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I use a MSI 990FXA-GD80V2 motherboard (V13.6B1 BIOS), a FX-8350, and a Radeon HD 7850 (open-source radeon driver). IOMMU is enabled in BIOS (64MB). dmesg says:
From my understanding, shouldn't PCI-DMA be mentioning something about GART instead of software since I have hardware IOMMU?
Using iommu=force doesn't change anything. Using iommu=pt iommu=1 adds a new line to dmesg and drops the Lazy IO/TLB flushing, but PCI-DMA still states software:
Disabling IOMMU in BIOS also gives the same messages as above (AMD-Vi still finds an IOMMU, remaps, and PCI-DMA still uses software), but some AGP aperture message is also shown early on (something about taking 64MB of RAM).
Code:
[ 0.963439] AMD-Vi: Found IOMMU at 0000:00:00.2 cap 0x40 [ 0.963440] AMD-Vi: Interrupt remapping enabled [ 0.969714] AMD-Vi: Lazy IO/TLB flushing enabled [ 1.036747] PCI-DMA: Using software bounce buffering for IO (SWIOTLB) [ 1.036749] software IO TLB [mem 0xbd498000-0xc1498000] (64MB) mapped at [ffff8800bd498000-ffff8800c1497fff]
Using iommu=force doesn't change anything. Using iommu=pt iommu=1 adds a new line to dmesg and drops the Lazy IO/TLB flushing, but PCI-DMA still states software:
Code:
[ 0.963468] AMD-Vi: Found IOMMU at 0000:00:00.2 cap 0x40 [ 0.963469] AMD-Vi: Interrupt remapping enabled [ 0.963600] AMD-Vi: Initialized for Passthrough Mode [ 1.030702] PCI-DMA: Using software bounce buffering for IO (SWIOTLB) [ 1.030704] software IO TLB [mem 0xbd198000-0xc1198000] (64MB) mapped at [ffff8800bd198000-ffff8800c1197fff]
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