APPLIED: [Patch 0/2 v2] [impish/linux-azure] Azure: not enough RAM under 4GB for CVM

[Tim Gardner]

Applied to impish/linux-azure:master-next. Thanks.

I updated the commit subject to include "UBUNTU: SAUCE:" on patch 2.

-rtg

On 4/4/22 07:16, Tim Gardner wrote:
> v2 - attach the 2nd patch which was forgotten the first time.
> 
> SRU Justification
> 
> [Impact]
> Can you please include one more patchset for the "no enough RAM under 4GB" issue
> for the v5.13 kernel (and v5.15 kernel):
> https://lwn.net/ml/linux-kernel/20220209122302.213882-2-ltykernel@gmail.com/
> https://lwn.net/ml/linux-kernel/20220209122302.213882-3-ltykernel@gmail.com/
> 
> Without the two patches, currently the 5.13 kernel (and 5.15 kernel) can't boot
> as a CVM guest on Azure. :-(
> 
> The background is: currently an Azure host only provides about 900 MB memory below
> the 4GB boundary while the swiotlb code (which is required by the CVM patchset)
> needs to allocate memory of a size of MIN(1GB, 6% of the total memory). There will
> be an Azure host update, with which the host will provide about 3GB memory below
> the 4GB boundary, but we still need to wait a few more weeks to know the ETA.
> Currently the above two patches can work around the issue from the guest side.
> 
> [Test Case]
> 
> Microsoft tested
> 
> [Where things could go wrong]
> 
> These patches could affect non-CVM instances.
> 
> [Other Info]
> 
> SF: #00323683
> 

-- 
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Tim Gardner
Canonical, Inc