Re: [PATCH v4 04/18] vdpa_sim: make IOTLB entries limit configurable

[Jason Wang]

On 2020/12/15 下午10:42, Stefano Garzarella wrote:

Some devices may require a higher limit for the number of IOTLB
entries, so let's make it configurable through a module parameter.

By default, it's initialized with the current limit (2048).

Suggested-by: Jason Wang <jasow...@redhat.com>
Signed-off-by: Stefano Garzarella <sgarz...@redhat.com>

Acked-by: Jason Wang <jasow...@redhat.com>

---
  drivers/vdpa/vdpa_sim/vdpa_sim.c | 7 ++++++-
  1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 07ccc8609784..d716bfaadb3b 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -31,6 +31,11 @@ static int batch_mapping = 1;
  module_param(batch_mapping, int, 0444);
  MODULE_PARM_DESC(batch_mapping, "Batched mapping 1 -Enable; 0 - Disable");

+static int max_iotlb_entries = 2048;

+module_param(max_iotlb_entries, int, 0444);
+MODULE_PARM_DESC(max_iotlb_entries,
+                "Maximum number of iotlb entries. 0 means unlimited. (default: 
2048)");
+
  static char *macaddr;
  module_param(macaddr, charp, 0);
  MODULE_PARM_DESC(macaddr, "Ethernet MAC address");
@@ -371,7 +376,7 @@ static struct vdpasim *vdpasim_create(void)
        if (!vdpasim->vqs)
                goto err_iommu;

- vdpasim->iommu = vhost_iotlb_alloc(2048, 0);

+       vdpasim->iommu = vhost_iotlb_alloc(max_iotlb_entries, 0);
        if (!vdpasim->iommu)
                goto err_iommu;