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Diffstat (limited to 'arch/arm/kvm/mmu.c')
-rw-r--r--arch/arm/kvm/mmu.c92
1 files changed, 86 insertions, 6 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 8664ff17cbbe..1dc9778a00af 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -612,6 +612,71 @@ static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
unmap_range(kvm, kvm->arch.pgd, start, size);
}
+static void stage2_unmap_memslot(struct kvm *kvm,
+ struct kvm_memory_slot *memslot)
+{
+ hva_t hva = memslot->userspace_addr;
+ phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
+ phys_addr_t size = PAGE_SIZE * memslot->npages;
+ hva_t reg_end = hva + size;
+
+ /*
+ * A memory region could potentially cover multiple VMAs, and any holes
+ * between them, so iterate over all of them to find out if we should
+ * unmap any of them.
+ *
+ * +--------------------------------------------+
+ * +---------------+----------------+ +----------------+
+ * | : VMA 1 | VMA 2 | | VMA 3 : |
+ * +---------------+----------------+ +----------------+
+ * | memory region |
+ * +--------------------------------------------+
+ */
+ do {
+ struct vm_area_struct *vma = find_vma(current->mm, hva);
+ hva_t vm_start, vm_end;
+
+ if (!vma || vma->vm_start >= reg_end)
+ break;
+
+ /*
+ * Take the intersection of this VMA with the memory region
+ */
+ vm_start = max(hva, vma->vm_start);
+ vm_end = min(reg_end, vma->vm_end);
+
+ if (!(vma->vm_flags & VM_PFNMAP)) {
+ gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
+ unmap_stage2_range(kvm, gpa, vm_end - vm_start);
+ }
+ hva = vm_end;
+ } while (hva < reg_end);
+}
+
+/**
+ * stage2_unmap_vm - Unmap Stage-2 RAM mappings
+ * @kvm: The struct kvm pointer
+ *
+ * Go through the memregions and unmap any reguler RAM
+ * backing memory already mapped to the VM.
+ */
+void stage2_unmap_vm(struct kvm *kvm)
+{
+ struct kvm_memslots *slots;
+ struct kvm_memory_slot *memslot;
+ int idx;
+
+ idx = srcu_read_lock(&kvm->srcu);
+ spin_lock(&kvm->mmu_lock);
+
+ slots = kvm_memslots(kvm);
+ kvm_for_each_memslot(memslot, slots)
+ stage2_unmap_memslot(kvm, memslot);
+
+ spin_unlock(&kvm->mmu_lock);
+ srcu_read_unlock(&kvm->srcu, idx);
+}
+
/**
* kvm_free_stage2_pgd - free all stage-2 tables
* @kvm: The KVM struct pointer for the VM.
@@ -853,6 +918,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
struct vm_area_struct *vma;
pfn_t pfn;
pgprot_t mem_type = PAGE_S2;
+ bool fault_ipa_uncached;
write_fault = kvm_is_write_fault(vcpu);
if (fault_status == FSC_PERM && !write_fault) {
@@ -919,6 +985,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
if (!hugetlb && !force_pte)
hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
+ fault_ipa_uncached = memslot->flags & KVM_MEMSLOT_INCOHERENT;
+
if (hugetlb) {
pmd_t new_pmd = pfn_pmd(pfn, mem_type);
new_pmd = pmd_mkhuge(new_pmd);
@@ -926,7 +994,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
kvm_set_s2pmd_writable(&new_pmd);
kvm_set_pfn_dirty(pfn);
}
- coherent_cache_guest_page(vcpu, hva & PMD_MASK, PMD_SIZE);
+ coherent_cache_guest_page(vcpu, hva & PMD_MASK, PMD_SIZE,
+ fault_ipa_uncached);
ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
} else {
pte_t new_pte = pfn_pte(pfn, mem_type);
@@ -934,7 +1003,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
kvm_set_s2pte_writable(&new_pte);
kvm_set_pfn_dirty(pfn);
}
- coherent_cache_guest_page(vcpu, hva, PAGE_SIZE);
+ coherent_cache_guest_page(vcpu, hva, PAGE_SIZE,
+ fault_ipa_uncached);
ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte,
pgprot_val(mem_type) == pgprot_val(PAGE_S2_DEVICE));
}
@@ -1294,11 +1364,12 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
hva = vm_end;
} while (hva < reg_end);
- if (ret) {
- spin_lock(&kvm->mmu_lock);
+ spin_lock(&kvm->mmu_lock);
+ if (ret)
unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size);
- spin_unlock(&kvm->mmu_lock);
- }
+ else
+ stage2_flush_memslot(kvm, memslot);
+ spin_unlock(&kvm->mmu_lock);
return ret;
}
@@ -1310,6 +1381,15 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
unsigned long npages)
{
+ /*
+ * Readonly memslots are not incoherent with the caches by definition,
+ * but in practice, they are used mostly to emulate ROMs or NOR flashes
+ * that the guest may consider devices and hence map as uncached.
+ * To prevent incoherency issues in these cases, tag all readonly
+ * regions as incoherent.
+ */
+ if (slot->flags & KVM_MEM_READONLY)
+ slot->flags |= KVM_MEMSLOT_INCOHERENT;
return 0;
}