[Qemu-devel] [PATCH] ppc/kvm: Use error_report() instead of cpu_abort() for user-triggerable errors

[Qemu-devel] [PATCH] ppc/kvm: Use error_report() instead of cpu_abort() for user-triggerable errors

[Thomas Huth]

Setting the KVM_CAP_PPC_PAPR capability can fail if either the KVM
kernel module does not support it, or if the specified vCPU type
is not a 64-bit Book3-S CPU type. For example, the user can trigger
it easily with "-M pseries -cpu G2leLS" when using the kvm-pr kernel
module. So the error should not be reported with cpu_abort() since
this function is rather meant for reporting programming errors than
reporting user-triggerable errors (it prints out all CPU registers
and then calls abort() to kills the program - two things that the
normal user does not expect here) . So let's use error_report() with
exit(1) here instead.
A similar problem exists in the code that sets the KVM_CAP_PPC_EPR
capability, so while we're at it, fix that, too.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 target-ppc/kvm.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 70ca296..762d6cf 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -23,6 +23,7 @@
 #include <linux/kvm.h>
 
 #include "qemu-common.h"
+#include "qemu/error-report.h"
 #include "qemu/timer.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/kvm.h"
@@ -1993,7 +1994,8 @@ void kvmppc_set_papr(PowerPCCPU *cpu)
 
     ret = kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_PAPR, 0);
     if (ret) {
-        cpu_abort(cs, "This KVM version does not support PAPR\n");
+        error_report("This vCPU type or KVM version does not support PAPR");
+        exit(1);
     }
 
     /* Update the capability flag so we sync the right information
@@ -2013,7 +2015,8 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
 
     ret = kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_EPR, 0, mpic_proxy);
     if (ret && mpic_proxy) {
-        cpu_abort(cs, "This KVM version does not support EPR\n");
+        error_report("This KVM version does not support EPR");
+        exit(1);
     }
 }
 
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH] ppc/kvm: Use error_report() instead of cpu_abort() for user-triggerable errors

[David Gibson]

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On Thu, Feb 18, 2016 at 10:01:38PM +0100, Thomas Huth wrote:
> Setting the KVM_CAP_PPC_PAPR capability can fail if either the KVM
> kernel module does not support it, or if the specified vCPU type
> is not a 64-bit Book3-S CPU type. For example, the user can trigger
> it easily with "-M pseries -cpu G2leLS" when using the kvm-pr kernel
> module. So the error should not be reported with cpu_abort() since
> this function is rather meant for reporting programming errors than
> reporting user-triggerable errors (it prints out all CPU registers
> and then calls abort() to kills the program - two things that the
> normal user does not expect here) . So let's use error_report() with
> exit(1) here instead.
> A similar problem exists in the code that sets the KVM_CAP_PPC_EPR
> capability, so while we're at it, fix that, too.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Applied to ppc-for-2.6, thanks.

> ---
>  target-ppc/kvm.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index 70ca296..762d6cf 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -23,6 +23,7 @@
>  #include <linux/kvm.h>
>  
>  #include "qemu-common.h"
> +#include "qemu/error-report.h"
>  #include "qemu/timer.h"
>  #include "sysemu/sysemu.h"
>  #include "sysemu/kvm.h"
> @@ -1993,7 +1994,8 @@ void kvmppc_set_papr(PowerPCCPU *cpu)
>  
>      ret = kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_PAPR, 0);
>      if (ret) {
> -        cpu_abort(cs, "This KVM version does not support PAPR\n");
> +        error_report("This vCPU type or KVM version does not support PAPR");
> +        exit(1);
>      }
>  
>      /* Update the capability flag so we sync the right information
> @@ -2013,7 +2015,8 @@ void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>  
>      ret = kvm_vcpu_enable_cap(cs, KVM_CAP_PPC_EPR, 0, mpic_proxy);
>      if (ret && mpic_proxy) {
> -        cpu_abort(cs, "This KVM version does not support EPR\n");
> +        error_report("This KVM version does not support EPR");
> +        exit(1);
>      }
>  }
>  

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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