Re: [PATCH] KVM: PPC: Book3S: Ratelimit copy data failure error messages

[Vipin K Parashar <vipin@linux.vnet.ibm.com>]

v2 for this patch with 'printk_ratelimit' replaced with

'printk_ratelimited' is available at mailing list.


https://patchwork.ozlabs.org/patch/728831/



On Tuesday 14 February 2017 11:50 AM, Vipin K Parashar wrote:
> Forwarded same patch to kvm@vger.kernel.org
>
> and kvm-ppc@vger.kernel.org too.
>
>
> On Tuesday 14 February 2017 12:26 AM, Vipin K Parashar wrote:
>> kvm_ppc_mmu_book3s_32/64 xlat() log "KVM can't copy data" error
>> upon failing to copy user data to kernel space. This floods kernel
>> log once such fails occur in short time period. Ratelimit this
>> error to avoid flooding kernel logs upon copy data failures.
>>
>> Signed-off-by: Vipin K Parashar <vipin@linux.vnet.ibm.com>
>> ---
>>   arch/powerpc/kvm/book3s_32_mmu.c | 3 ++-
>>   arch/powerpc/kvm/book3s_64_mmu.c | 3 ++-
>>   2 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/powerpc/kvm/book3s_32_mmu.c 
>> b/arch/powerpc/kvm/book3s_32_mmu.c
>> index a2eb6d3..ca8f960 100644
>> --- a/arch/powerpc/kvm/book3s_32_mmu.c
>> +++ b/arch/powerpc/kvm/book3s_32_mmu.c
>> @@ -224,7 +224,8 @@ static int kvmppc_mmu_book3s_32_xlate_pte(struct 
>> kvm_vcpu *vcpu, gva_t eaddr,
>>       ptem = kvmppc_mmu_book3s_32_get_ptem(sre, eaddr, primary);
>>
>>       if(copy_from_user(pteg, (void __user *)ptegp, sizeof(pteg))) {
>> -        printk(KERN_ERR "KVM: Can't copy data from 0x%lx!\n", ptegp);
>> +        if (printk_ratelimit())
>> +            printk(KERN_ERR "KVM: Can't copy data from 0x%lx!\n", 
>> ptegp);
>>           goto no_page_found;
>>       }
>>
>> diff --git a/arch/powerpc/kvm/book3s_64_mmu.c 
>> b/arch/powerpc/kvm/book3s_64_mmu.c
>> index b9131aa..b420aca 100644
>> --- a/arch/powerpc/kvm/book3s_64_mmu.c
>> +++ b/arch/powerpc/kvm/book3s_64_mmu.c
>> @@ -265,7 +265,8 @@ static int kvmppc_mmu_book3s_64_xlate(struct 
>> kvm_vcpu *vcpu, gva_t eaddr,
>>           goto no_page_found;
>>
>>       if(copy_from_user(pteg, (void __user *)ptegp, sizeof(pteg))) {
>> -        printk(KERN_ERR "KVM can't copy data from 0x%lx!\n", ptegp);
>> +        if (printk_ratelimit())
>> +            printk(KERN_ERR "KVM can't copy data from 0x%lx!\n", 
>> ptegp);
>>           goto no_page_found;
>>       }
>>
>