_attach(struct xen_pcibk_device *pdev, int gnt_ref,
pdev->sh_info = vaddr;
- err = bind_interdomain_evtchn_to_irqhandler(
+ err = bind_interdomain_evtchn_to_irqhandler_lateeoi(
pdev->xdev->otherend_id, remote_evtchn, xen_pcibk_handle_event,
0, DRV_NAME, pdev);
if (err < 0) {
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 1e8cfd8..4acc4e8 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -91,7 +91,6 @@ struct vscsibk_info {
unsigned int irq;
struct vscsiif_back_ring ring;
- int ring_error;
spinlock_t ring_lock;
atomic_t nr_unreplied_reqs;
@@ -722,7 +721,8 @@ static struct vscsibk_pend *prepare_pending_reqs(struct vscsibk_info *info,
return pending_req;
}
-static int scsiback_do_cmd_fn(struct vscsibk_info *info)
+static int scsiback_do_cmd_fn(struct vscsibk_info *info,
+ unsigned int *eoi_flags)
{
struct vscsiif_back_ring *ring = &info->ring;
struct vscsiif_request ring_req;
@@ -739,11 +739,12 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
rc = ring->rsp_prod_pvt;
pr_warn("Dom%d provided bogus ring requests (%#x - %#x = %u). Halting ring processing\n",
info->domid, rp, rc, rp - rc);
- info->ring_error = 1;
- return 0;
+ return -EINVAL;
}
while ((rc != rp)) {
+ *eoi_flags &= ~XEN_EOI_FLAG_SPURIOUS;
+
if (RING_REQUEST_CONS_OVERFLOW(ring, rc))
break;
@@ -802,13 +803,16 @@ static int scsiback_do_cmd_fn(struct vscsibk_info *info)
static irqreturn_t scsiback_irq_fn(int irq, void *dev_id)
{
struct vscsibk_info *info = dev_id;
+ int rc;
+ unsigned int eoi_flags = XEN_EOI_FLAG_SPURIOUS;
- if (info->ring_error)
- return IRQ_HANDLED;
-
- while (scsiback_do_cmd_fn(info))
+ while ((rc = scsiback_do_cmd_fn(info, &eoi_flags)) > 0)
cond_resched();
+ /* In case of a ring error we keep the event channel masked. */
+ if (!rc)
+ xen_irq_lateeoi(irq, eoi_flags);
+
return IRQ_HANDLED;
}
@@ -829,7 +833,7 @@ static int scsiback_init_sring(struct vscsibk_info *info, grant_ref_t ring_ref,
sring = (struct vscsiif_sring *)area;
BACK_RING_INIT(&info->ring, sring, PAGE_SIZE);
- err = bind_interdomain_evtchn_to_irq(info->domid, evtchn);
+ err = bind_interdomain_evtchn_to_irq_lateeoi(info->domid, evtchn);
if (err < 0)
goto unmap_page;
@@ -1253,7 +1257,6 @@ static int scsiback_probe(struct xenbus_device *dev,
info->domid = dev->otherend_id;
spin_lock_init(&info->ring_lock);
- info->ring_error = 0;
atomic_set(&info->nr_unreplied_reqs, 0);
init_waitqueue_head(&info->waiting_to_free);
info->dev = dev;
diff --git a/include/xen/events.h b/include/xen/events.h
index df1e6391..3b8155c 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -15,10 +15,15 @@
unsigned xen_evtchn_nr_channels(void);
int bind_evtchn_to_irq(evtchn_port_t evtchn);
+int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn);
int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
irq_handler_t handler,
unsigned long irqflags, const char *devname,
void *dev_id);
+int bind_evtchn_to_irqhandler_lateeoi(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags, const char *devname,
+ void *dev_id);
int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu);
int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
irq_handler_t handler,
@@ -32,12 +37,20 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi,
void *dev_id);
int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
evtchn_port_t remote_port);
+int bind_interdomain_evtchn_to_irq_lateeoi(unsigned int remote_domain,
+ evtchn_port_t remote_port);
int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
evtchn_port_t remote_port,
irq_handler_t handler,
unsigned long irqflags,
const char *devname,
void *dev_id);
+int bind_interdomain_evtchn_to_irqhandler_lateeoi(unsigned int remote_domain,
+ evtchn_port_t remote_port,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname,
+ void *dev_id);
/*
* Common unbind function for all event sources. Takes IRQ to unbind from.
@@ -46,6 +59,14 @@ int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
*/
void unbind_from_irqhandler(unsigned int irq, void *dev_id);
+/*
+ * Send late EOI for an IRQ bound to an event channel via one of the *_lateeoi
+ * functions above.
+ */
+void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags);
+/* Signal an event was spurious, i.e. there was no action resulting from it. */
+#define XEN_EOI_FLAG_SPURIOUS 0x00000001
+
#define XEN_IRQ_PRIORITY_MAX EVTCHN_FIFO_PRIORITY_MAX
#define XEN_IRQ_PRIORITY_DEFAULT EVTCHN_FIFO_PRIORITY_DEFAULT
#define XEN_IRQ_PRIORITY_MIN EVTCHN_FIFO_PRIORITY_MIN
