From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>
Cc: kvmarm@lists.linux.dev, kvm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Quentin Perret <qperret@google.com>,
Will Deacon <will@kernel.org>, Fuad Tabba <tabba@google.com>
Subject: Re: [PATCH v2 06/17] arm64: Allow EL1 physical timer access when running VHE
Date: Thu, 1 Jun 2023 06:34:19 +0000 [thread overview]
Message-ID: <ZHg76wizp5RSXTLG@linux.dev> (raw)
In-Reply-To: <20230526143348.4072074-7-maz@kernel.org>
Hey Marc,
On Fri, May 26, 2023 at 03:33:37PM +0100, Marc Zyngier wrote:
> To initialise the timer access from EL2 when HCR_EL2.E2H is set,
> we must make use the CNTHCTL_EL2 formap used is appropriate.
>
> This amounts to shifting the timer/counter enable bits by 10
> to the left.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arch/arm64/include/asm/el2_setup.h | 5 +++++
> arch/arm64/kvm/hyp/nvhe/hyp-init.S | 9 +++++++++
> 2 files changed, 14 insertions(+)
>
> diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
> index 037724b19c5c..225bf1f2514d 100644
> --- a/arch/arm64/include/asm/el2_setup.h
> +++ b/arch/arm64/include/asm/el2_setup.h
> @@ -34,6 +34,11 @@
> */
> .macro __init_el2_timers
> mov x0, #3 // Enable EL1 physical timers
> + mrs x1, hcr_el2
> + and x1, x1, #HCR_E2H
> + cbz x1, .LnVHE_\@
> + lsl x0, x0, #10
> +.LnVHE_\@:
> msr cnthctl_el2, x0
> msr cntvoff_el2, xzr // Clear virtual offset
> .endm
> diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
> index a6d67c2bb5ae..f9ee10e29497 100644
> --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S
> +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
> @@ -95,6 +95,15 @@ SYM_CODE_START_LOCAL(___kvm_hyp_init)
> ldr x1, [x0, #NVHE_INIT_HCR_EL2]
> msr hcr_el2, x1
>
> + mov x2, #HCR_E2H
> + and x2, x1, x2
> + cbz x2, 1f
> +
> + mrs x1, cnthctl_el2
> + and x1, x1, #~(BIT(0) | BIT(1))
> + orr x1, x1, #(BIT(10) | BIT(11))
> + msr cnthctl_el2, x1
> +1:
Can this be done with an alternative block keyed on ARM64_KVM_HVHE?
I get that __init_el2_timers needs to run before the cpu caps have been
evaluated, but I don't think the same applies for ___kvm_hyp_init
--
Thanks,
Oliver
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next prev parent reply other threads:[~2023-06-01 6:34 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-26 14:33 [PATCH v2 00/17] KVM: arm64: Allow using VHE in the nVHE hypervisor Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 01/17] KVM: arm64: Drop is_kernel_in_hyp_mode() from __invalidate_icache_guest_page() Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 02/17] arm64: Prevent the use of is_kernel_in_hyp_mode() in hypervisor code Marc Zyngier
2023-05-30 19:54 ` Oliver Upton
2023-05-31 7:17 ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 03/17] arm64: Turn kaslr_feature_override into a generic SW feature override Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 04/17] arm64: Add KVM_HVHE capability and has_hvhe() predicate Marc Zyngier
2023-06-01 7:06 ` Oliver Upton
2023-06-01 12:27 ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 05/17] arm64: Don't enable VHE for the kernel if OVERRIDE_HVHE is set Marc Zyngier
2023-06-01 7:32 ` Oliver Upton
2023-06-01 12:48 ` Marc Zyngier
2023-06-01 20:10 ` Oliver Upton
2023-05-26 14:33 ` [PATCH v2 06/17] arm64: Allow EL1 physical timer access when running VHE Marc Zyngier
2023-06-01 6:34 ` Oliver Upton [this message]
2023-06-01 11:59 ` Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 07/17] arm64: Use CPACR_EL1 format to set CPTR_EL2 when E2H is set Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 08/17] KVM: arm64: Remove alternatives from sysreg accessors in VHE hypervisor context Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 09/17] KVM: arm64: Key use of VHE instructions in nVHE code off ARM64_KVM_HVHE Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 10/17] KVM: arm64: Force HCR_EL2.E2H when ARM64_KVM_HVHE is set Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 11/17] KVM: arm64: Disable TTBR1_EL2 when using ARM64_KVM_HVHE Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 12/17] KVM: arm64: Adjust EL2 stage-1 leaf AP bits when ARM64_KVM_HVHE is set Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 13/17] KVM: arm64: Rework CPTR_EL2 programming for HVHE configuration Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 14/17] KVM: arm64: Program the timer traps with VHE layout in hVHE mode Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 15/17] KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is set Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 16/17] arm64: Allow arm64_sw.hvhe on command line Marc Zyngier
2023-05-26 14:33 ` [PATCH v2 17/17] KVM: arm64: Terrible timer hack for M1 with hVHE Marc Zyngier
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