From d3fccc7ef831d1d829b4da5eaa081db55b1e38f3 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 10 Nov 2014 09:33:56 +0100 Subject: [PATCH] kvm: fix kvm_is_mmio_pfn() and rename to kvm_is_reserved_pfn() This reverts commit 85c8555ff0 ("KVM: check for !is_zero_pfn() in kvm_is_mmio_pfn()") and renames the function to kvm_is_reserved_pfn. The problem being addressed by the patch above was that some ARM code based the memory mapping attributes of a pfn on the return value of kvm_is_mmio_pfn(), whose name indeed suggests that such pfns should be mapped as device memory. However, kvm_is_mmio_pfn() doesn't do quite what it says on the tin, and the existing non-ARM users were already using it in a way which suggests that its name should probably have been 'kvm_is_reserved_pfn' from the beginning, e.g., whether or not to call get_page/put_page on it etc. This means that returning false for the zero page is a mistake and the patch above should be reverted. Signed-off-by: Ard Biesheuvel Signed-off-by: Paolo Bonzini --- arch/ia64/kvm/kvm-ia64.c | 2 +- arch/x86/kvm/mmu.c | 6 +++--- include/linux/kvm_host.h | 2 +- virt/kvm/kvm_main.c | 16 ++++++++-------- 4 files changed, 13 insertions(+), 13 deletions(-) diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index ec6b9ac..dbe46f4 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -1563,7 +1563,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, for (i = 0; i < npages; i++) { pfn = gfn_to_pfn(kvm, base_gfn + i); - if (!kvm_is_mmio_pfn(pfn)) { + if (!kvm_is_reserved_pfn(pfn)) { kvm_set_pmt_entry(kvm, base_gfn + i, pfn << PAGE_SHIFT, _PAGE_AR_RWX | _PAGE_MA_WB); diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index ac1c4de..978f402 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -630,7 +630,7 @@ static int mmu_spte_clear_track_bits(u64 *sptep) * kvm mmu, before reclaiming the page, we should * unmap it from mmu first. */ - WARN_ON(!kvm_is_mmio_pfn(pfn) && !page_count(pfn_to_page(pfn))); + WARN_ON(!kvm_is_reserved_pfn(pfn) && !page_count(pfn_to_page(pfn))); if (!shadow_accessed_mask || old_spte & shadow_accessed_mask) kvm_set_pfn_accessed(pfn); @@ -2461,7 +2461,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, spte |= PT_PAGE_SIZE_MASK; if (tdp_enabled) spte |= kvm_x86_ops->get_mt_mask(vcpu, gfn, - kvm_is_mmio_pfn(pfn)); + kvm_is_reserved_pfn(pfn)); if (host_writable) spte |= SPTE_HOST_WRITEABLE; @@ -2737,7 +2737,7 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu, * PT_PAGE_TABLE_LEVEL and there would be no adjustment done * here. */ - if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn) && + if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn) && level == PT_PAGE_TABLE_LEVEL && PageTransCompound(pfn_to_page(pfn)) && !has_wrprotected_page(vcpu->kvm, gfn, PT_DIRECTORY_LEVEL)) { diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index ea53b04..a6059bd 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -703,7 +703,7 @@ void kvm_arch_sync_events(struct kvm *kvm); int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu); void kvm_vcpu_kick(struct kvm_vcpu *vcpu); -bool kvm_is_mmio_pfn(pfn_t pfn); +bool kvm_is_reserved_pfn(pfn_t pfn); struct kvm_irq_ack_notifier { struct hlist_node link; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 25ffac9..3cee7b1 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -107,10 +107,10 @@ EXPORT_SYMBOL_GPL(kvm_rebooting); static bool largepages_enabled = true; -bool kvm_is_mmio_pfn(pfn_t pfn) +bool kvm_is_reserved_pfn(pfn_t pfn) { if (pfn_valid(pfn)) - return !is_zero_pfn(pfn) && PageReserved(pfn_to_page(pfn)); + return PageReserved(pfn_to_page(pfn)); return true; } @@ -1321,7 +1321,7 @@ static pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, else if ((vma->vm_flags & VM_PFNMAP)) { pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; - BUG_ON(!kvm_is_mmio_pfn(pfn)); + BUG_ON(!kvm_is_reserved_pfn(pfn)); } else { if (async && vma_is_valid(vma, write_fault)) *async = true; @@ -1427,7 +1427,7 @@ static struct page *kvm_pfn_to_page(pfn_t pfn) if (is_error_noslot_pfn(pfn)) return KVM_ERR_PTR_BAD_PAGE; - if (kvm_is_mmio_pfn(pfn)) { + if (kvm_is_reserved_pfn(pfn)) { WARN_ON(1); return KVM_ERR_PTR_BAD_PAGE; } @@ -1456,7 +1456,7 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean); void kvm_release_pfn_clean(pfn_t pfn) { - if (!is_error_noslot_pfn(pfn) && !kvm_is_mmio_pfn(pfn)) + if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn)) put_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_release_pfn_clean); @@ -1477,7 +1477,7 @@ static void kvm_release_pfn_dirty(pfn_t pfn) void kvm_set_pfn_dirty(pfn_t pfn) { - if (!kvm_is_mmio_pfn(pfn)) { + if (!kvm_is_reserved_pfn(pfn)) { struct page *page = pfn_to_page(pfn); if (!PageReserved(page)) SetPageDirty(page); @@ -1487,14 +1487,14 @@ EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty); void kvm_set_pfn_accessed(pfn_t pfn) { - if (!kvm_is_mmio_pfn(pfn)) + if (!kvm_is_reserved_pfn(pfn)) mark_page_accessed(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed); void kvm_get_pfn(pfn_t pfn) { - if (!kvm_is_mmio_pfn(pfn)) + if (!kvm_is_reserved_pfn(pfn)) get_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_get_pfn); -- 1.9.1