From: Christoph Hellwig <hch@infradead.org>
To: Srujana Challa <schalla@marvell.com>
Cc: virtualization@lists.linux.dev, kvm@vger.kernel.org,
mst@redhat.com, jasowang@redhat.com, eperezma@redhat.com,
ndabilpuram@marvell.com, jerinj@marvell.com
Subject: Re: [PATCH v2 0/2] vhost-vdpa: Add support for NO-IOMMU mode
Date: Tue, 1 Oct 2024 01:47:26 -0700 [thread overview]
Message-ID: <Zvu3HktM4imgHpUw@infradead.org> (raw)
In-Reply-To: <20240920140530.775307-1-schalla@marvell.com>
On Fri, Sep 20, 2024 at 07:35:28PM +0530, Srujana Challa wrote:
> This patchset introduces support for an UNSAFE, no-IOMMU mode in the
> vhost-vdpa driver. When enabled, this mode provides no device isolation,
> no DMA translation, no host kernel protection, and cannot be used for
> device assignment to virtual machines. It requires RAWIO permissions
> and will taint the kernel.
>
> This mode requires enabling the "enable_vhost_vdpa_unsafe_noiommu_mode"
> option on the vhost-vdpa driver and also negotiate the feature flag
> VHOST_BACKEND_F_NOIOMMU. This mode would be useful to get
> better performance on specifice low end machines and can be leveraged
> by embedded platforms where applications run in controlled environment.
... and is completely broken and dangerous.
next prev parent reply other threads:[~2024-10-01 8:47 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-20 14:05 [PATCH v2 0/2] vhost-vdpa: Add support for NO-IOMMU mode Srujana Challa
2024-09-20 14:05 ` [PATCH v2 1/2] vhost-vdpa: introduce module parameter for no-IOMMU mode Srujana Challa
2024-09-21 17:28 ` kernel test robot
2024-09-20 14:05 ` [PATCH v2 2/2] vhost-vdpa: introduce NO-IOMMU backend feature bit Srujana Challa
2024-09-24 7:43 ` Jason Wang
2024-09-24 10:01 ` [EXTERNAL] " Srujana Challa
2024-10-01 8:47 ` Christoph Hellwig [this message]
2024-10-14 13:18 ` [EXTERNAL] Re: [PATCH v2 0/2] vhost-vdpa: Add support for NO-IOMMU mode Srujana Challa
2024-10-15 3:48 ` Christoph Hellwig
2024-10-16 17:28 ` Srujana Challa
2024-10-17 6:19 ` Christoph Hellwig
2024-10-17 8:53 ` Srujana Challa
2024-10-18 4:54 ` Jason Wang
2024-10-18 5:24 ` Christoph Hellwig
2024-10-18 13:08 ` Srujana Challa
2024-10-16 17:41 ` Michael S. Tsirkin
2024-10-17 6:16 ` Christoph Hellwig
2024-10-20 0:16 ` Michael S. Tsirkin
2024-10-23 6:58 ` Christoph Hellwig
2024-10-23 8:19 ` Michael S. Tsirkin
2024-10-24 9:05 ` Christoph Hellwig
2024-11-06 12:38 ` Srujana Challa
2024-11-06 15:45 ` Christoph Hellwig
2024-11-07 6:08 ` Srujana Challa
2024-11-12 7:11 ` Srujana Challa
2024-11-06 18:11 ` Michael S. Tsirkin
2024-11-06 18:14 ` Michael S. Tsirkin
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