The new interface allows to detect if the page is protected. A protected page cannot be accessed directly by the host: it has to be mapped manually.
This is preparation for the next patch. Signed-off-by: Kirill A. Shutemov <[email protected]> --- arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +- arch/powerpc/kvm/book3s_64_mmu_radix.c | 2 +- arch/x86/kvm/mmu/mmu.c | 6 +++-- include/linux/kvm_host.h | 2 +- virt/kvm/kvm_main.c | 35 ++++++++++++++++++-------- 5 files changed, 32 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 2b35f9bcf892..e9a13ecf812f 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -587,7 +587,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, } else { /* Call KVM generic code to do the slow-path check */ pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL, - writing, &write_ok); + writing, &write_ok, NULL); if (is_error_noslot_pfn(pfn)) return -EFAULT; page = NULL; diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index aa12cd4078b3..58f8df466a94 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -798,7 +798,7 @@ int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu, /* Call KVM generic code to do the slow-path check */ pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL, - writing, upgrade_p); + writing, upgrade_p, NULL); if (is_error_noslot_pfn(pfn)) return -EFAULT; page = NULL; diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 8071952e9cf2..0fc095a66a3c 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4096,7 +4096,8 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); async = false; - *pfn = __gfn_to_pfn_memslot(slot, gfn, false, &async, write, writable); + *pfn = __gfn_to_pfn_memslot(slot, gfn, false, &async, write, writable, + NULL); if (!async) return false; /* *pfn has correct page already */ @@ -4110,7 +4111,8 @@ static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn, return true; } - *pfn = __gfn_to_pfn_memslot(slot, gfn, false, NULL, write, writable); + *pfn = __gfn_to_pfn_memslot(slot, gfn, false, NULL, write, writable, + NULL); return false; } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index d7072f6d6aa0..eca18ef9b1f4 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -724,7 +724,7 @@ kvm_pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn); kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn); kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic, bool *async, bool write_fault, - bool *writable); + bool *writable, bool *protected); void kvm_release_pfn_clean(kvm_pfn_t pfn); void kvm_release_pfn_dirty(kvm_pfn_t pfn); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 63282def3760..8bcf3201304a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1779,9 +1779,10 @@ static bool hva_to_pfn_fast(unsigned long addr, bool write_fault, * 1 indicates success, -errno is returned if error is detected. */ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, - bool *writable, kvm_pfn_t *pfn) + bool *writable, bool *protected, kvm_pfn_t *pfn) { unsigned int flags = FOLL_HWPOISON | FOLL_KVM; + struct vm_area_struct *vma; struct page *page; int npages = 0; @@ -1795,9 +1796,15 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, if (async) flags |= FOLL_NOWAIT; - npages = get_user_pages_unlocked(addr, 1, &page, flags); - if (npages != 1) + down_read(¤t->mm->mmap_sem); + npages = get_user_pages(addr, 1, flags, &page, &vma); + if (npages != 1) { + up_read(¤t->mm->mmap_sem); return npages; + } + if (protected) + *protected = vma_is_kvm_protected(vma); + up_read(¤t->mm->mmap_sem); /* map read fault as writable if possible */ if (unlikely(!write_fault) && writable) { @@ -1888,7 +1895,7 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma, * whether the mapping is writable. */ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, - bool write_fault, bool *writable) + bool write_fault, bool *writable, bool *protected) { struct vm_area_struct *vma; kvm_pfn_t pfn = 0; @@ -1903,7 +1910,8 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, if (atomic) return KVM_PFN_ERR_FAULT; - npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn); + npages = hva_to_pfn_slow(addr, async, write_fault, writable, protected, + &pfn); if (npages == 1) return pfn; @@ -1937,7 +1945,7 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, bool atomic, bool *async, bool write_fault, - bool *writable) + bool *writable, bool *protected) { unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault); @@ -1960,7 +1968,7 @@ kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn, } return hva_to_pfn(addr, atomic, async, write_fault, - writable); + writable, protected); } EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot); @@ -1968,19 +1976,26 @@ kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, bool *writable) { return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL, - write_fault, writable); + write_fault, writable, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_prot); kvm_pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn) { - return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL); + return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot); +static kvm_pfn_t gfn_to_pfn_memslot_protected(struct kvm_memory_slot *slot, + gfn_t gfn, bool *protected) +{ + return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL, + protected); +} + kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn) { - return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL); + return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic); -- 2.26.2
