On Wed, Sep 11, 2024 at 1:27 PM Zhenzhong Duan <zhenzhong.d...@intel.com> wrote:
>
> According to VTD spec, stage-1 page table could support 4-level and
> 5-level paging.
>
> However, 5-level paging translation emulation is unsupported yet.
> That means the only supported value for aw_bits is 48.
>
> So default aw_bits to 48 in scalable modern mode. In other cases,
> it is still default to 39 for compatibility.
>
> Add a check to ensure user specified value is 48 in modern mode
> for now.
>
> Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
> Reviewed-by: Clément Mathieu--Drif<clement.mathieu--d...@eviden.com>
> ---
> include/hw/i386/intel_iommu.h | 2 +-
> hw/i386/intel_iommu.c | 10 +++++++++-
> 2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> index b843d069cc..48134bda11 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -45,7 +45,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(IntelIOMMUState,
> INTEL_IOMMU_DEVICE)
> #define DMAR_REG_SIZE 0x230
> #define VTD_HOST_AW_39BIT 39
> #define VTD_HOST_AW_48BIT 48
> -#define VTD_HOST_ADDRESS_WIDTH VTD_HOST_AW_39BIT
> +#define VTD_HOST_AW_AUTO 0xff
> #define VTD_HAW_MASK(aw) ((1ULL << (aw)) - 1)
>
> #define DMAR_REPORT_F_INTR (1)
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index c25211ddaf..949f120456 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -3771,7 +3771,7 @@ static Property vtd_properties[] = {
> ON_OFF_AUTO_AUTO),
> DEFINE_PROP_BOOL("x-buggy-eim", IntelIOMMUState, buggy_eim, false),
> DEFINE_PROP_UINT8("aw-bits", IntelIOMMUState, aw_bits,
> - VTD_HOST_ADDRESS_WIDTH),
> + VTD_HOST_AW_AUTO),
Such command line API seems to be wired.
I think we can stick the current default and when scalable modern is
enabled by aw is not specified, we can change aw to 48?
> DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode, FALSE),
> DEFINE_PROP_BOOL("x-scalable-mode", IntelIOMMUState, scalable_mode,
> FALSE),
> DEFINE_PROP_BOOL("snoop-control", IntelIOMMUState, snoop_control, false),
> @@ -4686,6 +4686,14 @@ static bool vtd_decide_config(IntelIOMMUState *s,
> Error **errp)
> }
> }
>
> + if (s->aw_bits == VTD_HOST_AW_AUTO) {
> + if (s->scalable_modern) {
> + s->aw_bits = VTD_HOST_AW_48BIT;
> + } else {
> + s->aw_bits = VTD_HOST_AW_39BIT;
> + }
> + }
> +
> if ((s->aw_bits != VTD_HOST_AW_39BIT) &&
> (s->aw_bits != VTD_HOST_AW_48BIT) &&
> !s->scalable_modern) {
> --
> 2.34.1
>
Thanks
