Re: [PATCH v3 10/15] intel-iommu: Implement IOMMU_ATTR_MAX_IOVA get_attr() attribute - Philippe Mathieu-Daudé

From: "Philippe Mathieu-Daudé" <philmd@linaro.org>
To: Joao Martins <joao.m.martins@oracle.com>, qemu-devel@nongnu.org
Cc: Alex Williamson <alex.williamson@redhat.com>,
	Cedric Le Goater <clg@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>, Peter Xu <peterx@redhat.com>,
	David Hildenbrand <david@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,
	Jason Wang <jasowang@redhat.com>,
	Richard Henderson <richard.henderson@linaro.org>,
	Eduardo Habkost <eduardo@habkost.net>,
	Avihai Horon <avihaih@nvidia.com>,
	Jason Gunthorpe <jgg@nvidia.com>
Subject: Re: [PATCH v3 10/15] intel-iommu: Implement IOMMU_ATTR_MAX_IOVA get_attr() attribute
Date: Tue, 30 May 2023 23:45:06 +0200	[thread overview]
Message-ID: <20790526-6640-3fd0-920a-ef09e5b306c0@linaro.org> (raw)
In-Reply-To: <20230530175937.24202-11-joao.m.martins@oracle.com>

On 30/5/23 19:59, Joao Martins wrote:
> From: Avihai Horon <avihaih@nvidia.com>
> 
> Implement get_attr() method and use the address width property to report
> the IOMMU_ATTR_MAX_IOVA attribute.
> 
> Signed-off-by: Avihai Horon <avihaih@nvidia.com>
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> ---
>   hw/i386/intel_iommu.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index 1906f3a67960..829dd6eadc6c 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -3876,6 +3876,13 @@ static int vtd_iommu_get_attr(IOMMUMemoryRegion *iommu_mr,
>           *enabled = s->dma_translation;
>           break;
>       }
> +    case IOMMU_ATTR_MAX_IOVA:
> +    {
> +        hwaddr *max_iova = data;

Shouldn't we cast to uintptr_t to be safe?

> +        *max_iova = (1ULL << s->aw_bits) - 1;

Alternatively:

            *max_iova = MAKE_64BIT_MASK(0, s->aw_bits);

> +        break;
> +    }
>       default:
>           ret = -EINVAL;
>           break;