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SAEximRunCond expanded to false X-Rspamd-Queue-Id: DD546120022 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: c4uab96ke3je6by74sd6kca5knnew5oo X-HE-Tag: 1708708052-502125 X-HE-Meta: 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 5ZA7Earz O47PLJx5U9GUNIq9gMqH/jkq+d1unbL3B2QyeLTfX6eS3j7AOr4lC0zngf23COBXxQzfe9yfDr3vC7Ilz6teRFq3gUmWem7OkRXPwasEGmRNdF/OeamOyFtKhlO+fF4yblYvCRoNDhzONa3QFFl/h8fATnCKgKdKYE4eV8m5rF3VEjD/IXT58o0+A7p2kWWeVPQxtgzArU8THCjECvEmGSWUZHV7+XZmBpxJHDmHAAXURqnLuz7nwgLv+Y1MyME96sRzli+126df2BZU= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, 20 Feb 2024 07:29:25 +0000, wrote: > > From: Ankit Agrawal > > To provide VM with the ability to get device IO memory with NormalNC > property, map device MMIO in KVM for ARM64 at stage2 as NormalNC. > Having NormalNC S2 default puts guests in control (based on [1], > "Combining stage 1 and stage 2 memory type attributes") of device > MMIO regions memory mappings. The rules are summarized below: > ([(S1) - stage1], [(S2) - stage 2]) > > S1 | S2 | Result > NORMAL-WB | NORMAL-NC | NORMAL-NC > NORMAL-WT | NORMAL-NC | NORMAL-NC > NORMAL-NC | NORMAL-NC | NORMAL-NC > DEVICE | NORMAL-NC | DEVICE > > Still this cannot be generalized to non PCI devices such as GICv2. > There is insufficient information and uncertainity in the behavior > of non PCI driver. A driver must indicate support using the > new flag VM_ALLOW_ANY_UNCACHED. > > Adapt KVM to make use of the flag VM_ALLOW_ANY_UNCACHED as indicator to > activate the S2 setting to NormalNc. > > [1] section D8.5.5 of DDI0487J_a_a-profile_architecture_reference_manual.pdf > > Suggested-by: Catalin Marinas > Acked-by: Jason Gunthorpe > Reviewed-by: Catalin Marinas > Signed-off-by: Ankit Agrawal Since people have asked for various commit message updates, I'll add my own: for the KVM/arm64 tree, the convention for the subject line is "KVM: arm64: Something starting with a capital". Thanks, M. -- Without deviation from the norm, progress is not possible.