KVM: x86: Unify pr_fmt to use module name for all KVM modules

Define pr_fmt using KBUILD_MODNAME for all KVM x86 code so that printks
use consistent formatting across common x86, Intel, and AMD code.  In
addition to providing consistent print formatting, using KBUILD_MODNAME,
e.g. kvm_amd and kvm_intel, allows referencing SVM and VMX (and SEV and
SGX and ...) as technologies without generating weird messages, and
without causing naming conflicts with other kernel code, e.g. "SEV: ",
"tdx: ", "sgx: " etc.. are all used by the kernel for non-KVM subsystems.

Opportunistically move away from printk() for prints that need to be
modified anyways, e.g. to drop a manual "kvm: " prefix.

Opportunistically convert a few SGX WARNs that are similarly modified to
WARN_ONCE; in the very unlikely event that the WARNs fire, odds are good
that they would fire repeatedly and spam the kernel log without providing
unique information in each print.

Note, defining pr_fmt yields undesirable results for code that uses KVM's
printk wrappers, e.g. vcpu_unimpl().  But, that's a pre-existing problem
as SVM/kvm_amd already defines a pr_fmt, and thankfully use of KVM's
wrappers is relatively limited in KVM x86 code.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Message-Id: <20221130230934.1014142-35-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

6 files changed, 10 insertions, 7 deletions

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 9c7198544195..aeb240b339f5 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -14,6 +14,7 @@
  *   Yaniv Kamay  <yaniv@qumranet.com>
  *   Avi Kivity   <avi@qumranet.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include "irq.h"
 #include "ioapic.h"
@@ -3456,8 +3457,7 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 		}
 
 		if (++retry_count > 4) {
-			printk_once(KERN_WARNING
-				"kvm: Fast #PF retrying more than 4 times.\n");
+			pr_warn_once("Fast #PF retrying more than 4 times.\n");
 			break;
 		}
 
@@ -6647,7 +6647,7 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen)
 	 * zap all shadow pages.
 	 */
 	if (unlikely(gen == 0)) {
-		kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n");
+		kvm_debug_ratelimited("zapping shadow pages for mmio generation wraparound\n");
 		kvm_mmu_zap_all_fast(kvm);
 	}
 }
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 2e09d1b6249f..0a2ac438d647 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -10,6 +10,7 @@
  * Author:
  *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include <linux/rculist.h>
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index c0fd7e049b4e..fce6f047399f 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -7,7 +7,7 @@
  * Copyright (C) 2006 Qumranet, Inc.
  * Copyright 2020 Red Hat, Inc. and/or its affiliates.
  */
-
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include "mmu.h"
@@ -352,7 +352,7 @@ u64 mark_spte_for_access_track(u64 spte)
 
 	WARN_ONCE(spte & (SHADOW_ACC_TRACK_SAVED_BITS_MASK <<
 			  SHADOW_ACC_TRACK_SAVED_BITS_SHIFT),
-		  "kvm: Access Tracking saved bit locations are not zero\n");
+		  "Access Tracking saved bit locations are not zero\n");
 
 	spte |= (spte & SHADOW_ACC_TRACK_SAVED_BITS_MASK) <<
 		SHADOW_ACC_TRACK_SAVED_BITS_SHIFT;
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index 6f54dc9409c9..0d8deefee66c 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -435,11 +435,11 @@ static inline void check_spte_writable_invariants(u64 spte)
 {
 	if (spte & shadow_mmu_writable_mask)
 		WARN_ONCE(!(spte & shadow_host_writable_mask),
-			  "kvm: MMU-writable SPTE is not Host-writable: %llx",
+			  KBUILD_MODNAME ": MMU-writable SPTE is not Host-writable: %llx",
 			  spte);
 	else
 		WARN_ONCE(is_writable_pte(spte),
-			  "kvm: Writable SPTE is not MMU-writable: %llx", spte);
+			  KBUILD_MODNAME ": Writable SPTE is not MMU-writable: %llx", spte);
 }
 
 static inline bool is_mmu_writable_spte(u64 spte)
diff --git a/arch/x86/kvm/mmu/tdp_iter.c b/arch/x86/kvm/mmu/tdp_iter.c
index 39b48e7d7d1a..e26e744df1d1 100644
--- a/arch/x86/kvm/mmu/tdp_iter.c
+++ b/arch/x86/kvm/mmu/tdp_iter.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include "mmu_internal.h"
 #include "tdp_iter.h"
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index cc1fb9a65620..bba33aea0fb0 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include "mmu.h"
 #include "mmu_internal.h"