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[PULL 21/47] hw/riscv/riscv-iommu: add Address Translation Cache (IOATC)
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From: |
Alistair Francis |
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Subject: |
[PULL 21/47] hw/riscv/riscv-iommu: add Address Translation Cache (IOATC) |
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Date: |
Thu, 12 Sep 2024 15:29:26 +1000 |
From: Tomasz Jeznach <tjeznach@rivosinc.com>
The RISC-V IOMMU spec predicts that the IOMMU can use translation caches
to hold entries from the DDT. This includes implementation for all cache
commands that are marked as 'not implemented'.
There are some artifacts included in the cache that predicts s-stage and
g-stage elements, although we don't support it yet. We'll introduce them
next.
Signed-off-by: Tomasz Jeznach <tjeznach@rivosinc.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20240903201633.93182-9-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
hw/riscv/riscv-iommu.h | 3 +
hw/riscv/riscv-iommu.c | 205 ++++++++++++++++++++++++++++++++++++++++-
2 files changed, 204 insertions(+), 4 deletions(-)
diff --git a/hw/riscv/riscv-iommu.h b/hw/riscv/riscv-iommu.h
index 95b4ce8d50..ddf5d50cf9 100644
--- a/hw/riscv/riscv-iommu.h
+++ b/hw/riscv/riscv-iommu.h
@@ -72,6 +72,9 @@ struct RISCVIOMMUState {
GHashTable *ctx_cache; /* Device translation Context Cache */
QemuMutex ctx_lock; /* Device translation Cache update lock */
+ GHashTable *iot_cache; /* IO Translated Address Cache */
+ QemuMutex iot_lock; /* IO TLB Cache update lock */
+ unsigned iot_limit; /* IO Translation Cache size limit */
/* MMIO Hardware Interface */
MemoryRegion regs_mr;
diff --git a/hw/riscv/riscv-iommu.c b/hw/riscv/riscv-iommu.c
index 061a5efe19..fe81072b1c 100644
--- a/hw/riscv/riscv-iommu.c
+++ b/hw/riscv/riscv-iommu.c
@@ -65,6 +65,16 @@ struct RISCVIOMMUContext {
uint64_t msiptp; /* MSI redirection page table pointer */
};
+/* Address translation cache entry */
+struct RISCVIOMMUEntry {
+ uint64_t iova:44; /* IOVA Page Number */
+ uint64_t pscid:20; /* Process Soft-Context identifier */
+ uint64_t phys:44; /* Physical Page Number */
+ uint64_t gscid:16; /* Guest Soft-Context identifier */
+ uint64_t perm:2; /* IOMMU_RW flags */
+ uint64_t __rfu:2;
+};
+
/* IOMMU index for transactions without process_id specified. */
#define RISCV_IOMMU_NOPROCID 0
@@ -1156,13 +1166,130 @@ static AddressSpace *riscv_iommu_space(RISCVIOMMUState
*s, uint32_t devid)
return &as->iova_as;
}
+/* Translation Object cache support */
+static gboolean __iot_equal(gconstpointer v1, gconstpointer v2)
+{
+ RISCVIOMMUEntry *t1 = (RISCVIOMMUEntry *) v1;
+ RISCVIOMMUEntry *t2 = (RISCVIOMMUEntry *) v2;
+ return t1->gscid == t2->gscid && t1->pscid == t2->pscid &&
+ t1->iova == t2->iova;
+}
+
+static guint __iot_hash(gconstpointer v)
+{
+ RISCVIOMMUEntry *t = (RISCVIOMMUEntry *) v;
+ return (guint)t->iova;
+}
+
+/* GV: 1 PSCV: 1 AV: 1 */
+static void __iot_inval_pscid_iova(gpointer key, gpointer value, gpointer data)
+{
+ RISCVIOMMUEntry *iot = (RISCVIOMMUEntry *) value;
+ RISCVIOMMUEntry *arg = (RISCVIOMMUEntry *) data;
+ if (iot->gscid == arg->gscid &&
+ iot->pscid == arg->pscid &&
+ iot->iova == arg->iova) {
+ iot->perm = IOMMU_NONE;
+ }
+}
+
+/* GV: 1 PSCV: 1 AV: 0 */
+static void __iot_inval_pscid(gpointer key, gpointer value, gpointer data)
+{
+ RISCVIOMMUEntry *iot = (RISCVIOMMUEntry *) value;
+ RISCVIOMMUEntry *arg = (RISCVIOMMUEntry *) data;
+ if (iot->gscid == arg->gscid &&
+ iot->pscid == arg->pscid) {
+ iot->perm = IOMMU_NONE;
+ }
+}
+
+/* GV: 1 GVMA: 1 */
+static void __iot_inval_gscid_gpa(gpointer key, gpointer value, gpointer data)
+{
+ RISCVIOMMUEntry *iot = (RISCVIOMMUEntry *) value;
+ RISCVIOMMUEntry *arg = (RISCVIOMMUEntry *) data;
+ if (iot->gscid == arg->gscid) {
+ /* simplified cache, no GPA matching */
+ iot->perm = IOMMU_NONE;
+ }
+}
+
+/* GV: 1 GVMA: 0 */
+static void __iot_inval_gscid(gpointer key, gpointer value, gpointer data)
+{
+ RISCVIOMMUEntry *iot = (RISCVIOMMUEntry *) value;
+ RISCVIOMMUEntry *arg = (RISCVIOMMUEntry *) data;
+ if (iot->gscid == arg->gscid) {
+ iot->perm = IOMMU_NONE;
+ }
+}
+
+/* GV: 0 */
+static void __iot_inval_all(gpointer key, gpointer value, gpointer data)
+{
+ RISCVIOMMUEntry *iot = (RISCVIOMMUEntry *) value;
+ iot->perm = IOMMU_NONE;
+}
+
+/* caller should keep ref-count for iot_cache object */
+static RISCVIOMMUEntry *riscv_iommu_iot_lookup(RISCVIOMMUContext *ctx,
+ GHashTable *iot_cache, hwaddr iova)
+{
+ RISCVIOMMUEntry key = {
+ .gscid = get_field(ctx->gatp, RISCV_IOMMU_DC_IOHGATP_GSCID),
+ .pscid = get_field(ctx->ta, RISCV_IOMMU_DC_TA_PSCID),
+ .iova = PPN_DOWN(iova),
+ };
+ return g_hash_table_lookup(iot_cache, &key);
+}
+
+/* caller should keep ref-count for iot_cache object */
+static void riscv_iommu_iot_update(RISCVIOMMUState *s,
+ GHashTable *iot_cache, RISCVIOMMUEntry *iot)
+{
+ if (!s->iot_limit) {
+ return;
+ }
+
+ qemu_mutex_lock(&s->iot_lock);
+ if (g_hash_table_size(s->iot_cache) >= s->iot_limit) {
+ iot_cache = g_hash_table_new_full(__iot_hash, __iot_equal,
+ g_free, NULL);
+ g_hash_table_unref(qatomic_xchg(&s->iot_cache, iot_cache));
+ }
+ g_hash_table_add(iot_cache, iot);
+ qemu_mutex_unlock(&s->iot_lock);
+}
+
+static void riscv_iommu_iot_inval(RISCVIOMMUState *s, GHFunc func,
+ uint32_t gscid, uint32_t pscid, hwaddr iova)
+{
+ GHashTable *iot_cache;
+ RISCVIOMMUEntry key = {
+ .gscid = gscid,
+ .pscid = pscid,
+ .iova = PPN_DOWN(iova),
+ };
+
+ iot_cache = g_hash_table_ref(s->iot_cache);
+ qemu_mutex_lock(&s->iot_lock);
+ g_hash_table_foreach(iot_cache, func, &key);
+ qemu_mutex_unlock(&s->iot_lock);
+ g_hash_table_unref(iot_cache);
+}
+
static int riscv_iommu_translate(RISCVIOMMUState *s, RISCVIOMMUContext *ctx,
- IOMMUTLBEntry *iotlb)
+ IOMMUTLBEntry *iotlb, bool enable_cache)
{
+ RISCVIOMMUEntry *iot;
+ IOMMUAccessFlags perm;
bool enable_pid;
bool enable_pri;
+ GHashTable *iot_cache;
int fault;
+ iot_cache = g_hash_table_ref(s->iot_cache);
/*
* TC[32] is reserved for custom extensions, used here to temporarily
* enable automatic page-request generation for ATS queries.
@@ -1170,9 +1297,45 @@ static int riscv_iommu_translate(RISCVIOMMUState *s,
RISCVIOMMUContext *ctx,
enable_pri = (iotlb->perm == IOMMU_NONE) && (ctx->tc & BIT_ULL(32));
enable_pid = (ctx->tc & RISCV_IOMMU_DC_TC_PDTV);
+ qemu_mutex_lock(&s->iot_lock);
+ iot = riscv_iommu_iot_lookup(ctx, iot_cache, iotlb->iova);
+ qemu_mutex_unlock(&s->iot_lock);
+ perm = iot ? iot->perm : IOMMU_NONE;
+ if (perm != IOMMU_NONE) {
+ iotlb->translated_addr = PPN_PHYS(iot->phys);
+ iotlb->addr_mask = ~TARGET_PAGE_MASK;
+ iotlb->perm = perm;
+ fault = 0;
+ goto done;
+ }
+
/* Translate using device directory / page table information. */
fault = riscv_iommu_spa_fetch(s, ctx, iotlb);
+ if (!fault && iotlb->target_as == &s->trap_as) {
+ /* Do not cache trapped MSI translations */
+ goto done;
+ }
+
+ /*
+ * We made an implementation choice to not cache identity-mapped
+ * translations, as allowed by the specification, to avoid
+ * translation cache evictions for other devices sharing the
+ * IOMMU hardware model.
+ */
+ if (!fault && iotlb->translated_addr != iotlb->iova && enable_cache) {
+ iot = g_new0(RISCVIOMMUEntry, 1);
+ iot->iova = PPN_DOWN(iotlb->iova);
+ iot->phys = PPN_DOWN(iotlb->translated_addr);
+ iot->gscid = get_field(ctx->gatp, RISCV_IOMMU_DC_IOHGATP_GSCID);
+ iot->pscid = get_field(ctx->ta, RISCV_IOMMU_DC_TA_PSCID);
+ iot->perm = iotlb->perm;
+ riscv_iommu_iot_update(s, iot_cache, iot);
+ }
+
+done:
+ g_hash_table_unref(iot_cache);
+
if (enable_pri && fault) {
struct riscv_iommu_pq_record pr = {0};
if (enable_pid) {
@@ -1312,13 +1475,40 @@ static void riscv_iommu_process_cq_tail(RISCVIOMMUState
*s)
if (cmd.dword0 & RISCV_IOMMU_CMD_IOTINVAL_PSCV) {
/* illegal command arguments IOTINVAL.GVMA & PSCV == 1 */
goto cmd_ill;
+ } else if (!(cmd.dword0 & RISCV_IOMMU_CMD_IOTINVAL_GV)) {
+ /* invalidate all cache mappings */
+ func = __iot_inval_all;
+ } else if (!(cmd.dword0 & RISCV_IOMMU_CMD_IOTINVAL_AV)) {
+ /* invalidate cache matching GSCID */
+ func = __iot_inval_gscid;
+ } else {
+ /* invalidate cache matching GSCID and ADDR (GPA) */
+ func = __iot_inval_gscid_gpa;
}
- /* translation cache not implemented yet */
+ riscv_iommu_iot_inval(s, func,
+ get_field(cmd.dword0, RISCV_IOMMU_CMD_IOTINVAL_GSCID), 0,
+ cmd.dword1 & TARGET_PAGE_MASK);
break;
case RISCV_IOMMU_CMD(RISCV_IOMMU_CMD_IOTINVAL_FUNC_VMA,
RISCV_IOMMU_CMD_IOTINVAL_OPCODE):
- /* translation cache not implemented yet */
+ if (!(cmd.dword0 & RISCV_IOMMU_CMD_IOTINVAL_GV)) {
+ /* invalidate all cache mappings, simplified model */
+ func = __iot_inval_all;
+ } else if (!(cmd.dword0 & RISCV_IOMMU_CMD_IOTINVAL_PSCV)) {
+ /* invalidate cache matching GSCID, simplified model */
+ func = __iot_inval_gscid;
+ } else if (!(cmd.dword0 & RISCV_IOMMU_CMD_IOTINVAL_AV)) {
+ /* invalidate cache matching GSCID and PSCID */
+ func = __iot_inval_pscid;
+ } else {
+ /* invalidate cache matching GSCID and PSCID and ADDR (IOVA) */
+ func = __iot_inval_pscid_iova;
+ }
+ riscv_iommu_iot_inval(s, func,
+ get_field(cmd.dword0, RISCV_IOMMU_CMD_IOTINVAL_GSCID),
+ get_field(cmd.dword0, RISCV_IOMMU_CMD_IOTINVAL_PSCID),
+ cmd.dword1 & TARGET_PAGE_MASK);
break;
case RISCV_IOMMU_CMD(RISCV_IOMMU_CMD_IODIR_FUNC_INVAL_DDT,
@@ -1857,6 +2047,10 @@ static void riscv_iommu_realize(DeviceState *dev, Error
**errp)
g_free, NULL);
qemu_mutex_init(&s->ctx_lock);
+ s->iot_cache = g_hash_table_new_full(__iot_hash, __iot_equal,
+ g_free, NULL);
+ qemu_mutex_init(&s->iot_lock);
+
s->iommus.le_next = NULL;
s->iommus.le_prev = NULL;
QLIST_INIT(&s->spaces);
@@ -1869,6 +2063,7 @@ static void riscv_iommu_unrealize(DeviceState *dev)
RISCVIOMMUState *s = RISCV_IOMMU(dev);
qemu_mutex_destroy(&s->core_lock);
+ g_hash_table_unref(s->iot_cache);
g_hash_table_unref(s->ctx_cache);
}
@@ -1876,6 +2071,8 @@ static Property riscv_iommu_properties[] = {
DEFINE_PROP_UINT32("version", RISCVIOMMUState, version,
RISCV_IOMMU_SPEC_DOT_VER),
DEFINE_PROP_UINT32("bus", RISCVIOMMUState, bus, 0x0),
+ DEFINE_PROP_UINT32("ioatc-limit", RISCVIOMMUState, iot_limit,
+ LIMIT_CACHE_IOT),
DEFINE_PROP_BOOL("intremap", RISCVIOMMUState, enable_msi, TRUE),
DEFINE_PROP_BOOL("off", RISCVIOMMUState, enable_off, TRUE),
DEFINE_PROP_BOOL("s-stage", RISCVIOMMUState, enable_s_stage, TRUE),
@@ -1930,7 +2127,7 @@ static IOMMUTLBEntry riscv_iommu_memory_region_translate(
/* Translation disabled or invalid. */
iotlb.addr_mask = 0;
iotlb.perm = IOMMU_NONE;
- } else if (riscv_iommu_translate(as->iommu, ctx, &iotlb)) {
+ } else if (riscv_iommu_translate(as->iommu, ctx, &iotlb, true)) {
/* Translation disabled or fault reported. */
iotlb.addr_mask = 0;
iotlb.perm = IOMMU_NONE;
--
2.46.0
- [PULL 11/47] util/util/cpuinfo-riscv.c: fix riscv64 build on musl libc, (continued)
- [PULL 11/47] util/util/cpuinfo-riscv.c: fix riscv64 build on musl libc, Alistair Francis, 2024/09/12
- [PULL 12/47] target/riscv: Preliminary textra trigger CSR writting support, Alistair Francis, 2024/09/12
- [PULL 13/47] target/riscv: Add textra matching condition for the triggers, Alistair Francis, 2024/09/12
- [PULL 14/47] exec/memtxattr: add process identifier to the transaction attributes, Alistair Francis, 2024/09/12
- [PULL 15/47] hw/riscv: add riscv-iommu-bits.h, Alistair Francis, 2024/09/12
- [PULL 17/47] pci-ids.rst: add Red Hat pci-id for RISC-V IOMMU device, Alistair Francis, 2024/09/12
- [PULL 16/47] hw/riscv: add RISC-V IOMMU base emulation, Alistair Francis, 2024/09/12
- [PULL 18/47] hw/riscv: add riscv-iommu-pci reference device, Alistair Francis, 2024/09/12
- [PULL 19/47] hw/riscv/virt.c: support for RISC-V IOMMU PCIDevice hotplug, Alistair Francis, 2024/09/12
- [PULL 20/47] test/qtest: add riscv-iommu-pci tests, Alistair Francis, 2024/09/12
- [PULL 21/47] hw/riscv/riscv-iommu: add Address Translation Cache (IOATC),
Alistair Francis <=
- [PULL 22/47] hw/riscv/riscv-iommu: add ATS support, Alistair Francis, 2024/09/12
- [PULL 26/47] bsd-user: Implement RISC-V CPU initialization and main loop, Alistair Francis, 2024/09/12
- [PULL 27/47] bsd-user: Add RISC-V CPU execution loop and syscall handling, Alistair Francis, 2024/09/12
- [PULL 23/47] hw/riscv/riscv-iommu: add DBG support, Alistair Francis, 2024/09/12
- [PULL 30/47] bsd-user: Add RISC-V ELF definitions and hardware capability detection, Alistair Francis, 2024/09/12
- [PULL 35/47] bsd-user: Define RISC-V VM parameters and helper functions, Alistair Francis, 2024/09/12
- [PULL 25/47] docs/specs: add riscv-iommu, Alistair Francis, 2024/09/12
- [PULL 28/47] bsd-user: Implement RISC-V CPU register cloning and reset functions, Alistair Francis, 2024/09/12
- [PULL 29/47] bsd-user: Implement RISC-V TLS register setup, Alistair Francis, 2024/09/12