hw/arm/smmu-common: VMSAv8-64 page table walk

This patch implements the page table walk for VMSAv8-64.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Prem Mallappa <prem.mallappa@broadcom.com>
Message-id: 1524665762-31355-4-git-send-email-eric.auger@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 222 insertions, 0 deletions

diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c
index 3d64bcfac2..01c7be82b6 100644
--- a/hw/arm/smmu-common.c
+++ b/hw/arm/smmu-common.c
@@ -27,6 +27,228 @@
 
 #include "qemu/error-report.h"
 #include "hw/arm/smmu-common.h"
+#include "smmu-internal.h"
+
+/* VMSAv8-64 Translation */
+
+/**
+ * get_pte - Get the content of a page table entry located at
+ * @base_addr[@index]
+ */
+static int get_pte(dma_addr_t baseaddr, uint32_t index, uint64_t *pte,
+                   SMMUPTWEventInfo *info)
+{
+    int ret;
+    dma_addr_t addr = baseaddr + index * sizeof(*pte);
+
+    /* TODO: guarantee 64-bit single-copy atomicity */
+    ret = dma_memory_read(&address_space_memory, addr,
+                          (uint8_t *)pte, sizeof(*pte));
+
+    if (ret != MEMTX_OK) {
+        info->type = SMMU_PTW_ERR_WALK_EABT;
+        info->addr = addr;
+        return -EINVAL;
+    }
+    trace_smmu_get_pte(baseaddr, index, addr, *pte);
+    return 0;
+}
+
+/* VMSAv8-64 Translation Table Format Descriptor Decoding */
+
+/**
+ * get_page_pte_address - returns the L3 descriptor output address,
+ * ie. the page frame
+ * ARM ARM spec: Figure D4-17 VMSAv8-64 level 3 descriptor format
+ */
+static inline hwaddr get_page_pte_address(uint64_t pte, int granule_sz)
+{
+    return PTE_ADDRESS(pte, granule_sz);
+}
+
+/**
+ * get_table_pte_address - return table descriptor output address,
+ * ie. address of next level table
+ * ARM ARM Figure D4-16 VMSAv8-64 level0, level1, and level 2 descriptor formats
+ */
+static inline hwaddr get_table_pte_address(uint64_t pte, int granule_sz)
+{
+    return PTE_ADDRESS(pte, granule_sz);
+}
+
+/**
+ * get_block_pte_address - return block descriptor output address and block size
+ * ARM ARM Figure D4-16 VMSAv8-64 level0, level1, and level 2 descriptor formats
+ */
+static inline hwaddr get_block_pte_address(uint64_t pte, int level,
+                                           int granule_sz, uint64_t *bsz)
+{
+    int n = (granule_sz - 3) * (4 - level) + 3;
+
+    *bsz = 1 << n;
+    return PTE_ADDRESS(pte, n);
+}
+
+SMMUTransTableInfo *select_tt(SMMUTransCfg *cfg, dma_addr_t iova)
+{
+    bool tbi = extract64(iova, 55, 1) ? TBI1(cfg->tbi) : TBI0(cfg->tbi);
+    uint8_t tbi_byte = tbi * 8;
+
+    if (cfg->tt[0].tsz &&
+        !extract64(iova, 64 - cfg->tt[0].tsz, cfg->tt[0].tsz - tbi_byte)) {
+        /* there is a ttbr0 region and we are in it (high bits all zero) */
+        return &cfg->tt[0];
+    } else if (cfg->tt[1].tsz &&
+           !extract64(iova, 64 - cfg->tt[1].tsz, cfg->tt[1].tsz - tbi_byte)) {
+        /* there is a ttbr1 region and we are in it (high bits all one) */
+        return &cfg->tt[1];
+    } else if (!cfg->tt[0].tsz) {
+        /* ttbr0 region is "everything not in the ttbr1 region" */
+        return &cfg->tt[0];
+    } else if (!cfg->tt[1].tsz) {
+        /* ttbr1 region is "everything not in the ttbr0 region" */
+        return &cfg->tt[1];
+    }
+    /* in the gap between the two regions, this is a Translation fault */
+    return NULL;
+}
+
+/**
+ * smmu_ptw_64 - VMSAv8-64 Walk of the page tables for a given IOVA
+ * @cfg: translation config
+ * @iova: iova to translate
+ * @perm: access type
+ * @tlbe: IOMMUTLBEntry (out)
+ * @info: handle to an error info
+ *
+ * Return 0 on success, < 0 on error. In case of error, @info is filled
+ * and tlbe->perm is set to IOMMU_NONE.
+ * Upon success, @tlbe is filled with translated_addr and entry
+ * permission rights.
+ */
+static int smmu_ptw_64(SMMUTransCfg *cfg,
+                       dma_addr_t iova, IOMMUAccessFlags perm,
+                       IOMMUTLBEntry *tlbe, SMMUPTWEventInfo *info)
+{
+    dma_addr_t baseaddr, indexmask;
+    int stage = cfg->stage;
+    SMMUTransTableInfo *tt = select_tt(cfg, iova);
+    uint8_t level, granule_sz, inputsize, stride;
+
+    if (!tt || tt->disabled) {
+        info->type = SMMU_PTW_ERR_TRANSLATION;
+        goto error;
+    }
+
+    granule_sz = tt->granule_sz;
+    stride = granule_sz - 3;
+    inputsize = 64 - tt->tsz;
+    level = 4 - (inputsize - 4) / stride;
+    indexmask = (1ULL << (inputsize - (stride * (4 - level)))) - 1;
+    baseaddr = extract64(tt->ttb, 0, 48);
+    baseaddr &= ~indexmask;
+
+    tlbe->iova = iova;
+    tlbe->addr_mask = (1 << granule_sz) - 1;
+
+    while (level <= 3) {
+        uint64_t subpage_size = 1ULL << level_shift(level, granule_sz);
+        uint64_t mask = subpage_size - 1;
+        uint32_t offset = iova_level_offset(iova, inputsize, level, granule_sz);
+        uint64_t pte;
+        dma_addr_t pte_addr = baseaddr + offset * sizeof(pte);
+        uint8_t ap;
+
+        if (get_pte(baseaddr, offset, &pte, info)) {
+                goto error;
+        }
+        trace_smmu_ptw_level(level, iova, subpage_size,
+                             baseaddr, offset, pte);
+
+        if (is_invalid_pte(pte) || is_reserved_pte(pte, level)) {
+            trace_smmu_ptw_invalid_pte(stage, level, baseaddr,
+                                       pte_addr, offset, pte);
+            info->type = SMMU_PTW_ERR_TRANSLATION;
+            goto error;
+        }
+
+        if (is_page_pte(pte, level)) {
+            uint64_t gpa = get_page_pte_address(pte, granule_sz);
+
+            ap = PTE_AP(pte);
+            if (is_permission_fault(ap, perm)) {
+                info->type = SMMU_PTW_ERR_PERMISSION;
+                goto error;
+            }
+
+            tlbe->translated_addr = gpa + (iova & mask);
+            tlbe->perm = PTE_AP_TO_PERM(ap);
+            trace_smmu_ptw_page_pte(stage, level, iova,
+                                    baseaddr, pte_addr, pte, gpa);
+            return 0;
+        }
+        if (is_block_pte(pte, level)) {
+            uint64_t block_size;
+            hwaddr gpa = get_block_pte_address(pte, level, granule_sz,
+                                               &block_size);
+
+            ap = PTE_AP(pte);
+            if (is_permission_fault(ap, perm)) {
+                info->type = SMMU_PTW_ERR_PERMISSION;
+                goto error;
+            }
+
+            trace_smmu_ptw_block_pte(stage, level, baseaddr,
+                                     pte_addr, pte, iova, gpa,
+                                     block_size >> 20);
+
+            tlbe->translated_addr = gpa + (iova & mask);
+            tlbe->perm = PTE_AP_TO_PERM(ap);
+            return 0;
+        }
+
+        /* table pte */
+        ap = PTE_APTABLE(pte);
+
+        if (is_permission_fault(ap, perm)) {
+            info->type = SMMU_PTW_ERR_PERMISSION;
+            goto error;
+        }
+        baseaddr = get_table_pte_address(pte, granule_sz);
+        level++;
+    }
+
+    info->type = SMMU_PTW_ERR_TRANSLATION;
+
+error:
+    tlbe->perm = IOMMU_NONE;
+    return -EINVAL;
+}
+
+/**
+ * smmu_ptw - Walk the page tables for an IOVA, according to @cfg
+ *
+ * @cfg: translation configuration
+ * @iova: iova to translate
+ * @perm: tentative access type
+ * @tlbe: returned entry
+ * @info: ptw event handle
+ *
+ * return 0 on success
+ */
+inline int smmu_ptw(SMMUTransCfg *cfg, dma_addr_t iova, IOMMUAccessFlags perm,
+             IOMMUTLBEntry *tlbe, SMMUPTWEventInfo *info)
+{
+    if (!cfg->aa64) {
+        /*
+         * This code path is not entered as we check this while decoding
+         * the configuration data in the derived SMMU model.
+         */
+        g_assert_not_reached();
+    }
+
+    return smmu_ptw_64(cfg, iova, perm, tlbe, info);
+}
 
 /**
  * The bus number is used for lookup when SID based invalidation occurs.