Re: [PATCH v3 0/2] amd_iommu: Fixes

[Sairaj Kodilkar <sarunkod@amd.com>]

On 5/16/2025 4:06 PM, Michael S. Tsirkin wrote:
> On Fri, May 16, 2025 at 03:35:33PM +0530, Sairaj Kodilkar wrote:
>> Fix following two issues in the amd viommu
>> 1. The guest fails to setup the passthrough device when for following setup
>>     because amd iommu enables the no DMA memory region even when guest is
>>     using DMA remapping mode.
>>
>>      -device amd-iommu,intremap=on,xtsup=on,pt=on \
>>      -device vfio-pci,host=<DEVID> \
>>
>>      and guest forcing DMA remap mode e.g. 'iommu.passthrough=0'
>>
>>      which will cause failures from QEMU:
>>
>>      qemu-system-x86_64: AHCI: Failed to start DMA engine: bad command list buffer address
>>      qemu-system-x86_64: AHCI: Failed to start FIS receive engine: bad FIS receive buffer address
>>      qemu-system-x86_64: AHCI: Failed to start DMA engine: bad command list buffer address
>>      qemu-system-x86_64: AHCI: Failed to start FIS receive engine: bad FIS receive buffer address
>>      qemu-system-x86_64: AHCI: Failed to start DMA engine: bad command list buffer address
>>
>>
>> 2. The guest fails to boot with xtsup=on and <= 255 vCPUs, because amd_iommu
>>     does not enable x2apic mode.
>>
>> base commit 56c6e249b6988c1b6edc2dd34ebb0f1e570a1365 (v10.0.0-rc3)
>>
>> Sairaj Kodilkar (1):
>>    hw/i386/amd_iommu: Fix device setup failure when PT is on.
>>
>> Vasant Hegde (1):
>>    hw/i386/amd_iommu: Fix xtsup when vcpus < 255
>>
>>   hw/i386/amd_iommu.c | 20 ++++++++++----------
>>   1 file changed, 10 insertions(+), 10 deletions(-)
> 
> changelog?
> 

Sorry I forgot to update the cover-letter (Rookie mistake).

Changes Since v2:
Patch 1: Updated commit message [mst]
Patch 2: Updated commit message [mst]
v2: 
https://lore.kernel.org/qemu-devel/20250509064526.15500-1-sarunkod@amd.com/

Changes Since v1:
Patch 1: Updated commit message [Alejandro]
Patch 2: None
v1: 
https://lore.kernel.org/qemu-devel/20250410064447.29583-1-sarunkod@amd.com/

Regards
Sairaj Kodilkar
>> -- 
>> 2.34.1
>