similar to: [PATCH v5] virtio: new feature to detect IOMMU device quirk

The interaction between virtio and IOMMUs is messy. On most systems with virtio, physical addresses match bus addresses, and it doesn't particularly matter which one we use to program the device. On some systems, including Xen and any system with a physical device that speaks virtio behind a physical IOMMU, we must program the IOMMU for virtio DMA to work at all. On other systems, including

The interaction between virtio and IOMMUs is messy. On most systems with virtio, physical addresses match bus addresses, and it doesn't particularly matter which one we use to program the device. On some systems, including Xen and any system with a physical device that speaks virtio behind a physical IOMMU, we must program the IOMMU for virtio DMA to work at all. On other systems, including

The interaction between virtio and IOMMUs is messy. On most systems with virtio, physical addresses match bus addresses, and it doesn't particularly matter which one we use to program the device. On some systems, including Xen and any system with a physical device that speaks virtio behind a physical IOMMU, we must program the IOMMU for virtio DMA to work at all. On other systems, including

The interaction between virtio and IOMMUs is messy. On most systems with virtio, physical addresses match bus addresses, and it doesn't particularly matter which one we use to program the device. On some systems, including Xen and any system with a physical device that speaks virtio behind a physical IOMMU, we must program the IOMMU for virtio DMA to work at all. On other systems, including

Rename the bit to match latest virtio spec. Add a compat macro to avoid breaking existing userspace. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- arch/um/drivers/virtio_uml.c | 2 +- drivers/vdpa/ifcvf/ifcvf_base.h | 2 +- drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 ++-- drivers/vhost/net.c | 4 ++-- drivers/vhost/vdpa.c | 2 +-

Rename the bit to match latest virtio spec. Add a compat macro to avoid breaking existing userspace. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- arch/um/drivers/virtio_uml.c | 2 +- drivers/vdpa/ifcvf/ifcvf_base.h | 2 +- drivers/vdpa/vdpa_sim/vdpa_sim.c | 4 ++-- drivers/vhost/net.c | 4 ++-- drivers/vhost/vdpa.c | 2 +-

Now that the corresponding feature bit has been renamed, rename the quirk too - it's about special ways to do DMA, not necessarily about the IOMMU. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/gpu/drm/virtio/virtgpu_object.c | 2 +- drivers/gpu/drm/virtio/virtgpu_vq.c | 4 ++-- drivers/virtio/virtio_ring.c | 2 +- include/linux/virtio_config.h

From: Thiago Jung Bauermann <bauerman at linux.ibm.com> Normally, virtio enables DMA API with VIRTIO_F_IOMMU_PLATFORM, which must be set by both device and guest driver. However, as a hack, when DMA API returns physical addresses, guest driver can use the DMA API; even though device does not set VIRTIO_F_IOMMU_PLATFORM and just uses physical addresses. Doing this works-around POWER secure

From: Thiago Jung Bauermann <bauerman at linux.ibm.com> Normally, virtio enables DMA API with VIRTIO_F_IOMMU_PLATFORM, which must be set by both device and guest driver. However, as a hack, when DMA API returns physical addresses, guest driver can use the DMA API; even though device does not set VIRTIO_F_IOMMU_PLATFORM and just uses physical addresses. Doing this works-around POWER secure

On Tue, Jul 19, 2016 at 05:38:23AM +0300, Michael S. Tsirkin wrote: > > On other systems, including SPARC and PPC64, virtio-pci devices are > enumerated as though they are behind an IOMMU, but the virtio host > ignores the IOMMU, so we must either pretend that the IOMMU isn't > there or somehow map everything as the identity. > > Add a feature bit to detect that quirk:

Use generic names for the quirks to make it clear it is not just about the IOMMU, it's about DMA access in general. changes from v1: added patch 2 Michael S. Tsirkin (2): virtio: VIRTIO_F_IOMMU_PLATFORM -> VIRTIO_F_ACCESS_PLATFORM virtio: virtio_has_iommu_quirk -> virtio_has_dma_quirk arch/um/drivers/virtio_uml.c | 2 +- drivers/gpu/drm/virtio/virtgpu_object.c | 2

On 07/20/2018 06:45 PM, Michael S. Tsirkin wrote: > On Fri, Jul 20, 2018 at 09:29:41AM +0530, Anshuman Khandual wrote: >> Subject: Re: [RFC 4/4] virtio: Add platform specific DMA API translation for >> virito devices > > s/virito/virtio/ Oops, will fix it. Thanks for pointing out. > >> This adds a hook which a platform can define in order to allow it to >>

On Mon, 29 Aug 2016 21:23:25 -0600 Alex Williamson <alex.williamson at redhat.com> wrote: > On Tue, 30 Aug 2016 05:27:17 +0300 > "Michael S. Tsirkin" <mst at redhat.com> wrote: > > > Modern virtio pci devices can set VIRTIO_F_IOMMU_PLATFORM > > to signal they are safe to use with an IOMMU. > > > > Without this bit, exposing the device to

On Mon, Aug 29, 2016 at 10:53:04PM -0600, Alex Williamson wrote: > On Mon, 29 Aug 2016 21:52:20 -0600 > Alex Williamson <alex.williamson at redhat.com> wrote: > > > On Mon, 29 Aug 2016 21:23:25 -0600 > > Alex Williamson <alex.williamson at redhat.com> wrote: > > > > > On Tue, 30 Aug 2016 05:27:17 +0300 > > > "Michael S. Tsirkin"

On Mon, 2018-06-04 at 19:21 +0300, Michael S. Tsirkin wrote: > > > > > - First qemu doesn't know that the guest will switch to "secure mode" > > > > in advance. There is no difference between a normal and a secure > > > > partition until the partition does the magic UV call to "enter secure > > > > mode" and qemu

Modern virtio pci devices can set VIRTIO_F_IOMMU_PLATFORM to signal they are safe to use with an IOMMU. Without this bit, exposing the device to userspace is unsafe, so probe and fail VFIO initialization unless noiommu is enabled. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vfio/pci/vfio_pci_private.h | 1 + drivers/vfio/pci/vfio_pci.c | 11 +++

Modern virtio pci devices can set VIRTIO_F_IOMMU_PLATFORM to signal they are safe to use with an IOMMU. Without this bit, exposing the device to userspace is unsafe, so probe and fail VFIO initialization unless noiommu is enabled. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/vfio/pci/vfio_pci_private.h | 1 + drivers/vfio/pci/vfio_pci.c | 14 ++++

On Thu, Apr 5, 2018 at 8:56 PM, Anshuman Khandual <khandual at linux.vnet.ibm.com> wrote: > There are certian platforms which would like to use SWIOTLB based DMA API > for bouncing purpose without actually requiring an IOMMU back end. But the > virtio core does not allow such mechanism. Right now DMA MAP API is only > selected for devices which have an IOMMU and then the

This is a design and an initial patch for kernel side for AER support in VFIO. 0. What happens now (PCIE AER only) Fatal errors cause a link reset. Non fatal errors don't. All errors stop the VM eventually, but not immediately because it's detected and reported asynchronously. Interrupts are forwarded as usual. Correctable errors are not reported to guest at all.

This is a design and an initial patch for kernel side for AER support in VFIO. 0. What happens now (PCIE AER only) Fatal errors cause a link reset. Non fatal errors don't. All errors stop the VM eventually, but not immediately because it's detected and reported asynchronously. Interrupts are forwarded as usual. Correctable errors are not reported to guest at all.