Re: [Qemu-devel] [PATCH] s390x/pci: Set the iommu region size as guest wants

[Cornelia Huck <cohuck@redhat.com>]

On Tue,  8 Jan 2019 18:33:39 +0100
Pierre Morel <pmorel@linux.ibm.com> wrote:

> The size of the accessible iommu memory region in the guest
> is calculated by the gues as:

s/gues/guest/

>     (PCI Address Limit) - (PCI Base Address) + 1.
> 
> Let's use this value to limit the IOMMU region size.

These are values provided by the guest in the mpcifc call, aren't they?
Let's mention that in the patch description, so it is more obvious :)

> 
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  hw/s390x/s390-pci-bus.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
> index 69e0671..e97696a 100644
> --- a/hw/s390x/s390-pci-bus.c
> +++ b/hw/s390x/s390-pci-bus.c
> @@ -660,7 +660,7 @@ void s390_pci_iommu_enable(S390PCIIOMMU *iommu)
>      char *name = g_strdup_printf("iommu-s390-%04x", iommu->pbdev->uid);
>      memory_region_init_iommu(&iommu->iommu_mr, sizeof(iommu->iommu_mr),
>                               TYPE_S390_IOMMU_MEMORY_REGION, OBJECT(&iommu->mr),
> -                             name, iommu->pal + 1);
> +                             name, iommu->pal - iommu->pba + 1);
>      iommu->enabled = true;
>      memory_region_add_subregion(&iommu->mr, 0, MEMORY_REGION(&iommu->iommu_mr));
>      g_free(name);