[Qemu-devel] [RFC v2 2/3] intel_iommu: add 256 bits qi_desc support

[Yi Sun <yi.y.sun@linux.intel.com>]

From: "Liu, Yi L" <yi.l.liu@intel.com>

Per Intel(R) VT-d 3.0, the qi_desc is 256 bits in Scalable
Mode. This patch adds emulation of 256bits qi_desc.

Signed-off-by: Liu, Yi L <yi.l.liu@intel.com>
[Yi Sun is co-developer to rebase and refine the patch.]
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
---
v2:
    - modify s-o-b position.
    - remove unnecessary macros.
    - change 'iq_dw' type to bool.
    - remove initialization to 'inv_desc->val[]'.
    - modify 'VTDInvDesc' to add a union 'val[4]' to be compatible
      with both legacy mode and scalable mode.
---
 hw/i386/intel_iommu.c          | 40 +++++++++++++++++++++++++++++-----------
 hw/i386/intel_iommu_internal.h |  9 ++++++++-
 include/hw/i386/intel_iommu.h  |  1 +
 3 files changed, 38 insertions(+), 12 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 109fdbc..d1eb0c5 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -2028,7 +2028,7 @@ static void vtd_handle_gcmd_qie(IntelIOMMUState *s, bool en)
     if (en) {
         s->iq = iqa_val & VTD_IQA_IQA_MASK(s->aw_bits);
         /* 2^(x+8) entries */
-        s->iq_size = 1UL << ((iqa_val & VTD_IQA_QS) + 8);
+        s->iq_size = 1UL << ((iqa_val & VTD_IQA_QS) + 8 - (s->iq_dw ? 1 : 0));
         s->qi_enabled = true;
         trace_vtd_inv_qi_setup(s->iq, s->iq_size);
         /* Ok - report back to driver */
@@ -2195,19 +2195,24 @@ static void vtd_handle_iotlb_write(IntelIOMMUState *s)
 }
 
 /* Fetch an Invalidation Descriptor from the Invalidation Queue */
-static bool vtd_get_inv_desc(dma_addr_t base_addr, uint32_t offset,
+static bool vtd_get_inv_desc(IntelIOMMUState *s,
                              VTDInvDesc *inv_desc)
 {
-    dma_addr_t addr = base_addr + offset * sizeof(*inv_desc);
-    if (dma_memory_read(&address_space_memory, addr, inv_desc,
-        sizeof(*inv_desc))) {
-        error_report_once("Read INV DESC failed");
-        inv_desc->lo = 0;
-        inv_desc->hi = 0;
+    dma_addr_t base_addr = s->iq;
+    uint32_t offset = s->iq_head;
+    uint32_t dw = s->iq_dw ? 32 : 16;
+    dma_addr_t addr = base_addr + offset * dw;
+
+    if (dma_memory_read(&address_space_memory, addr, inv_desc, dw)) {
+        error_report_once("Read INV DESC failed.");
         return false;
     }
     inv_desc->lo = le64_to_cpu(inv_desc->lo);
     inv_desc->hi = le64_to_cpu(inv_desc->hi);
+    if (dw == 32) {
+        inv_desc->val[2] = le64_to_cpu(inv_desc->val[2]);
+        inv_desc->val[3] = le64_to_cpu(inv_desc->val[3]);
+    }
     return true;
 }
 
@@ -2413,10 +2418,11 @@ static bool vtd_process_inv_desc(IntelIOMMUState *s)
     uint8_t desc_type;
 
     trace_vtd_inv_qi_head(s->iq_head);
-    if (!vtd_get_inv_desc(s->iq, s->iq_head, &inv_desc)) {
+    if (!vtd_get_inv_desc(s, &inv_desc)) {
         s->iq_last_desc_type = VTD_INV_DESC_NONE;
         return false;
     }
+
     desc_type = inv_desc.lo & VTD_INV_DESC_TYPE;
     /* FIXME: should update at first or at last? */
     s->iq_last_desc_type = desc_type;
@@ -2501,7 +2507,12 @@ static void vtd_handle_iqt_write(IntelIOMMUState *s)
 {
     uint64_t val = vtd_get_quad_raw(s, DMAR_IQT_REG);
 
-    s->iq_tail = VTD_IQT_QT(val);
+    if (s->iq_dw && val & VTD_IQT_QT_256_RSV_BIT) {
+        error_report_once("%s: RSV bit is set: val=0x%"PRIx64,
+                          __func__, val);
+        return;
+    }
+    s->iq_tail = VTD_IQT_QT(s->iq_dw, val);
     trace_vtd_inv_qi_tail(s->iq_tail);
 
     if (s->qi_enabled && !(vtd_get_long_raw(s, DMAR_FSTS_REG) & VTD_FSTS_IQE)) {
@@ -2770,6 +2781,12 @@ static void vtd_mem_write(void *opaque, hwaddr addr,
         } else {
             vtd_set_quad(s, addr, val);
         }
+        if (s->ecap & VTD_ECAP_SMTS &&
+            val & VTD_IQA_DW_MASK) {
+            s->iq_dw = true;
+        } else {
+            s->iq_dw = false;
+        }
         break;
 
     case DMAR_IQA_REG_HI:
@@ -3477,6 +3494,7 @@ static void vtd_init(IntelIOMMUState *s)
     s->iq_size = 0;
     s->qi_enabled = false;
     s->iq_last_desc_type = VTD_INV_DESC_NONE;
+    s->iq_dw = false;
     s->next_frcd_reg = 0;
     s->cap = VTD_CAP_FRO | VTD_CAP_NFR | VTD_CAP_ND |
              VTD_CAP_MAMV | VTD_CAP_PSI | VTD_CAP_SLLPS |
@@ -3554,7 +3572,7 @@ static void vtd_init(IntelIOMMUState *s)
 
     vtd_define_quad(s, DMAR_IQH_REG, 0, 0, 0);
     vtd_define_quad(s, DMAR_IQT_REG, 0, 0x7fff0ULL, 0);
-    vtd_define_quad(s, DMAR_IQA_REG, 0, 0xfffffffffffff007ULL, 0);
+    vtd_define_quad(s, DMAR_IQA_REG, 0, 0xfffffffffffff807ULL, 0);
     vtd_define_long(s, DMAR_ICS_REG, 0, 0, 0x1UL);
     vtd_define_long(s, DMAR_IECTL_REG, 0x80000000UL, 0x80000000UL, 0);
     vtd_define_long(s, DMAR_IEDATA_REG, 0, 0xffffffffUL, 0);
diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index fe72bc3..016fa4c 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -190,6 +190,7 @@
 #define VTD_ECAP_EIM                (1ULL << 4)
 #define VTD_ECAP_PT                 (1ULL << 6)
 #define VTD_ECAP_MHMV               (15ULL << 20)
+#define VTD_ECAP_SMTS               (1ULL << 43)
 
 /* CAP_REG */
 /* (offset >> 4) << 24 */
@@ -218,11 +219,14 @@
 #define VTD_CAP_SAGAW_48bit         (0x4ULL << VTD_CAP_SAGAW_SHIFT)
 
 /* IQT_REG */
-#define VTD_IQT_QT(val)             (((val) >> 4) & 0x7fffULL)
+#define VTD_IQT_QT(dw_bit, val)     (dw_bit ? (((val) >> 5) & 0x3fffULL) : \
+                                     (((val) >> 4) & 0x7fffULL))
+#define VTD_IQT_QT_256_RSV_BIT      0x10
 
 /* IQA_REG */
 #define VTD_IQA_IQA_MASK(aw)        (VTD_HAW_MASK(aw) ^ 0xfffULL)
 #define VTD_IQA_QS                  0x7ULL
+#define VTD_IQA_DW_MASK             0x800
 
 /* IQH_REG */
 #define VTD_IQH_QH_SHIFT            4
@@ -324,6 +328,9 @@ union VTDInvDesc {
         uint64_t lo;
         uint64_t hi;
     };
+    struct {
+        uint64_t val[4];
+    };
     union {
         VTDInvDescIEC iec;
     };
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index 72c5ca6..2877c94 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -238,6 +238,7 @@ struct IntelIOMMUState {
     uint16_t iq_tail;               /* Current invalidation queue tail */
     dma_addr_t iq;                  /* Current invalidation queue pointer */
     uint16_t iq_size;               /* IQ Size in number of entries */
+    bool iq_dw;                     /* IQ descriptor width 256bit or not */
     bool qi_enabled;                /* Set if the QI is enabled */
     uint8_t iq_last_desc_type;      /* The type of last completed descriptor */
 
-- 
1.9.1