On Sat, Oct 25, 2014 at 04:24:53PM +0800, john.liuli wrote:
> From: Li Liu <john.liuli@xxxxxxxxxx>
>
> Add a new register offset VIRTIO_MMIO_ISRMEM which help to
> estblish a shared memory region between virtio-mmio driver
> and qemu with two purposes:
>
> 1.Guest virtio-mmio driver can get the interrupt reason.
> 2.Check irqfd enabled or not to register different irq handler.
>
> Signed-off-by: Li Liu <john.liuli@xxxxxxxxxx>
> ---
> drivers/virtio/virtio_mmio.c | 21 ++++++++++++++++++++-
> include/linux/virtio_mmio.h | 3 +++
> 2 files changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
> index ef9a165..28ddb55 100644
> --- a/drivers/virtio/virtio_mmio.c
> +++ b/drivers/virtio/virtio_mmio.c
> @@ -122,6 +122,8 @@ struct virtio_mmio_device {
> /* a list of queues so we can dispatch IRQs */
> spinlock_t lock;
> struct list_head virtqueues;
> +
> + uint8_t *isr_mem;
> };
>
> struct virtio_mmio_vq_info {
> @@ -443,6 +445,7 @@ static int virtio_mmio_probe(struct platform_device *pdev)
> struct virtio_mmio_device *vm_dev;
> struct resource *mem;
> unsigned long magic;
> + int err;
>
> mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (!mem)
> @@ -481,6 +484,15 @@ static int virtio_mmio_probe(struct platform_device *pdev)
> return -ENXIO;
> }
>
> + vm_dev->isr_mem = alloc_pages_exact(PAGE_SIZE, GFP_KERNEL|__GFP_ZERO);
> + if (vm_dev->isr_mem == NULL) {
> + dev_err(&pdev->dev, "Allocate isr memory failed!\n");
> + return -ENOMEM;
> + }
> +
> + writel(virt_to_phys(vm_dev->isr_mem),
> + vm_dev->base + VIRTIO_MMIO_ISRMEM);
> +
What happens to existing devices?
then might not expect writes at this address.
> vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
> vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
>
> @@ -488,13 +500,20 @@ static int virtio_mmio_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, vm_dev);
>
> - return register_virtio_device(&vm_dev->vdev);
> + err = register_virtio_device(&vm_dev->vdev);
> + if (err) {
> + free_pages_exact(vm_dev->isr_mem, PAGE_SIZE);
> + vm_dev->isr_mem = NULL;
> + }
> +
> + return err;
> }
>
> static int virtio_mmio_remove(struct platform_device *pdev)
> {
> struct virtio_mmio_device *vm_dev = platform_get_drvdata(pdev);
>
> + free_pages_exact(vm_dev->isr_mem, PAGE_SIZE);
> unregister_virtio_device(&vm_dev->vdev);
>
> return 0;
> diff --git a/include/linux/virtio_mmio.h b/include/linux/virtio_mmio.h
> index 5c7b6f0..b1e3ec7 100644
> --- a/include/linux/virtio_mmio.h
> +++ b/include/linux/virtio_mmio.h
> @@ -95,6 +95,9 @@
> /* Device status register - Read Write */
> #define VIRTIO_MMIO_STATUS 0x070
>
> +/* Allocate ISRMEM for interrupt reason - Write Only */
> +#define VIRTIO_MMIO_ISRMEM 0x080
> +
> /* The config space is defined by each driver as
> * the per-driver configuration space - Read Write */
> #define VIRTIO_MMIO_CONFIG 0x100
> --
> 1.7.9.5
>
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
