Patch "KVM: arm/arm64: Reduce verbosity of KVM init log" has been added to the 4.14-stable tree

This is a note to let you know that I've just added the patch titled

KVM: arm/arm64: Reduce verbosity of KVM init log

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
kvm-arm-arm64-reduce-verbosity-of-kvm-init-log.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Ard Biesheuvel <[email protected]>
Date: Fri, 2 Mar 2018 08:16:30 +0000
Subject: KVM: arm/arm64: Reduce verbosity of KVM init log

From: Ard Biesheuvel <[email protected]>

commit 76600428c3677659e3c3633bb4f2ea302220a275 upstream.

On my GICv3 system, the following is printed to the kernel log at boot:

kvm [1]: 8-bit VMID
kvm [1]: IDMAP page: d20e35000
kvm [1]: HYP VA range: 800000000000:ffffffffffff kvm [1]: vgic-v2@2c020000
kvm [1]: GIC system register CPU interface enabled kvm [1]: vgic interrupt IRQ1
kvm [1]: virtual timer IRQ4
kvm [1]: Hyp mode initialized successfully

The KVM IDMAP is a mapping of a statically allocated kernel structure, and so printing its physical address leaks the physical placement of the kernel when physical KASLR in effect. So change the kvm_info() to kvm_debug() to remove it from the log output.

While at it, trim the output a bit more: IRQ numbers can be found in /proc/interrupts, and the HYP VA and vgic-v2 lines are not highly informational either.

---
 virt/kvm/arm/arch_timer.c   |    2 +-
 virt/kvm/arm/mmu.c          |    6 +++---
 virt/kvm/arm/vgic/vgic-v2.c |    2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

@@ -602,7 +602,7 @@ int kvm_timer_hyp_init(void)
 		return err;
 	}
 
-	kvm_info("virtual timer IRQ%d\n", host_vtimer_irq);
+	kvm_debug("virtual timer IRQ%d\n", host_vtimer_irq);
 
 	cpuhp_setup_state(CPUHP_AP_KVM_ARM_TIMER_STARTING,
 			  "kvm/arm/timer:starting", kvm_timer_starting_cpu,

@@ -1760,9 +1760,9 @@ int kvm_mmu_init(void)
 	 */
 	BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
 
-	kvm_info("IDMAP page: %lx\n", hyp_idmap_start);
-	kvm_info("HYP VA range: %lx:%lx\n",
-		 kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL));
+	kvm_debug("IDMAP page: %lx\n", hyp_idmap_start);
+	kvm_debug("HYP VA range: %lx:%lx\n",
+		  kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL));
 
 	if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
 	    hyp_idmap_start <  kern_hyp_va(~0UL) &&

@@ -380,7 +380,7 @@ int vgic_v2_probe(const struct gic_kvm_i
 	kvm_vgic_global_state.type = VGIC_V2;
 	kvm_vgic_global_state.max_gic_vcpus = VGIC_V2_MAX_CPUS;
 
-	kvm_info("vgic-v2@%llx\n", info->vctrl.start);
+	kvm_debug("vgic-v2@%llx\n", info->vctrl.start);
 
 	return 0;
 out:

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/kvm-arm-arm64-reduce-verbosity-of-kvm-init-log.patch