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From: Will Deacon <will@kernel.org>
To: Fuad Tabba <tabba@google.com>
Cc: kvmarm@lists.cs.columbia.edu, maz@kernel.org,
	james.morse@arm.com, alexandru.elisei@arm.com,
	suzuki.poulose@arm.com, mark.rutland@arm.com,
	christoffer.dall@arm.com, pbonzini@redhat.com,
	drjones@redhat.com, qperret@google.com, kvm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, kernel-team@android.com
Subject: Re: [PATCH v2 05/13] KVM: arm64: Restore mdcr_el2 from vcpu
Date: Thu, 1 Jul 2021 14:17:33 +0100	[thread overview]
Message-ID: <20210701131733.GE9757@willie-the-truck> (raw)
In-Reply-To: <20210615133950.693489-6-tabba@google.com>

On Tue, Jun 15, 2021 at 02:39:42PM +0100, Fuad Tabba wrote:
> On deactivating traps, restore the value of mdcr_el2 from the
> vcpu context, rather than directly reading the hardware register.
> Currently, the two values are the same, i.e., the hardware
> register and the vcpu one. A future patch will be changing the
> value of mdcr_el2 on activating traps, and this ensures that its
> value will be restored.
> 
> No functional change intended.
> 
> Signed-off-by: Fuad Tabba <tabba@google.com>
> ---
>  arch/arm64/kvm/hyp/nvhe/switch.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
> index f7af9688c1f7..430b5bae8761 100644
> --- a/arch/arm64/kvm/hyp/nvhe/switch.c
> +++ b/arch/arm64/kvm/hyp/nvhe/switch.c
> @@ -73,7 +73,7 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
>  
>  	___deactivate_traps(vcpu);
>  
> -	mdcr_el2 = read_sysreg(mdcr_el2);
> +	mdcr_el2 = vcpu->arch.mdcr_el2;

Do you need to change the VHE code too?

Will

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  reply	other threads:[~2021-07-01 13:19 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-15 13:39 [PATCH v2 00/13] KVM: arm64: Fixed features for protected VMs Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 01/13] KVM: arm64: Remove trailing whitespace in comments Fuad Tabba
2021-07-01 12:55   ` Will Deacon
2021-07-01 13:24     ` Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 02/13] KVM: arm64: MDCR_EL2 is a 64-bit register Fuad Tabba
2021-07-01 12:53   ` Will Deacon
2021-07-01 13:24     ` Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 03/13] KVM: arm64: Fix names of config register fields Fuad Tabba
2021-07-01 13:01   ` Will Deacon
2021-07-01 13:44     ` Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 04/13] KVM: arm64: Refactor sys_regs.h,c for nVHE reuse Fuad Tabba
2021-07-01 13:09   ` [PATCH v2 04/13] KVM: arm64: Refactor sys_regs.h, c " Will Deacon
2021-07-01 14:04     ` Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 05/13] KVM: arm64: Restore mdcr_el2 from vcpu Fuad Tabba
2021-07-01 13:17   ` Will Deacon [this message]
2021-07-01 14:05     ` Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 06/13] KVM: arm64: Add feature register flag definitions Fuad Tabba
2021-07-01 13:22   ` Will Deacon
2021-07-01 14:31     ` Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 07/13] KVM: arm64: Add config register bit definitions Fuad Tabba
2021-07-01 13:33   ` Will Deacon
2021-07-01 14:52     ` Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 08/13] KVM: arm64: Guest exit handlers for nVHE hyp Fuad Tabba
2021-07-01 13:48   ` Will Deacon
2021-07-01 14:58     ` Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 09/13] KVM: arm64: Add trap handlers for protected VMs Fuad Tabba
2021-07-01 14:08   ` Will Deacon
2021-07-14 20:01     ` Andrew Jones
2021-06-15 13:39 ` [PATCH v2 10/13] KVM: arm64: Move sanitized copies of CPU features Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 11/13] KVM: arm64: Trap access to pVM restricted features Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 12/13] KVM: arm64: Handle protected guests at 32 bits Fuad Tabba
2021-06-15 13:39 ` [PATCH v2 13/13] KVM: arm64: Check vcpu features at pVM creation Fuad Tabba

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