From: Marc Zyngier <maz@kernel.org>
To: "Jonathan Neuschäfer" <j.ne@posteo.net>
Cc: Srinivas Ramana <sramana@codeaurora.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Hector Martin <marcan@marcan.st>,
linux-kernel@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
Will Deacon <will@kernel.org>,
Ajay Patil <pajay@qti.qualcomm.com>,
Prasad Sodagudi <psodagud@codeaurora.org>,
kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v7 23/23] [DO NOT MERGE] arm64: Cope with CPUs stuck in VHE mode
Date: Mon, 22 Feb 2021 09:47:06 +0000 [thread overview]
Message-ID: <4d4e9a5cff65dbd8861f829089f570e5@kernel.org> (raw)
In-Reply-To: <YDN6BtDhzmF5OtBO@latitude>
Hi Jonathan,
On 2021-02-22 09:35, Jonathan Neuschäfer wrote:
> Hi,
>
> On Mon, Feb 08, 2021 at 09:57:32AM +0000, Marc Zyngier wrote:
>> It seems that the CPU known as Apple M1 has the terrible habit
>> of being stuck with HCR_EL2.E2H==1, in violation of the architecture.
>
> Minor nitpick from the sideline: The M1 SoC has two kinds of CPU in it
> (Icestorm and Firestorm), which makes "CPU known as Apple M1" a bit
> imprecise.
Fair enough. How about something along the lines of:
"At least some of the CPUs integrated in the Apple M1 SoC have
the terrible habit..."
> In practicality it seems unlikely though, that Icestorm and Firestorm
> act differently with regards to the code in this patch.
This is my hunch as well. And if they did, it shouldn't be a big deal:
the "architecture compliant" CPUs would simply transition via EL1
as expected, and join their buggy friends running at EL2 slightly later.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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next prev parent reply other threads:[~2021-02-22 9:48 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-08 9:57 [PATCH v7 00/23] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 01/23] arm64: Fix labels in el2_setup macros Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 02/23] arm64: Fix outdated TCR setup comment Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 03/23] arm64: Turn the MMU-on sequence into a macro Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 04/23] arm64: Provide an 'upgrade to VHE' stub hypercall Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 05/23] arm64: Initialise as nVHE before switching to VHE Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 06/23] arm64: Drop early setting of MDSCR_EL2.TPMS Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 07/23] arm64: Move VHE-specific SPE setup to mutate_to_vhe() Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 08/23] arm64: Simplify init_el2_state to be non-VHE only Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 09/23] arm64: Move SCTLR_EL1 initialisation to EL-agnostic code Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 10/23] arm64: cpufeature: Add global feature override facility Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 11/23] arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding() Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 12/23] arm64: Extract early FDT mapping from kaslr_early_init() Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 13/23] arm64: cpufeature: Add an early command-line cpufeature override facility Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 14/23] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 15/23] arm64: Honor VHE being disabled from the command-line Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 16/23] arm64: Add an aliasing facility for the idreg override Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 17/23] arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0 Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 18/23] KVM: arm64: Document HVC_VHE_RESTART stub hypercall Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 19/23] arm64: Move "nokaslr" over to the early cpufeature infrastructure Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 20/23] arm64: cpufeatures: Allow disabling of BTI from the command-line Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 21/23] arm64: Defer enabling pointer authentication on boot core Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 22/23] arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line Marc Zyngier
2021-02-08 9:57 ` [PATCH v7 23/23] [DO NOT MERGE] arm64: Cope with CPUs stuck in VHE mode Marc Zyngier
2021-02-22 9:35 ` Jonathan Neuschäfer
2021-02-22 9:47 ` Marc Zyngier [this message]
2021-02-08 14:32 ` [PATCH v7 00/23] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth Will Deacon
2021-02-08 14:40 ` Ard Biesheuvel
2021-02-08 15:02 ` Marc Zyngier
2021-02-08 16:30 ` Marc Zyngier
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