From: Will Deacon <will.deacon@arm.com>
To: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org,
kvmarm@lists.cs.columbia.edu, marc.zyngier@arm.com,
linux-kernel@vger.kernel.org, kristina.martsenko@arm.com,
peter.maydell@linaro.org, pbonzini@redhat.com,
rkrcmar@redhat.com, ard.biesheuvel@linaro.org,
mark.rutland@arm.com, catalin.marinas@arm.com
Subject: Re: [PATCH 00/16] kvm: arm64: Support for dynamic IPA size
Date: Thu, 8 Feb 2018 11:25:41 +0000 [thread overview]
Message-ID: <20180208112540.GA17775@arm.com> (raw)
In-Reply-To: <20180208111844.GN29286@cbox>
I can comment on one part here:
On Thu, Feb 08, 2018 at 12:18:44PM +0100, Christoffer Dall wrote:
> Wasn't this also the decision taken for IOMMU page table allocation, and
> why was that the right approach for the IOMMU but not for KVM stage 2
> page tables? Is there room for reuse of the IOMMU page table allocation
> logic in KVM as well?
There were a few reasons we did this for IOMMU page tables:
* Ability to use different page size/VA bits/levels from the CPU
* Ability to support different page table formats (e.g. short descriptor)
* Ability to determine page table attributes at runtime
* Requirement to map/unmap in atomic context
* Ability to cope with non-coherent page table walkers
* Ability to create both stage-1 and stage-2 mappings
* Easier to hook in our own TLB invalidation routines
* Support for lockless concurrent map/unmap within confines of the DMA API
usage
Will
WARNING: multiple messages have this Message-ID (diff)
From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 00/16] kvm: arm64: Support for dynamic IPA size
Date: Thu, 8 Feb 2018 11:25:41 +0000 [thread overview]
Message-ID: <20180208112540.GA17775@arm.com> (raw)
In-Reply-To: <20180208111844.GN29286@cbox>
I can comment on one part here:
On Thu, Feb 08, 2018 at 12:18:44PM +0100, Christoffer Dall wrote:
> Wasn't this also the decision taken for IOMMU page table allocation, and
> why was that the right approach for the IOMMU but not for KVM stage 2
> page tables? Is there room for reuse of the IOMMU page table allocation
> logic in KVM as well?
There were a few reasons we did this for IOMMU page tables:
* Ability to use different page size/VA bits/levels from the CPU
* Ability to support different page table formats (e.g. short descriptor)
* Ability to determine page table attributes at runtime
* Requirement to map/unmap in atomic context
* Ability to cope with non-coherent page table walkers
* Ability to create both stage-1 and stage-2 mappings
* Easier to hook in our own TLB invalidation routines
* Support for lockless concurrent map/unmap within confines of the DMA API
usage
Will
next prev parent reply other threads:[~2018-02-08 11:25 UTC|newest]
Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-09 19:03 [PATCH 00/16] kvm: arm64: Support for dynamic IPA size Suzuki K Poulose
2018-01-09 19:03 ` Suzuki K Poulose
2018-01-09 19:03 ` [PATCH v1 01/16] virtio: Validate queue pfn for 32bit transports Suzuki K Poulose
2018-01-09 19:03 ` Suzuki K Poulose
2018-01-09 23:29 ` Michael S. Tsirkin
2018-01-09 23:29 ` Michael S. Tsirkin
2018-01-10 10:54 ` Suzuki K Poulose
2018-01-10 10:54 ` Suzuki K Poulose
2018-01-10 10:54 ` Suzuki K Poulose
2018-01-10 11:06 ` Michael S. Tsirkin
2018-01-10 11:06 ` Michael S. Tsirkin
2018-01-10 11:06 ` Michael S. Tsirkin
2018-01-10 11:18 ` Suzuki K Poulose
2018-01-10 11:18 ` Suzuki K Poulose
2018-01-10 11:19 ` Peter Maydell
2018-01-10 11:19 ` Peter Maydell
2018-01-10 11:19 ` Peter Maydell
2018-01-10 11:25 ` Jean-Philippe Brucker
2018-01-10 11:25 ` Jean-Philippe Brucker
2018-01-12 10:21 ` Peter Maydell
2018-01-12 10:21 ` Peter Maydell
2018-01-12 10:21 ` Peter Maydell
2018-01-12 11:01 ` Jean-Philippe Brucker
2018-01-12 11:01 ` Jean-Philippe Brucker
2018-01-10 11:30 ` Michael S. Tsirkin
2018-01-10 11:30 ` Michael S. Tsirkin
2018-01-09 19:03 ` [PATCH v1 02/16] irqchip: gicv3-its: Add helpers for handling 52bit address Suzuki K Poulose
2018-01-09 19:03 ` Suzuki K Poulose
2018-01-09 19:03 ` Suzuki K Poulose
2018-02-07 15:10 ` Christoffer Dall
2018-02-07 15:10 ` Christoffer Dall
2018-02-08 11:20 ` Suzuki K Poulose
2018-02-08 11:20 ` Suzuki K Poulose
2018-02-08 11:36 ` Robin Murphy
2018-02-08 11:36 ` Robin Murphy
2018-02-08 13:45 ` Christoffer Dall
2018-02-08 13:45 ` Christoffer Dall
2018-02-08 13:45 ` Christoffer Dall
2018-01-09 19:03 ` [PATCH v1 03/16] arm64: Make page table helpers reusable Suzuki K Poulose
2018-01-09 19:03 ` Suzuki K Poulose
2018-01-09 19:03 ` Suzuki K Poulose
2018-01-09 19:03 ` [PATCH v1 04/16] arm64: Refactor pud_huge for reusability Suzuki K Poulose
2018-01-09 19:03 ` Suzuki K Poulose
2018-01-09 19:04 ` [PATCH v1 05/16] arm64: Helper for parange to PASize Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-02-08 11:00 ` Christoffer Dall
2018-02-08 11:00 ` Christoffer Dall
2018-02-08 11:08 ` Suzuki K Poulose
2018-02-08 11:08 ` Suzuki K Poulose
2018-02-08 11:21 ` Christoffer Dall
2018-02-08 11:21 ` Christoffer Dall
2018-01-09 19:04 ` [PATCH v1 06/16] kvm: arm/arm64: Fix stage2_flush_memslot for 4 level page table Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-02-08 11:00 ` Christoffer Dall
2018-02-08 11:00 ` Christoffer Dall
2018-01-09 19:04 ` [PATCH v1 07/16] kvm: arm/arm64: Remove spurious WARN_ON Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-02-08 11:00 ` Christoffer Dall
2018-02-08 11:00 ` Christoffer Dall
2018-01-09 19:04 ` [PATCH v1 08/16] kvm: arm/arm64: Clean up stage2 pgd life time Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-02-08 11:00 ` Christoffer Dall
2018-02-08 11:00 ` Christoffer Dall
2018-02-08 17:19 ` Suzuki K Poulose
2018-02-08 17:19 ` Suzuki K Poulose
2018-02-09 8:11 ` Christoffer Dall
2018-02-09 8:11 ` Christoffer Dall
2018-01-09 19:04 ` [PATCH v1 09/16] kvm: arm/arm64: Delay stage2 page table allocation Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-02-08 11:01 ` Christoffer Dall
2018-02-08 11:01 ` Christoffer Dall
2018-02-08 17:20 ` Suzuki K Poulose
2018-02-08 17:20 ` Suzuki K Poulose
2018-01-09 19:04 ` [PATCH v1 10/16] kvm: arm/arm64: Prepare for VM specific stage2 translations Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` [PATCH v1 11/16] kvm: arm64: Make stage2 page table layout dynamic Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` [PATCH v1 12/16] kvm: arm64: Dynamic configuration of VTCR and VTTBR mask Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` [PATCH v1 13/16] kvm: arm64: Configure VTCR per VM Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-02-08 18:04 ` Christoffer Dall
2018-02-08 18:04 ` Christoffer Dall
2018-03-15 15:24 ` Suzuki K Poulose
2018-03-15 15:24 ` Suzuki K Poulose
2018-01-09 19:04 ` [PATCH v1 14/16] kvm: arm64: Switch to per VM IPA Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-02-08 11:00 ` Christoffer Dall
2018-02-08 11:00 ` Christoffer Dall
2018-02-08 17:22 ` Suzuki K Poulose
2018-02-08 17:22 ` Suzuki K Poulose
2018-02-08 17:22 ` Suzuki K Poulose
2018-02-09 8:12 ` Christoffer Dall
2018-02-09 8:12 ` Christoffer Dall
2018-01-09 19:04 ` [PATCH v1 15/16] kvm: arm64: Allow configuring physical address space size Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-02-08 11:14 ` Christoffer Dall
2018-02-08 11:14 ` Christoffer Dall
2018-02-08 17:53 ` Suzuki K Poulose
2018-02-08 17:53 ` Suzuki K Poulose
2018-02-09 8:16 ` Christoffer Dall
2018-02-09 8:16 ` Christoffer Dall
2018-02-09 9:27 ` Andrew Jones
2018-02-09 9:27 ` Andrew Jones
2018-02-09 9:27 ` Andrew Jones
2018-03-15 11:06 ` Suzuki K Poulose
2018-03-15 11:06 ` Suzuki K Poulose
2018-01-09 19:04 ` [PATCH v1 16/16] vgic: its: Add support for 52bit guest physical address Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` [kvmtool hack 1/3] virtio: Handle aborts using invalid PFN Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` [kvmtool hack 2/3] kvmtool: arm64: Add support for guest physical address size Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-01-09 19:04 ` [kvmtool hack 3/3] kvmtool: arm64: Switch memory layout Suzuki K Poulose
2018-01-09 19:04 ` Suzuki K Poulose
2018-02-08 11:18 ` [PATCH 00/16] kvm: arm64: Support for dynamic IPA size Christoffer Dall
2018-02-08 11:18 ` Christoffer Dall
2018-02-08 11:25 ` Will Deacon [this message]
2018-02-08 11:25 ` Will Deacon
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