On 19.09.19 14:35, Julien Grall wrote:
Hi Oleksandr,
Hi, Julien.
On 13/09/2019 16:35, Oleksandr Tyshchenko wrote:
From: Oleksandr Tyshchenko <oleksandr_tyshche...@epam.com>
The main puprose of this patch is to add a way to register DT device
(which is behind the IOMMU) using the generic IOMMU DT bindings [1]
before assigning that device to a domain.
So, this patch adds new "iommu_add_dt_device" API for adding DT device
to the IOMMU using generic IOMMU DT bindings and previously added
"iommu_fwspec" support. It is called when constructing Dom0 since
"iommu_assign_dt_device" can be called for Dom0 also.
The last sentence is misleading. Yes some devices may be assigned to
the hardware domain (aka dom0) but other may be assigned to other
domains.
Here you are (ab)using the construction of the hardware domain to add
all the devices to the IOMMU. This works fine now because the hardware
domain will always be the first domain to be initialized. But I am not
sure that whether this is correct to do long term.
As mentioned earlier, my preference is to keep "add" and "assign"
separated. So maybe what we want to do is:
if ( need_mapping )
{
iommu_add_dt_device(d, dev);
if ( dt_device_is_protected(d) )
{
res = iommu_assign_dt_device(...);
if ( res )
/* error */
}
}
We would need similar code in iommu_do_dt_domctl. Although, device
should alway be protected in this case.
Well, will modify this way.
diff --git a/xen/drivers/passthrough/arm/iommu.c
b/xen/drivers/passthrough/arm/iommu.c
index 5a3d1d5..dea79ed 100644
--- a/xen/drivers/passthrough/arm/iommu.c
+++ b/xen/drivers/passthrough/arm/iommu.c
@@ -20,6 +20,7 @@
#include <xen/lib.h>
#include <asm/device.h>
+#include <asm/iommu_fwspec.h>
/*
* Deferred probe list is used to keep track of devices for which
driver
@@ -141,3 +142,65 @@ int arch_iommu_populate_page_table(struct domain
*d)
void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
{
}
+
+int __init iommu_add_dt_device(struct dt_device_node *np)
Sorry to only realise it now. Would it make sense to have this
function implemented in xen/passthrough/device_tree.c?
Not entirely sure. device_tree.c is a common code. The iommu_fwspec
stuff (widely used in this function) is ARM code.
--
Regards,
Oleksandr Tyshchenko
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