[Xen-devel] [PATCH v4 4/7] xen/arm: read ACTLR on the pcpu where the vcpu will run

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On big.LITTLE systems not all cores have the same ACTLR. Instead of
reading ACTLR and setting v->arch.actlr in vcpu_initialise, do it later
on the same pcpu where the vcpu will run.

This way, assuming that the vcpu has been created with the right pcpu
affinity, the guest will be able to read the right ACTLR value, matching
the one of the physical cpu.

Also move processor_vcpu_initialise(v) to continue_new_vcpu as it
can modify v->arch.actlr.

Signed-off-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Reviewed-by: Julien Grall <julien.grall@xxxxxxx>
---

Changes in v2:
- move processor_vcpu_initialise to continue_new_vcpu
- remove inaccurate sentence from commit message
---
 xen/arch/arm/domain.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index a74ff1c..5e76809 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -314,6 +314,9 @@ static void schedule_tail(struct vcpu *prev)
 
 static void continue_new_vcpu(struct vcpu *prev)
 {
+    current->arch.actlr = READ_SYSREG32(ACTLR_EL1);
+    processor_vcpu_initialise(current);
+
     schedule_tail(prev);
 
     if ( is_idle_vcpu(current) )
@@ -540,12 +543,8 @@ int vcpu_initialise(struct vcpu *v)
 
     v->arch.vmpidr = MPIDR_SMP | vcpuid_to_vaffinity(v->vcpu_id);
 
-    v->arch.actlr = READ_SYSREG32(ACTLR_EL1);
-
     v->arch.hcr_el2 = get_default_hcr_flags();
 
-    processor_vcpu_initialise(v);
-
     if ( (rc = vcpu_vgic_init(v)) != 0 )
         goto fail;
 
-- 
1.9.1


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