linux-kernel - [PATCH] kvm: x86: don't print warning messages for unimplemented msrs

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Date:   Tue, 15 Nov 2016 01:27:58 -0500
From:   Bandan Das <bsd@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>, Dave Jones <dsj@...com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH] kvm: x86: don't print warning messages for unimplemented msrs


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@...hat.com>
---
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 | 5 +++++
 3 files changed, 9 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..e4c0980 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 +453,8 @@ 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("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)
 #define vcpu_err(vcpu, fmt, ...)					\
 	kvm_err("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)
 
-- 
2.5.5