From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Stevens Date: Fri, 25 Jun 2021 07:36:16 +0000 Subject: [PATCH v2 5/5] KVM: mmu: remove over-aggressive warnings Message-Id: <20210625073616.2184426-6-stevensd@google.com> List-Id: References: <20210625073616.2184426-1-stevensd@google.com> In-Reply-To: <20210625073616.2184426-1-stevensd@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Marc Zyngier , Huacai Chen , Aleksandar Markovic , Paul Mackerras , Paolo Bonzini , Nick Piggin Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , Will Deacon , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Zhenyu Wang , Zhi Wang , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, David Stevens From: David Stevens 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 --- 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 dd5cb6e33591..0c47245594c6 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -607,13 +607,6 @@ 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 1de8702845ac..ce7126bab4b0 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