[Qemu-devel] [PATCH v7 13/19] spapr: add an extra OV5 field to the sPAPR IRQ backend

["Cédric Le Goater" <clg@kaod.org>]

This field defines the interrupt modes supported by the hypervisor in
the "ibm,arch-vec-5-platform-support" property. The CAS negotiation
process will select which mode to use.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 include/hw/ppc/spapr.h     |  6 ++++++
 include/hw/ppc/spapr_irq.h |  1 +
 hw/ppc/spapr.c             | 23 ++++++++++++++++++-----
 hw/ppc/spapr_irq.c         |  3 +++
 4 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index 6bf028a02fe2..daced428a42c 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -824,5 +824,11 @@ int spapr_caps_post_migration(sPAPRMachineState *spapr);
 
 void spapr_check_pagesize(sPAPRMachineState *spapr, hwaddr pagesize,
                           Error **errp);
+/*
+ * XIVE definitions
+ */
+#define SPAPR_OV5_XIVE_LEGACY   0x0
+#define SPAPR_OV5_XIVE_EXPLOIT  0x40
+#define SPAPR_OV5_XIVE_BOTH     0x80
 
 #endif /* HW_SPAPR_H */
diff --git a/include/hw/ppc/spapr_irq.h b/include/hw/ppc/spapr_irq.h
index 63061a009b4c..b34d5a00381b 100644
--- a/include/hw/ppc/spapr_irq.h
+++ b/include/hw/ppc/spapr_irq.h
@@ -33,6 +33,7 @@ void spapr_irq_msi_reset(sPAPRMachineState *spapr);
 typedef struct sPAPRIrq {
     uint32_t    nr_irqs;
     uint32_t    nr_msis;
+    uint8_t     ov5;
 
     void (*init)(sPAPRMachineState *spapr, Error **errp);
     int (*claim)(sPAPRMachineState *spapr, int irq, bool lsi, Error **errp);
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 98d69f09e080..5ef87a00f68b 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1095,12 +1095,14 @@ static void spapr_dt_rtas(sPAPRMachineState *spapr, void *fdt)
     spapr_dt_rtas_tokens(fdt, rtas);
 }
 
-/* Prepare ibm,arch-vec-5-platform-support, which indicates the MMU features
- * that the guest may request and thus the valid values for bytes 24..26 of
- * option vector 5: */
-static void spapr_dt_ov5_platform_support(void *fdt, int chosen)
+/* Prepare ibm,arch-vec-5-platform-support, which indicates the MMU
+ * and the XIVE features that the guest may request and thus the valid
+ * values for bytes 23..26 of option vector 5: */
+static void spapr_dt_ov5_platform_support(sPAPRMachineState *spapr, void *fdt,
+                                          int chosen)
 {
     PowerPCCPU *first_ppc_cpu = POWERPC_CPU(first_cpu);
+    sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
 
     char val[2 * 4] = {
         23, 0x00, /* Xive mode, filled in below. */
@@ -1121,7 +1123,13 @@ static void spapr_dt_ov5_platform_support(void *fdt, int chosen)
         } else {
             val[3] = 0x00; /* Hash */
         }
+        /* If the KVM XIVE device is not available, the machine can
+         * still operate with kernel_irqchip=off
+         */
+        val[1] = smc->irq->ov5;
     } else {
+        val[1] = smc->irq->ov5;
+
         /* V3 MMU supports both hash and radix in tcg (with dynamic switching) */
         val[3] = 0xC0;
     }
@@ -1189,7 +1197,7 @@ static void spapr_dt_chosen(sPAPRMachineState *spapr, void *fdt)
         _FDT(fdt_setprop_string(fdt, chosen, "stdout-path", stdout_path));
     }
 
-    spapr_dt_ov5_platform_support(fdt, chosen);
+    spapr_dt_ov5_platform_support(spapr, fdt, chosen);
 
     g_free(stdout_path);
     g_free(bootlist);
@@ -2622,6 +2630,11 @@ static void spapr_machine_init(MachineState *machine)
     /* advertise support for ibm,dyamic-memory-v2 */
     spapr_ovec_set(spapr->ov5, OV5_DRMEM_V2);
 
+    /* advertise XIVE */
+    if (smc->irq->ov5 == SPAPR_OV5_XIVE_EXPLOIT) {
+        spapr_ovec_set(spapr->ov5, OV5_XIVE_EXPLOIT);
+    }
+
     /* init CPUs */
     spapr_init_cpus(spapr);
 
diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
index 04f5c9665550..7a0d4f529763 100644
--- a/hw/ppc/spapr_irq.c
+++ b/hw/ppc/spapr_irq.c
@@ -220,6 +220,7 @@ static void spapr_irq_reset_xics(sPAPRMachineState *spapr, Error **errp)
 sPAPRIrq spapr_irq_xics = {
     .nr_irqs     = SPAPR_IRQ_XICS_NR_IRQS,
     .nr_msis     = SPAPR_IRQ_XICS_NR_MSIS,
+    .ov5         = SPAPR_OV5_XIVE_LEGACY,
 
     .init        = spapr_irq_init_xics,
     .claim       = spapr_irq_claim_xics,
@@ -358,6 +359,7 @@ static void spapr_irq_reset_xive(sPAPRMachineState *spapr, Error **errp)
 sPAPRIrq spapr_irq_xive = {
     .nr_irqs     = SPAPR_IRQ_XIVE_NR_IRQS,
     .nr_msis     = SPAPR_IRQ_XIVE_NR_MSIS,
+    .ov5         = SPAPR_OV5_XIVE_EXPLOIT,
 
     .init        = spapr_irq_init_xive,
     .claim       = spapr_irq_claim_xive,
@@ -482,6 +484,7 @@ int spapr_irq_find(sPAPRMachineState *spapr, int num, bool align, Error **errp)
 sPAPRIrq spapr_irq_xics_legacy = {
     .nr_irqs     = SPAPR_IRQ_XICS_LEGACY_NR_IRQS,
     .nr_msis     = SPAPR_IRQ_XICS_LEGACY_NR_IRQS,
+    .ov5         = SPAPR_OV5_XIVE_LEGACY,
 
     .init        = spapr_irq_init_xics,
     .claim       = spapr_irq_claim_xics,
-- 
2.17.2