From mboxrd@z Thu Jan 1 00:00:00 1970 From: catalin.marinas@arm.com (Catalin Marinas) Date: Thu, 26 Feb 2015 11:27:18 +0000 Subject: [PATCH v3] arm64: mm: increase VA range of identity map In-Reply-To: <1424942215-5505-1-git-send-email-ard.biesheuvel@linaro.org> References: <1424942215-5505-1-git-send-email-ard.biesheuvel@linaro.org> Message-ID: <20150226112717.GA17992@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Feb 26, 2015 at 09:16:55AM +0000, Ard Biesheuvel wrote: > The page size and the number of translation levels, and hence the supported > virtual address range, are build-time configurables on arm64 whose optimal > values are use case dependent. However, in the current implementation, if > the system's RAM is located at a very high offset, the virtual address range > needs to reflect that merely because the identity mapping, which is only used > to enable or disable the MMU, requires the extended virtual range to map the > physical memory at an equal virtual offset. > > This patch relaxes that requirement, by increasing the number of translation > levels for the identity mapping only, and only when actually needed, i.e., > when system RAM's offset is found to be out of reach at runtime. > > Tested-by: Laura Abbott > Signed-off-by: Ard Biesheuvel The patch looks fine to me, though most likely for 4.1; in the meantime: Reviewed-by: Catalin Marinas Do you plan to look at the KVM aspect as well or we leave it with the KVM maintainers? -- Catalin