[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Xen-devel] [PATCH v14 9/9] mm / iommu: split need_iommu() into has_iommu_pt() and need_iommu_pt_sync()
- To: Paul Durrant <paul.durrant@xxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxxx
- From: Julien Grall <julien.grall@xxxxxxx>
- Date: Thu, 4 Oct 2018 18:15:42 +0100
- Cc: Kevin Tian <kevin.tian@xxxxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Wei Liu <wei.liu2@xxxxxxxxxx>, Jun Nakajima <jun.nakajima@xxxxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>, George Dunlap <George.Dunlap@xxxxxxxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Ian Jackson <ian.jackson@xxxxxxxxxxxxx>, Tim Deegan <tim@xxxxxxx>, Tamas K Lengyel <tamas@xxxxxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>, Brian Woods <brian.woods@xxxxxxx>, Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
- Delivery-date: Thu, 04 Oct 2018 17:15:58 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
Hi Paul,
On 04/10/2018 11:45, Paul Durrant wrote:
The name 'need_iommu()' is a little confusing as it suggests a domain needs
to use the IOMMU but something might not be set up yet, when in fact it
represents a tri-state value (not a boolean as might be expected) where
-1 means 'IOMMU mappings being set up' and 1 means 'IOMMU mappings have
been fully set up'.
Two different meanings are also inferred from the macro it in various
places in the code:
- Some callers want to test whether a domain has IOMMU mappings at all
- Some callers want to test whether they need to synchronize the domain's
P2M and IOMMU mappings
This patch replaces the 'need_iommu' tri-state value with a defined
enumeration and adds a boolean flag 'need_sync' to separate these meanings,
and places both of these in struct domain_iommu, rather than directly in
struct domain.
This patch also creates two new boolean macros:
- 'has_iommu_pt()' evaluates to true if a domain has IOMMU mappings, even
if they are still under construction.
- 'need_iommu_pt_sync()' evaluates to true if a domain requires explicit
synchronization of the P2M and IOMMU mappings.
All callers of need_iommu() are then modified to use the macro appropriate
to what they are trying to test, except for the instance in
xen/drivers/passthrough/pci.c:assign_device() which has simply been
removed since it appears to be unnecessary.
NOTE: There are some callers of need_iommu() that strictly operate on
the hardware domain. In some of these case a more global flag is
used instead.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Acked-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>
For the Arm bits:
Acked-by: Julien Grall <julien.grall@xxxxxxx>
Cheers,
--
Julien Grall
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel
|
