[PATCH] KVM: Clean up and extend rate-limited output

[PATCH] KVM: Clean up and extend rate-limited output

[Jan Kiszka]

The use of printk_ratelimit is discouraged, replace it with
pr*_ratelimited or __ratelimit. While at it, convert remaining
guest-triggerable printks to rate-limited variants.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 arch/x86/kvm/i8259.c     |   15 ++++++++-------
 arch/x86/kvm/mmu_audit.c |    6 +++---
 arch/x86/kvm/vmx.c       |   13 ++++++-------
 include/linux/kvm_host.h |    8 +++-----
 4 files changed, 20 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 6b869ce..cac4746 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -34,6 +34,9 @@
 #include <linux/kvm_host.h>
 #include "trace.h"
 
+#define pr_pic_unimpl(fmt, ...)	\
+	pr_err_ratelimited("kvm: pic: " fmt, ## __VA_ARGS__)
+
 static void pic_irq_request(struct kvm *kvm, int level);
 
 static void pic_lock(struct kvm_pic *s)
@@ -306,10 +309,10 @@ static void pic_ioport_write(void *opaque, u32 addr, u32 val)
 			}
 			s->init_state = 1;
 			if (val & 0x02)
-				printk(KERN_ERR "single mode not supported");
+				pr_pic_unimpl("single mode not supported");
 			if (val & 0x08)
-				printk(KERN_ERR
-				       "level sensitive irq not supported");
+				pr_pic_unimpl(
+					"level sensitive irq not supported");
 		} else if (val & 0x08) {
 			if (val & 0x04)
 				s->poll = 1;
@@ -467,8 +470,7 @@ static int picdev_write(struct kvm_pic *s,
 		return -EOPNOTSUPP;
 
 	if (len != 1) {
-		if (printk_ratelimit())
-			printk(KERN_ERR "PIC: non byte write\n");
+		pr_pic_unimpl("non byte write\n");
 		return 0;
 	}
 	pic_lock(s);
@@ -496,8 +498,7 @@ static int picdev_read(struct kvm_pic *s,
 		return -EOPNOTSUPP;
 
 	if (len != 1) {
-		if (printk_ratelimit())
-			printk(KERN_ERR "PIC: non byte read\n");
+		pr_pic_unimpl("non byte read\n");
 		return 0;
 	}
 	pic_lock(s);
diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c
index 2460a26..746ec25 100644
--- a/arch/x86/kvm/mmu_audit.c
+++ b/arch/x86/kvm/mmu_audit.c
@@ -121,16 +121,16 @@ static void audit_mappings(struct kvm_vcpu *vcpu, u64 *sptep, int level)
 
 static void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)
 {
+	static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
 	unsigned long *rmapp;
 	struct kvm_mmu_page *rev_sp;
 	gfn_t gfn;
 
-
 	rev_sp = page_header(__pa(sptep));
 	gfn = kvm_mmu_page_get_gfn(rev_sp, sptep - rev_sp->spt);
 
 	if (!gfn_to_memslot(kvm, gfn)) {
-		if (!printk_ratelimit())
+		if (!__ratelimit(&ratelimit_state))
 			return;
 		audit_printk(kvm, "no memslot for gfn %llx\n", gfn);
 		audit_printk(kvm, "index %ld of sp (gfn=%llx)\n",
@@ -141,7 +141,7 @@ static void inspect_spte_has_rmap(struct kvm *kvm, u64 *sptep)
 
 	rmapp = gfn_to_rmap(kvm, gfn, rev_sp->role.level);
 	if (!*rmapp) {
-		if (!printk_ratelimit())
+		if (!__ratelimit(&ratelimit_state))
 			return;
 		audit_printk(kvm, "no rmap for writable spte %llx\n",
 			     *sptep);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 21217b6..a0d6bd9 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2762,8 +2762,8 @@ static void enter_lmode(struct kvm_vcpu *vcpu)
 
 	guest_tr_ar = vmcs_read32(GUEST_TR_AR_BYTES);
 	if ((guest_tr_ar & AR_TYPE_MASK) != AR_TYPE_BUSY_64_TSS) {
-		printk(KERN_DEBUG "%s: tss fixup for long mode. \n",
-		       __func__);
+		pr_debug_ratelimited("%s: tss fixup for long mode. \n",
+				     __func__);
 		vmcs_write32(GUEST_TR_AR_BYTES,
 			     (guest_tr_ar & ~AR_TYPE_MASK)
 			     | AR_TYPE_BUSY_64_TSS);
@@ -5634,8 +5634,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
 		return 0;
 
 	if (unlikely(vmx->fail)) {
-		printk(KERN_INFO "%s failed vm entry %x\n",
-		       __func__, vmcs_read32(VM_INSTRUCTION_ERROR));
+		pr_info_ratelimited("%s failed vm entry %x\n", __func__,
+				    vmcs_read32(VM_INSTRUCTION_ERROR));
 		return 1;
 	}
 
@@ -6612,9 +6612,8 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 	if (vmcs12->vm_entry_msr_load_count > 0 ||
 	    vmcs12->vm_exit_msr_load_count > 0 ||
 	    vmcs12->vm_exit_msr_store_count > 0) {
-		if (printk_ratelimit())
-			printk(KERN_WARNING
-			  "%s: VMCS MSR_{LOAD,STORE} unsupported\n", __func__);
+		pr_warn_ratelimited("%s: VMCS MSR_{LOAD,STORE} unsupported\n",
+				    __func__);
 		nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD);
 		return 1;
 	}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d0e42f3..2a414f6 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -18,6 +18,7 @@
 #include <linux/msi.h>
 #include <linux/slab.h>
 #include <linux/rcupdate.h>
+#include <linux/ratelimit.h>
 #include <asm/signal.h>
 
 #include <linux/kvm.h>
@@ -282,11 +283,8 @@ struct kvm {
 
 /* The guest did something we don't support. */
 #define pr_unimpl(vcpu, fmt, ...)					\
- do {									\
-	if (printk_ratelimit())						\
-		printk(KERN_ERR "kvm: %i: cpu%i " fmt,			\
-		       current->tgid, (vcpu)->vcpu_id , ## __VA_ARGS__); \
- } while (0)
+	pr_err_ratelimited("kvm: %i: cpu%i " fmt,			\
+			   current->tgid, (vcpu)->vcpu_id , ## __VA_ARGS__)
 
 #define kvm_printf(kvm, fmt ...) printk(KERN_DEBUG fmt)
 #define vcpu_printf(vcpu, fmt...) kvm_printf(vcpu->kvm, fmt)
-- 
1.7.3.4

Re: [PATCH] KVM: Clean up and extend rate-limited output

[Marcelo Tosatti]

On Mon, Sep 12, 2011 at 11:26:22AM +0200, Jan Kiszka wrote:
> The use of printk_ratelimit is discouraged, replace it with
> pr*_ratelimited or __ratelimit. While at it, convert remaining
> guest-triggerable printks to rate-limited variants.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>  arch/x86/kvm/i8259.c     |   15 ++++++++-------
>  arch/x86/kvm/mmu_audit.c |    6 +++---
>  arch/x86/kvm/vmx.c       |   13 ++++++-------
>  include/linux/kvm_host.h |    8 +++-----
>  4 files changed, 20 insertions(+), 22 deletions(-)

Applied all, thanks.