[PATCH v2 2/2] spapr/xive: Set the OS CAM line at reset

["Cédric Le Goater" <clg@kaod.org>]

When a Virtual Processor is scheduled to run on a HW thread, the
hypervisor pushes its identifier in the OS CAM line. When running with
kernel_irqchip=off, QEMU needs to emulate the same behavior.

Set the OS CAM line when the interrupt presenter of the sPAPR core is
reseted. This will also cover the case of hot-plugged CPUs.

This change also has the benefit to remove the use of CPU_FOREACH()
which can be unsafe.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 include/hw/ppc/spapr_xive.h |  1 -
 hw/intc/spapr_xive.c        | 18 +++---------------
 2 files changed, 3 insertions(+), 16 deletions(-)

diff --git a/include/hw/ppc/spapr_xive.h b/include/hw/ppc/spapr_xive.h
index d84bd5c229f0..742b7e834f2a 100644
--- a/include/hw/ppc/spapr_xive.h
+++ b/include/hw/ppc/spapr_xive.h
@@ -57,7 +57,6 @@ typedef struct SpaprXive {
 void spapr_xive_pic_print_info(SpaprXive *xive, Monitor *mon);
 
 void spapr_xive_hcall_init(SpaprMachineState *spapr);
-void spapr_xive_set_tctx_os_cam(XiveTCTX *tctx);
 void spapr_xive_mmio_set_enabled(SpaprXive *xive, bool enable);
 void spapr_xive_map_mmio(SpaprXive *xive);
 
diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
index 258b1c5fb5ff..4f584e582b6c 100644
--- a/hw/intc/spapr_xive.c
+++ b/hw/intc/spapr_xive.c
@@ -210,7 +210,7 @@ void spapr_xive_mmio_set_enabled(SpaprXive *xive, bool enable)
  * hypervisor pushes its identifier in the OS CAM line. Emulate the
  * same behavior under QEMU.
  */
-void spapr_xive_set_tctx_os_cam(XiveTCTX *tctx)
+static void spapr_xive_set_tctx_os_cam(XiveTCTX *tctx)
 {
     uint8_t  nvt_blk;
     uint32_t nvt_idx;
@@ -544,12 +544,6 @@ static int spapr_xive_cpu_intc_create(SpaprInterruptController *intc,
     }
 
     spapr_cpu->tctx = XIVE_TCTX(obj);
-
-    /*
-     * (TCG) Early setting the OS CAM line for hotplugged CPUs as they
-     * don't beneficiate from the reset of the XIVE IRQ backend
-     */
-    spapr_xive_set_tctx_os_cam(spapr_cpu->tctx);
     return 0;
 }
 
@@ -557,6 +551,8 @@ static void spapr_xive_cpu_intc_reset(SpaprInterruptController *intc,
                                      PowerPCCPU *cpu)
 {
     xive_tctx_reset(spapr_cpu_state(cpu)->tctx);
+
+    spapr_xive_set_tctx_os_cam(spapr_cpu_state(cpu)->tctx);
 }
 
 static void spapr_xive_set_irq(SpaprInterruptController *intc, int irq, int val)
@@ -649,14 +645,6 @@ static void spapr_xive_dt(SpaprInterruptController *intc, uint32_t nr_servers,
 static int spapr_xive_activate(SpaprInterruptController *intc, Error **errp)
 {
     SpaprXive *xive = SPAPR_XIVE(intc);
-    CPUState *cs;
-
-    CPU_FOREACH(cs) {
-        PowerPCCPU *cpu = POWERPC_CPU(cs);
-
-        /* (TCG) Set the OS CAM line of the thread interrupt context. */
-        spapr_xive_set_tctx_os_cam(spapr_cpu_state(cpu)->tctx);
-    }
 
     if (kvm_enabled()) {
         int rc = spapr_irq_init_kvm(kvmppc_xive_connect, intc, errp);
-- 
2.21.0