Merge tag 'kvmarm-fixes-for-5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm fixes for 5.3, take #2

- Fix our system register reset so that we stop writing
  non-sensical values to them, and track which registers
  get reset instead.
- Sync VMCR back from the GIC on WFI so that KVM has an
  exact vue of PMR.
- Reevaluate state of HW-mapped, level triggered interrupts
  on enable.

6 files changed, 54 insertions, 2 deletions

diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 3f7bea930acf..35a069815baf 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -318,6 +318,17 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 
 void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
 {
+        /*
+         * If we're about to block (most likely because we've just hit a
+         * WFI), we need to sync back the state of the GIC CPU interface
+         * so that we have the lastest PMR and group enables. This ensures
+         * that kvm_arch_vcpu_runnable has up-to-date data to decide
+         * whether we have pending interrupts.
+         */
+        preempt_disable();
+        kvm_vgic_vmcr_sync(vcpu);
+        preempt_enable();
+
         kvm_vgic_v4_enable_doorbell(vcpu);
 }
 
diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
index 3ba7278fb533..44efc2ff863f 100644
--- a/virt/kvm/arm/vgic/vgic-mmio.c
+++ b/virt/kvm/arm/vgic/vgic-mmio.c
@@ -113,6 +113,22 @@ void vgic_mmio_write_senable(struct kvm_vcpu *vcpu,
                 struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i);
 
                 raw_spin_lock_irqsave(&irq->irq_lock, flags);
+                if (vgic_irq_is_mapped_level(irq)) {
+                        bool was_high = irq->line_level;
+
+                        /*
+                         * We need to update the state of the interrupt because
+                         * the guest might have changed the state of the device
+                         * while the interrupt was disabled at the VGIC level.
+                         */
+                        irq->line_level = vgic_get_phys_line_level(irq);
+                        /*
+                         * Deactivate the physical interrupt so the GIC will let
+                         * us know when it is asserted again.
+                         */
+                        if (!irq->active && was_high && !irq->line_level)
+                                vgic_irq_set_phys_active(irq, false);
+                }
                 irq->enabled = true;
                 vgic_queue_irq_unlock(vcpu->kvm, irq, flags);
 
diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
index 6dd5ad706c92..96aab77d0471 100644
--- a/virt/kvm/arm/vgic/vgic-v2.c
+++ b/virt/kvm/arm/vgic/vgic-v2.c
@@ -484,10 +484,17 @@ void vgic_v2_load(struct kvm_vcpu *vcpu)
                        kvm_vgic_global_state.vctrl_base + GICH_APR);
 }
 
-void vgic_v2_put(struct kvm_vcpu *vcpu)
+void vgic_v2_vmcr_sync(struct kvm_vcpu *vcpu)
 {
         struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
 
         cpu_if->vgic_vmcr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VMCR);
+}
+
+void vgic_v2_put(struct kvm_vcpu *vcpu)
+{
+        struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+
+        vgic_v2_vmcr_sync(vcpu);
         cpu_if->vgic_apr = readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_APR);
 }
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index c2c9ce009f63..0c653a1e5215 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -662,12 +662,17 @@ void vgic_v3_load(struct kvm_vcpu *vcpu)
                 __vgic_v3_activate_traps(vcpu);
 }
 
-void vgic_v3_put(struct kvm_vcpu *vcpu)
+void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu)
 {
         struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3;
 
         if (likely(cpu_if->vgic_sre))
                 cpu_if->vgic_vmcr = kvm_call_hyp_ret(__vgic_v3_read_vmcr);
+}
+
+void vgic_v3_put(struct kvm_vcpu *vcpu)
+{
+        vgic_v3_vmcr_sync(vcpu);
 
         kvm_call_hyp(__vgic_v3_save_aprs, vcpu);
 
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index 04786c8ec77e..13d4b38a94ec 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -919,6 +919,17 @@ void kvm_vgic_put(struct kvm_vcpu *vcpu)
                 vgic_v3_put(vcpu);
 }
 
+void kvm_vgic_vmcr_sync(struct kvm_vcpu *vcpu)
+{
+        if (unlikely(!irqchip_in_kernel(vcpu->kvm)))
+                return;
+
+        if (kvm_vgic_global_state.type == VGIC_V2)
+                vgic_v2_vmcr_sync(vcpu);
+        else
+                vgic_v3_vmcr_sync(vcpu);
+}
+
 int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu)
 {
         struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 3b7525deec80..797e05004d80 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -193,6 +193,7 @@ int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
 void vgic_v2_init_lrs(void);
 void vgic_v2_load(struct kvm_vcpu *vcpu);
 void vgic_v2_put(struct kvm_vcpu *vcpu);
+void vgic_v2_vmcr_sync(struct kvm_vcpu *vcpu);
 
 void vgic_v2_save_state(struct kvm_vcpu *vcpu);
 void vgic_v2_restore_state(struct kvm_vcpu *vcpu);
@@ -223,6 +224,7 @@ bool vgic_v3_check_base(struct kvm *kvm);
 
 void vgic_v3_load(struct kvm_vcpu *vcpu);
 void vgic_v3_put(struct kvm_vcpu *vcpu);
+void vgic_v3_vmcr_sync(struct kvm_vcpu *vcpu);
 
 bool vgic_has_its(struct kvm *kvm);
 int kvm_vgic_register_its_device(void);