diff options
| author | Sebastien Boeuf <sebastien.boeuf@intel.com> | 2020-08-19 18:19:43 -0400 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2020-09-10 10:05:58 +0200 |
| commit | 38e895487afc2ed42c11045853cbb3fa20b52b6e (patch) | |
| tree | ccea9cd7d27900f957b79820f58dc08e97e55715 /drivers/virtio | |
| parent | 0dd4ff93f4c8dba016ad79384007da4938cd54a1 (diff) | |
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: Sebastien 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: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/virtio_mmio.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 627ac0487494..238383ff1064 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -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, }; |