* [PATCH V3 0/6] IRQ offloading for vDPA
@ 2020-07-22 9:49 Zhu Lingshan
2020-07-22 9:49 ` [PATCH V3 1/6] vhost: introduce vhost_vring_call Zhu Lingshan
0 siblings, 1 reply; 4+ messages in thread
From: Zhu Lingshan @ 2020-07-22 9:49 UTC (permalink / raw)
To: jasowang, alex.williamson, mst, pbonzini, sean.j.christopherson,
wanpengli
Cc: virtualization, netdev, kvm, Zhu Lingshan
This series intends to implement IRQ offloading for
vhost_vdpa.
By the feat of irq forwarding facilities like posted
interrupt on X86, irq bypass can help deliver
interrupts to vCPU directly.
vDPA devices have dedicated hardware backends like VFIO
pass-throughed devices. So it would be possible to setup
irq offloading(irq bypass) for vDPA devices and gain
performance improvements.
In my testing, with this feature, we can save 0.1ms
in a ping between two VFs on average.
changes from V2:
(1)rename struct vhost_call_ctx to vhost_vring_call
(2)add kvm_arch_end_assignment() in del_producer()
code path
(3)rename vDPA helpers to vdpa_devm_request_irq()
and vdpa_devm_free_irq(). Add better comments
for them.
(4)better comments for setup_vq_irq() and
unsetup_vq_irq()
(5)In vDPA VHOST_SET_VRING_CALL, will call vhost_vdpa_update_vq_irq()
without checking producer.irq, move this check into
vhost_vdpa_update_vq_irq(), so that get advantage of the spinlock.
(6)Add a function vhost_vdpa_clean_irq(), this function will unregister
the producer of vqs when vhost_vdpa_release(). This is safe
for control vq.
(7) minor improvements
changes from V1:
(1)dropped vfio changes.
(3)removed KVM_HVAE_IRQ_BYPASS checks
(4)locking fixes
(5)simplified vhost_vdpa_update_vq_irq()
(6)minor improvements
Zhu Lingshan (6):
vhost: introduce vhost_vring_call
kvm: detect assigned device via irqbypass manager
vDPA: implement vq IRQ allocate/free helpers in vDPA core
vhost_vdpa: implement IRQ offloading in vhost_vdpa
ifcvf: replace irq_request/free with vDPA helpers
irqbypass: do not start cons/prod when failed connect
arch/x86/kvm/x86.c | 11 +++++-
drivers/vdpa/ifcvf/ifcvf_main.c | 14 ++++---
drivers/vdpa/vdpa.c | 49 +++++++++++++++++++++++
drivers/vhost/Kconfig | 1 +
drivers/vhost/vdpa.c | 70 +++++++++++++++++++++++++++++++--
drivers/vhost/vhost.c | 22 ++++++++---
drivers/vhost/vhost.h | 9 ++++-
include/linux/vdpa.h | 13 ++++++
virt/lib/irqbypass.c | 16 +++++---
9 files changed, 182 insertions(+), 23 deletions(-)
--
2.18.4
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH V3 1/6] vhost: introduce vhost_vring_call
2020-07-22 9:49 [PATCH V3 0/6] IRQ offloading for vDPA Zhu Lingshan
@ 2020-07-22 9:49 ` Zhu Lingshan
2020-07-22 9:59 ` Zhu Lingshan
0 siblings, 1 reply; 4+ messages in thread
From: Zhu Lingshan @ 2020-07-22 9:49 UTC (permalink / raw)
To: jasowang, alex.williamson, mst, pbonzini, sean.j.christopherson,
wanpengli
Cc: virtualization, netdev, kvm, Zhu Lingshan, lszhu, Zhu Lingshan
From: Zhu Lingshan <lingshan.zhu@intel.com>
This commit introduces struct vhost_vring_call which replaced
raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue.
Besides eventfd_ctx, it contains a spin lock and an
irq_bypass_producer in its structure.
Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Signed-off-by: lszhu <lszhu@localhost.localdomain>
Signed-off-by: Zhu Lingshan <lingshan.zhu@live.com>
---
drivers/vhost/vdpa.c | 4 ++--
drivers/vhost/vhost.c | 22 ++++++++++++++++------
drivers/vhost/vhost.h | 9 ++++++++-
3 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index a54b60d6623f..df3cf386b0cd 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -96,7 +96,7 @@ static void handle_vq_kick(struct vhost_work *work)
static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
{
struct vhost_virtqueue *vq = private;
- struct eventfd_ctx *call_ctx = vq->call_ctx;
+ struct eventfd_ctx *call_ctx = vq->call_ctx.ctx;
if (call_ctx)
eventfd_signal(call_ctx, 1);
@@ -382,7 +382,7 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
break;
case VHOST_SET_VRING_CALL:
- if (vq->call_ctx) {
+ if (vq->call_ctx.ctx) {
cb.callback = vhost_vdpa_virtqueue_cb;
cb.private = vq;
} else {
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index d7b8df3edffc..9f1a845a9302 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -298,6 +298,13 @@ static void vhost_vq_meta_reset(struct vhost_dev *d)
__vhost_vq_meta_reset(d->vqs[i]);
}
+static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx)
+{
+ call_ctx->ctx = NULL;
+ memset(&call_ctx->producer, 0x0, sizeof(struct irq_bypass_producer));
+ spin_lock_init(&call_ctx->ctx_lock);
+}
+
static void vhost_vq_reset(struct vhost_dev *dev,
struct vhost_virtqueue *vq)
{
@@ -319,13 +326,13 @@ static void vhost_vq_reset(struct vhost_dev *dev,
vq->log_base = NULL;
vq->error_ctx = NULL;
vq->kick = NULL;
- vq->call_ctx = NULL;
vq->log_ctx = NULL;
vhost_reset_is_le(vq);
vhost_disable_cross_endian(vq);
vq->busyloop_timeout = 0;
vq->umem = NULL;
vq->iotlb = NULL;
+ vhost_vring_call_reset(&vq->call_ctx);
__vhost_vq_meta_reset(vq);
}
@@ -685,8 +692,8 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
eventfd_ctx_put(dev->vqs[i]->error_ctx);
if (dev->vqs[i]->kick)
fput(dev->vqs[i]->kick);
- if (dev->vqs[i]->call_ctx)
- eventfd_ctx_put(dev->vqs[i]->call_ctx);
+ if (dev->vqs[i]->call_ctx.ctx)
+ eventfd_ctx_put(dev->vqs[i]->call_ctx.ctx);
vhost_vq_reset(dev, dev->vqs[i]);
}
vhost_dev_free_iovecs(dev);
@@ -1629,7 +1636,10 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
r = PTR_ERR(ctx);
break;
}
- swap(ctx, vq->call_ctx);
+
+ spin_lock(&vq->call_ctx.ctx_lock);
+ swap(ctx, vq->call_ctx.ctx);
+ spin_unlock(&vq->call_ctx.ctx_lock);
break;
case VHOST_SET_VRING_ERR:
if (copy_from_user(&f, argp, sizeof f)) {
@@ -2440,8 +2450,8 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
{
/* Signal the Guest tell them we used something up. */
- if (vq->call_ctx && vhost_notify(dev, vq))
- eventfd_signal(vq->call_ctx, 1);
+ if (vq->call_ctx.ctx && vhost_notify(dev, vq))
+ eventfd_signal(vq->call_ctx.ctx, 1);
}
EXPORT_SYMBOL_GPL(vhost_signal);
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index c8e96a095d3b..38eb1aa3b68d 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -13,6 +13,7 @@
#include <linux/virtio_ring.h>
#include <linux/atomic.h>
#include <linux/vhost_iotlb.h>
+#include <linux/irqbypass.h>
struct vhost_work;
typedef void (*vhost_work_fn_t)(struct vhost_work *work);
@@ -60,6 +61,12 @@ enum vhost_uaddr_type {
VHOST_NUM_ADDRS = 3,
};
+struct vhost_vring_call {
+ struct eventfd_ctx *ctx;
+ struct irq_bypass_producer producer;
+ spinlock_t ctx_lock;
+};
+
/* The virtqueue structure describes a queue attached to a device. */
struct vhost_virtqueue {
struct vhost_dev *dev;
@@ -72,7 +79,7 @@ struct vhost_virtqueue {
vring_used_t __user *used;
const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
struct file *kick;
- struct eventfd_ctx *call_ctx;
+ struct vhost_vring_call call_ctx;
struct eventfd_ctx *error_ctx;
struct eventfd_ctx *log_ctx;
--
2.18.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH V3 1/6] vhost: introduce vhost_vring_call
2020-07-22 9:49 ` [PATCH V3 1/6] vhost: introduce vhost_vring_call Zhu Lingshan
@ 2020-07-22 9:59 ` Zhu Lingshan
0 siblings, 0 replies; 4+ messages in thread
From: Zhu Lingshan @ 2020-07-22 9:59 UTC (permalink / raw)
To: Zhu Lingshan, jasowang, alex.williamson, mst, pbonzini,
sean.j.christopherson, wanpengli
Cc: virtualization, netdev, kvm, Zhu Lingshan, lszhu
Please ignore this patchset incorrect metadata, will resend soon. Thanks!
On 7/22/2020 5:49 PM, Zhu Lingshan wrote:
> From: Zhu Lingshan <lingshan.zhu@intel.com>
>
> This commit introduces struct vhost_vring_call which replaced
> raw struct eventfd_ctx *call_ctx in struct vhost_virtqueue.
> Besides eventfd_ctx, it contains a spin lock and an
> irq_bypass_producer in its structure.
>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
> Signed-off-by: lszhu <lszhu@localhost.localdomain>
> Signed-off-by: Zhu Lingshan <lingshan.zhu@live.com>
> ---
> drivers/vhost/vdpa.c | 4 ++--
> drivers/vhost/vhost.c | 22 ++++++++++++++++------
> drivers/vhost/vhost.h | 9 ++++++++-
> 3 files changed, 26 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index a54b60d6623f..df3cf386b0cd 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -96,7 +96,7 @@ static void handle_vq_kick(struct vhost_work *work)
> static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
> {
> struct vhost_virtqueue *vq = private;
> - struct eventfd_ctx *call_ctx = vq->call_ctx;
> + struct eventfd_ctx *call_ctx = vq->call_ctx.ctx;
>
> if (call_ctx)
> eventfd_signal(call_ctx, 1);
> @@ -382,7 +382,7 @@ static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
> break;
>
> case VHOST_SET_VRING_CALL:
> - if (vq->call_ctx) {
> + if (vq->call_ctx.ctx) {
> cb.callback = vhost_vdpa_virtqueue_cb;
> cb.private = vq;
> } else {
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index d7b8df3edffc..9f1a845a9302 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -298,6 +298,13 @@ static void vhost_vq_meta_reset(struct vhost_dev *d)
> __vhost_vq_meta_reset(d->vqs[i]);
> }
>
> +static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx)
> +{
> + call_ctx->ctx = NULL;
> + memset(&call_ctx->producer, 0x0, sizeof(struct irq_bypass_producer));
> + spin_lock_init(&call_ctx->ctx_lock);
> +}
> +
> static void vhost_vq_reset(struct vhost_dev *dev,
> struct vhost_virtqueue *vq)
> {
> @@ -319,13 +326,13 @@ static void vhost_vq_reset(struct vhost_dev *dev,
> vq->log_base = NULL;
> vq->error_ctx = NULL;
> vq->kick = NULL;
> - vq->call_ctx = NULL;
> vq->log_ctx = NULL;
> vhost_reset_is_le(vq);
> vhost_disable_cross_endian(vq);
> vq->busyloop_timeout = 0;
> vq->umem = NULL;
> vq->iotlb = NULL;
> + vhost_vring_call_reset(&vq->call_ctx);
> __vhost_vq_meta_reset(vq);
> }
>
> @@ -685,8 +692,8 @@ void vhost_dev_cleanup(struct vhost_dev *dev)
> eventfd_ctx_put(dev->vqs[i]->error_ctx);
> if (dev->vqs[i]->kick)
> fput(dev->vqs[i]->kick);
> - if (dev->vqs[i]->call_ctx)
> - eventfd_ctx_put(dev->vqs[i]->call_ctx);
> + if (dev->vqs[i]->call_ctx.ctx)
> + eventfd_ctx_put(dev->vqs[i]->call_ctx.ctx);
> vhost_vq_reset(dev, dev->vqs[i]);
> }
> vhost_dev_free_iovecs(dev);
> @@ -1629,7 +1636,10 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg
> r = PTR_ERR(ctx);
> break;
> }
> - swap(ctx, vq->call_ctx);
> +
> + spin_lock(&vq->call_ctx.ctx_lock);
> + swap(ctx, vq->call_ctx.ctx);
> + spin_unlock(&vq->call_ctx.ctx_lock);
> break;
> case VHOST_SET_VRING_ERR:
> if (copy_from_user(&f, argp, sizeof f)) {
> @@ -2440,8 +2450,8 @@ static bool vhost_notify(struct vhost_dev *dev, struct vhost_virtqueue *vq)
> void vhost_signal(struct vhost_dev *dev, struct vhost_virtqueue *vq)
> {
> /* Signal the Guest tell them we used something up. */
> - if (vq->call_ctx && vhost_notify(dev, vq))
> - eventfd_signal(vq->call_ctx, 1);
> + if (vq->call_ctx.ctx && vhost_notify(dev, vq))
> + eventfd_signal(vq->call_ctx.ctx, 1);
> }
> EXPORT_SYMBOL_GPL(vhost_signal);
>
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index c8e96a095d3b..38eb1aa3b68d 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -13,6 +13,7 @@
> #include <linux/virtio_ring.h>
> #include <linux/atomic.h>
> #include <linux/vhost_iotlb.h>
> +#include <linux/irqbypass.h>
>
> struct vhost_work;
> typedef void (*vhost_work_fn_t)(struct vhost_work *work);
> @@ -60,6 +61,12 @@ enum vhost_uaddr_type {
> VHOST_NUM_ADDRS = 3,
> };
>
> +struct vhost_vring_call {
> + struct eventfd_ctx *ctx;
> + struct irq_bypass_producer producer;
> + spinlock_t ctx_lock;
> +};
> +
> /* The virtqueue structure describes a queue attached to a device. */
> struct vhost_virtqueue {
> struct vhost_dev *dev;
> @@ -72,7 +79,7 @@ struct vhost_virtqueue {
> vring_used_t __user *used;
> const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
> struct file *kick;
> - struct eventfd_ctx *call_ctx;
> + struct vhost_vring_call call_ctx;
> struct eventfd_ctx *error_ctx;
> struct eventfd_ctx *log_ctx;
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH V3 0/6] IRQ offloading for vDPA
@ 2020-07-22 10:08 Zhu Lingshan
0 siblings, 0 replies; 4+ messages in thread
From: Zhu Lingshan @ 2020-07-22 10:08 UTC (permalink / raw)
To: jasowang, alex.williamson, mst, pbonzini, sean.j.christopherson,
wanpengli
Cc: virtualization, netdev, kvm, Zhu Lingshan
This series intends to implement IRQ offloading for
vhost_vdpa.
By the feat of irq forwarding facilities like posted
interrupt on X86, irq bypass can help deliver
interrupts to vCPU directly.
vDPA devices have dedicated hardware backends like VFIO
pass-throughed devices. So it would be possible to setup
irq offloading(irq bypass) for vDPA devices and gain
performance improvements.
In my testing, with this feature, we can save 0.1ms
in a ping between two VFs on average.
changes from V2:
(1)rename struct vhost_call_ctx to vhost_vring_call
(2)add kvm_arch_end_assignment() in del_producer()
code path
(3)rename vDPA helpers to vdpa_devm_request_irq()
and vdpa_devm_free_irq(). Add better comments
for them.
(4)better comments for setup_vq_irq() and
unsetup_vq_irq()
(5)In vDPA VHOST_SET_VRING_CALL, will call vhost_vdpa_update_vq_irq()
without checking producer.irq, move this check into
vhost_vdpa_update_vq_irq(), so that get advantage of the spinlock.
(6)Add a function vhost_vdpa_clean_irq(), this function will unregister
the producer of vqs when vhost_vdpa_release(). This is safe
for control vq.
(7) minor improvements
changes from V1:
(1)dropped vfio changes.
(3)removed KVM_HVAE_IRQ_BYPASS checks
(4)locking fixes
(5)simplified vhost_vdpa_updat
Zhu Lingshan (6):
vhost: introduce vhost_vring_call
kvm: detect assigned device via irqbypass manager
vDPA: implement vq IRQ allocate/free helpers in vDPA core
vhost_vdpa: implement IRQ offloading in vhost_vdpa
ifcvf: replace irq_request/free with vDPA helpers
irqbypass: do not start cons/prod when failed connect
arch/x86/kvm/x86.c | 11 +++++-
drivers/vdpa/ifcvf/ifcvf_main.c | 14 ++++---
drivers/vdpa/vdpa.c | 49 +++++++++++++++++++++++
drivers/vhost/Kconfig | 1 +
drivers/vhost/vdpa.c | 70 +++++++++++++++++++++++++++++++--
drivers/vhost/vhost.c | 22 ++++++++---
drivers/vhost/vhost.h | 9 ++++-
include/linux/vdpa.h | 13 ++++++
virt/lib/irqbypass.c | 16 +++++---
9 files changed, 182 insertions(+), 23 deletions(-)
--
2.18.4
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-07-22 10:08 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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