fix(core/vm): remove unnecessary cpu_idle and vcpu_arch_run calls

This commit is structured into two parts:
- Removed unnecessary cpu_idle call from vcpu_run to prevent
redundant invocations. This change eliminates continuous calls to cpu_idle in
scenarios where the profile implementation does not jump to a predefined
wake-up point but instead returns directly.
In such cases, the stack was manually rewound, and control was transferred
to the cpu_idle_wakeup function, which then re-entered vcpu_run, leading to
repeated invocations of cpu_idle.
- Removed the vcpu_arch_run call to avoid repeating the same logic for ARM and
RISCV architectures. Instead now we call directly the vcpu_arch_entry if the
core is ready to run.

Signed-off-by: João Peixoto <[email protected]>

src/arch/armv8/vm.c

@@ -80,16 +80,7 @@ void vcpu_arch_reset(struct vcpu* vcpu, vaddr_t entry)
      */
 }
 
-static inline bool vcpu_psci_state_on(struct vcpu* vcpu)
+bool vcpu_arch_is_on(struct vcpu* vcpu)
 {
     return vcpu->arch.psci_ctx.state == ON;
 }
-
-void vcpu_arch_run(struct vcpu* vcpu)
-{
-    if (vcpu_psci_state_on(vcpu)) {
-        vcpu_arch_entry();
-    } else {
-        cpu_idle();
-    }
-}

src/arch/riscv/vm.c

@@ -90,11 +90,7 @@ void vcpu_writepc(struct vcpu* vcpu, unsigned long pc)
     vcpu->regs.sepc = pc;
 }
 
-void vcpu_arch_run(struct vcpu* vcpu)
+bool vcpu_arch_is_on(struct vcpu* vcpu)
 {
-    if (vcpu->arch.sbi_ctx.state == STARTED) {
-        vcpu_arch_entry();
-    } else {
-        cpu_idle();
-    }
+    return vcpu->arch.sbi_ctx.state == STARTED;
 }

src/core/inc/vm.h

@@ -174,7 +174,7 @@ unsigned long vcpu_readreg(struct vcpu* vcpu, unsigned long reg);
 void vcpu_writereg(struct vcpu* vcpu, unsigned long reg, unsigned long val);
 unsigned long vcpu_readpc(struct vcpu* vcpu);
 void vcpu_writepc(struct vcpu* vcpu, unsigned long pc);
-void vcpu_arch_run(struct vcpu* vcpu);
 void vcpu_arch_reset(struct vcpu* vcpu, vaddr_t entry);
+bool vcpu_arch_is_on(struct vcpu* vcpu);
 
 #endif /* __VM_H__ */

src/core/vm.c

@@ -350,9 +350,7 @@ __attribute__((weak)) cpumap_t vm_translate_to_vcpu_mask(struct vm* vm, cpumap_t
 
 void vcpu_run(struct vcpu* vcpu)
 {
-    if (vcpu->active == false) {
-        cpu_idle();
-    } else {
-        vcpu_arch_run(vcpu);
+    if (vcpu_arch_is_on(vcpu) && vcpu->active == true) {
+        vcpu_arch_entry();
     }
 }