From: Vincent Donnefort <vdonnefort@google.com>
To: Mostafa Saleh <smostafa@google.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev,
iommu@lists.linux.dev, catalin.marinas@arm.com, will@kernel.org,
maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com,
suzuki.poulose@arm.com, yuzenghui@huawei.com, joro@8bytes.org,
jgg@ziepe.ca, mark.rutland@arm.com, qperret@google.com,
tabba@google.com, sebastianene@google.com, keirf@google.com
Subject: Re: [PATCH v7 01/24] KVM: arm64: Add a generic clock
Date: Wed, 15 Jul 2026 15:34:09 +0100 [thread overview]
Message-ID: <aleaYVz5m19veRjT@google.com> (raw)
In-Reply-To: <aleVozZEcxiGE4Y3@google.com>
[...]
> > #define smmu_wait() {
> > static u32 window = arch_timer_get_cntfrq() / ARM_SMMU_EL2_POLL_TIMEOUT_US
> > u64 timeout = __arch_counter_get_cntvct() + window;
> > u64 cur;
> >
> > ...
> >
> > while (!(__cond)) {
> > ...
> >
> > cur = __arch_counter_get_cntvct();
> > if (cur >= timeout)
> > __ret = -ETIMEOUT;
> >
> >
> > No risk of overflowing u64
> > No init necessary
>
> It believe init will be needed as caching arch_timer_get_cntfrq()
> is much better that re-reading everytime. But I can make all of this
> contained in the SMMUv3 driver and remove this patch.
That's why I have made window static :) (well of course it is per callsite...)
>
> Thanks,
> Mostafa
>
next prev parent reply other threads:[~2026-07-15 14:34 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-15 11:58 [PATCH v7 00/24] KVM: arm64: SMMUv3 driver for pKVM (trap and emulate) Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 01/24] KVM: arm64: Add a generic clock Mostafa Saleh
2026-07-15 13:48 ` Vincent Donnefort
2026-07-15 14:13 ` Mostafa Saleh
2026-07-15 14:34 ` Vincent Donnefort [this message]
2026-07-15 11:58 ` [PATCH v7 02/24] KVM: arm64: Donate MMIO to the hypervisor Mostafa Saleh
2026-07-15 17:26 ` Vincent Donnefort
2026-07-15 18:28 ` Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 03/24] iommu/arm-smmu-v3: Split code with hyp Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 04/24] iommu/arm-smmu-v3: Move TLB range invalidation into common code Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 05/24] iommu/arm-smmu-v3: Move IDR parsing to common functions Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 06/24] KVM: arm64: iommu: Introduce IOMMU driver infrastructure Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 07/24] KVM: arm64: iommu: Shadow host stage-2 page table Mostafa Saleh
2026-07-15 17:56 ` Vincent Donnefort
2026-07-15 18:43 ` Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 08/24] KVM: arm64: iommu: Add memory pool Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 09/24] KVM: arm64: iommu: Support DABT for IOMMU Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 10/24] iommu/arm-smmu-v3-kvm: Add SMMUv3 driver Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 11/24] iommu/arm-smmu-v3-kvm: Add the kernel driver Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 12/24] iommu/arm-smmu-v3-kvm: Probe SMMU HW Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 13/24] iommu/arm-smmu-v3-kvm: Add MMIO emulation Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 14/24] iommu/arm-smmu-v3-kvm: Shadow the command queue Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 15/24] iommu/arm-smmu-v3-kvm: Add CMDQ functions Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 16/24] iommu/arm-smmu-v3-kvm: Emulate CMDQ for host Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 17/24] iommu/arm-smmu-v3-kvm: Shadow stream table Mostafa Saleh
2026-07-15 11:58 ` [PATCH v7 18/24] iommu/arm-smmu-v3-kvm: Shadow STEs Mostafa Saleh
2026-07-15 11:59 ` [PATCH v7 19/24] iommu/arm-smmu-v3-kvm: Share other queues Mostafa Saleh
2026-07-15 11:59 ` [PATCH v7 20/24] iommu/arm-smmu-v3-kvm: Emulate GBPA Mostafa Saleh
2026-07-15 11:59 ` [PATCH v7 21/24] iommu/io-pgtable-arm: Support io-pgtable-arm in the hypervisor Mostafa Saleh
2026-07-15 11:59 ` [PATCH v7 22/24] iommu/arm-smmu-v3-kvm: Shadow the CPU stage-2 page table Mostafa Saleh
2026-07-15 11:59 ` [PATCH v7 23/24] iommu/arm-smmu-v3-kvm: Enable nesting Mostafa Saleh
2026-07-15 11:59 ` [PATCH v7 24/24] KVM: arm64: Add documentation for pKVM DMA isolation Mostafa Saleh
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