Hi Zhenzhong
On 22/05/2024 08:23, Zhenzhong Duan wrote:
> Caution: External email. Do not open attachments or click links, unless this
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>
>
> 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>
> ---
> hw/i386/intel_iommu.c | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index e07daaba99..a4c241ea96 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -3748,7 +3748,7 @@ 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),
> + 0xff),
you could define a constant for this invalid value
> 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),
> @@ -4663,6 +4663,14 @@ static bool vtd_decide_config(IntelIOMMUState *s,
> Error **errp)
> }
> }
>
> + if (s->aw_bits == 0xff) {
> + 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) {
> @@ -4671,6 +4679,12 @@ static bool vtd_decide_config(IntelIOMMUState *s,
> Error **errp)
> return false;
> }
>
> + if ((s->aw_bits != VTD_HOST_AW_48BIT) && s->scalable_modern) {
> + error_setg(errp, "Supported values for aw-bits are: %d",
specify 'in modern mode' in the message?
> + VTD_HOST_AW_48BIT);
> + return false;
> + }
> +
> if (s->scalable_mode && !s->dma_drain) {
> error_setg(errp, "Need to set dma_drain for scalable mode");
> return false;
> --
> 2.34.1
>
#cmd
