[PATCH] iommu/amd-vi: make IOMMU list ro after init

[PATCH] iommu/amd-vi: make IOMMU list ro after init

[Roger Pau Monne]

The only functions to modify the list, amd_iommu_detect_one_acpi() and
amd_iommu_init_cleanup(), are already init.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
 xen/drivers/passthrough/amd/iommu_init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/drivers/passthrough/amd/iommu_init.c b/xen/drivers/passthrough/amd/iommu_init.c
index 6c0dc2d5cb69..302362502033 100644
--- a/xen/drivers/passthrough/amd/iommu_init.c
+++ b/xen/drivers/passthrough/amd/iommu_init.c
@@ -32,7 +32,7 @@ unsigned int __read_mostly amd_iommu_acpi_info;
 unsigned int __read_mostly ivrs_bdf_entries;
 u8 __read_mostly ivhd_type;
 static struct radix_tree_root ivrs_maps;
-LIST_HEAD_READ_MOSTLY(amd_iommu_head);
+LIST_HEAD_RO_AFTER_INIT(amd_iommu_head);
 bool iommuv2_enabled;
 
 bool __ro_after_init amd_iommu_perdev_intremap = true;
-- 
2.46.0

Re: [PATCH] iommu/amd-vi: make IOMMU list ro after init

[Jan Beulich]

On 30.09.2024 12:28, Roger Pau Monne wrote:
> The only functions to modify the list, amd_iommu_detect_one_acpi() and
> amd_iommu_init_cleanup(), are already init.
> 
> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>

Acked-by: Jan Beulich <jbeulich@suse.com>

Surely the same can be said for VT-d's acpi_*_units? And likely other
globals there and here?

Jan

Re: [PATCH] iommu/amd-vi: make IOMMU list ro after init

[Roger Pau Monné]

On Mon, Sep 30, 2024 at 12:33:56PM +0200, Jan Beulich wrote:
> On 30.09.2024 12:28, Roger Pau Monne wrote:
> > The only functions to modify the list, amd_iommu_detect_one_acpi() and
> > amd_iommu_init_cleanup(), are already init.
> > 
> > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
> 
> Acked-by: Jan Beulich <jbeulich@suse.com>
> 
> Surely the same can be said for VT-d's acpi_*_units? And likely other
> globals there and here?

Possibly, I wasn't explicitly looking for stuff in IOMMU code to
convert from read_mostly to ro_after_init, just came across this one
while looking at something in the area.

Thanks, Roger.