Re: [PATCH v3 15/17] intel_iommu: Modify x-scalable-mode to be string option to expose scalable modern mode

[CLEMENT MATHIEU--DRIF <clement.mathieu--drif@eviden.com>]

Reviewed-by: Clément Mathieu--Drif<clement.mathieu--drif@eviden.com>



On 11/09/2024 07:22, Zhenzhong Duan wrote:
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>
> From: Yi Liu <yi.l.liu@intel.com>
>
> Intel VT-d 3.0 introduces scalable mode, and it has a bunch of capabilities
> related to scalable mode translation, thus there are multiple combinations.
> While this vIOMMU implementation wants to simplify it for user by providing
> typical combinations. User could config it by "x-scalable-mode" option. The
> usage is as below:
>
> "-device intel-iommu,x-scalable-mode=["legacy"|"modern"|"off"]"
>
>   - "legacy": gives support for stage-2 page table
>   - "modern": gives support for stage-1 page table
>   - "off": no scalable mode support
>   - any other string, will throw error
>
> If x-scalable-mode is not configured, it is equivalent to x-scalable-mode=off.
>
> With scalable modern mode exposed to user, also accurate the pasid entry
> check in vtd_pe_type_check().
>
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> ---
>   hw/i386/intel_iommu_internal.h |  2 ++
>   include/hw/i386/intel_iommu.h  |  1 +
>   hw/i386/intel_iommu.c          | 46 ++++++++++++++++++++++++++--------
>   3 files changed, 39 insertions(+), 10 deletions(-)
>
> diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
> index 52bdbf3bc5..af99deb4cd 100644
> --- a/hw/i386/intel_iommu_internal.h
> +++ b/hw/i386/intel_iommu_internal.h
> @@ -195,6 +195,7 @@
>   #define VTD_ECAP_PASID              (1ULL << 40)
>   #define VTD_ECAP_SMTS               (1ULL << 43)
>   #define VTD_ECAP_SLTS               (1ULL << 46)
> +#define VTD_ECAP_FLTS               (1ULL << 47)
>
>   /* CAP_REG */
>   /* (offset >> 4) << 24 */
> @@ -211,6 +212,7 @@
>   #define VTD_CAP_SLLPS               ((1ULL << 34) | (1ULL << 35))
>   #define VTD_CAP_DRAIN_WRITE         (1ULL << 54)
>   #define VTD_CAP_DRAIN_READ          (1ULL << 55)
> +#define VTD_CAP_FS1GP               (1ULL << 56)
>   #define VTD_CAP_DRAIN               (VTD_CAP_DRAIN_READ | VTD_CAP_DRAIN_WRITE)
>   #define VTD_CAP_CM                  (1ULL << 7)
>   #define VTD_PASID_ID_SHIFT          20
> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> index 48134bda11..650641544c 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -263,6 +263,7 @@ struct IntelIOMMUState {
>
>       bool caching_mode;              /* RO - is cap CM enabled? */
>       bool scalable_mode;             /* RO - is Scalable Mode supported? */
> +    char *scalable_mode_str;        /* RO - admin's Scalable Mode config */
>       bool scalable_modern;           /* RO - is modern SM supported? */
>       bool snoop_control;             /* RO - is SNP filed supported? */
>
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index 949f120456..bb3ed48281 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -803,16 +803,18 @@ static inline bool vtd_is_fl_level_supported(IntelIOMMUState *s, uint32_t level)
>   }
>
>   /* Return true if check passed, otherwise false */
> -static inline bool vtd_pe_type_check(X86IOMMUState *x86_iommu,
> -                                     VTDPASIDEntry *pe)
> +static inline bool vtd_pe_type_check(IntelIOMMUState *s, VTDPASIDEntry *pe)
>   {
>       switch (VTD_PE_GET_TYPE(pe)) {
> -    case VTD_SM_PASID_ENTRY_SLT:
> -        return true;
> -    case VTD_SM_PASID_ENTRY_PT:
> -        return x86_iommu->pt_supported;
>       case VTD_SM_PASID_ENTRY_FLT:
> +        return !!(s->ecap & VTD_ECAP_FLTS);
> +    case VTD_SM_PASID_ENTRY_SLT:
> +        return !!(s->ecap & VTD_ECAP_SLTS);
>       case VTD_SM_PASID_ENTRY_NESTED:
> +        /* Not support NESTED page table type yet */
> +        return false;
> +    case VTD_SM_PASID_ENTRY_PT:
> +        return !!(s->ecap & VTD_ECAP_PT);
>       default:
>           /* Unknown type */
>           return false;
> @@ -861,7 +863,6 @@ static int vtd_get_pe_in_pasid_leaf_table(IntelIOMMUState *s,
>       uint8_t pgtt;
>       uint32_t index;
>       dma_addr_t entry_size;
> -    X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
>
>       index = VTD_PASID_TABLE_INDEX(pasid);
>       entry_size = VTD_PASID_ENTRY_SIZE;
> @@ -875,7 +876,7 @@ static int vtd_get_pe_in_pasid_leaf_table(IntelIOMMUState *s,
>       }
>
>       /* Do translation type check */
> -    if (!vtd_pe_type_check(x86_iommu, pe)) {
> +    if (!vtd_pe_type_check(s, pe)) {
>           return -VTD_FR_PASID_TABLE_ENTRY_INV;
>       }
>
> @@ -3773,7 +3774,7 @@ static Property vtd_properties[] = {
>       DEFINE_PROP_UINT8("aw-bits", IntelIOMMUState, aw_bits,
>                         VTD_HOST_AW_AUTO),
>       DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode, FALSE),
> -    DEFINE_PROP_BOOL("x-scalable-mode", IntelIOMMUState, scalable_mode, FALSE),
> +    DEFINE_PROP_STRING("x-scalable-mode", IntelIOMMUState, scalable_mode_str),
>       DEFINE_PROP_BOOL("snoop-control", IntelIOMMUState, snoop_control, false),
>       DEFINE_PROP_BOOL("x-pasid-mode", IntelIOMMUState, pasid, false),
>       DEFINE_PROP_BOOL("dma-drain", IntelIOMMUState, dma_drain, true),
> @@ -4504,7 +4505,10 @@ static void vtd_cap_init(IntelIOMMUState *s)
>       }
>
>       /* TODO: read cap/ecap from host to decide which cap to be exposed. */
> -    if (s->scalable_mode) {
> +    if (s->scalable_modern) {
> +        s->ecap |= VTD_ECAP_SMTS | VTD_ECAP_FLTS;
> +        s->cap |= VTD_CAP_FS1GP;
> +    } else if (s->scalable_mode) {
>           s->ecap |= VTD_ECAP_SMTS | VTD_ECAP_SRS | VTD_ECAP_SLTS;
>       }
>
> @@ -4686,6 +4690,28 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
>           }
>       }
>
> +    if (s->scalable_mode_str &&
> +        (strcmp(s->scalable_mode_str, "off") &&
> +         strcmp(s->scalable_mode_str, "modern") &&
> +         strcmp(s->scalable_mode_str, "legacy"))) {
> +        error_setg(errp, "Invalid x-scalable-mode config,"
> +                         "Please use \"modern\", \"legacy\" or \"off\"");
> +        return false;
> +    }
> +
> +    if (s->scalable_mode_str &&
> +        !strcmp(s->scalable_mode_str, "legacy")) {
> +        s->scalable_mode = true;
> +        s->scalable_modern = false;
> +    } else if (s->scalable_mode_str &&
> +        !strcmp(s->scalable_mode_str, "modern")) {
> +        s->scalable_mode = true;
> +        s->scalable_modern = true;
> +    } else {
> +        s->scalable_mode = false;
> +        s->scalable_modern = false;
> +    }
> +
>       if (s->aw_bits == VTD_HOST_AW_AUTO) {
>           if (s->scalable_modern) {
>               s->aw_bits = VTD_HOST_AW_48BIT;
> --
> 2.34.1
>