9 files changed, 99 insertions, 10 deletions

diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
index 76e61c883347..b2f60ca8b60c 100644
--- a/Documentation/virtual/kvm/devices/arm-vgic.txt
+++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
@@ -83,6 +83,12 @@ Groups:
 
     Bits for undefined preemption levels are RAZ/WI.
 
+    For historical reasons and to provide ABI compatibility with userspace we
+    export the GICC_PMR register in the format of the GICH_VMCR.VMPriMask
+    field in the lower 5 bits of a word, meaning that userspace must always
+    use the lower 5 bits to communicate with the KVM device and must shift the
+    value left by 3 places to obtain the actual priority mask level.
+
   Limitations:
     - Priorities are not implemented, and registers are RAZ/WI
     - Currently only implemented for KVM_DEV_TYPE_ARM_VGIC_V2.
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 96dba7cd8be7..314eb6abe1ff 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -1124,6 +1124,9 @@ static void cpu_hyp_reinit(void)
                 if (__hyp_get_vectors() == hyp_default_vectors)
                         cpu_init_hyp_mode(NULL);
         }
+
+        if (vgic_present)
+                kvm_vgic_init_cpu_hardware();
 }
 
 static void cpu_hyp_reset(void)
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 962616fd4ddd..582a972371cf 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -292,11 +292,18 @@ static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
         phys_addr_t addr = start, end = start + size;
         phys_addr_t next;
 
+        assert_spin_locked(&kvm->mmu_lock);
         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
         do {
                 next = stage2_pgd_addr_end(addr, end);
                 if (!stage2_pgd_none(*pgd))
                         unmap_stage2_puds(kvm, pgd, addr, next);
+                /*
+                 * If the range is too large, release the kvm->mmu_lock
+                 * to prevent starvation and lockup detector warnings.
+                 */
+                if (next != end)
+                        cond_resched_lock(&kvm->mmu_lock);
         } while (pgd++, addr = next, addr != end);
 }
 
@@ -803,6 +810,7 @@ void stage2_unmap_vm(struct kvm *kvm)
         int idx;
 
         idx = srcu_read_lock(&kvm->srcu);
+        down_read(&current->mm->mmap_sem);
         spin_lock(&kvm->mmu_lock);
 
         slots = kvm_memslots(kvm);
@@ -810,6 +818,7 @@ void stage2_unmap_vm(struct kvm *kvm)
                 stage2_unmap_memslot(kvm, memslot);
 
         spin_unlock(&kvm->mmu_lock);
+        up_read(&current->mm->mmap_sem);
         srcu_read_unlock(&kvm->srcu, idx);
 }
 
@@ -829,7 +838,10 @@ void kvm_free_stage2_pgd(struct kvm *kvm)
         if (kvm->arch.pgd == NULL)
                 return;
 
+        spin_lock(&kvm->mmu_lock);
         unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
+        spin_unlock(&kvm->mmu_lock);
+
         /* Free the HW pgd, one page at a time */
         free_pages_exact(kvm->arch.pgd, S2_PGD_SIZE);
         kvm->arch.pgd = NULL;
@@ -1801,6 +1813,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
             (KVM_PHYS_SIZE >> PAGE_SHIFT))
                 return -EFAULT;
 
+        down_read(&current->mm->mmap_sem);
         /*
          * A memory region could potentially cover multiple VMAs, and any holes
          * between them, so iterate over all of them to find out if we can map
@@ -1844,8 +1857,10 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
                         pa += vm_start - vma->vm_start;
 
                         /* IO region dirty page logging not allowed */
-                        if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES)
-                                return -EINVAL;
+                        if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) {
+                                ret = -EINVAL;
+                                goto out;
+                        }
 
                         ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
                                                     vm_end - vm_start,
@@ -1857,7 +1872,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
         } while (hva < reg_end);
 
         if (change == KVM_MR_FLAGS_ONLY)
-                return ret;
+                goto out;
 
         spin_lock(&kvm->mmu_lock);
         if (ret)
@@ -1865,6 +1880,8 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
         else
                 stage2_flush_memslot(kvm, memslot);
         spin_unlock(&kvm->mmu_lock);
+out:
+        up_read(&current->mm->mmap_sem);
         return ret;
 }
 
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index b72dd2ad5f44..c0b3d999c266 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -295,6 +295,7 @@ void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu);
 void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu);
 int kvm_vgic_map_resources(struct kvm *kvm);
 int kvm_vgic_hyp_init(void);
+void kvm_vgic_init_cpu_hardware(void);
 
 int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
                         bool level);
diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h
index eafc965b3eb8..dc30f3d057eb 100644
--- a/include/linux/irqchip/arm-gic.h
+++ b/include/linux/irqchip/arm-gic.h
@@ -96,6 +96,9 @@
 #define GICH_MISR_EOI                   (1 << 0)
 #define GICH_MISR_U                     (1 << 1)
 
+#define GICV_PMR_PRIORITY_SHIFT         3
+#define GICV_PMR_PRIORITY_MASK          (0x1f << GICV_PMR_PRIORITY_SHIFT)
+
 #ifndef __ASSEMBLY__
 
 #include <linux/irqdomain.h>
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 276139a24e6f..702f8108608d 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -392,6 +392,25 @@ static irqreturn_t vgic_maintenance_handler(int irq, void *data)
 }
 
 /**
+ * kvm_vgic_init_cpu_hardware - initialize the GIC VE hardware
+ *
+ * For a specific CPU, initialize the GIC VE hardware.
+ */
+void kvm_vgic_init_cpu_hardware(void)
+{
+        BUG_ON(preemptible());
+
+        /*
+         * We want to make sure the list registers start out clear so that we
+         * only have the program the used registers.
+         */
+        if (kvm_vgic_global_state.type == VGIC_V2)
+                vgic_v2_init_lrs();
+        else
+                kvm_call_hyp(__vgic_v3_init_lrs);
+}
+
+/**
  * kvm_vgic_hyp_init: populates the kvm_vgic_global_state variable
  * according to the host GIC model. Accordingly calls either
  * vgic_v2/v3_probe which registers the KVM_DEVICE that can be
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index a3ad7ff95c9b..0a4283ed9aa7 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c