[Qemu-devel] [PATCH v2 13/19] spapr: add device tree support for the XIVE interrupt mode

[Cédric Le Goater]

The XIVE interface for the guest is described in the device tree under
the "interrupt-controller" node. A couple of new properties are
specific to XIVE :

 - "reg"

   contains the base address and size of the thread interrupt
   managnement areas (TIMA), also called rings, for the User level and
   for the Guest OS level. Only the Guest OS level is taken into
   account today.

 - "ibm,xive-eq-sizes"

   the size of the event queues. One cell per size supported, contains
   log2 of size, in ascending order.

 - "ibm,xive-lisn-ranges"

   the IRQ interrupt number ranges assigned to the guest for the IPIs.

and also under the root node :

 - "ibm,plat-res-int-priorities"

   contains a list of priorities that the hypervisor has reserved for
   its own use. OPAL uses the priority 7 queue to automatically
   escalate interrupts for all other queues (DD2.X POWER9). So only
   priorities [0..6] are allowed for the guest.

When the XIVE exploitation interrupt mode is activated after the CAS
negotiation, the machine will perform a reboot to rebuild the device
tree.

Signed-off-by: Cédric Le Goater <address@hidden>
---

 Changes since v1:

 - added a unit id to the nodename
 - added properties for the LSIs
 - simplified the array for the "ibm,plat-res-int-priorities"  property
 - renamed to spapr_dt_xive()

 hw/intc/spapr_xive_hcall.c  | 64 +++++++++++++++++++++++++++++++++++++++++++++
 hw/ppc/spapr.c              |  7 ++++-
 hw/ppc/spapr_hcall.c        |  6 +++++
 include/hw/ppc/spapr_xive.h |  2 ++
 4 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/hw/intc/spapr_xive_hcall.c b/hw/intc/spapr_xive_hcall.c
index 86dec6c02401..8aa2fb8a32d1 100644
--- a/hw/intc/spapr_xive_hcall.c
+++ b/hw/intc/spapr_xive_hcall.c
@@ -857,3 +857,67 @@ void spapr_xive_hcall_init(sPAPRMachineState *spapr)
     spapr_register_hypercall(H_INT_SYNC, h_int_sync);
     spapr_register_hypercall(H_INT_RESET, h_int_reset);
 }
+
+void spapr_dt_xive(sPAPRMachineState *spapr, int nr_servers,
+                         void *fdt, uint32_t phandle)
+{
+    sPAPRXive *xive = spapr->xive;
+    int node;
+    uint64_t timas[2 * 2];
+    /* Interrupt number ranges for the IPIs */
+    uint32_t lisn_ranges[] = {
+        cpu_to_be32(0),
+        cpu_to_be32(nr_servers),
+    };
+    uint32_t eq_sizes[] = {
+        cpu_to_be32(12), /* 4K */
+        cpu_to_be32(16), /* 64K */
+        cpu_to_be32(21), /* 2M */
+        cpu_to_be32(24), /* 16M */
+    };
+    /* The following array is in sync with the 'priority_is_valid'
+     * routine above. Linux is expected to choose priority 6.
+     */
+    uint32_t plat_res_int_priorities[] = {
+        cpu_to_be32(7),    /* start */
+        cpu_to_be32(0xf8), /* count */
+    };
+    int i;
+    gchar *nodename;
+
+    /* Thread Interrupt Management Area : User and OS views */
+    for (i = 0; i < 2; i++) {
+        timas[i * 2] = cpu_to_be64(xive->tm_base + i * (1ull << TM_SHIFT));
+        timas[i * 2 + 1] = cpu_to_be64(1ull << TM_SHIFT);
+    }
+
+    nodename = g_strdup_printf("address@hidden" PRIx64, xive->tm_base);
+    _FDT(node = fdt_add_subnode(fdt, 0, nodename));
+    g_free(nodename);
+
+    _FDT(fdt_setprop_string(fdt, node, "device_type", "power-ivpe"));
+    _FDT(fdt_setprop(fdt, node, "reg", timas, sizeof(timas)));
+
+    _FDT(fdt_setprop_string(fdt, node, "compatible", "ibm,power-ivpe"));
+    _FDT(fdt_setprop(fdt, node, "ibm,xive-eq-sizes", eq_sizes,
+                     sizeof(eq_sizes)));
+    _FDT(fdt_setprop(fdt, node, "ibm,xive-lisn-ranges", lisn_ranges,
+                     sizeof(lisn_ranges)));
+
+    /* For Linux to link the LSIs to the main interrupt controller.
+     * These properties are not in XIVE exploitation mode sPAPR
+     * specs
+     */
+    _FDT(fdt_setprop(fdt, node, "interrupt-controller", NULL, 0));
+    _FDT(fdt_setprop_cell(fdt, node, "#interrupt-cells", 2));
+
+    /* For SLOF */
+    _FDT(fdt_setprop_cell(fdt, node, "linux,phandle", phandle));
+    _FDT(fdt_setprop_cell(fdt, node, "phandle", phandle));
+
+    /* The "ibm,plat-res-int-priorities" property defines the priority
+     * ranges reserved by the hypervisor
+     */
+    _FDT(fdt_setprop(fdt, 0, "ibm,plat-res-int-priorities",
+                     plat_res_int_priorities, 
sizeof(plat_res_int_priorities)));
+}
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 1a71bf613b9e..2e15ee8a9333 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1155,7 +1155,12 @@ static void *spapr_build_fdt(sPAPRMachineState *spapr,
     _FDT(fdt_setprop_cell(fdt, 0, "#size-cells", 2));
 
     /* /interrupt controller */
-    spapr_dt_xics(xics_max_server_number(), fdt, PHANDLE_XICP);
+    if (!spapr_ovec_test(spapr->ov5_cas, OV5_XIVE_EXPLOIT)) {
+        spapr_dt_xics(xics_max_server_number(), fdt, PHANDLE_XICP);
+    } else {
+        /* Populate device tree for XIVE */
+        spapr_dt_xive(spapr, xics_max_server_number(), fdt, PHANDLE_XICP);
+    }
 
     ret = spapr_populate_memory(spapr, fdt);
     if (ret < 0) {
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index be22a6b2895f..e2a1665beee9 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -1646,6 +1646,12 @@ static target_ulong 
h_client_architecture_support(PowerPCCPU *cpu,
             (spapr_h_cas_compose_response(spapr, args[1], args[2],
                                           ov5_updates) != 0);
     }
+
+    /* We need to rebuild the device tree for XIVE, generate a reset */
+    if (!spapr->cas_reboot) {
+        spapr->cas_reboot = spapr_ovec_test(ov5_updates, OV5_XIVE_EXPLOIT);
+    }
+
     spapr_ovec_cleanup(ov5_updates);
 
     if (spapr->cas_reboot) {
diff --git a/include/hw/ppc/spapr_xive.h b/include/hw/ppc/spapr_xive.h
index 0385df69b028..8c3b9cb194a9 100644
--- a/include/hw/ppc/spapr_xive.h
+++ b/include/hw/ppc/spapr_xive.h
@@ -63,5 +63,7 @@ void spapr_xive_nvt_pic_print_info(sPAPRXiveNVT *nvt, Monitor 
*mon);
 typedef struct sPAPRMachineState sPAPRMachineState;
 
 void spapr_xive_hcall_init(sPAPRMachineState *spapr);
+void spapr_dt_xive(sPAPRMachineState *spapr, int nr_servers, void *fdt,
+                         uint32_t phandle);
 
 #endif /* PPC_SPAPR_XIVE_H */
-- 
2.13.6