Re: [PATCH 5/6] amd_iommu: Fix the calculation for Device Table size

[Vasant Hegde <vasant.hegde@amd.com>]

Alejandro,


On 3/11/2025 8:54 PM, Alejandro Jimenez wrote:
> Correctly calculate the Device Table size using the format encoded in the
> Device Table Base Address Register (MMIO Offset 0000h).
> 
> Cc: qemu-stable@nongnu.org
> Fixes: d29a09ca6842 ("hw/i386: Introduce AMD IOMMU")

I understand its a fix. But its not breaking anything. So not sure whether its
worth to backport.


> Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>

-Vasant



> ---
>  hw/i386/amd_iommu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
> index 8b97abe28c..cf00450ebe 100644
> --- a/hw/i386/amd_iommu.c
> +++ b/hw/i386/amd_iommu.c
> @@ -665,8 +665,8 @@ static inline void amdvi_handle_devtab_write(AMDVIState *s)
>      uint64_t val = amdvi_readq(s, AMDVI_MMIO_DEVICE_TABLE);
>      s->devtab = (val & AMDVI_MMIO_DEVTAB_BASE_MASK);
>  
> -    /* set device table length */
> -    s->devtab_len = ((val & AMDVI_MMIO_DEVTAB_SIZE_MASK) + 1 *
> +    /* set device table length (i.e. number of entries table can hold) */
> +    s->devtab_len = (((val & AMDVI_MMIO_DEVTAB_SIZE_MASK) + 1) *
>                      (AMDVI_MMIO_DEVTAB_SIZE_UNIT /
>                       AMDVI_MMIO_DEVTAB_ENTRY_SIZE));
>  }