Hi Sairaj, On 10/17/25 2:13 AM, Sairaj Kodilkar wrote:
This series provide fixes for following two issues:1. AMD IOMMU fails to detect the devices when they are attached to PCI bus with bus id != 0. e.g. With following command line, dhclient command fails inside the guest -device pcie-root-port,port=0x10,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x5 \ -netdev user,id=USER0,hostfwd=tcp::3333-:22 \ -device virtio-net-pci,id=vnet0,iommu_platform=on,disable-legacy=on,romfile=,netdev=USER0,bus=pci.1,addr=0 \ 2. Current AMD IOMMU supports IOVAs upto 60 bit which cause failure while setting up the devices when guest is booted with command line "iommu.forcedac=1". One example of the failure is when there are two virtio ethernet devices attached to the guest with command line-netdev user,id=USER0 \-netdev user,id=USER1 \ -device virtio-net-pci,id=vnet0,iommu_platform=on,disable-legacy=on,romfile=,netdev=USER0 \ -device virtio-net-pci,id=vnet1,iommu_platform=on,disable-legacy=on,romfile=,netdev=USER1 \In this case dhclient fails for second device with following dmesg [ 24.802644] virtio_net virtio0 enp0s1: TX timeout on queue: 0, sq: output.0, vq: 0x1, name: output.0, 5664000 usecs ago[ 29.856716] virtio_net virtio0 enp0s1: NETDEV WATCHDOG: CPU: 59: transmit queue 0 timed out 10720 ms [ 29.858585] virtio_net virtio0 enp0s1: TX timeout on queue: 0, sq: output.0, vq: 0x1, name: output.0, 10720000 usecs ago
Besides the above issues, I can also confirm that in combination with a patched VFIO driver in the host kernel, this series addresses the problems I mentioned earlier with VFIO passthrough devices + DMA remap mode + forcedac=1 on guest reboot. Thank you!
For the series: Reviewed-by: Alejandro Jimenez <[email protected]> Tested-by: Alejandro Jimenez <[email protected]>
------------------------------------------------------------------------------- Change log: ---------- * Changes since V2: https://lore.kernel.org/qemu-devel/[email protected]/ P1: - Remove cast from the pointer assignment [MST] - Rename struct amdvi_as_key to AMDViAsKey [Alejandro, MST] - Fix compilation error due to missing 'static' [Alejandro] P2: - Rename struct amdvi_iotlb_key to AMDViIOTLBKey [Alejandro, MST] - Fix compilation error [Alejandro] * Changes Since V1: https://lore.kernel.org/qemu-devel/[email protected]/ P1: - Use fixed type uint8_t for devfn - Use uintptr_t instead of uint64_t - Build hash key using lower 56 bits of bus pointer and 8 bits of devfn - Use gboolean instead of int for amdvi_find_as_by_devid - Update comments - Use IOMMU_NOTIFIER_NONE instead of IOMMU_NONE P2: - Reword commit message - Correctly initialize `struct amdvi_iotlb_key` - Remove unused macro ------------------------------------------------------------------------------- Base commit: (qemu uptream) eb7abb4a719f ------------------------------------------------------------------------------- Sairaj Kodilkar (2): amd_iommu: Fix handling device on buses != 0 amd_iommu: Support 64 bit address for IOTLB lookup hw/i386/amd_iommu.c | 179 +++++++++++++++++++++++++++----------------- hw/i386/amd_iommu.h | 6 +- 2 files changed, 113 insertions(+), 72 deletions(-)
