Messages in this thread Patch in this message | | | From | Jerry Snitselaar <> | Subject | Question about domain_init (v5.3-v5.7) | Date | Wed, 25 Nov 2020 13:27:31 -0700 |
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Is there a reason we check the requested guest address width against the iommu's mgaw, instead of the agaw that we already know for the iommu? I've run into a case with a new system where the mgaw reported is 57, but if they set PAE to 46 instead of 52 in the bios, then sagaw reports the highest supported agaw is 48 and the domain_init code fails here. In other places like prepare_domain_attach_device, the dmar domain agaw gets adjusted down to the iommu agaw. The agaw of the iommu gets determined based off what is reported for sagaw. I'm wondering if it can't instead do:
--- drivers/iommu/intel-iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 6ca5c92ef2e5..a8e41ec36d9e 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1862,8 +1862,8 @@ static int domain_init(struct dmar_domain *domain, struct intel_iommu *iommu, domain_reserve_special_ranges(domain);
/* calculate AGAW */ - if (guest_width > cap_mgaw(iommu->cap)) - guest_width = cap_mgaw(iommu->cap); + if (guest_width > agaw_to_width(iommu->agaw)) + guest_width = agaw_to_width(iommu->agaw); domain->gaw = guest_width; adjust_width = guestwidth_to_adjustwidth(guest_width); agaw = width_to_agaw(adjust_width); -- 2.27.0
Thoughts? With the former code the ehci device for the ilo fails when trying to get a private domain.
Thanks, Jerry
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