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

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 at 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.

Cc <[email protected]>

Signed-off-by Ard Biesheuvel <[email protected]>

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

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 at 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.

Cc <[email protected]>

Signed-off-by Ard Biesheuvel <[email protected]>

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

virt/kvm/arm/arch_timer.c +1 -1

index 70268c0bec79..0bf76ab1ec0b 100644
@@ -755,7 +755,7 @@ int kvm_timer_hyp_init(bool has_gic)
                }
        }
 
-       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,

virt/kvm/arm/mmu.c +3 -3

index ec62d1cccab7..b960acdd0c05 100644
@@ -1810,9 +1810,9 @@ 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) &&

virt/kvm/arm/vgic/vgic-init.c +1 -1

index 743ca5cb05ef..f99ff0f33ef0 100644
@@ -520,7 +520,7 @@ int kvm_vgic_hyp_init(void)
                goto out_free_irq;
        }
 
-       kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
+       kvm_debug("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
        return 0;
 
 out_free_irq:

virt/kvm/arm/vgic/vgic-v2.c +1 -2

index c32d7b93ffd1..e9d840a75e7b 100644
@@ -410,7 +410,7 @@ int vgic_v2_probe(const struct gic_kvm_info *info)
        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:
--

2.11.0