Re: [PATCH 01/14] iommu: Implement IOMMU LU FLB callbacks

[Samiullah Khawaja]

On Fri, Mar 13, 2026 at 03:36:33PM +0000, Pranjal Shrivastava wrote:
> On Thu, Mar 12, 2026 at 04:43:00PM +0000, Samiullah Khawaja wrote:
> > On Wed, Mar 11, 2026 at 09:07:00PM +0000, Pranjal Shrivastava wrote:
> > > On Tue, Feb 03, 2026 at 10:09:35PM +0000, Samiullah Khawaja wrote:
> > > > Add liveupdate FLB for IOMMU state preservation. Use KHO preserve memory
> > > > alloc/free helper functions to allocate memory for the IOMMU LU FLB
> > > > object and the serialization structs for device, domain and iommu.
> > > >
> > > > During retrieve, walk through the preserved objs nodes and restore each
> > > > folio. Also recreate the FLB obj.
> > > >
> > > > Signed-off-by: Samiullah Khawaja <skhawaja@xxxxxxxxxx>
> > > > ---
> > > >  drivers/iommu/Kconfig         |  11 +++
> > > >  drivers/iommu/Makefile        |   1 +
> > > >  drivers/iommu/liveupdate.c    | 177 ++++++++++++++++++++++++++++++++++
> > > >  include/linux/iommu-lu.h      |  17 ++++
> > > >  include/linux/kho/abi/iommu.h | 119 +++++++++++++++++++++++
> > > >  5 files changed, 325 insertions(+)
> > > >  create mode 100644 drivers/iommu/liveupdate.c
> > > >  create mode 100644 include/linux/iommu-lu.h
> > > >  create mode 100644 include/linux/kho/abi/iommu.h
> > > >
> > > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> > > > index f86262b11416..fdcfbedee5ed 100644
> > > > --- a/drivers/iommu/Kconfig
> > > > +++ b/drivers/iommu/Kconfig
> > > > @@ -11,6 +11,17 @@ config IOMMUFD_DRIVER
> > > >  	bool
> > > >  	default n
> > > >
>
> [ snip ---- >8 -----]
>
> > >
> > > > +enum iommu_lu_type {
> > > > +	IOMMU_INVALID,
> > > > +	IOMMU_INTEL,
> > > > +};
> > > > +
> > > > +struct iommu_obj_ser {
> > > > +	u32 idx;
> > > > +	u32 ref_count;
> > > > +	u32 deleted:1;
> > > > +	u32 incoming:1;
> > > > +} __packed;
> > > > +
> > > > +struct iommu_domain_ser {
> > > > +	struct iommu_obj_ser obj;
> > > > +	u64 top_table;
> > > > +	u64 top_level;
> > > > +	struct iommu_domain *restored_domain;
> > > > +} __packed;
> > > > +
> > > > +struct device_domain_iommu_ser {
> > > > +	u32 did;
> > > > +	u64 domain_phys;
> > > > +	u64 iommu_phys;
> > > > +} __packed;
> > > > +
> > > > +struct device_ser {
> > > > +	struct iommu_obj_ser obj;
> > > > +	u64 token;
> > > > +	u32 devid;
> > > > +	u32 pci_domain;
> > > > +	struct device_domain_iommu_ser domain_iommu_ser;
> > > > +	enum iommu_lu_type type;
> > > > +} __packed;
> > > > +
> > > > +struct iommu_intel_ser {
> > > > +	u64 phys_addr;
> > > > +	u64 root_table;
> > > > +} __packed;
> > > > +
>
> One more thing here, let's add the "intel" stuff with the intel patches

Agreed. Will move these to intel specific patches.
> Thanks,
> Praan
>
> > > > +struct iommu_ser {
> > > > +	struct iommu_obj_ser obj;
> > > > +	u64 token;
> > > > +	enum iommu_lu_type type;
> > > > +	union {
> > > > +		struct iommu_intel_ser intel;
> > > > +	};
> > > > +} __packed;
> > > > +
> > > > +struct iommu_objs_ser {
> > > > +	u64 next_objs;
> > > > +	u64 nr_objs;
> > > > +} __packed;
> > > > +
> > > > +struct iommus_ser {
> > > > +	struct iommu_objs_ser objs;
> > > > +	struct iommu_ser iommus[];
> > > > +} __packed;
> > > > +
> > > > +struct iommu_domains_ser {
> > > > +	struct iommu_objs_ser objs;
> > > > +	struct iommu_domain_ser iommu_domains[];
> > > > +} __packed;
> > > > +
> > > > +struct devices_ser {
> > > > +	struct iommu_objs_ser objs;
> > > > +	struct device_ser devices[];
> > > > +} __packed;
> > > > +
>
> Thanks,
> Praan

Thanks,
Sami