On 2022-06-17 03:53, Tian, Kevin wrote:
From: Nicolin Chen <nicolinc@xxxxxxxxxx>
Sent: Friday, June 17, 2022 6:41 AM
...
- if (resv_msi) {
+ if (resv_msi && !domain->msi_cookie) {
ret = iommu_get_msi_cookie(domain->domain,
resv_msi_base);
if (ret && ret != -ENODEV)
goto out_detach;
+ domain->msi_cookie = true;
}
why not moving to alloc_attach_domain() then no need for the new
domain field? It's required only when a new domain is allocated.
When reusing an existing domain that doesn't have an msi_cookie,
we can do iommu_get_msi_cookie() if resv_msi is found. So it is
not limited to a new domain.
Looks msi_cookie requirement is per platform (currently only
for smmu. see arm_smmu_get_resv_regions()). If there is
no mixed case then above check is not required.
But let's hear whether Robin has a different thought here.
Yes, the cookie should logically be tied to the lifetime of the domain
itself. In the relevant context, "an existing domain that doesn't have
an msi_cookie" should never exist.
Thanks,
Robin.
