From: Marc Zyngier <maz@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
David Brazdil <dbrazdil@google.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
Jing Zhang <jingzhangos@google.com>,
Ajay Patil <pajay@qti.qualcomm.com>,
Prasad Sodagudi <psodagud@codeaurora.org>,
Srinivas Ramana <sramana@codeaurora.org>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
kernel-team@android.com
Subject: Re: [PATCH v4 14/21] arm64: Honor VHE being disabled from the command-line
Date: Sun, 24 Jan 2021 15:59:07 +0000 [thread overview]
Message-ID: <87wnw2jph0.wl-maz@kernel.org> (raw)
In-Reply-To: <YAwtuZZpTwwoMqrk@Catalins-MacBook-Air.local>
On Sat, 23 Jan 2021 14:07:53 +0000,
Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Mon, Jan 18, 2021 at 09:45:26AM +0000, Marc Zyngier wrote:
> > diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
> > index 59820f9b8522..bbab2148a2a2 100644
> > --- a/arch/arm64/kernel/hyp-stub.S
> > +++ b/arch/arm64/kernel/hyp-stub.S
> > @@ -77,13 +77,24 @@ SYM_CODE_END(el1_sync)
> > SYM_CODE_START_LOCAL(mutate_to_vhe)
> > // Sanity check: MMU *must* be off
> > mrs x0, sctlr_el2
> > - tbnz x0, #0, 1f
> > + tbnz x0, #0, 2f
> >
> > // Needs to be VHE capable, obviously
> > mrs x0, id_aa64mmfr1_el1
> > ubfx x0, x0, #ID_AA64MMFR1_VHE_SHIFT, #4
> > - cbz x0, 1f
> > + cbz x0, 2f
> >
> > + // Check whether VHE is disabled from the command line
> > + adr_l x1, id_aa64mmfr1_val
> > + ldr x0, [x1]
> > + adr_l x1, id_aa64mmfr1_mask
> > + ldr x1, [x1]
> > + ubfx x0, x0, #ID_AA64MMFR1_VHE_SHIFT, #4
> > + ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4
> > + cbz x1, 1f
> > + and x0, x0, x1
> > + cbz x0, 2f
> > +1:
>
> I can see the advantage here in separate id_aa64mmfr1_val/mask but we
> could use some asm offsets here and keep the pointer indirection simpler
> in C code. You'd just need something like 'adr_l mmfr1_ovrd + VAL_OFFSET'.
>
> Anyway, if you have a strong preference for the current approach, leave
> it as is.
I've now moved over to a structure containing both val/mask, meaning
that we only need to keep a single pointer around in the various
feature descriptors. It certainly looks better.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Prasad Sodagudi <psodagud@codeaurora.org>,
Srinivas Ramana <sramana@codeaurora.org>,
linux-kernel@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
Ajay Patil <pajay@qti.qualcomm.com>,
kernel-team@android.com, Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4 14/21] arm64: Honor VHE being disabled from the command-line
Date: Sun, 24 Jan 2021 15:59:07 +0000 [thread overview]
Message-ID: <87wnw2jph0.wl-maz@kernel.org> (raw)
In-Reply-To: <YAwtuZZpTwwoMqrk@Catalins-MacBook-Air.local>
On Sat, 23 Jan 2021 14:07:53 +0000,
Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Mon, Jan 18, 2021 at 09:45:26AM +0000, Marc Zyngier wrote:
> > diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
> > index 59820f9b8522..bbab2148a2a2 100644
> > --- a/arch/arm64/kernel/hyp-stub.S
> > +++ b/arch/arm64/kernel/hyp-stub.S
> > @@ -77,13 +77,24 @@ SYM_CODE_END(el1_sync)
> > SYM_CODE_START_LOCAL(mutate_to_vhe)
> > // Sanity check: MMU *must* be off
> > mrs x0, sctlr_el2
> > - tbnz x0, #0, 1f
> > + tbnz x0, #0, 2f
> >
> > // Needs to be VHE capable, obviously
> > mrs x0, id_aa64mmfr1_el1
> > ubfx x0, x0, #ID_AA64MMFR1_VHE_SHIFT, #4
> > - cbz x0, 1f
> > + cbz x0, 2f
> >
> > + // Check whether VHE is disabled from the command line
> > + adr_l x1, id_aa64mmfr1_val
> > + ldr x0, [x1]
> > + adr_l x1, id_aa64mmfr1_mask
> > + ldr x1, [x1]
> > + ubfx x0, x0, #ID_AA64MMFR1_VHE_SHIFT, #4
> > + ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4
> > + cbz x1, 1f
> > + and x0, x0, x1
> > + cbz x0, 2f
> > +1:
>
> I can see the advantage here in separate id_aa64mmfr1_val/mask but we
> could use some asm offsets here and keep the pointer indirection simpler
> in C code. You'd just need something like 'adr_l mmfr1_ovrd + VAL_OFFSET'.
>
> Anyway, if you have a strong preference for the current approach, leave
> it as is.
I've now moved over to a structure containing both val/mask, meaning
that we only need to keep a single pointer around in the various
feature descriptors. It certainly looks better.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Jing Zhang <jingzhangos@google.com>,
Prasad Sodagudi <psodagud@codeaurora.org>,
Srinivas Ramana <sramana@codeaurora.org>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
linux-kernel@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Ajay Patil <pajay@qti.qualcomm.com>,
kernel-team@android.com, David Brazdil <dbrazdil@google.com>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4 14/21] arm64: Honor VHE being disabled from the command-line
Date: Sun, 24 Jan 2021 15:59:07 +0000 [thread overview]
Message-ID: <87wnw2jph0.wl-maz@kernel.org> (raw)
In-Reply-To: <YAwtuZZpTwwoMqrk@Catalins-MacBook-Air.local>
On Sat, 23 Jan 2021 14:07:53 +0000,
Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Mon, Jan 18, 2021 at 09:45:26AM +0000, Marc Zyngier wrote:
> > diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
> > index 59820f9b8522..bbab2148a2a2 100644
> > --- a/arch/arm64/kernel/hyp-stub.S
> > +++ b/arch/arm64/kernel/hyp-stub.S
> > @@ -77,13 +77,24 @@ SYM_CODE_END(el1_sync)
> > SYM_CODE_START_LOCAL(mutate_to_vhe)
> > // Sanity check: MMU *must* be off
> > mrs x0, sctlr_el2
> > - tbnz x0, #0, 1f
> > + tbnz x0, #0, 2f
> >
> > // Needs to be VHE capable, obviously
> > mrs x0, id_aa64mmfr1_el1
> > ubfx x0, x0, #ID_AA64MMFR1_VHE_SHIFT, #4
> > - cbz x0, 1f
> > + cbz x0, 2f
> >
> > + // Check whether VHE is disabled from the command line
> > + adr_l x1, id_aa64mmfr1_val
> > + ldr x0, [x1]
> > + adr_l x1, id_aa64mmfr1_mask
> > + ldr x1, [x1]
> > + ubfx x0, x0, #ID_AA64MMFR1_VHE_SHIFT, #4
> > + ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4
> > + cbz x1, 1f
> > + and x0, x0, x1
> > + cbz x0, 2f
> > +1:
>
> I can see the advantage here in separate id_aa64mmfr1_val/mask but we
> could use some asm offsets here and keep the pointer indirection simpler
> in C code. You'd just need something like 'adr_l mmfr1_ovrd + VAL_OFFSET'.
>
> Anyway, if you have a strong preference for the current approach, leave
> it as is.
I've now moved over to a structure containing both val/mask, meaning
that we only need to keep a single pointer around in the various
feature descriptors. It certainly looks better.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-01-24 16:00 UTC|newest]
Thread overview: 166+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-18 9:45 [PATCH v4 00/21] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 01/21] arm64: Fix labels in el2_setup macros Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 11:13 ` David Brazdil
2021-01-18 11:13 ` David Brazdil
2021-01-18 11:13 ` David Brazdil
2021-01-18 9:45 ` [PATCH v4 02/21] arm64: Fix outdated TCR setup comment Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-20 18:18 ` Catalin Marinas
2021-01-20 18:18 ` Catalin Marinas
2021-01-20 18:18 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 03/21] arm64: Turn the MMU-on sequence into a macro Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-20 18:18 ` Catalin Marinas
2021-01-20 18:18 ` Catalin Marinas
2021-01-20 18:18 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 04/21] arm64: Provide an 'upgrade to VHE' stub hypercall Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 11:25 ` David Brazdil
2021-01-18 11:25 ` David Brazdil
2021-01-18 11:25 ` David Brazdil
2021-01-24 18:44 ` Marc Zyngier
2021-01-24 18:44 ` Marc Zyngier
2021-01-24 18:44 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 05/21] arm64: Initialise as nVHE before switching to VHE Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 06/21] arm64: Move VHE-specific SPE setup to mutate_to_vhe() Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 07/21] arm64: Simplify init_el2_state to be non-VHE only Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 08/21] arm64: Move SCTLR_EL1 initialisation to EL-agnostic code Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-20 18:35 ` Catalin Marinas
2021-01-20 18:35 ` Catalin Marinas
2021-01-20 18:35 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 09/21] arm64: cpufeature: Add global feature override facility Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-22 18:41 ` Catalin Marinas
2021-01-22 18:41 ` Catalin Marinas
2021-01-22 18:41 ` Catalin Marinas
2021-01-23 15:59 ` Suzuki K Poulose
2021-01-23 15:59 ` Suzuki K Poulose
2021-01-23 15:59 ` Suzuki K Poulose
2021-01-18 9:45 ` [PATCH v4 10/21] arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding() Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-22 18:53 ` Catalin Marinas
2021-01-22 18:53 ` Catalin Marinas
2021-01-22 18:53 ` Catalin Marinas
2021-01-23 16:04 ` Suzuki K Poulose
2021-01-23 16:04 ` Suzuki K Poulose
2021-01-23 16:04 ` Suzuki K Poulose
2021-01-18 9:45 ` [PATCH v4 11/21] arm64: Extract early FDT mapping from kaslr_early_init() Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-22 18:55 ` Catalin Marinas
2021-01-22 18:55 ` Catalin Marinas
2021-01-22 18:55 ` Catalin Marinas
2021-01-23 13:25 ` Catalin Marinas
2021-01-23 13:25 ` Catalin Marinas
2021-01-23 13:25 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 12/21] arm64: cpufeature: Add an early command-line cpufeature override facility Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 13:07 ` David Brazdil
2021-01-18 13:07 ` David Brazdil
2021-01-18 13:07 ` David Brazdil
2021-01-23 13:23 ` Catalin Marinas
2021-01-23 13:23 ` Catalin Marinas
2021-01-23 13:23 ` Catalin Marinas
2021-01-23 13:43 ` Catalin Marinas
2021-01-23 13:43 ` Catalin Marinas
2021-01-23 13:43 ` Catalin Marinas
2021-01-24 16:21 ` Marc Zyngier
2021-01-24 16:21 ` Marc Zyngier
2021-01-24 16:21 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 13/21] arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-23 14:04 ` Catalin Marinas
2021-01-23 14:04 ` Catalin Marinas
2021-01-23 14:04 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 14/21] arm64: Honor VHE being disabled from the command-line Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 13:14 ` David Brazdil
2021-01-18 13:14 ` David Brazdil
2021-01-18 13:14 ` David Brazdil
2021-01-23 14:07 ` Catalin Marinas
2021-01-23 14:07 ` Catalin Marinas
2021-01-23 14:07 ` Catalin Marinas
2021-01-24 15:59 ` Marc Zyngier [this message]
2021-01-24 15:59 ` Marc Zyngier
2021-01-24 15:59 ` Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 15/21] arm64: Add an aliasing facility for the idreg override Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 13:18 ` David Brazdil
2021-01-18 13:18 ` David Brazdil
2021-01-18 13:18 ` David Brazdil
2021-01-24 19:01 ` Marc Zyngier
2021-01-24 19:01 ` Marc Zyngier
2021-01-24 19:01 ` Marc Zyngier
2021-01-23 14:12 ` Catalin Marinas
2021-01-23 14:12 ` Catalin Marinas
2021-01-23 14:12 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 16/21] arm64: Make kvm-arm.mode={nvhe,protected} an alias of id_aa64mmfr1.vh=0 Marc Zyngier
2021-01-18 9:45 ` [PATCH v4 16/21] arm64: Make kvm-arm.mode={nvhe, protected} " Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-23 14:15 ` [PATCH v4 16/21] arm64: Make kvm-arm.mode={nvhe,protected} " Catalin Marinas
2021-01-23 14:15 ` Catalin Marinas
2021-01-23 14:15 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 17/21] KVM: arm64: Document HVC_VHE_RESTART stub hypercall Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 13:29 ` David Brazdil
2021-01-18 13:29 ` David Brazdil
2021-01-18 13:29 ` David Brazdil
2021-01-18 9:45 ` [PATCH v4 18/21] arm64: Move "nokaslr" over to the early cpufeature infrastructure Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 14:46 ` David Brazdil
2021-01-18 14:46 ` David Brazdil
2021-01-18 14:46 ` David Brazdil
2021-01-24 18:41 ` Marc Zyngier
2021-01-24 18:41 ` Marc Zyngier
2021-01-24 18:41 ` Marc Zyngier
2021-01-23 14:19 ` Catalin Marinas
2021-01-23 14:19 ` Catalin Marinas
2021-01-23 14:19 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 19/21] arm64: cpufeatures: Allow disabling of BTI from the command-line Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-23 14:24 ` Catalin Marinas
2021-01-23 14:24 ` Catalin Marinas
2021-01-23 14:24 ` Catalin Marinas
2021-01-26 20:35 ` Srinivas Ramana
2021-01-26 20:35 ` Srinivas Ramana
2021-01-18 9:45 ` [PATCH v4 20/21] arm64: Defer enabling pointer authentication on boot core Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-23 14:26 ` Catalin Marinas
2021-01-23 14:26 ` Catalin Marinas
2021-01-23 14:26 ` Catalin Marinas
2021-01-18 9:45 ` [PATCH v4 21/21] arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-18 9:45 ` Marc Zyngier
2021-01-23 14:28 ` Catalin Marinas
2021-01-23 14:28 ` Catalin Marinas
2021-01-23 14:28 ` Catalin Marinas
2021-01-26 20:30 ` Srinivas Ramana
2021-01-26 20:30 ` Srinivas Ramana
2021-01-18 14:54 ` [PATCH v4 00/21] arm64: Early CPU feature override, and applications to VHE, BTI and PAuth David Brazdil
2021-01-18 14:54 ` David Brazdil
2021-01-18 14:54 ` David Brazdil
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