On 14.04.2024 02:32, Marek Marczykowski-Górecki wrote:
> On Wed, Apr 03, 2024 at 09:10:40AM +0200, Jan Beulich wrote:
>> On 27.03.2024 03:53, Marek Marczykowski-Górecki wrote:
>>> The IOMMU driver checks if RMRR/IVMD are marked as reserved in memory
>>> map. This should be true for addresses coming from the firmware, but
>>> when extra pages used by Xen itself are included in the mapping, those
>>> are taken from usable RAM used. Mark those pages as reserved too.
>>>
>>> Not marking the pages as reserved didn't caused issues before due to
>>> another a bug in IOMMU driver code, that was fixed in 83afa3135830
>>> ("amd-vi: fix IVMD memory type checks").
>>>
>>> Failing to reserve memory will lead to panic in IOMMU setup code. And
>>> not including the page in IOMMU mapping will lead to broken console (due
>>> to IOMMU faults). The pages chosen by the XHCI console driver should
>>> still be usable by the CPU though, and the console code already can deal
>>> with too slow console by dropping characters (and console not printing
>>> anything is a special case of "slow"). When reserving fails print an error
>>> message showing which pages failed and who requested them. This should
>>> be enough hint to find why XHCI console doesn't work.
>>>
>>> Fixes: 3a1a7b809ffa "drivers/char: mark DMA buffers as reserved for the
>>> XHCI"
>>> Signed-off-by: Marek Marczykowski-Górecki <marma...@invisiblethingslab.com>
>>
>> Acked-by: Jan Beulich <jbeul...@suse.com>
>
> Is any ack missing here, or has it just fallen through the cracks?
??? (commit dd5101a6169f89b9e3f3b72f0b0fcdb38db2fb35)
Jan
