On Mon, Jul 01, 2024 at 11:02:33AM +0000, Mostafa Saleh wrote:
> When nested translation is requested, do the following:
>
> - Translate stage-1 table address IPA into PA through stage-2.
> - Translate stage-1 table walk output (IPA) through stage-2.
> - Create a single TLB entry from stage-1 and stage-2 translations
> using logic introduced before.
>
> For stage-1 table translation, the spec (ARM IHI 0070 F.b) says in:
> 7.3.12 F_WALK_EABT:
> Translation of an IPA for Stage 1 descriptor fetch:
> S2 == 1 (stage 2), CLASS == T
> So, F_WALK_EABT is used which propagtes to CLASS == TT.
I don't think the text applies to this case, the context is:
A stage 2 table walk can encounter EABT accessing the physical
address of a stage 2 descriptor, because of a:
[...]
* Translation of an IPA for Stage 1 descriptor fetch
So EABT is when failing to load the stage 2 descriptor. I can't find
exact text for this case but looking at the flowchart 15.5, I think
this should be F_TRANSLATION/F_ADDR_SIZE/F_PERMISSION/F_ACCESS with
CLASS=TT and S2.
Thanks,
Jean
>
> smmu_ptw() has a new argument SMMUState which include the TLB as
> stage-1 table address can be cached in there.
>
> Also in smmu_ptw() a separate path used for nesting to simplify the
> code, although some logic can be combined.
>
> Signed-off-by: Mostafa Saleh <smost...@google.com>
> ---
> hw/arm/smmu-common.c | 72 +++++++++++++++++++++++++++++++-----
> include/hw/arm/smmu-common.h | 2 +-
> 2 files changed, 64 insertions(+), 10 deletions(-)
>
> diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
> index 24b7d09e2b..71afd486ba 100644
> --- a/hw/arm/smmu-common.c
> +++ b/hw/arm/smmu-common.c
> @@ -318,6 +318,38 @@ SMMUTransTableInfo *select_tt(SMMUTransCfg *cfg,
> dma_addr_t iova)
> return NULL;
> }
>
> +/* Translate stage-1 table address using stage-2 page table. */
> +static inline int translate_table_addr_ipa(dma_addr_t *table_addr,
> + SMMUTransCfg *cfg,
> + SMMUPTWEventInfo *info,
> + SMMUState *bs)
> +{
> + dma_addr_t addr = *table_addr;
> + SMMUTLBEntry *cached_entry;
> + int asid;
> +
> + /*
> + * The translation table walks performed from TTB0 or TTB1 are always
> + * performed in IPA space if stage 2 translations are enabled.
> + */
> + asid = cfg->asid;
> + cfg->stage = SMMU_STAGE_2;
> + cfg->asid = -1;
> + cached_entry = smmu_translate(bs, cfg, addr, IOMMU_RO, info);
> + cfg->asid = asid;
> + cfg->stage = SMMU_NESTED;
> +
> + if (cached_entry) {
> + *table_addr = CACHED_ENTRY_TO_ADDR(cached_entry, addr);
> + return 0;
> + }
> +
> + info->stage = SMMU_STAGE_2;
> + info->type = SMMU_PTW_ERR_WALK_EABT;
> + info->addr = addr;
> + return -EINVAL;
> +}
> +
> /**
> * smmu_ptw_64_s1 - VMSAv8-64 Walk of the page tables for a given IOVA
> * @cfg: translation config
> @@ -333,7 +365,8 @@ SMMUTransTableInfo *select_tt(SMMUTransCfg *cfg,
> dma_addr_t iova)
> */
> static int smmu_ptw_64_s1(SMMUTransCfg *cfg,
> dma_addr_t iova, IOMMUAccessFlags perm,
> - SMMUTLBEntry *tlbe, SMMUPTWEventInfo *info)
> + SMMUTLBEntry *tlbe, SMMUPTWEventInfo *info,
> + SMMUState *bs)
> {
> dma_addr_t baseaddr, indexmask;
> SMMUStage stage = cfg->stage;
> @@ -381,6 +414,11 @@ static int smmu_ptw_64_s1(SMMUTransCfg *cfg,
> goto error;
> }
> baseaddr = get_table_pte_address(pte, granule_sz);
> + if (cfg->stage == SMMU_NESTED) {
> + if (translate_table_addr_ipa(&baseaddr, cfg, info, bs)) {
> + goto error;
> + }
> + }
> level++;
> continue;
> } else if (is_page_pte(pte, level)) {
> @@ -568,10 +606,8 @@ error:
> * combine S1 and S2 TLB entries into a single entry.
> * As a result the S1 entry is overriden with combined data.
> */
> -static void __attribute__((unused)) combine_tlb(SMMUTLBEntry *tlbe,
> - SMMUTLBEntry *tlbe_s2,
> - dma_addr_t iova,
> - SMMUTransCfg *cfg)
> +static void combine_tlb(SMMUTLBEntry *tlbe, SMMUTLBEntry *tlbe_s2,
> + dma_addr_t iova, SMMUTransCfg *cfg)
> {
> if (tlbe_s2->entry.addr_mask < tlbe->entry.addr_mask) {
> tlbe->entry.addr_mask = tlbe_s2->entry.addr_mask;
> @@ -596,14 +632,19 @@ static void __attribute__((unused))
> combine_tlb(SMMUTLBEntry *tlbe,
> * @perm: tentative access type
> * @tlbe: returned entry
> * @info: ptw event handle
> + * @bs: smmu state which includes TLB instance
> *
> * return 0 on success
> */
> int smmu_ptw(SMMUTransCfg *cfg, dma_addr_t iova, IOMMUAccessFlags perm,
> - SMMUTLBEntry *tlbe, SMMUPTWEventInfo *info)
> + SMMUTLBEntry *tlbe, SMMUPTWEventInfo *info, SMMUState *bs)
> {
> + int ret;
> + SMMUTLBEntry tlbe_s2;
> + dma_addr_t ipa;
> +
> if (cfg->stage == SMMU_STAGE_1) {
> - return smmu_ptw_64_s1(cfg, iova, perm, tlbe, info);
> + return smmu_ptw_64_s1(cfg, iova, perm, tlbe, info, bs);
> } else if (cfg->stage == SMMU_STAGE_2) {
> /*
> * If bypassing stage 1(or unimplemented), the input address is
> passed
> @@ -621,7 +662,20 @@ int smmu_ptw(SMMUTransCfg *cfg, dma_addr_t iova,
> IOMMUAccessFlags perm,
> return smmu_ptw_64_s2(cfg, iova, perm, tlbe, info);
> }
>
> - g_assert_not_reached();
> + /* SMMU_NESTED. */
> + ret = smmu_ptw_64_s1(cfg, iova, perm, tlbe, info, bs);
> + if (ret) {
> + return ret;
> + }
> +
> + ipa = CACHED_ENTRY_TO_ADDR(tlbe, iova);
> + ret = smmu_ptw_64_s2(cfg, ipa, perm, &tlbe_s2, info);
> + if (ret) {
> + return ret;
> + }
> +
> + combine_tlb(tlbe, &tlbe_s2, iova, cfg);
> + return 0;
> }
>
> SMMUTLBEntry *smmu_translate(SMMUState *bs, SMMUTransCfg *cfg, dma_addr_t
> addr,
> @@ -677,7 +731,7 @@ SMMUTLBEntry *smmu_translate(SMMUState *bs, SMMUTransCfg
> *cfg, dma_addr_t addr,
> }
>
> cached_entry = g_new0(SMMUTLBEntry, 1);
> - status = smmu_ptw(cfg, aligned_addr, flag, cached_entry, info);
> + status = smmu_ptw(cfg, aligned_addr, flag, cached_entry, info, bs);
> if (status) {
> g_free(cached_entry);
> return NULL;
> diff --git a/include/hw/arm/smmu-common.h b/include/hw/arm/smmu-common.h
> index 1db566d451..cf0fd3ec74 100644
> --- a/include/hw/arm/smmu-common.h
> +++ b/include/hw/arm/smmu-common.h
> @@ -185,7 +185,7 @@ static inline uint16_t smmu_get_sid(SMMUDevice *sdev)
> * pair, according to @cfg translation config
> */
> int smmu_ptw(SMMUTransCfg *cfg, dma_addr_t iova, IOMMUAccessFlags perm,
> - SMMUTLBEntry *tlbe, SMMUPTWEventInfo *info);
> + SMMUTLBEntry *tlbe, SMMUPTWEventInfo *info, SMMUState *bs);
>
>
> /*
> --
> 2.45.2.803.g4e1b14247a-goog
>
