From: Hector Martin 'marcan' <marcan@marcan.st>
To: Marc Zyngier <maz@kernel.org>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Jing Zhang <jingzhangos@google.com>,
kernel-team@android.com, Srinivas Ramana <sramana@codeaurora.org>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Ard Biesheuvel <ardb@kernel.org>, Will Deacon <will@kernel.org>,
James Morse <james.morse@arm.com>,
Ajay Patil <pajay@qti.qualcomm.com>,
Prasad Sodagudi <psodagud@codeaurora.org>,
Alexandru Elisei <alexandru.elisei@arm.com>,
David Brazdil <dbrazdil@google.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: Re: [PATCH v6 05/21] arm64: Initialise as nVHE before switching to VHE
Date: Fri, 5 Feb 2021 21:01:46 +0900 [thread overview]
Message-ID: <1dbffcd4-5b20-404c-94af-c985a96785e2@marcan.st> (raw)
In-Reply-To: <20210201115637.3123740-6-maz@kernel.org>
On 01/02/2021 20.56, Marc Zyngier wrote:
> As we are aiming to be able to control whether we enable VHE or
> not, let's always drop down to EL1 first, and only then upgrade
> to VHE if at all possible.
>
> This means that if the kernel is booted at EL2, we always start
> with a nVHE init, drop to EL1 to initialise the the kernel, and
> only then upgrade the kernel EL to EL2 if possible (the process
> is obviously shortened for secondary CPUs).
Unfortunately, this is going to break on Apple SoCs, where it turns out
HCR_EL2.E2H is hard-wired to 1 - there is no nVHE mode. :(
>>> mrs(HCR_EL2) & (1<<34)
0x400000000
>>> msr(HCR_EL2, mrs(HCR_EL2) & ~(1<<34))
>>> mrs(HCR_EL2) & (1<<34)
0x400000000
--
Hector Martin "marcan" (marcan@marcan.st)
Public Key: https://mrcn.st/pub
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next prev parent reply other threads:[~2021-02-05 12:03 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 11:56 [PATCH v6 00/21] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 01/21] arm64: Fix labels in el2_setup macros Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 02/21] arm64: Fix outdated TCR setup comment Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 03/21] arm64: Turn the MMU-on sequence into a macro Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 04/21] arm64: Provide an 'upgrade to VHE' stub hypercall Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 05/21] arm64: Initialise as nVHE before switching to VHE Marc Zyngier
2021-02-05 12:01 ` Hector Martin 'marcan' [this message]
2021-02-05 14:04 ` Marc Zyngier
2021-02-06 14:29 ` Hector Martin 'marcan'
2021-02-01 11:56 ` [PATCH v6 06/21] arm64: Move VHE-specific SPE setup to mutate_to_vhe() Marc Zyngier
2021-02-03 21:13 ` Will Deacon
2021-02-04 9:30 ` Marc Zyngier
2021-02-04 9:34 ` Will Deacon
2021-02-04 9:50 ` Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 07/21] arm64: Simplify init_el2_state to be non-VHE only Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 08/21] arm64: Move SCTLR_EL1 initialisation to EL-agnostic code Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 09/21] arm64: cpufeature: Add global feature override facility Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 10/21] arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding() Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 11/21] arm64: Extract early FDT mapping from kaslr_early_init() Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 12/21] arm64: cpufeature: Add an early command-line cpufeature override facility Marc Zyngier
2021-02-05 16:35 ` Will Deacon
2021-02-05 16:42 ` Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 13/21] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 14/21] arm64: Honor VHE being disabled from the command-line Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 15/21] arm64: Add an aliasing facility for the idreg override Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 16/21] arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0 Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 17/21] KVM: arm64: Document HVC_VHE_RESTART stub hypercall Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 18/21] arm64: Move "nokaslr" over to the early cpufeature infrastructure Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 19/21] arm64: cpufeatures: Allow disabling of BTI from the command-line Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 20/21] arm64: Defer enabling pointer authentication on boot core Marc Zyngier
2021-02-01 11:56 ` [PATCH v6 21/21] arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line Marc Zyngier
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