From: Marc Zyngier <maz@kernel.org>
To: Fuad Tabba <fuad.tabba@linux.dev>
Cc: Oliver Upton <oupton@kernel.org>,
kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Joey Gouly <joey.gouly@arm.com>,
Steffen Eiden <seiden@linux.ibm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Vincent Donnefort <vdonnefort@google.com>,
Quentin Perret <qperret@google.com>,
Sebastian Ene <sebastianene@google.com>,
Hyunwoo Kim <imv4bel@gmail.com>, Fuad Tabba <tabba@google.com>
Subject: Re: [PATCH v5 2/8] KVM: arm64: Make vcpu_{read,write}_sys_reg available to HYP code
Date: Tue, 14 Jul 2026 16:19:30 +0100 [thread overview]
Message-ID: <86ik6hoayl.wl-maz@kernel.org> (raw)
In-Reply-To: <20260714101601.4142645-3-fuad.tabba@linux.dev>
On Tue, 14 Jul 2026 11:15:55 +0100,
Fuad Tabba <fuad.tabba@linux.dev> wrote:
>
> The vcpu_{read,write}_sys_reg() accessors are only valid on a VHE host,
> so helpers built on them such as kvm_vcpu_set_be()/kvm_vcpu_is_be()
> cannot be shared with hyp code. exception.c already wraps them in local
> helpers that pick the host- or hyp-side accessor via has_vhe().
>
> Rename the host-only implementations to __vcpu_{read,write}_sysreg_vhe()
I'm a bit puzzled by this. There is nothing that makes these functions
VHE-specific. Look at where they are called from: plenty of non-VHE
uses. These helpers are the canonical accessors for any system
register, and they don't cater for any particular mode.
m.
--
Without deviation from the norm, progress is not possible.
next prev parent reply other threads:[~2026-07-14 15:19 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-14 10:15 [PATCH v5 0/8] KVM: arm64: pKVM vCPU state management at EL2 (series A) Fuad Tabba
2026-07-14 10:15 ` [PATCH v5 1/8] KVM: arm64: Extract MPIDR computation into a shared header Fuad Tabba
2026-07-14 10:15 ` [PATCH v5 2/8] KVM: arm64: Make vcpu_{read,write}_sys_reg available to HYP code Fuad Tabba
2026-07-14 10:52 ` Vincent Donnefort
2026-07-14 15:19 ` Marc Zyngier [this message]
2026-07-14 15:32 ` Fuad Tabba
2026-07-14 16:39 ` Marc Zyngier
2026-07-14 16:44 ` Fuad Tabba
2026-07-14 10:15 ` [PATCH v5 3/8] KVM: arm64: Factor out reusable vCPU reset helpers Fuad Tabba
2026-07-14 10:15 ` [PATCH v5 4/8] KVM: arm64: Move PSCI helper functions to a shared header Fuad Tabba
2026-07-14 10:15 ` [PATCH v5 5/8] KVM: arm64: Add host and hypervisor vCPU lookup primitives Fuad Tabba
2026-07-14 10:15 ` [PATCH v5 6/8] KVM: arm64: Minimise EL2's exposure of host VGIC state during world switch Fuad Tabba
2026-07-14 10:16 ` [PATCH v5 7/8] KVM: arm64: Add primitives to flush/sync the VGIC state at EL2 Fuad Tabba
2026-07-14 10:16 ` [PATCH v5 8/8] KVM: arm64: Implement lazy vCPU state sync for non-protected guests Fuad Tabba
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