A simple in-kernel notifier framework for EOI. Callbacks can be
registered for EOI for level-triggered interrupts. This is to be
used for irqfd support for level-triggered interrupts.
Signed-off-by: Vineeth Pillai <viremana@xxxxxxxxxxxxxxxxxxx>
---
drivers/hv/hv_eventfd.c | 38 ++++++++++++++++++++++++++++++++++++
drivers/hv/hv_synic.c | 22 +++++++++++++++++++++
drivers/hv/mshv_main.c | 4 ++++
include/linux/mshv.h | 9 +++++++++
include/linux/mshv_eventfd.h | 6 ++++++
5 files changed, 79 insertions(+)
diff --git a/drivers/hv/hv_eventfd.c b/drivers/hv/hv_eventfd.c
index 5ed77901fb0b..0bfb088dcb80 100644
--- a/drivers/hv/hv_eventfd.c
+++ b/drivers/hv/hv_eventfd.c
@@ -22,6 +22,44 @@
static struct workqueue_struct *irqfd_cleanup_wq;
+void
+mshv_register_irq_ack_notifier(struct mshv_partition *partition,
+ struct mshv_irq_ack_notifier *mian)
+{
+ spin_lock(&partition->irq_lock);
+ hlist_add_head_rcu(&mian->link, &partition->irq_ack_notifier_list);
+ spin_unlock(&partition->irq_lock);
+}
+
+void
+mshv_unregister_irq_ack_notifier(struct mshv_partition *partition,
+ struct mshv_irq_ack_notifier *mian)
+{
+ spin_lock(&partition->irq_lock);
+ hlist_del_init_rcu(&mian->link);
+ spin_unlock(&partition->irq_lock);
+ synchronize_rcu();
+}
+
+bool
+mshv_notify_acked_gsi(struct mshv_partition *partition, int gsi)
+{
+ struct mshv_irq_ack_notifier *mian;
+ bool acked = false;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(mian, &partition->irq_ack_notifier_list,
+ link) {
+ if (mian->gsi == gsi) {
+ mian->irq_acked(mian);
+ acked = true;
+ }
+ }
+ rcu_read_unlock();
+
+ return acked;
+}
+
static void
irqfd_inject(struct mshv_kernel_irqfd *irqfd)
{
diff --git a/drivers/hv/hv_synic.c b/drivers/hv/hv_synic.c
index af6653967209..1296928675e3 100644
--- a/drivers/hv/hv_synic.c
+++ b/drivers/hv/hv_synic.c
@@ -14,6 +14,7 @@
#include <linux/io.h>
#include <linux/random.h>
#include <linux/mshv.h>
+#include <linux/mshv_eventfd.h>
#include <asm/mshyperv.h>
#include "mshv.h"
@@ -158,6 +159,27 @@ mshv_intercept_isr(struct hv_message *msg)
goto unlock_out;
}
+ if (msg->header.message_type == HVMSG_X64_APIC_EOI) {
+ /*
+ * Check if this gsi is registered in the
+ * ack_notifier list and invoke the callback
+ * if registered.
+ */
+ struct hv_x64_apic_eoi_message *eoi_msg =
+ (struct hv_x64_apic_eoi_message *)msg->u.payload;
+
+ /*
+ * If there is a notifier, the ack callback is supposed
+ * to handle the VMEXIT. So we need not pass this message
+ * to vcpu thread.
+ */
+ if (mshv_notify_acked_gsi(partition,
+ eoi_msg->interrupt_vector)) {
+ handled = true;
+ goto unlock_out;
+ }
+ }
+
/*
* Since we directly index the vp, and it has to exist for us to be here
* (because the vp is only deleted when the partition is), no additional
diff --git a/drivers/hv/mshv_main.c b/drivers/hv/mshv_main.c
index e1caecd27f09..6f93813ad465 100644
--- a/drivers/hv/mshv_main.c
+++ b/drivers/hv/mshv_main.c
@@ -1047,6 +1047,10 @@ mshv_ioctl_create_partition(void __user *user_arg)
mutex_init(&partition->mutex);
+ spin_lock_init(&partition->irq_lock);
+
+ INIT_HLIST_HEAD(&partition->irq_ack_notifier_list);
+
fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0) {
ret = fd;
diff --git a/include/linux/mshv.h b/include/linux/mshv.h
index 217c91725828..2cee4832fc7f 100644
--- a/include/linux/mshv.h
+++ b/include/linux/mshv.h
@@ -35,6 +35,12 @@ struct mshv_mem_region {
struct page **pages;
};
+struct mshv_irq_ack_notifier {
+ struct hlist_node link;
+ unsigned int gsi;
+ void (*irq_acked)(struct mshv_irq_ack_notifier *mian);
+};
+
struct mshv_partition {
u64 id;
refcount_t ref_count;
@@ -48,6 +54,9 @@ struct mshv_partition {
struct mshv_vp *array[MSHV_MAX_VPS];
} vps;
+ spinlock_t irq_lock;
+ struct hlist_head irq_ack_notifier_list;
+
struct {
spinlock_t lock;
struct list_head items;
diff --git a/include/linux/mshv_eventfd.h b/include/linux/mshv_eventfd.h
index fd0012f72616..b4d587208294 100644
--- a/include/linux/mshv_eventfd.h
+++ b/include/linux/mshv_eventfd.h
@@ -15,6 +15,12 @@
void mshv_eventfd_init(struct mshv_partition *partition);
void mshv_eventfd_release(struct mshv_partition *partition);
+void mshv_register_irq_ack_notifier(struct mshv_partition *partition,
+ struct mshv_irq_ack_notifier *mian);
+void mshv_unregister_irq_ack_notifier(struct mshv_partition *partition,
+ struct mshv_irq_ack_notifier *mian);
+bool mshv_notify_acked_gsi(struct mshv_partition *partition, int gsi);
+
struct mshv_kernel_irqfd {
struct mshv_partition *partition;
struct eventfd_ctx *eventfd;
--
2.25.1
