From: Jason Gunthorpe <jgg@ziepe.ca>
To: Andrew Jones <ajones@ventanamicro.com>
Cc: iommu@lists.linux.dev, kvm-riscv@lists.infradead.org,
kvm@vger.kernel.org, linux-riscv@lists.infradead.org,
linux-kernel@vger.kernel.org, tjeznach@rivosinc.com,
zong.li@sifive.com, joro@8bytes.org, will@kernel.org,
robin.murphy@arm.com, anup@brainfault.org, atishp@atishpatra.org,
tglx@linutronix.de, alex.williamson@redhat.com,
paul.walmsley@sifive.com, palmer@dabbelt.com,
aou@eecs.berkeley.edu
Subject: Re: [RFC PATCH 08/15] iommu/riscv: Add IRQ domain for interrupt remapping
Date: Mon, 25 Nov 2024 11:07:27 -0400 [thread overview]
Message-ID: <20241125150727.GD773835@ziepe.ca> (raw)
In-Reply-To: <20241122-8c00551e2383787346c5249f@orel>
On Fri, Nov 22, 2024 at 06:07:59PM +0100, Andrew Jones wrote:
> > What you are trying to do is not supported by the software stack right
> > now. You need to make much bigger, more intrusive changes, if you
> > really want to make interrupt remapping dynamic.
> >
>
> Let the fun begin. I'll look into this more. It also looks like I need to
> collect some test cases to ensure I can support all use cases with
> whatever I propose next. Pointers for those would be welcome.
Sorry, I don't really have anything.. But iommufd allows changing the
translation at will and we expect this to happen in normal VMM
scenarios. So blocking, paging, nesting are all expected to be
dynamically selectable and non-disruptive to interrupts.
So, you can't decide if remapping is enabled or not for a device based
only on the domain attachment.
I think you'd need to create a way for VFIO to request dynamic
interrupt remapping be enabled for the device very, very early in it's
process and that would remain fixed while VFIO is using the device.
The dynamic state of interrupt remapping would constrain what iommu
attachment configurations are permitted.
Jason
next prev parent reply other threads:[~2024-11-25 15:07 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-14 16:18 [RFC PATCH 00/15] iommu/riscv: Add irqbypass support Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 01/15] irqchip/riscv-imsic: Use hierarchy to reach irq_set_affinity Andrew Jones
2024-12-03 13:53 ` Thomas Gleixner
2024-12-03 16:27 ` Andrew Jones
2024-12-03 16:50 ` Thomas Gleixner
2024-12-05 16:12 ` Andrew Jones
2024-12-03 16:37 ` Anup Patel
2024-12-03 20:55 ` Thomas Gleixner
2024-12-03 22:59 ` Thomas Gleixner
2024-12-04 3:43 ` Anup Patel
2024-12-04 13:05 ` Thomas Gleixner
2024-11-14 16:18 ` [RFC PATCH 02/15] genirq/msi: Provide DOMAIN_BUS_MSI_REMAP Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 03/15] irqchip/riscv-imsic: Add support for DOMAIN_BUS_MSI_REMAP Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 04/15] iommu/riscv: report iommu capabilities Andrew Jones
2024-11-15 15:20 ` Robin Murphy
2024-11-19 8:28 ` Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 05/15] iommu/riscv: use data structure instead of individual values Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 06/15] iommu/riscv: support GSCID and GVMA invalidation command Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 07/15] iommu/riscv: Move definitions to iommu.h Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 08/15] iommu/riscv: Add IRQ domain for interrupt remapping Andrew Jones
2024-11-18 18:43 ` Jason Gunthorpe
2024-11-19 7:49 ` Andrew Jones
2024-11-19 14:00 ` Jason Gunthorpe
2024-11-19 15:03 ` Andrew Jones
2024-11-19 15:36 ` Jason Gunthorpe
2024-11-22 15:11 ` Andrew Jones
2024-11-22 15:33 ` Jason Gunthorpe
2024-11-22 17:07 ` Andrew Jones
2024-11-25 15:07 ` Jason Gunthorpe [this message]
2024-11-14 16:18 ` [RFC PATCH 09/15] RISC-V: KVM: Enable KVM_VFIO interfaces on RISC-V arch Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 10/15] RISC-V: KVM: Add irqbypass skeleton Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 11/15] RISC-V: Define irqbypass vcpu_info Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 12/15] iommu/riscv: Add guest file irqbypass support Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 13/15] RISC-V: KVM: " Andrew Jones
2024-11-14 16:18 ` [RFC PATCH 14/15] vfio: enable IOMMU_TYPE1 for RISC-V Andrew Jones
2024-11-14 16:19 ` [RFC PATCH 15/15] RISC-V: defconfig: Add VFIO modules Andrew Jones
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