Re: [PATCH v2] kvm: x86: don't print warning messages for unimplemented msrs

From: Paolo Bonzini
Date: Thu Nov 17 2016 - 13:05:08 EST




On 15/11/2016 07:36, Bandan Das wrote:
>
> Change unimplemented msrs messages to use pr_debug.
> If CONFIG_DYNAMIC_DEBUG is set, then these messages can be
> enabled at run time or else -DDEBUG can be used at compile
> time to enable them. These messages will still be printed if
> ignore_msrs=1.
>
> Signed-off-by: Bandan Das <bsd@xxxxxxxxxx>

Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
> v2:
> use kvm_debug_ratelimited for vcpu_debug_ratelimited
>
> This is a follow up to RFC posted by Dave at
> https://patchwork.kernel.org/patch/9238227/ which uses pr_debug_ratelimited
> when ignore_msrs is not set.
>
> arch/x86/kvm/mmu.c | 2 +-
> arch/x86/kvm/x86.c | 5 +++--
> include/linux/kvm_host.h | 6 ++++++
> 3 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index d9c7e98..1b3f241 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -4958,7 +4958,7 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, struct kvm_memslots *slots)
> * zap all shadow pages.
> */
> if (unlikely((slots->generation & MMIO_GEN_MASK) == 0)) {
> - printk_ratelimited(KERN_DEBUG "kvm: zapping shadow pages for mmio generation wraparound\n");
> + kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n");
> kvm_mmu_invalidate_zap_all_pages(kvm);
> }
> }
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 3017de0..5d50403 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -2280,7 +2280,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
> if (kvm_pmu_is_valid_msr(vcpu, msr))
> return kvm_pmu_set_msr(vcpu, msr_info);
> if (!ignore_msrs) {
> - vcpu_unimpl(vcpu, "unhandled wrmsr: 0x%x data 0x%llx\n",
> + vcpu_debug_ratelimited(vcpu, "unhandled wrmsr: 0x%x data 0x%llx\n",
> msr, data);
> return 1;
> } else {
> @@ -2492,7 +2492,8 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
> if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
> return kvm_pmu_get_msr(vcpu, msr_info->index, &msr_info->data);
> if (!ignore_msrs) {
> - vcpu_unimpl(vcpu, "unhandled rdmsr: 0x%x\n", msr_info->index);
> + vcpu_debug_ratelimited(vcpu, "unhandled rdmsr: 0x%x\n",
> + msr_info->index);
> return 1;
> } else {
> vcpu_unimpl(vcpu, "ignored rdmsr: 0x%x\n", msr_info->index);
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 01c0b9c..274bf34 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -439,6 +439,9 @@ struct kvm {
> pr_info("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__)
> #define kvm_debug(fmt, ...) \
> pr_debug("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__)
> +#define kvm_debug_ratelimited(fmt, ...) \
> + pr_debug_ratelimited("kvm [%i]: " fmt, task_pid_nr(current), \
> + ## __VA_ARGS__)
> #define kvm_pr_unimpl(fmt, ...) \
> pr_err_ratelimited("kvm [%i]: " fmt, \
> task_tgid_nr(current), ## __VA_ARGS__)
> @@ -450,6 +453,9 @@ struct kvm {
>
> #define vcpu_debug(vcpu, fmt, ...) \
> kvm_debug("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)
> +#define vcpu_debug_ratelimited(vcpu, fmt, ...) \
> + kvm_debug_ratelimited("vcpu%i " fmt, (vcpu)->vcpu_id, \
> + ## __VA_ARGS__)
> #define vcpu_err(vcpu, fmt, ...) \
> kvm_err("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)
>
>