From 448179e33ea850acaf4bd3c2410acc911080e40b Mon Sep 17 00:00:00 2001 From: Jean-Philippe Brucker Date: Mon, 14 Feb 2022 12:43:54 +0000 Subject: virtio-iommu: Default to bypass during boot Currently the virtio-iommu device must be programmed before it allows DMA from any PCI device. This can make the VM entirely unusable when a virtio-iommu driver isn't present, for example in a bootloader that loads the OS from storage. Similarly to the other vIOMMU implementations, default to DMA bypassing the IOMMU during boot. Add a "boot-bypass" property, defaulting to true, that lets users change this behavior. Replace the VIRTIO_IOMMU_F_BYPASS feature, which didn't support bypass before feature negotiation, with VIRTIO_IOMMU_F_BYPASS_CONFIG. We add the bypass field to the migration stream without introducing subsections, based on the assumption that this virtio-iommu device isn't being used in production enough to require cross-version migration at the moment (all previous version required workarounds since they didn't support ACPI and boot-bypass). Reviewed-by: Eric Auger Signed-off-by: Jean-Philippe Brucker Message-Id: <20220214124356.872985-3-jean-philippe@linaro.org> Acked-by: Cornelia Huck Reviewed-by: Eric Auger Tested-by: Eric Auger Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- include/hw/virtio/virtio-iommu.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h index e2339e5b72..84391f8448 100644 --- a/include/hw/virtio/virtio-iommu.h +++ b/include/hw/virtio/virtio-iommu.h @@ -58,6 +58,7 @@ struct VirtIOIOMMU { GTree *domains; QemuMutex mutex; GTree *endpoints; + bool boot_bypass; }; #endif -- cgit v1.2.3