[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <3e56c6f74002987e22f364d883cbad177cd9ad9c.1747827066.git.viresh.kumar@linaro.org>
Date: Wed, 21 May 2025 17:03:46 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: "Michael S. Tsirkin" <mst@...hat.com>,
Jason Wang <jasowang@...hat.com>,
Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
Eugenio Pérez <eperezma@...hat.com>
Cc: Viresh Kumar <viresh.kumar@...aro.org>,
Vincent Guittot <vincent.guittot@...aro.org>,
Alex Bennée <alex.bennee@...aro.org>,
Bill Mills <bill.mills@...aro.org>,
virtualization@...ts.linux.dev,
linux-kernel@...r.kernel.org
Subject: [PATCH] virtio-mmio: Remove virtqueue list from mmio device
The MMIO transport implementation creates a list of virtqueues for a
virtio device, while the same is already available in the struct
virtio_device.
Don't create a duplicate list, and use the other one instead.
While at it, fix the virtio_device_for_each_vq() macro to accept an
argument like "&vm_dev->vdev" (which currently fails to build).
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
I have tested this with a Xen/Qemu based setup to test guest to host virtio-i2c
communication. Works fine, not sure why this code was added in the first place.
drivers/virtio/virtio_mmio.c | 52 +++---------------------------------
include/linux/virtio.h | 2 +-
2 files changed, 4 insertions(+), 50 deletions(-)
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 5d78c2d572ab..b152a1eca05a 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -65,7 +65,6 @@
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/slab.h>
-#include <linux/spinlock.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <uapi/linux/virtio_mmio.h>
@@ -88,22 +87,8 @@ struct virtio_mmio_device {
void __iomem *base;
unsigned long version;
-
- /* a list of queues so we can dispatch IRQs */
- spinlock_t lock;
- struct list_head virtqueues;
-};
-
-struct virtio_mmio_vq_info {
- /* the actual virtqueue */
- struct virtqueue *vq;
-
- /* the list node for the virtqueues list */
- struct list_head node;
};
-
-
/* Configuration interface */
static u64 vm_get_features(struct virtio_device *vdev)
@@ -300,9 +285,8 @@ static bool vm_notify_with_data(struct virtqueue *vq)
static irqreturn_t vm_interrupt(int irq, void *opaque)
{
struct virtio_mmio_device *vm_dev = opaque;
- struct virtio_mmio_vq_info *info;
+ struct virtqueue *vq;
unsigned long status;
- unsigned long flags;
irqreturn_t ret = IRQ_NONE;
/* Read and acknowledge interrupts */
@@ -315,10 +299,8 @@ static irqreturn_t vm_interrupt(int irq, void *opaque)
}
if (likely(status & VIRTIO_MMIO_INT_VRING)) {
- spin_lock_irqsave(&vm_dev->lock, flags);
- list_for_each_entry(info, &vm_dev->virtqueues, node)
- ret |= vring_interrupt(irq, info->vq);
- spin_unlock_irqrestore(&vm_dev->lock, flags);
+ virtio_device_for_each_vq(&vm_dev->vdev, vq)
+ ret |= vring_interrupt(irq, vq);
}
return ret;
@@ -329,14 +311,8 @@ static irqreturn_t vm_interrupt(int irq, void *opaque)
static void vm_del_vq(struct virtqueue *vq)
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
- struct virtio_mmio_vq_info *info = vq->priv;
- unsigned long flags;
unsigned int index = vq->index;
- spin_lock_irqsave(&vm_dev->lock, flags);
- list_del(&info->node);
- spin_unlock_irqrestore(&vm_dev->lock, flags);
-
/* Select and deactivate the queue */
writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
if (vm_dev->version == 1) {
@@ -347,8 +323,6 @@ static void vm_del_vq(struct virtqueue *vq)
}
vring_del_virtqueue(vq);
-
- kfree(info);
}
static void vm_del_vqs(struct virtio_device *vdev)
@@ -375,9 +349,7 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
bool (*notify)(struct virtqueue *vq);
- struct virtio_mmio_vq_info *info;
struct virtqueue *vq;
- unsigned long flags;
unsigned int num;
int err;
@@ -399,13 +371,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
goto error_available;
}
- /* Allocate and fill out our active queue description */
- info = kmalloc(sizeof(*info), GFP_KERNEL);
- if (!info) {
- err = -ENOMEM;
- goto error_kmalloc;
- }
-
num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
if (num == 0) {
err = -ENOENT;
@@ -463,13 +428,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
}
- vq->priv = info;
- info->vq = vq;
-
- spin_lock_irqsave(&vm_dev->lock, flags);
- list_add(&info->node, &vm_dev->virtqueues);
- spin_unlock_irqrestore(&vm_dev->lock, flags);
-
return vq;
error_bad_pfn:
@@ -481,8 +439,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
}
- kfree(info);
-error_kmalloc:
error_available:
return ERR_PTR(err);
}
@@ -627,8 +583,6 @@ static int virtio_mmio_probe(struct platform_device *pdev)
vm_dev->vdev.dev.release = virtio_mmio_release_dev;
vm_dev->vdev.config = &virtio_mmio_config_ops;
vm_dev->pdev = pdev;
- INIT_LIST_HEAD(&vm_dev->virtqueues);
- spin_lock_init(&vm_dev->lock);
vm_dev->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(vm_dev->base)) {
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 64cb4b04be7a..8b745ce0cf5f 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -196,7 +196,7 @@ int virtio_device_reset_done(struct virtio_device *dev);
size_t virtio_max_dma_size(const struct virtio_device *vdev);
#define virtio_device_for_each_vq(vdev, vq) \
- list_for_each_entry(vq, &vdev->vqs, list)
+ list_for_each_entry(vq, &(vdev)->vqs, list)
/**
* struct virtio_driver - operations for a virtio I/O driver
--
2.31.1.272.g89b43f80a514
Powered by blists - more mailing lists