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

From: Jason Wang
Date: Wed Dec 16 2020 - 23:31:35 EST



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 <jasowang@xxxxxxxxxx>
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>


Acked-by: Jason Wang <jasowang@xxxxxxxxxx>


---
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;