From 43c475504a39e98f10f5e6ec4d9d9ed60672a753 Mon Sep 17 00:00:00 2001 From: Quentin Perret Date: Wed, 16 Apr 2025 15:26:47 +0000 Subject: [PATCH] KVM: arm64: Unconditionally cross check hyp state Now that the hypervisor's state is stored in the hyp_vmemmap, we no longer need an expensive page-table walk to read it. This means we can now afford to cross check the hyp-state during all memory ownership transitions where the hyp is involved unconditionally, hence avoiding problems such as [1]. [1] https://lore.kernel.org/kvmarm/20241128154406.602875-1-qperret@google.com/ Reviewed-by: Marc Zyngier Signed-off-by: Quentin Perret Link: https://lore.kernel.org/r/20250416152648.2982950-8-qperret@google.com Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 91b757e3fb4c..709d286999a1 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -702,11 +702,9 @@ int __pkvm_host_share_hyp(u64 pfn) ret = __host_check_page_state_range(phys, size, PKVM_PAGE_OWNED); if (ret) goto unlock; - if (IS_ENABLED(CONFIG_NVHE_EL2_DEBUG)) { - ret = __hyp_check_page_state_range(phys, size, PKVM_NOPAGE); - if (ret) - goto unlock; - } + ret = __hyp_check_page_state_range(phys, size, PKVM_NOPAGE); + if (ret) + goto unlock; __hyp_set_page_state_range(phys, size, PKVM_PAGE_SHARED_BORROWED); WARN_ON(__host_set_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED)); @@ -762,11 +760,9 @@ int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages) ret = __host_check_page_state_range(phys, size, PKVM_PAGE_OWNED); if (ret) goto unlock; - if (IS_ENABLED(CONFIG_NVHE_EL2_DEBUG)) { - ret = __hyp_check_page_state_range(phys, size, PKVM_NOPAGE); - if (ret) - goto unlock; - } + ret = __hyp_check_page_state_range(phys, size, PKVM_NOPAGE); + if (ret) + goto unlock; __hyp_set_page_state_range(phys, size, PKVM_PAGE_OWNED); WARN_ON(pkvm_create_mappings_locked(virt, virt + size, PAGE_HYP)); @@ -792,11 +788,9 @@ int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages) ret = __hyp_check_page_state_range(phys, size, PKVM_PAGE_OWNED); if (ret) goto unlock; - if (IS_ENABLED(CONFIG_NVHE_EL2_DEBUG)) { - ret = __host_check_page_state_range(phys, size, PKVM_NOPAGE); - if (ret) - goto unlock; - } + ret = __host_check_page_state_range(phys, size, PKVM_NOPAGE); + if (ret) + goto unlock; __hyp_set_page_state_range(phys, size, PKVM_NOPAGE); WARN_ON(kvm_pgtable_hyp_unmap(&pkvm_pgtable, virt, size) != size); -- 2.50.1