[PATCH v4 10/20] intel_iommu: Handle PASID entry removal and update

[Zhenzhong Duan <zhenzhong.duan@intel.com>]

This adds an new entry VTDPASIDCacheEntry in VTDAddressSpace to cache the
pasid entry and track PASID usage and future PASID tagged DMA address
translation support in vIOMMU.

VTDAddressSpace of PCI_NO_PASID is allocated when device is plugged and
never freed. For other pasid, VTDAddressSpace instance is created/destroyed
per the guest pasid entry set up/destroy.

When guest removes or updates a PASID entry, QEMU will capture the guest pasid
selective pasid cache invalidation, removes VTDAddressSpace or update cached
PASID entry.

vIOMMU emulator could figure out the reason by fetching latest guest pasid entry
and compare it with cached PASID entry.

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 |  27 ++++-
 include/hw/i386/intel_iommu.h  |   6 +
 hw/i386/intel_iommu.c          | 196 +++++++++++++++++++++++++++++++--
 hw/i386/trace-events           |   3 +
 4 files changed, 220 insertions(+), 12 deletions(-)

diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
index f7510861d1..b9b76dd996 100644
--- a/hw/i386/intel_iommu_internal.h
+++ b/hw/i386/intel_iommu_internal.h
@@ -316,6 +316,7 @@ typedef enum VTDFaultReason {
                                   * request while disabled */
     VTD_FR_IR_SID_ERR = 0x26,   /* Invalid Source-ID */
 
+    VTD_FR_RTADDR_INV_TTM = 0x31,  /* Invalid TTM in RTADDR */
     /* PASID directory entry access failure */
     VTD_FR_PASID_DIR_ACCESS_ERR = 0x50,
     /* The Present(P) field of pasid directory entry is 0 */
@@ -493,6 +494,15 @@ typedef union VTDInvDesc VTDInvDesc;
 #define VTD_INV_DESC_PIOTLB_RSVD_VAL0     0xfff000000000f1c0ULL
 #define VTD_INV_DESC_PIOTLB_RSVD_VAL1     0xf80ULL
 
+/* PASID-cache Invalidate Descriptor (pc_inv_dsc) fields */
+#define VTD_INV_DESC_PASIDC_G(x)        extract64((x)->val[0], 4, 2)
+#define VTD_INV_DESC_PASIDC_G_DSI       0
+#define VTD_INV_DESC_PASIDC_G_PASID_SI  1
+#define VTD_INV_DESC_PASIDC_G_GLOBAL    3
+#define VTD_INV_DESC_PASIDC_DID(x)      extract64((x)->val[0], 16, 16)
+#define VTD_INV_DESC_PASIDC_PASID(x)    extract64((x)->val[0], 32, 20)
+#define VTD_INV_DESC_PASIDC_RSVD_VAL0   0xfff000000000f1c0ULL
+
 /* Information about page-selective IOTLB invalidate */
 struct VTDIOTLBPageInvInfo {
     uint16_t domain_id;
@@ -553,6 +563,21 @@ typedef struct VTDRootEntry VTDRootEntry;
 #define VTD_SM_CONTEXT_ENTRY_RSVD_VAL0(aw)  (0x1e0ULL | ~VTD_HAW_MASK(aw))
 #define VTD_SM_CONTEXT_ENTRY_RSVD_VAL1      0xffffffffffe00000ULL
 
+typedef enum VTDPCInvType {
+    /* VTD spec defined PASID cache invalidation type */
+    VTD_PASID_CACHE_DOMSI = VTD_INV_DESC_PASIDC_G_DSI,
+    VTD_PASID_CACHE_PASIDSI = VTD_INV_DESC_PASIDC_G_PASID_SI,
+    VTD_PASID_CACHE_GLOBAL_INV = VTD_INV_DESC_PASIDC_G_GLOBAL,
+} VTDPCInvType;
+
+typedef struct VTDPASIDCacheInfo {
+    VTDPCInvType type;
+    uint16_t did;
+    uint32_t pasid;
+    PCIBus *bus;
+    uint16_t devfn;
+} VTDPASIDCacheInfo;
+
 /* PASID Table Related Definitions */
 #define VTD_PASID_DIR_BASE_ADDR_MASK  (~0xfffULL)
 #define VTD_PASID_TABLE_BASE_ADDR_MASK (~0xfffULL)
@@ -574,7 +599,7 @@ typedef struct VTDRootEntry VTDRootEntry;
 #define VTD_SM_PASID_ENTRY_PT          (4ULL << 6)
 
 #define VTD_SM_PASID_ENTRY_AW          7ULL /* Adjusted guest-address-width */
-#define VTD_SM_PASID_ENTRY_DID(val)    ((val) & VTD_DOMAIN_ID_MASK)
+#define VTD_SM_PASID_ENTRY_DID(x)      extract64((x)->val[1], 0, 16)
 
 #define VTD_SM_PASID_ENTRY_FLPM          3ULL
 #define VTD_SM_PASID_ENTRY_FLPTPTR       (~0xfffULL)
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index 50f9b27a45..0e3826f6f0 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -95,6 +95,11 @@ struct VTDPASIDEntry {
     uint64_t val[8];
 };
 
+typedef struct VTDPASIDCacheEntry {
+    struct VTDPASIDEntry pasid_entry;
+    bool valid;
+} VTDPASIDCacheEntry;
+
 struct VTDAddressSpace {
     PCIBus *bus;
     uint8_t devfn;
@@ -107,6 +112,7 @@ struct VTDAddressSpace {
     MemoryRegion iommu_ir_fault; /* Interrupt region for catching fault */
     IntelIOMMUState *iommu_state;
     VTDContextCacheEntry context_cache_entry;
+    VTDPASIDCacheEntry pasid_cache_entry;
     QLIST_ENTRY(VTDAddressSpace) next;
     /* Superset of notifier flags that this address space has */
     IOMMUNotifierFlag notifier_flags;
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index eb0e799e4a..cc849acd20 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -1675,7 +1675,7 @@ static uint16_t vtd_get_domain_id(IntelIOMMUState *s,
 
     if (s->root_scalable) {
         vtd_ce_get_pasid_entry(s, ce, &pe, pasid);
-        return VTD_SM_PASID_ENTRY_DID(pe.val[1]);
+        return VTD_SM_PASID_ENTRY_DID(&pe);
     }
 
     return VTD_CONTEXT_ENTRY_DID(ce->hi);
@@ -3109,6 +3109,183 @@ static bool vtd_process_piotlb_desc(IntelIOMMUState *s,
     return true;
 }
 
+static inline int vtd_dev_get_pe_from_pasid(VTDAddressSpace *vtd_as,
+                                            uint32_t pasid, VTDPASIDEntry *pe)
+{
+    IntelIOMMUState *s = vtd_as->iommu_state;
+    VTDContextEntry ce;
+    int ret;
+
+    if (!s->root_scalable) {
+        return -VTD_FR_RTADDR_INV_TTM;
+    }
+
+    ret = vtd_dev_to_context_entry(s, pci_bus_num(vtd_as->bus), vtd_as->devfn,
+                                   &ce);
+    if (ret) {
+        return ret;
+    }
+
+    return vtd_ce_get_pasid_entry(s, &ce, pe, pasid);
+}
+
+static bool vtd_pasid_entry_compare(VTDPASIDEntry *p1, VTDPASIDEntry *p2)
+{
+    return !memcmp(p1, p2, sizeof(*p1));
+}
+
+/*
+ * This function is a loop function which return value determines if
+ * vtd_as including cached pasid entry is removed.
+ *
+ * For PCI_NO_PASID, when corresponding cached pasid entry is cleared,
+ * it returns false so that vtd_as is reserved as it's owned by PCI
+ * sub-system. For other pasid, it returns true so vtd_as is removed.
+ */
+static gboolean vtd_flush_pasid_locked(gpointer key, gpointer value,
+                                       gpointer user_data)
+{
+    VTDPASIDCacheInfo *pc_info = user_data;
+    VTDAddressSpace *vtd_as = value;
+    VTDPASIDCacheEntry *pc_entry = &vtd_as->pasid_cache_entry;
+    VTDPASIDEntry pe;
+    uint16_t did;
+    uint32_t pasid;
+    int ret;
+
+    if (!pc_entry->valid) {
+        return false;
+    }
+    did = VTD_SM_PASID_ENTRY_DID(&pc_entry->pasid_entry);
+
+    if (vtd_as_to_iommu_pasid_locked(vtd_as, &pasid)) {
+        goto remove;
+    }
+
+    switch (pc_info->type) {
+    case VTD_PASID_CACHE_PASIDSI:
+        if (pc_info->pasid != pasid) {
+            return false;
+        }
+        /* fall through */
+    case VTD_PASID_CACHE_DOMSI:
+        if (pc_info->did != did) {
+            return false;
+        }
+        /* fall through */
+    case VTD_PASID_CACHE_GLOBAL_INV:
+        break;
+    default:
+        error_setg(&error_fatal, "invalid pc_info->type for flush");
+    }
+
+    /*
+     * pasid cache invalidation may indicate a present pasid entry to present
+     * pasid entry modification. To cover such case, vIOMMU emulator needs to
+     * fetch latest guest pasid entry and compares with cached pasid entry,
+     * then update pasid cache.
+     */
+    ret = vtd_dev_get_pe_from_pasid(vtd_as, pasid, &pe);
+    if (ret) {
+        /*
+         * No valid pasid entry in guest memory. e.g. pasid entry was modified
+         * to be either all-zero or non-present. Either case means existing
+         * pasid cache should be removed.
+         */
+        goto remove;
+    }
+
+    /*
+     * Update cached pasid entry if it's stale compared to what's in guest
+     * memory.
+     */
+    if (!vtd_pasid_entry_compare(&pe, &pc_entry->pasid_entry)) {
+        pc_entry->pasid_entry = pe;
+    }
+    return false;
+
+remove:
+    pc_entry->valid = false;
+
+    /*
+     * Don't remove address space of PCI_NO_PASID which is created for PCI
+     * sub-system.
+     */
+    if (vtd_as->pasid == PCI_NO_PASID) {
+        return false;
+    }
+    return true;
+}
+
+/*
+ * For a PASID cache invalidation, this function handles below scenarios:
+ * a) a present cached pasid entry needs to be removed
+ * b) a present cached pasid entry needs to be updated
+ */
+static void vtd_pasid_cache_sync(IntelIOMMUState *s, VTDPASIDCacheInfo *pc_info)
+{
+    if (!s->flts || !s->root_scalable || !s->dmar_enabled) {
+        return;
+    }
+
+    vtd_iommu_lock(s);
+    /*
+     * a,b): loop all the existing vtd_as instances for pasid cache removal
+       or update.
+     */
+    g_hash_table_foreach_remove(s->vtd_address_spaces, vtd_flush_pasid_locked,
+                                pc_info);
+    vtd_iommu_unlock(s);
+}
+
+static bool vtd_process_pasid_desc(IntelIOMMUState *s,
+                                   VTDInvDesc *inv_desc)
+{
+    uint16_t did;
+    uint32_t pasid;
+    VTDPASIDCacheInfo pc_info;
+    uint64_t mask[4] = {VTD_INV_DESC_PASIDC_RSVD_VAL0, VTD_INV_DESC_ALL_ONE,
+                        VTD_INV_DESC_ALL_ONE, VTD_INV_DESC_ALL_ONE};
+
+    if (!vtd_inv_desc_reserved_check(s, inv_desc, mask, true,
+                                     __func__, "pasid cache inv")) {
+        return false;
+    }
+
+    did = VTD_INV_DESC_PASIDC_DID(inv_desc);
+    pasid = VTD_INV_DESC_PASIDC_PASID(inv_desc);
+
+    switch (VTD_INV_DESC_PASIDC_G(inv_desc)) {
+    case VTD_INV_DESC_PASIDC_G_DSI:
+        trace_vtd_pasid_cache_dsi(did);
+        pc_info.type = VTD_PASID_CACHE_DOMSI;
+        pc_info.did = did;
+        break;
+
+    case VTD_INV_DESC_PASIDC_G_PASID_SI:
+        /* PASID selective implies a DID selective */
+        trace_vtd_pasid_cache_psi(did, pasid);
+        pc_info.type = VTD_PASID_CACHE_PASIDSI;
+        pc_info.did = did;
+        pc_info.pasid = pasid;
+        break;
+
+    case VTD_INV_DESC_PASIDC_G_GLOBAL:
+        trace_vtd_pasid_cache_gsi();
+        pc_info.type = VTD_PASID_CACHE_GLOBAL_INV;
+        break;
+
+    default:
+        error_report_once("invalid granularity field in PASID-cache invalidate "
+                          "descriptor, hi: 0x%"PRIx64" lo: 0x%" PRIx64,
+                           inv_desc->val[1], inv_desc->val[0]);
+        return false;
+    }
+
+    vtd_pasid_cache_sync(s, &pc_info);
+    return true;
+}
+
 static bool vtd_process_inv_iec_desc(IntelIOMMUState *s,
                                      VTDInvDesc *inv_desc)
 {
@@ -3271,6 +3448,13 @@ static bool vtd_process_inv_desc(IntelIOMMUState *s)
         }
         break;
 
+    case VTD_INV_DESC_PC:
+        trace_vtd_inv_desc("pasid-cache", inv_desc.val[1], inv_desc.val[0]);
+        if (!vtd_process_pasid_desc(s, &inv_desc)) {
+            return false;
+        }
+        break;
+
     case VTD_INV_DESC_PIOTLB:
         trace_vtd_inv_desc("p-iotlb", inv_desc.val[1], inv_desc.val[0]);
         if (!vtd_process_piotlb_desc(s, &inv_desc)) {
@@ -3306,16 +3490,6 @@ static bool vtd_process_inv_desc(IntelIOMMUState *s)
         }
         break;
 
-    /*
-     * TODO: the entity of below two cases will be implemented in future series.
-     * To make guest (which integrates scalable mode support patch set in
-     * iommu driver) work, just return true is enough so far.
-     */
-    case VTD_INV_DESC_PC:
-        if (s->scalable_mode) {
-            break;
-        }
-    /* fallthrough */
     default:
         error_report_once("%s: invalid inv desc: hi=%"PRIx64", lo=%"PRIx64
                           " (unknown type)", __func__, inv_desc.hi,
diff --git a/hw/i386/trace-events b/hw/i386/trace-events
index ac9e1a10aa..ae5bbfcdc0 100644
--- a/hw/i386/trace-events
+++ b/hw/i386/trace-events
@@ -24,6 +24,9 @@ vtd_inv_qi_head(uint16_t head) "read head %d"
 vtd_inv_qi_tail(uint16_t head) "write tail %d"
 vtd_inv_qi_fetch(void) ""
 vtd_context_cache_reset(void) ""
+vtd_pasid_cache_gsi(void) ""
+vtd_pasid_cache_dsi(uint16_t domain) "Domain selective PC invalidation domain 0x%"PRIx16
+vtd_pasid_cache_psi(uint16_t domain, uint32_t pasid) "PASID selective PC invalidation domain 0x%"PRIx16" pasid 0x%"PRIx32
 vtd_re_not_present(uint8_t bus) "Root entry bus %"PRIu8" not present"
 vtd_ce_not_present(uint8_t bus, uint8_t devfn) "Context entry bus %"PRIu8" devfn %"PRIu8" not present"
 vtd_iotlb_page_hit(uint16_t sid, uint64_t addr, uint64_t slpte, uint16_t domain) "IOTLB page hit sid 0x%"PRIx16" iova 0x%"PRIx64" slpte 0x%"PRIx64" domain 0x%"PRIx16
-- 
2.47.1