Re: [Qemu-devel] [PATCH qemu v2] vfio/spapr: Allow fallback to SPAPR TCE IOMMU v1

[Alexey Kardashevskiy <aik@ozlabs.ru>]

[-- Attachment #1: Type: text/plain, Size: 1740 bytes --]

On 15/12/17 17:01, David Gibson wrote:
> On Tue, Dec 12, 2017 at 04:16:19PM +1100, Alexey Kardashevskiy wrote:
>> The vfio_iommu_spapr_tce driver advertises kernel's support for
>> v1 and v2 IOMMU support, however it is not always possible to use
>> the requested IOMMU type. For example, a pseries host platform does not
>> support dynamic DMA windows so v2 cannot initialize and QEMU fails to
>> start.
>>
>> This adds a fallback to the v1 IOMMU if v2 cannot be used.
>>
>> Fixes: 318f67ce1371 "vfio: spapr: Add DMA memory preregistering (SPAPR IOMMU v2)"
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> 
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> 
> Alex, will you take this through your tree, or should I take it
> through mine?


It is already in upstream.

> 
>> ---
>> Changes:
>> v2:
>> * updated commit log
>>
>> ---
>>  hw/vfio/common.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>> index 7b2924c..cd81cc9 100644
>> --- a/hw/vfio/common.c
>> +++ b/hw/vfio/common.c
>> @@ -1040,6 +1040,11 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
>>              v2 ? VFIO_SPAPR_TCE_v2_IOMMU : VFIO_SPAPR_TCE_IOMMU;
>>          ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type);
>>          if (ret) {
>> +            container->iommu_type = VFIO_SPAPR_TCE_IOMMU;
>> +            v2 = false;
>> +            ret = ioctl(fd, VFIO_SET_IOMMU, container->iommu_type);
>> +        }
>> +        if (ret) {
>>              error_setg_errno(errp, errno, "failed to set iommu for container");
>>              ret = -errno;
>>              goto free_container_exit;
> 


-- 
Alexey


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 854 bytes --]