[Qemu-devel] [PATCH v2] spapr_iommu: Enable multiple TCE requests

[Alexey Kardashevskiy <aik@ozlabs.ru>]

Currently only single TCE entry per request is supported (H_PUT_TCE).
However PAPR+ specification allows multiple entry requests such as
H_PUT_TCE_INDIRECT and H_STUFF_TCE. Having less transitions to the host
kernel via ioctls, support of these calls can accelerate IOMMU operations.

This implements H_STUFF_TCE and H_PUT_TCE_INDIRECT.

This advertises "multi-tce" capability to the guest if the host kernel
supports it (KVM_CAP_SPAPR_MULTITCE) or guest is running in TCG mode.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
Changes:
v2:
* multi-tce enabled explicitely for TCG, it was implicit
* kvmppc_spapr_use_multitce() does not handle TCG anymore

v1:
* removed checks for liobn as the check is performed already in
spapr_tce_find_by_liobn
* added hcall-multi-tce if the host kernel supports the capability
---
 hw/ppc/spapr.c       |  3 ++
 hw/ppc/spapr_iommu.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 target-ppc/kvm.c     |  7 +++++
 target-ppc/kvm_ppc.h |  6 ++++
 trace-events         |  2 ++
 5 files changed, 96 insertions(+)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 3b28211..697fba6 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -498,6 +498,9 @@ static void *spapr_create_fdt_skel(hwaddr initrd_base,
     /* RTAS */
     _FDT((fdt_begin_node(fdt, "rtas")));
 
+    if (!kvm_enabled() || kvmppc_spapr_use_multitce()) {
+        add_str(hypertas, "hcall-multi-tce");
+    }
     _FDT((fdt_property(fdt, "ibm,hypertas-functions", hypertas->str,
                        hypertas->len)));
     g_string_free(hypertas, TRUE);
diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
index 72493d8..ab5037c 100644
--- a/hw/ppc/spapr_iommu.c
+++ b/hw/ppc/spapr_iommu.c
@@ -224,6 +224,82 @@ static target_ulong put_tce_emu(sPAPRTCETable *tcet, target_ulong ioba,
     return H_SUCCESS;
 }
 
+static target_ulong h_put_tce_indirect(PowerPCCPU *cpu,
+                                       sPAPREnvironment *spapr,
+                                       target_ulong opcode, target_ulong *args)
+{
+    int i;
+    target_ulong liobn = args[0];
+    target_ulong ioba = args[1];
+    target_ulong ioba1 = ioba;
+    target_ulong tce_list = args[2];
+    target_ulong npages = args[3];
+    target_ulong ret = H_PARAMETER;
+    sPAPRTCETable *tcet = spapr_tce_find_by_liobn(liobn);
+    CPUState *cs = CPU(cpu);
+
+    if (!tcet) {
+        return H_PARAMETER;
+    }
+
+    if (npages > 512) {
+        return H_PARAMETER;
+    }
+
+    ioba &= ~SPAPR_TCE_PAGE_MASK;
+    tce_list &= ~SPAPR_TCE_PAGE_MASK;
+
+    for (i = 0; i < npages; ++i, ioba += SPAPR_TCE_PAGE_SIZE) {
+        target_ulong tce = ldq_phys(cs->as, tce_list +
+                                    i * sizeof(target_ulong));
+        ret = put_tce_emu(tcet, ioba, tce);
+        if (ret) {
+            break;
+        }
+    }
+
+    /* Trace last successful or the first problematic entry */
+    i = i ? (i - 1) : 0;
+    trace_spapr_iommu_indirect(liobn, ioba1, tce_list, i,
+                               ldq_phys(cs->as,
+                               tce_list + i * sizeof(target_ulong)),
+                               ret);
+
+    return ret;
+}
+
+static target_ulong h_stuff_tce(PowerPCCPU *cpu, sPAPREnvironment *spapr,
+                              target_ulong opcode, target_ulong *args)
+{
+    int i;
+    target_ulong liobn = args[0];
+    target_ulong ioba = args[1];
+    target_ulong tce_value = args[2];
+    target_ulong npages = args[3];
+    target_ulong ret = H_PARAMETER;
+    sPAPRTCETable *tcet = spapr_tce_find_by_liobn(liobn);
+
+    if (!tcet) {
+        return H_PARAMETER;
+    }
+
+    if (npages > tcet->nb_table) {
+        return H_PARAMETER;
+    }
+
+    ioba &= ~SPAPR_TCE_PAGE_MASK;
+
+    for (i = 0; i < npages; ++i, ioba += SPAPR_TCE_PAGE_SIZE) {
+        ret = put_tce_emu(tcet, ioba, tce_value);
+        if (ret) {
+            break;
+        }
+    }
+    trace_spapr_iommu_stuff(liobn, ioba, tce_value, npages, ret);
+
+    return ret;
+}
+
 static target_ulong h_put_tce(PowerPCCPU *cpu, sPAPREnvironment *spapr,
                               target_ulong opcode, target_ulong *args)
 {
@@ -332,6 +408,8 @@ static void spapr_tce_table_class_init(ObjectClass *klass, void *data)
     /* hcall-tce */
     spapr_register_hypercall(H_PUT_TCE, h_put_tce);
     spapr_register_hypercall(H_GET_TCE, h_get_tce);
+    spapr_register_hypercall(H_PUT_TCE_INDIRECT, h_put_tce_indirect);
+    spapr_register_hypercall(H_STUFF_TCE, h_stuff_tce);
 }
 
 static TypeInfo spapr_tce_table_info = {
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index ca31027..bcf2db8 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -62,6 +62,7 @@ static int cap_booke_sregs;
 static int cap_ppc_smt;
 static int cap_ppc_rma;
 static int cap_spapr_tce;
+static int cap_spapr_multitce;
 static int cap_hior;
 static int cap_one_reg;
 static int cap_epr;
@@ -98,6 +99,7 @@ int kvm_arch_init(KVMState *s)
     cap_ppc_smt = kvm_check_extension(s, KVM_CAP_PPC_SMT);
     cap_ppc_rma = kvm_check_extension(s, KVM_CAP_PPC_RMA);
     cap_spapr_tce = kvm_check_extension(s, KVM_CAP_SPAPR_TCE);
+    cap_spapr_multitce = kvm_check_extension(s, KVM_CAP_SPAPR_MULTITCE);
     cap_one_reg = kvm_check_extension(s, KVM_CAP_ONE_REG);
     cap_hior = kvm_check_extension(s, KVM_CAP_PPC_HIOR);
     cap_epr = kvm_check_extension(s, KVM_CAP_PPC_EPR);
@@ -1608,6 +1610,11 @@ uint64_t kvmppc_rma_size(uint64_t current_size, unsigned int hash_shift)
 }
 #endif
 
+bool kvmppc_spapr_use_multitce(void)
+{
+    return cap_spapr_multitce;
+}
+
 void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd)
 {
     struct kvm_create_spapr_tce args = {
diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
index ff077ec..b90d31b 100644
--- a/target-ppc/kvm_ppc.h
+++ b/target-ppc/kvm_ppc.h
@@ -31,6 +31,7 @@ int kvmppc_set_tcr(PowerPCCPU *cpu);
 int kvmppc_booke_watchdog_enable(PowerPCCPU *cpu);
 #ifndef CONFIG_USER_ONLY
 off_t kvmppc_alloc_rma(const char *name, MemoryRegion *sysmem);
+bool kvmppc_spapr_use_multitce(void);
 void *kvmppc_create_spapr_tce(uint32_t liobn, uint32_t window_size, int *pfd);
 int kvmppc_remove_spapr_tce(void *table, int pfd, uint32_t window_size);
 int kvmppc_reset_htab(int shift_hint);
@@ -130,6 +131,11 @@ static inline off_t kvmppc_alloc_rma(const char *name, MemoryRegion *sysmem)
     return 0;
 }
 
+static inline bool kvmppc_spapr_use_multitce(void)
+{
+    return false;
+}
+
 static inline void *kvmppc_create_spapr_tce(uint32_t liobn,
                                             uint32_t window_size, int *fd)
 {
diff --git a/trace-events b/trace-events
index 5997846..89719c7 100644
--- a/trace-events
+++ b/trace-events
@@ -1186,6 +1186,8 @@ xics_ics_eoi(int nr) "ics_eoi: irq %#x"
 # hw/ppc/spapr_iommu.c
 spapr_iommu_put(uint64_t liobn, uint64_t ioba, uint64_t tce, uint64_t ret) "liobn=%"PRIx64" ioba=0x%"PRIx64" tce=0x%"PRIx64" ret=%"PRId64
 spapr_iommu_get(uint64_t liobn, uint64_t ioba, uint64_t ret, uint64_t tce) "liobn=%"PRIx64" ioba=0x%"PRIx64" ret=%"PRId64" tce=0x%"PRIx64
+spapr_iommu_indirect(uint64_t liobn, uint64_t ioba, uint64_t tce, uint64_t iobaN, uint64_t tceN, uint64_t ret) "liobn=%"PRIx64" ioba=0x%"PRIx64" tcelist=0x%"PRIx64" iobaN=0x%"PRIx64" tceN=0x%"PRIx64" ret=%"PRId64
+spapr_iommu_stuff(uint64_t liobn, uint64_t ioba, uint64_t tce_value, uint64_t npages, uint64_t ret) "liobn=%"PRIx64" ioba=0x%"PRIx64" tcevalue=0x%"PRIx64" npages=%"PRId64" ret=%"PRId64
 spapr_iommu_xlate(uint64_t liobn, uint64_t ioba, uint64_t tce, unsigned perm, unsigned pgsize) "liobn=%"PRIx64" 0x%"PRIx64" -> 0x%"PRIx64" perm=%u mask=%x"
 spapr_iommu_new_table(uint64_t liobn, void *tcet, void *table, int fd) "liobn=%"PRIx64" tcet=%p table=%p fd=%d"
 
-- 
1.9.rc0