[PATCH 5/6] KVM: mmu: remove over-aggressive warnings
From: David Stevens <hidden>
Date: 2021-06-24 04:00:08
Also in:
dri-devel, intel-gfx, kvm, kvmarm, linux-arm-kernel, linuxppc-dev, lkml
Subsystem:
kernel virtual machine (kvm), kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Paolo Bonzini, Sean Christopherson, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: David Stevens <redacted> Remove two warnings that require ref counts for pages to be non-zero, as mapped pfns from follow_pfn may not have an initialized ref count. Signed-off-by: David Stevens <redacted> --- arch/x86/kvm/mmu/mmu.c | 7 ------- virt/kvm/kvm_main.c | 2 +- 2 files changed, 1 insertion(+), 8 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 8fa4a4a411ba..19249ad4b5b8 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c@@ -546,13 +546,6 @@ static int mmu_spte_clear_track_bits(u64 *sptep) pfn = spte_to_pfn(old_spte); - /* - * KVM does not hold the refcount of the page used by - * kvm mmu, before reclaiming the page, we should - * unmap it from mmu first. - */ - WARN_ON(!kvm_is_reserved_pfn(pfn) && !page_count(pfn_to_page(pfn))); - if (is_accessed_spte(old_spte)) kvm_set_pfn_accessed(pfn);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 898e90be4d0e..671361f30476 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c@@ -168,7 +168,7 @@ bool kvm_is_zone_device_pfn(kvm_pfn_t pfn) * the device has been pinned, e.g. by get_user_pages(). WARN if the * page_count() is zero to help detect bad usage of this helper. */ - if (!pfn_valid(pfn) || WARN_ON_ONCE(!page_count(pfn_to_page(pfn)))) + if (!pfn_valid(pfn) || !page_count(pfn_to_page(pfn))) return false; return is_zone_device_page(pfn_to_page(pfn));
--
2.32.0.93.g670b81a890-goog