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

Cc: <[email protected]>
Acked-by: Will Deacon <[email protected]>
Acked-by: Christoffer Dall <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
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Ard Biesheuvel authored and Marc Zyngier committed Mar 14, 2018
1 parent 413aa80 commit 7660042
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Showing 3 changed files with 5 additions and 5 deletions.
2 changes: 1 addition & 1 deletion virt/kvm/arm/arch_timer.c
Original file line number Diff line number Diff line change
Expand Up @@ -771,7 +771,7 @@ int kvm_timer_hyp_init(bool has_gic)
static_branch_enable(&has_gic_active_state);
}

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,
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6 changes: 3 additions & 3 deletions virt/kvm/arm/mmu.c
Original file line number Diff line number Diff line change
Expand Up @@ -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) &&
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2 changes: 1 addition & 1 deletion virt/kvm/arm/vgic/vgic-v2.c
Original file line number Diff line number Diff line change
Expand Up @@ -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:
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