target/ppc: Allow cpu compatiblity checks based on type, not instance

ppc_check_compat() is used in a number of places to check if a cpu object
supports a certain compatiblity mode, subject to various constraints.

It takes a PowerPCCPU *, however it really only depends on the cpu's class.
We have upcoming cases where it would be useful to make compatibility
checks before we fully instantiate the cpu objects.

ppc_type_check_compat() will now make an equivalent check, but based on a
CPU's QOM typename instead of an instantiated CPU object.

We make use of the new interface in several places in spapr, where we're
essentially making a global check, rather than one specific to a particular
cpu.  This avoids some ugly uses of first_cpu to grab a "representative"
instance.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>

1 files changed, 4 insertions, 6 deletions

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 3174468fc5..bc179f6f89 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1616,8 +1616,8 @@ static void spapr_machine_reset(void)
 
     first_ppc_cpu = POWERPC_CPU(first_cpu);
     if (kvm_enabled() && kvmppc_has_cap_mmu_radix() &&
-        ppc_check_compat(first_ppc_cpu, CPU_POWERPC_LOGICAL_3_00, 0,
-                         spapr->max_compat_pvr)) {
+        ppc_type_check_compat(machine->cpu_type, CPU_POWERPC_LOGICAL_3_00, 0,
+                              spapr->max_compat_pvr)) {
         /* If using KVM with radix mode available, VCPUs can be started
          * without a HPT because KVM will start them in radix mode.
          * Set the GR bit in PATB so that we know there is no HPT. */
@@ -2520,7 +2520,6 @@ static void spapr_machine_init(MachineState *machine)
     long load_limit, fw_size;
     char *filename;
     Error *resize_hpt_err = NULL;
-    PowerPCCPU *first_ppc_cpu;
 
     msi_nonbroken = true;
 
@@ -2618,10 +2617,9 @@ static void spapr_machine_init(MachineState *machine)
     /* init CPUs */
     spapr_init_cpus(spapr);
 
-    first_ppc_cpu = POWERPC_CPU(first_cpu);
     if ((!kvm_enabled() || kvmppc_has_cap_mmu_radix()) &&
-        ppc_check_compat(first_ppc_cpu, CPU_POWERPC_LOGICAL_3_00, 0,
-                         spapr->max_compat_pvr)) {
+        ppc_type_check_compat(machine->cpu_type, CPU_POWERPC_LOGICAL_3_00, 0,
+                              spapr->max_compat_pvr)) {
         /* KVM and TCG always allow GTSE with radix... */
         spapr_ovec_set(spapr->ov5, OV5_MMU_RADIX_GTSE);
     }