[Qemu-devel] [PATCH] ppc: remove redundant capability check for unset irq

[Qemu-devel] [PATCH] ppc: remove redundant capability check for unset irq

[Shivaprasad G Bhat]

The KVM_CAP_PPC_UNSET_IRQ is part of kernel since v2.6.36.
Kernels older than that are not supported anymore.
So, remove the checks.

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
---
 target/ppc/kvm.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 5ab5e6c6a9..94a2ecb84f 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -55,7 +55,6 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_LAST_INFO
 };
 
-static int cap_interrupt_unset;
 static int cap_segstate;
 static int cap_booke_sregs;
 static int cap_ppc_smt;
@@ -104,7 +103,6 @@ static int kvmppc_get_dec_bits(void);
 
 int kvm_arch_init(MachineState *ms, KVMState *s)
 {
-    cap_interrupt_unset = kvm_check_extension(s, KVM_CAP_PPC_UNSET_IRQ);
     cap_segstate = kvm_check_extension(s, KVM_CAP_PPC_SEGSTATE);
     cap_booke_sregs = kvm_check_extension(s, KVM_CAP_PPC_BOOKE_SREGS);
     cap_ppc_smt_possible = kvm_vm_check_extension(s, KVM_CAP_PPC_SMT_POSSIBLE);
@@ -1309,7 +1307,7 @@ int kvmppc_set_interrupt(PowerPCCPU *cpu, int irq, int level)
         return 0;
     }
 
-    if (!kvm_enabled() || !cap_interrupt_unset) {
+    if (!kvm_enabled()) {
         return 0;
     }
 

Re: [Qemu-devel] [PATCH] ppc: remove redundant capability check for unset irq

[Greg Kurz]

On Thu, 25 Jul 2019 10:40:11 -0500
Shivaprasad G Bhat <sbhat@linux.ibm.com> wrote:

> The KVM_CAP_PPC_UNSET_IRQ is part of kernel since v2.6.36.
> Kernels older than that are not supported anymore.
> So, remove the checks.
> 

Ok to drop the dead paths but we do need this cap to be present.

int kvmppc_set_interrupt(PowerPCCPU *cpu, int irq, int level)
{
    unsigned virq = level ? KVM_INTERRUPT_SET_LEVEL : KVM_INTERRUPT_UNSET;
...
}

Please add an error message and exit in kvm_arch_init() like you did for
SET_LEVEL.

> Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
> ---
>  target/ppc/kvm.c |    4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index 5ab5e6c6a9..94a2ecb84f 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -55,7 +55,6 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
>      KVM_CAP_LAST_INFO
>  };
>  
> -static int cap_interrupt_unset;
>  static int cap_segstate;
>  static int cap_booke_sregs;
>  static int cap_ppc_smt;
> @@ -104,7 +103,6 @@ static int kvmppc_get_dec_bits(void);
>  
>  int kvm_arch_init(MachineState *ms, KVMState *s)
>  {
> -    cap_interrupt_unset = kvm_check_extension(s, KVM_CAP_PPC_UNSET_IRQ);
>      cap_segstate = kvm_check_extension(s, KVM_CAP_PPC_SEGSTATE);
>      cap_booke_sregs = kvm_check_extension(s, KVM_CAP_PPC_BOOKE_SREGS);
>      cap_ppc_smt_possible = kvm_vm_check_extension(s, KVM_CAP_PPC_SMT_POSSIBLE);
> @@ -1309,7 +1307,7 @@ int kvmppc_set_interrupt(PowerPCCPU *cpu, int irq, int level)
>          return 0;
>      }
>  
> -    if (!kvm_enabled() || !cap_interrupt_unset) {
> +    if (!kvm_enabled()) {
>          return 0;
>      }
>  
>