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From: "Michael S. Tsirkin" <mst@redhat.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	virtio-fs@redhat.com, miklos@szeredi.hu, stefanha@redhat.com,
	dgilbert@redhat.com, Sebastien Boeuf <sebastien.boeuf@intel.com>,
	kvm@vger.kernel.org
Subject: Re: [PATCH v2 05/20] virtio: Implement get_shm_region for MMIO transport
Date: Mon, 10 Aug 2020 10:03:17 -0400	[thread overview]
Message-ID: <20200810100240-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20200807195526.426056-6-vgoyal@redhat.com>

On Fri, Aug 07, 2020 at 03:55:11PM -0400, Vivek Goyal wrote:
> From: Sebastien Boeuf <sebastien.boeuf@intel.com>
> 
> On MMIO a new set of registers is defined for finding SHM
> regions.  Add their definitions and use them to find the region.
> 
> Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
> Cc: kvm@vger.kernel.org
> Cc: "Michael S. Tsirkin" <mst@redhat.com>


Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  drivers/virtio/virtio_mmio.c     | 32 ++++++++++++++++++++++++++++++++
>  include/uapi/linux/virtio_mmio.h | 11 +++++++++++
>  2 files changed, 43 insertions(+)
> 
> diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
> index 627ac0487494..2697c492cf78 100644
> --- a/drivers/virtio/virtio_mmio.c
> +++ b/drivers/virtio/virtio_mmio.c
> @@ -498,6 +498,37 @@ static const char *vm_bus_name(struct virtio_device *vdev)
>  	return vm_dev->pdev->name;
>  }
>  
> +static bool vm_get_shm_region(struct virtio_device *vdev,
> +			      struct virtio_shm_region *region, u8 id)
> +{
> +	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
> +	u64 len, addr;
> +
> +	/* Select the region we're interested in */
> +	writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL);
> +
> +	/* Read the region size */
> +	len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW);
> +	len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32;
> +
> +	region->len = len;
> +
> +	/* Check if region length is -1. If that's the case, the shared memory
> +	 * region does not exist and there is no need to proceed further.
> +	 */
> +	if (len == ~(u64)0) {
> +		return false;
> +	}
> +

It might make sense to validate that addr/len do not overlap.
Will be useful for PCI too.
Can be a patch on top.

> +	/* Read the region base address */
> +	addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW);
> +	addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32;
> +
> +	region->addr = addr;
> +
> +	return true;
> +}
> +
>  static const struct virtio_config_ops virtio_mmio_config_ops = {
>  	.get		= vm_get,
>  	.set		= vm_set,
> @@ -510,6 +541,7 @@ static const struct virtio_config_ops virtio_mmio_config_ops = {
>  	.get_features	= vm_get_features,
>  	.finalize_features = vm_finalize_features,
>  	.bus_name	= vm_bus_name,
> +	.get_shm_region = vm_get_shm_region,
>  };
>  
>  
> diff --git a/include/uapi/linux/virtio_mmio.h b/include/uapi/linux/virtio_mmio.h
> index c4b09689ab64..0650f91bea6c 100644
> --- a/include/uapi/linux/virtio_mmio.h
> +++ b/include/uapi/linux/virtio_mmio.h
> @@ -122,6 +122,17 @@
>  #define VIRTIO_MMIO_QUEUE_USED_LOW	0x0a0
>  #define VIRTIO_MMIO_QUEUE_USED_HIGH	0x0a4
>  
> +/* Shared memory region id */
> +#define VIRTIO_MMIO_SHM_SEL             0x0ac
> +
> +/* Shared memory region length, 64 bits in two halves */
> +#define VIRTIO_MMIO_SHM_LEN_LOW         0x0b0
> +#define VIRTIO_MMIO_SHM_LEN_HIGH        0x0b4
> +
> +/* Shared memory region base address, 64 bits in two halves */
> +#define VIRTIO_MMIO_SHM_BASE_LOW        0x0b8
> +#define VIRTIO_MMIO_SHM_BASE_HIGH       0x0bc
> +
>  /* Configuration atomicity value */
>  #define VIRTIO_MMIO_CONFIG_GENERATION	0x0fc
>  
> -- 
> 2.25.4
> 


  reply	other threads:[~2020-08-10 14:03 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-07 19:55 [PATCH v2 00/20] virtiofs: Add DAX support Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 01/20] dax: Modify bdev_dax_pgoff() to handle NULL bdev Vivek Goyal
2020-08-17 16:57   ` Jan Kara
2020-08-07 19:55 ` [PATCH v2 02/20] dax: Create a range version of dax_layout_busy_page() Vivek Goyal
2020-08-17 16:53   ` Jan Kara
2020-08-17 17:22     ` Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 03/20] virtio: Add get_shm_region method Vivek Goyal
2020-08-10 13:47   ` Michael S. Tsirkin
2020-08-10 13:54     ` Vivek Goyal
2020-08-10 14:02   ` Michael S. Tsirkin
2020-08-10 14:06   ` Michael S. Tsirkin
2020-08-07 19:55 ` [PATCH v2 04/20] virtio: Implement get_shm_region for PCI transport Vivek Goyal
2020-08-10 14:05   ` Michael S. Tsirkin
2020-08-10 14:50     ` Vivek Goyal
     [not found]       ` <CAAfnVBk+Hmcm2ftd3wOK-P2NyYQ7z4Wrf1JKhLJaNkCZBLoo6g@mail.gmail.com>
2020-08-17 20:29         ` Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 05/20] virtio: Implement get_shm_region for MMIO transport Vivek Goyal
2020-08-10 14:03   ` Michael S. Tsirkin [this message]
2020-08-07 19:55 ` [PATCH v2 06/20] virtiofs: Provide a helper function for virtqueue initialization Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 07/20] fuse: Get rid of no_mount_options Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 08/20] fuse,virtiofs: Add a mount option to enable dax Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 09/20] virtio_fs, dax: Set up virtio_fs dax_device Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 10/20] fuse,virtiofs: Keep a list of free dax memory ranges Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 11/20] fuse: implement FUSE_INIT map_alignment field Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 12/20] fuse: Introduce setupmapping/removemapping commands Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 13/20] fuse, dax: Implement dax read/write operations Vivek Goyal
2020-08-10 22:06   ` Dave Chinner
2020-08-11 17:44     ` Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 14/20] fuse,dax: add DAX mmap support Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 15/20] fuse, dax: Take ->i_mmap_sem lock during dax page fault Vivek Goyal
2020-08-10 22:22   ` Dave Chinner
2020-08-11 17:55     ` Vivek Goyal
2020-08-12  1:23       ` Dave Chinner
2020-08-12 21:10         ` Vivek Goyal
2020-08-13  5:12           ` Dave Chinner
2020-08-07 19:55 ` [PATCH v2 16/20] fuse,virtiofs: Define dax address space operations Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 17/20] fuse,virtiofs: Maintain a list of busy elements Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 18/20] fuse: Release file in process context Vivek Goyal
2020-08-10  8:29   ` Miklos Szeredi
2020-08-10 15:48     ` Vivek Goyal
2020-08-10 19:37     ` Vivek Goyal
2020-08-10 19:39       ` Miklos Szeredi
2020-08-07 19:55 ` [PATCH v2 19/20] fuse: Take inode lock for dax inode truncation Vivek Goyal
2020-08-07 19:55 ` [PATCH v2 20/20] fuse,virtiofs: Add logic to free up a memory range Vivek Goyal
2020-08-10  7:29 ` [PATCH v2 00/20] virtiofs: Add DAX support Miklos Szeredi
2020-08-10 13:08   ` Vivek Goyal

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