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 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: kvm-arm-arm64-reduce-verbosity-of-kvm-init-log.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 76600428c3677659e3c3633bb4f2ea302220a275 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel ard.biesheuvel@linaro.org Date: Fri, 2 Mar 2018 08:16:30 +0000 Subject: KVM: arm/arm64: Reduce verbosity of KVM init log
From: Ard Biesheuvel ard.biesheuvel@linaro.org
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.
Cc: stable@vger.kernel.org Acked-by: Will Deacon will.deacon@arm.com Acked-by: Christoffer Dall cdall@kernel.org Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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(-)
--- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -773,7 +773,7 @@ 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, --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -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) && --- a/virt/kvm/arm/vgic/vgic-v2.c +++ b/virt/kvm/arm/vgic/vgic-v2.c @@ -381,7 +381,7 @@ 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 ard.biesheuvel@linaro.org are
queue-4.15/kvm-arm-arm64-reduce-verbosity-of-kvm-init-log.patch