Commit 38e89548 authored by Sebastien Boeuf's avatar Sebastien Boeuf Committed by Miklos Szeredi
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virtio: Implement get_shm_region for MMIO transport 



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: default avatarSebastien Boeuf <sebastien.boeuf@intel.com>
Cc: kvm@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 0dd4ff93

drivers/virtio/virtio_mmio.c

+31 −0
Original line number Diff line number Diff line
@@ -498,6 +498,36 @@ 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;



	/* 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 +540,7 @@ 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,

};

include/uapi/linux/virtio_mmio.h

+11 −0
Original line number Diff line number Diff line
@@ -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

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