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Re: [RFC PATCH 03/12] hw/arm/smmu: Add stage to TLB
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From: |
Mostafa Saleh |
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Subject: |
Re: [RFC PATCH 03/12] hw/arm/smmu: Add stage to TLB |
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Date: |
Wed, 3 Apr 2024 09:55:10 +0000 |
On Wed, Apr 03, 2024 at 09:22:03AM +0200, Eric Auger wrote:
> Hi Mostafa,
>
> On 4/2/24 20:47, Mostafa Saleh wrote:
> > Hi Eric,
> >
> > On Tue, Apr 02, 2024 at 07:15:20PM +0200, Eric Auger wrote:
> >> Hi Mostafa,
> >>
> >> On 3/25/24 11:13, Mostafa Saleh wrote:
> >>> TLBs for nesting will be extended to be combined, a new index is added
> >>> "stage", with 2 valid values:
> >>> - SMMU_STAGE_1: Meaning this translates VA to PADDR, this entry can
> >>> be cached from fully nested configuration or from stage-1 only.
> >>> We don't support separate cached entries (VA to IPA)
> >>>
> >>> - SMMU_STAGE_2: Meaning this translates IPA to PADDR, cached from
> >>> stage-2 only configuration.
> >>>
> >>> For TLB invalidation:
> >>> - by VA: Invalidate TLBs tagged with SMMU_STAGE_1
> >>> - by IPA: Invalidate TLBs tagged with SMMU_STAGE_2
> >>> - All: Will invalidate both, this is communicated to the TLB as
> >>> SMMU_NESTED which is (SMMU_STAGE_1 | SMMU_STAGE_2) which uses
> >>> it as a mask.
> >> I don't really get why you need this extra stage field in the key. Why
> >> aren't the asid and vmid tags enough?
> >>
> > Looking again, I think we can do it with ASID and VMID only, but that
> > requires some rework in the invalidation path.
> >
> > With nested SMMUs, we can cache entries from:
> > - Stage-1 (or nested): Tagged with VMID and ASID
> > - Stage-2: Tagged with VMID only (ASID = -1)
> >
> > That should be enough for caching/lookup, but for invalidation, we
> > should be able to invalidate IPAs which are cached from stage-2.
> >
> > At the moment, we represent ASIDs with < 0 as a wildcard for
> > invalidation or stage-2 and they were mutually exclusive.
> >
> > An example is:
> > - CMD_TLBI_NH_VAA: Invalidate stage-1 for a VMID, all ASIDs (we use ASID =
> > -1)
> > - CMD_TLBI_NH_VA: Invalidate stage-1 for a VMID, an ASID ( > 0)
> > - CMD_TLBI_S2_IPA: Invalidate stage-2 for a VMID (we use ASID = -1)
> >
> > We need to distinguish between case 1) and 3) otherwise we over invalidate.
> OK I see your point when passing the asid param to smmuv3_range_inval()
> in smmuv3_range_inval().
> Well if you can have separate functions for handling S1 and S2 cases
> while keeping the current key that may be interesting. It may be clearer
> now we have extended support. This can also help in debugging/tracing.
> >
> > Similarly, CMD_TLBI_NH_ALL(invalidate all stage-1 by VMID) and
> > CMD_TLBI_S12_VMALL(invalidate both stages by VMID).
> >
> > I guess we can add variants of these functions that operate on ASIDs
> > (>= 0) or (< 0) which is basically stage-1 or stage-2.
> worth to try indeed.
I will switch to that in V2.
Thanks,
Mostafa
>
> Thanks
>
> Eric
> >
> > Another case I can think of which is not implemented in QEMU is
> > global entries, where we would like to look up entries for all ASIDs
> > (-1), but that’s not a problem for now.
> >
> > I don’t have a strong opinion, I can try to do it this way.
> >
> > Thanks,
> > Mostafa
> >
> >> Eric
> >>> This briefly described in the user manual (ARM IHI 0070 F.b) in
> >>> "16.2.1 Caching combined structures".
> >>>
> >>> Signed-off-by: Mostafa Saleh <smostafa@google.com>
> >>> ---
> >>> hw/arm/smmu-common.c | 27 +++++++++++++++++----------
> >>> hw/arm/smmu-internal.h | 2 ++
> >>> hw/arm/smmuv3.c | 5 +++--
> >>> hw/arm/trace-events | 3 ++-
> >>> include/hw/arm/smmu-common.h | 8 ++++++--
> >>> 5 files changed, 30 insertions(+), 15 deletions(-)
> >>>
> >>> diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
> >>> index 20630eb670..677dcf9a13 100644
> >>> --- a/hw/arm/smmu-common.c
> >>> +++ b/hw/arm/smmu-common.c
> >>> @@ -38,7 +38,7 @@ static guint smmu_iotlb_key_hash(gconstpointer v)
> >>>
> >>> /* Jenkins hash */
> >>> a = b = c = JHASH_INITVAL + sizeof(*key);
> >>> - a += key->asid + key->vmid + key->level + key->tg;
> >>> + a += key->asid + key->vmid + key->level + key->tg + key->stage;
> >>> b += extract64(key->iova, 0, 32);
> >>> c += extract64(key->iova, 32, 32);
> >>>
> >>> @@ -54,14 +54,14 @@ static gboolean smmu_iotlb_key_equal(gconstpointer
> >>> v1, gconstpointer v2)
> >>>
> >>> return (k1->asid == k2->asid) && (k1->iova == k2->iova) &&
> >>> (k1->level == k2->level) && (k1->tg == k2->tg) &&
> >>> - (k1->vmid == k2->vmid);
> >>> + (k1->vmid == k2->vmid) && (k1->stage == k2->stage);
> >>> }
> >>>
> >>> SMMUIOTLBKey smmu_get_iotlb_key(uint16_t asid, uint16_t vmid, uint64_t
> >>> iova,
> >>> - uint8_t tg, uint8_t level)
> >>> + uint8_t tg, uint8_t level, SMMUStage
> >>> stage)
> >>> {
> >>> SMMUIOTLBKey key = {.asid = asid, .vmid = vmid, .iova = iova,
> >>> - .tg = tg, .level = level};
> >>> + .tg = tg, .level = level, .stage = stage};
> >>>
> >>> return key;
> >>> }
> >>> @@ -81,7 +81,8 @@ SMMUTLBEntry *smmu_iotlb_lookup(SMMUState *bs,
> >>> SMMUTransCfg *cfg,
> >>> SMMUIOTLBKey key;
> >>>
> >>> key = smmu_get_iotlb_key(cfg->asid, cfg->s2cfg.vmid,
> >>> - iova & ~mask, tg, level);
> >>> + iova & ~mask, tg, level,
> >>> + SMMU_STAGE_TO_TLB_TAG(cfg->stage));
> >>> entry = g_hash_table_lookup(bs->iotlb, &key);
> >>> if (entry) {
> >>> break;
> >>> @@ -109,15 +110,16 @@ void smmu_iotlb_insert(SMMUState *bs, SMMUTransCfg
> >>> *cfg, SMMUTLBEntry *new)
> >>> {
> >>> SMMUIOTLBKey *key = g_new0(SMMUIOTLBKey, 1);
> >>> uint8_t tg = (new->granule - 10) / 2;
> >>> + SMMUStage stage_tag = SMMU_STAGE_TO_TLB_TAG(cfg->stage);
> >>>
> >>> if (g_hash_table_size(bs->iotlb) >= SMMU_IOTLB_MAX_SIZE) {
> >>> smmu_iotlb_inv_all(bs);
> >>> }
> >>>
> >>> *key = smmu_get_iotlb_key(cfg->asid, cfg->s2cfg.vmid,
> >>> new->entry.iova,
> >>> - tg, new->level);
> >>> + tg, new->level, stage_tag);
> >>> trace_smmu_iotlb_insert(cfg->asid, cfg->s2cfg.vmid, new->entry.iova,
> >>> - tg, new->level);
> >>> + tg, new->level, stage_tag);
> >>> g_hash_table_insert(bs->iotlb, key, new);
> >>> }
> >>>
> >>> @@ -159,18 +161,22 @@ static gboolean
> >>> smmu_hash_remove_by_asid_vmid_iova(gpointer key, gpointer value,
> >>> if (info->vmid >= 0 && info->vmid != SMMU_IOTLB_VMID(iotlb_key)) {
> >>> return false;
> >>> }
> >>> + if (!(info->stage & SMMU_IOTLB_STAGE(iotlb_key))) {
> >>> + return false;
> >>> + }
> >>> return ((info->iova & ~entry->addr_mask) == entry->iova) ||
> >>> ((entry->iova & ~info->mask) == info->iova);
> >>> }
> >>>
> >>> void smmu_iotlb_inv_iova(SMMUState *s, int asid, int vmid, dma_addr_t
> >>> iova,
> >>> - uint8_t tg, uint64_t num_pages, uint8_t ttl)
> >>> + uint8_t tg, uint64_t num_pages, uint8_t ttl,
> >>> + SMMUStage stage)
> >>> {
> >>> /* if tg is not set we use 4KB range invalidation */
> >>> uint8_t granule = tg ? tg * 2 + 10 : 12;
> >>>
> >>> if (ttl && (num_pages == 1) && (asid >= 0)) {
> >>> - SMMUIOTLBKey key = smmu_get_iotlb_key(asid, vmid, iova, tg, ttl);
> >>> + SMMUIOTLBKey key = smmu_get_iotlb_key(asid, vmid, iova, tg, ttl,
> >>> stage);
> >>>
> >>> if (g_hash_table_remove(s->iotlb, &key)) {
> >>> return;
> >>> @@ -184,6 +190,7 @@ void smmu_iotlb_inv_iova(SMMUState *s, int asid, int
> >>> vmid, dma_addr_t iova,
> >>> SMMUIOTLBPageInvInfo info = {
> >>> .asid = asid, .iova = iova,
> >>> .vmid = vmid,
> >>> + .stage = stage,
> >>> .mask = (num_pages * 1 << granule) - 1};
> >>>
> >>> g_hash_table_foreach_remove(s->iotlb,
> >>> @@ -597,7 +604,7 @@ SMMUTLBEntry *smmu_translate(SMMUState *bs,
> >>> SMMUTransCfg *cfg, dma_addr_t addr,
> >>> if (cached_entry) {
> >>> if ((flag & IOMMU_WO) && !(cached_entry->entry.perm & IOMMU_WO))
> >>> {
> >>> info->type = SMMU_PTW_ERR_PERMISSION;
> >>> - info->stage = cfg->stage;
> >>> + info->stage = SMMU_STAGE_TO_TLB_TAG(cfg->stage);
> >>> return NULL;
> >>> }
> >>> return cached_entry;
> >>> diff --git a/hw/arm/smmu-internal.h b/hw/arm/smmu-internal.h
> >>> index 843bebb185..6caa0ddf21 100644
> >>> --- a/hw/arm/smmu-internal.h
> >>> +++ b/hw/arm/smmu-internal.h
> >>> @@ -133,12 +133,14 @@ static inline int pgd_concat_idx(int start_level,
> >>> int granule_sz,
> >>>
> >>> #define SMMU_IOTLB_ASID(key) ((key).asid)
> >>> #define SMMU_IOTLB_VMID(key) ((key).vmid)
> >>> +#define SMMU_IOTLB_STAGE(key) ((key).stage)
> >>>
> >>> typedef struct SMMUIOTLBPageInvInfo {
> >>> int asid;
> >>> int vmid;
> >>> uint64_t iova;
> >>> uint64_t mask;
> >>> + SMMUStage stage;
> >>> } SMMUIOTLBPageInvInfo;
> >>>
> >>> typedef struct SMMUSIDRange {
> >>> diff --git a/hw/arm/smmuv3.c b/hw/arm/smmuv3.c
> >>> index f081ff0cc4..b27bf297e1 100644
> >>> --- a/hw/arm/smmuv3.c
> >>> +++ b/hw/arm/smmuv3.c
> >>> @@ -1087,7 +1087,7 @@ static void smmuv3_range_inval(SMMUState *s, Cmd
> >>> *cmd)
> >>> if (!tg) {
> >>> trace_smmuv3_range_inval(vmid, asid, addr, tg, 1, ttl, leaf);
> >>> smmuv3_inv_notifiers_iova(s, asid, vmid, addr, tg, 1);
> >>> - smmu_iotlb_inv_iova(s, asid, vmid, addr, tg, 1, ttl);
> >>> + smmu_iotlb_inv_iova(s, asid, vmid, addr, tg, 1, ttl,
> >>> SMMU_NESTED);
> >>> return;
> >>> }
> >>>
> >>> @@ -1105,7 +1105,8 @@ static void smmuv3_range_inval(SMMUState *s, Cmd
> >>> *cmd)
> >>> num_pages = (mask + 1) >> granule;
> >>> trace_smmuv3_range_inval(vmid, asid, addr, tg, num_pages, ttl,
> >>> leaf);
> >>> smmuv3_inv_notifiers_iova(s, asid, vmid, addr, tg, num_pages);
> >>> - smmu_iotlb_inv_iova(s, asid, vmid, addr, tg, num_pages, ttl);
> >>> + smmu_iotlb_inv_iova(s, asid, vmid, addr, tg,
> >>> + num_pages, ttl, SMMU_NESTED);
> >>> addr += mask + 1;
> >>> }
> >>> }
> >>> diff --git a/hw/arm/trace-events b/hw/arm/trace-events
> >>> index cc12924a84..3000c3bf14 100644
> >>> --- a/hw/arm/trace-events
> >>> +++ b/hw/arm/trace-events
> >>> @@ -14,10 +14,11 @@ smmu_iotlb_inv_all(void) "IOTLB invalidate all"
> >>> smmu_iotlb_inv_asid(uint16_t asid) "IOTLB invalidate asid=%d"
> >>> smmu_iotlb_inv_vmid(uint16_t vmid) "IOTLB invalidate vmid=%d"
> >>> smmu_iotlb_inv_iova(uint16_t asid, uint64_t addr) "IOTLB invalidate
> >>> asid=%d addr=0x%"PRIx64
> >>> +smmu_iotlb_inv_stage(int stage) "Stage invalidate stage=%d"
> >>> smmu_inv_notifiers_mr(const char *name) "iommu mr=%s"
> >>> smmu_iotlb_lookup_hit(uint16_t asid, uint16_t vmid, uint64_t addr,
> >>> uint32_t hit, uint32_t miss, uint32_t p) "IOTLB cache HIT asid=%d vmid=%d
> >>> addr=0x%"PRIx64" hit=%d miss=%d hit rate=%d"
> >>> smmu_iotlb_lookup_miss(uint16_t asid, uint16_t vmid, uint64_t addr,
> >>> uint32_t hit, uint32_t miss, uint32_t p) "IOTLB cache MISS asid=%d
> >>> vmid=%d addr=0x%"PRIx64" hit=%d miss=%d hit rate=%d"
> >>> -smmu_iotlb_insert(uint16_t asid, uint16_t vmid, uint64_t addr, uint8_t
> >>> tg, uint8_t level) "IOTLB ++ asid=%d vmid=%d addr=0x%"PRIx64" tg=%d
> >>> level=%d"
> >>> +smmu_iotlb_insert(uint16_t asid, uint16_t vmid, uint64_t addr, uint8_t
> >>> tg, uint8_t level, int stage) "IOTLB ++ asid=%d vmid=%d addr=0x%"PRIx64"
> >>> tg=%d level=%d stage=%d"
> >>>
> >>> # smmuv3.c
> >>> smmuv3_read_mmio(uint64_t addr, uint64_t val, unsigned size, uint32_t r)
> >>> "addr: 0x%"PRIx64" val:0x%"PRIx64" size: 0x%x(%d)"
> >>> diff --git a/include/hw/arm/smmu-common.h b/include/hw/arm/smmu-common.h
> >>> index 876e78975c..695d6d10ad 100644
> >>> --- a/include/hw/arm/smmu-common.h
> >>> +++ b/include/hw/arm/smmu-common.h
> >>> @@ -37,6 +37,8 @@
> >>> #define VMSA_IDXMSK(isz, strd, lvl) ((1ULL << \
> >>> VMSA_BIT_LVL(isz, strd,
> >>> lvl)) - 1)
> >>>
> >>> +#define SMMU_STAGE_TO_TLB_TAG(stage) (((stage) == SMMU_NESTED) ? \
> >>> + SMMU_STAGE_1 : (stage))
> >>> /*
> >>> * Page table walk error types
> >>> */
> >>> @@ -136,6 +138,7 @@ typedef struct SMMUIOTLBKey {
> >>> uint16_t vmid;
> >>> uint8_t tg;
> >>> uint8_t level;
> >>> + SMMUStage stage;
> >>> } SMMUIOTLBKey;
> >>>
> >>> struct SMMUState {
> >>> @@ -203,12 +206,13 @@ SMMUTLBEntry *smmu_iotlb_lookup(SMMUState *bs,
> >>> SMMUTransCfg *cfg,
> >>> SMMUTransTableInfo *tt, hwaddr iova);
> >>> void smmu_iotlb_insert(SMMUState *bs, SMMUTransCfg *cfg, SMMUTLBEntry
> >>> *entry);
> >>> SMMUIOTLBKey smmu_get_iotlb_key(uint16_t asid, uint16_t vmid, uint64_t
> >>> iova,
> >>> - uint8_t tg, uint8_t level);
> >>> + uint8_t tg, uint8_t level, SMMUStage
> >>> stage);
> >>> void smmu_iotlb_inv_all(SMMUState *s);
> >>> void smmu_iotlb_inv_asid(SMMUState *s, uint16_t asid);
> >>> void smmu_iotlb_inv_vmid(SMMUState *s, uint16_t vmid);
> >>> void smmu_iotlb_inv_iova(SMMUState *s, int asid, int vmid, dma_addr_t
> >>> iova,
> >>> - uint8_t tg, uint64_t num_pages, uint8_t ttl);
> >>> + uint8_t tg, uint64_t num_pages, uint8_t ttl,
> >>> + SMMUStage stage);
> >>>
> >>> /* Unmap the range of all the notifiers registered to any IOMMU mr */
> >>> void smmu_inv_notifiers_all(SMMUState *s);
>