The vgic virtual cpu and emulated distributor interfaces must
be mapped at a given physical address in the guest. This address is
provided through the KVM_SET_DEVICE_ADDRESS ioctl, which happens after
the KVM_CREATE_IRQCHIP ioctl is called, but before the first VCPU is
excuted thorugh KVM_RUN. We create the vgic on KVM_CREATE_IRQCHIP, but
query kvm_vgic_ready(kvm), which checks if the vgic.vctrl_base field has
been set, before we execute a VCPU, and if it has not been set, we call
kvm_vgic_init, which takes care of the remaining setup.
We use the IS_VGIC_ADDR_UNDEF() macro, which compares to the
VGIC_ADDR_UNDEF constant, to check if an address has been set; it's
unlikely that a device will sit on address 0, but since this is a part
of main kernel boot procedure if this stuff is enabled in the config,
I'm being paranoid.
The distributor and vcpu base addresses used to be a per-host setting
global for all VMs, but this is not a requirement and when we want to
emulate several boards on a single host, we need the flexibility of
storing these guest addresses on a per-VM basis.
Signed-off-by: Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx>
---
arch/arm/include/asm/kvm_vgic.h | 22 +++++++--
arch/arm/kvm/arm.c | 10 ++++
arch/arm/kvm/vgic.c | 97 ++++++++++++++++++++++++++++++---------
3 files changed, 102 insertions(+), 27 deletions(-)
diff --git a/arch/arm/include/asm/kvm_vgic.h b/arch/arm/include/asm/kvm_vgic.h
index a688132..3c71c79 100644
--- a/arch/arm/include/asm/kvm_vgic.h
+++ b/arch/arm/include/asm/kvm_vgic.h
@@ -154,13 +154,14 @@ static inline void vgic_bytemap_set_irq_val(struct vgic_bytemap *x,
struct vgic_dist {
#ifdef CONFIG_KVM_ARM_VGIC
spinlock_t lock;
+ bool ready;
/* Virtual control interface mapping */
void __iomem *vctrl_base;
- /* Distributor mapping in the guest */
- unsigned long vgic_dist_base;
- unsigned long vgic_dist_size;
+ /* Distributor and vcpu interface mapping in the guest */
+ phys_addr_t vgic_dist_base;
+ phys_addr_t vgic_cpu_base;
/* Distributor enabled */
u32 enabled;
@@ -243,6 +244,7 @@ struct kvm_exit_mmio;
#ifdef CONFIG_KVM_ARM_VGIC
int kvm_vgic_hyp_init(void);
int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr);
+int kvm_vgic_create(struct kvm *kvm);
int kvm_vgic_init(struct kvm *kvm);
void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu);
void kvm_vgic_sync_to_cpu(struct kvm_vcpu *vcpu);
@@ -252,8 +254,10 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
struct kvm_exit_mmio *mmio);
+bool irqchip_in_kernel(struct kvm *kvm);
-#define irqchip_in_kernel(k) (!!((k)->arch.vgic.vctrl_base))
+#define irqchip_in_kernel(k) ((k)->arch.vgic.vctrl_base)
+#define vgic_initialized(k) ((k)->arch.vgic.ready)
#define vgic_active_irq(v) (atomic_read(&(v)->arch.vgic_cpu.irq_active_count) == 0)
#else
@@ -267,6 +271,11 @@ static inline int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 add
return 0;
}
+static inline int kvm_vgic_create(struct kvm *kvm)
+{
+ return 0;
+}
+
static inline int kvm_vgic_init(struct kvm *kvm)
{
return 0;
@@ -298,6 +307,11 @@ static inline int irqchip_in_kernel(struct kvm *kvm)
return 0;
}
+static inline bool kvm_vgic_initialized(struct kvm *kvm)
+{
+ return true;
+}
+
static inline int vgic_active_irq(struct kvm_vcpu *vcpu)
{
return 0;
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 282794e..d64783e 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -636,6 +636,14 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
if (unlikely(vcpu->arch.target < 0))
return -ENOEXEC;
+ /* Initalize the VGIC before running the vcpu */
+ if (unlikely(irqchip_in_kernel(vcpu->kvm) &&
+ !vgic_initialized(vcpu->kvm))) {
+ ret = kvm_vgic_init(vcpu->kvm);
+ if (ret)
+ return ret;
+ }
+
if (run->exit_reason == KVM_EXIT_MMIO) {
ret = kvm_handle_mmio_return(vcpu, vcpu->run);
if (ret)
@@ -889,7 +897,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
#ifdef CONFIG_KVM_ARM_VGIC
case KVM_CREATE_IRQCHIP: {
if (vgic_present)
- return kvm_vgic_init(kvm);
+ return kvm_vgic_create(kvm);
else
return -EINVAL;
}
diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
index 82fba58..8fe0e70 100644
--- a/arch/arm/kvm/vgic.c
+++ b/arch/arm/kvm/vgic.c
@@ -65,12 +65,17 @@
* interrupt line to be sampled again.
*/
-/* Temporary hacks, need to be provided by userspace emulation */
-#define VGIC_DIST_BASE 0x2c001000
+#define VGIC_ADDR_UNDEF (-1)
+#define IS_VGIC_ADDR_UNDEF(_x) ((_x) == (typeof(_x))VGIC_ADDR_UNDEF)
+
+
#define VGIC_DIST_SIZE 0x1000
#define VGIC_CPU_BASE 0x2c002000
#define VGIC_CPU_SIZE 0x2000
+/* Physical address of vgic virtual cpu interface */
+static phys_addr_t vgic_vcpu_base;
+
/* Virtual control interface base address */
static void __iomem *vgic_vctrl_base;
@@ -538,7 +543,7 @@ bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run, struct kvm_exi
if (!irqchip_in_kernel(vcpu->kvm) ||
mmio->phys_addr < base ||
- (mmio->phys_addr + mmio->len) > (base + dist->vgic_dist_size))
+ (mmio->phys_addr + mmio->len) > (base + VGIC_DIST_SIZE))
return false;
range = find_matching_range(vgic_ranges, mmio, base);
@@ -1027,7 +1032,7 @@ void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
vgic_cpu->vgic_irq_lr_map[i] = LR_EMPTY;
}
- BUG_ON(!vcpu->kvm->arch.vgic.vctrl_base);
+ BUG_ON(IS_VGIC_ADDR_UNDEF(vcpu->kvm->arch.vgic.vctrl_base));
reg = readl_relaxed(vcpu->kvm->arch.vgic.vctrl_base + GICH_VTR);
vgic_cpu->nr_lr = (reg & 0x1f) + 1;
@@ -1049,6 +1054,7 @@ int kvm_vgic_hyp_init(void)
int ret;
unsigned int irq;
struct resource vctrl_res;
+ struct resource vcpu_res;
vgic_node = of_find_compatible_node(NULL, NULL, "arm,cortex-a15-gic");
if (!vgic_node)
@@ -1089,6 +1095,13 @@ int kvm_vgic_hyp_init(void)
kvm_info("%s@%llx IRQ%d\n", vgic_node->name, vctrl_res.start, irq);
on_each_cpu(vgic_init_maintenance_interrupt, &irq, 1);
+ if (of_address_to_resource(vgic_node, 3, &vcpu_res)) {
+ kvm_err("Cannot obtain VCPU resource\n");
+ ret = -ENXIO;
+ goto out_unmap;
+ }
+ vgic_vcpu_base = vcpu_res.start;
+
return 0;
out_unmap:
@@ -1101,29 +1114,23 @@ out_free_irq:
int kvm_vgic_init(struct kvm *kvm)
{
- int ret, i;
- struct resource vcpu_res;
+ int ret = 0, i;
mutex_lock(&kvm->lock);
- if (of_address_to_resource(vgic_node, 3, &vcpu_res)) {
- kvm_err("Cannot obtain VCPU resource\n");
- ret = -ENXIO;
+ if (vgic_initialized(kvm))
goto out;
- }
- if (atomic_read(&kvm->online_vcpus) || kvm->arch.vgic.vctrl_base) {
- ret = -EEXIST;
+ if (IS_VGIC_ADDR_UNDEF(kvm->arch.vgic.vgic_dist_base) ||
+ IS_VGIC_ADDR_UNDEF(kvm->arch.vgic.vgic_cpu_base)) {
+ kvm_err("Need to set vgic cpu and dist addresses first\n");
+ ret = -ENXIO;
goto out;
}
- spin_lock_init(&kvm->arch.vgic.lock);
- kvm->arch.vgic.vctrl_base = vgic_vctrl_base;
- kvm->arch.vgic.vgic_dist_base = VGIC_DIST_BASE;
- kvm->arch.vgic.vgic_dist_size = VGIC_DIST_SIZE;
+ ret = kvm_phys_addr_ioremap(kvm, kvm->arch.vgic.vgic_cpu_base,
+ vgic_vcpu_base, VGIC_CPU_SIZE);
- ret = kvm_phys_addr_ioremap(kvm, VGIC_CPU_BASE,
- vcpu_res.start, VGIC_CPU_SIZE);
if (ret) {
kvm_err("Unable to remap VGIC CPU to VCPU\n");
goto out;
@@ -1132,18 +1139,52 @@ int kvm_vgic_init(struct kvm *kvm)
for (i = 32; i < VGIC_NR_IRQS; i += 4)
vgic_set_target_reg(kvm, 0, i);
+ kvm_timer_init(kvm);
+ kvm->arch.vgic.ready = true;
out:
mutex_unlock(&kvm->lock);
+ return ret;
+}
+
+int kvm_vgic_create(struct kvm *kvm)
+{
+ int ret;
+
+ mutex_lock(&kvm->lock);
+
+ if (atomic_read(&kvm->online_vcpus) || kvm->arch.vgic.vctrl_base) {
+ ret = -EEXIST;
+ goto out;
+ }
- if (!ret)
- kvm_timer_init(kvm);
+ spin_lock_init(&kvm->arch.vgic.lock);
+ kvm->arch.vgic.vctrl_base = vgic_vctrl_base;
+ kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
+ kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+ ret = 0;
+out:
+ mutex_unlock(&kvm->lock);
return ret;
}
+static bool vgic_ioaddr_overlap(struct kvm *kvm)
+{
+ phys_addr_t dist = kvm->arch.vgic.vgic_dist_base;
+ phys_addr_t cpu = kvm->arch.vgic.vgic_cpu_base;
+
+ if (IS_VGIC_ADDR_UNDEF(dist) || IS_VGIC_ADDR_UNDEF(cpu))
+ return false;
+ if ((dist <= cpu && dist + VGIC_DIST_SIZE > cpu) ||
+ (cpu <= dist && cpu + VGIC_CPU_SIZE > dist))
+ return true;
+ return false;
+}
+
int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)
{
int r = 0;
+ struct vgic_dist *vgic = &kvm->arch.vgic;
if (addr & ~KVM_PHYS_MASK)
return -E2BIG;
@@ -1154,17 +1195,29 @@ int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)
mutex_lock(&kvm->lock);
switch (type) {
case KVM_VGIC_V2_ADDR_TYPE_DIST:
- if (addr != VGIC_DIST_BASE)
+ if (!IS_VGIC_ADDR_UNDEF(vgic->vgic_dist_base))
+ return -EEXIST;
+ if (addr + VGIC_DIST_SIZE < addr)
return -EINVAL;
+ kvm->arch.vgic.vgic_dist_base = addr;
break;
case KVM_VGIC_V2_ADDR_TYPE_CPU:
- if (addr != VGIC_CPU_BASE)
+ if (!IS_VGIC_ADDR_UNDEF(vgic->vgic_cpu_base))
+ return -EEXIST;
+ if (addr + VGIC_CPU_SIZE < addr)
return -EINVAL;
+ kvm->arch.vgic.vgic_cpu_base = addr;
break;
default:
r = -ENODEV;
}
+ if (vgic_ioaddr_overlap(kvm)) {
+ kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
+ kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+ return -EINVAL;
+ }
+
mutex_unlock(&kvm->lock);
return r;
}
--
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