Being able to lock/unlock all vcpus in one go is a feature that
only the vgic has enjoyed so far. Let's be brave and expose it
to the world.
Reviewed-by: Colton Lewis <coltonlewis@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 3 ++
arch/arm64/kvm/arm.c | 43 +++++++++++++++++++++++++++
arch/arm64/kvm/vgic/vgic-kvm-device.c | 38 -----------------------
arch/arm64/kvm/vgic/vgic.h | 3 --
4 files changed, 46 insertions(+), 41 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index bcd774d74f34..002a10cbade2 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -922,6 +922,9 @@ void kvm_reset_sys_regs(struct kvm_vcpu *vcpu);
int __init kvm_sys_reg_table_init(void);
+bool lock_all_vcpus(struct kvm *kvm);
+void unlock_all_vcpus(struct kvm *kvm);
+
/* MMIO helpers */
void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 3bd732eaf087..ae5110cc3bad 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1484,6 +1484,49 @@ long kvm_arch_vm_ioctl(struct file *filp,
}
}
+/* unlocks vcpus from @vcpu_lock_idx and smaller */
+static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx)
+{
+ struct kvm_vcpu *tmp_vcpu;
+
+ for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
+ tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
+ mutex_unlock(&tmp_vcpu->mutex);
+ }
+}
+
+void unlock_all_vcpus(struct kvm *kvm)
+{
+ lockdep_assert_held(&kvm->lock);
+
+ unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1);
+}
+
+/* Returns true if all vcpus were locked, false otherwise */
+bool lock_all_vcpus(struct kvm *kvm)
+{
+ struct kvm_vcpu *tmp_vcpu;
+ unsigned long c;
+
+ lockdep_assert_held(&kvm->lock);
+
+ /*
+ * Any time a vcpu is in an ioctl (including running), the
+ * core KVM code tries to grab the vcpu->mutex.
+ *
+ * By grabbing the vcpu->mutex of all VCPUs we ensure that no
+ * other VCPUs can fiddle with the state while we access it.
+ */
+ kvm_for_each_vcpu(c, tmp_vcpu, kvm) {
+ if (!mutex_trylock(&tmp_vcpu->mutex)) {
+ unlock_vcpus(kvm, c - 1);
+ return false;
+ }
+ }
+
+ return true;
+}
+
static unsigned long nvhe_percpu_size(void)
{
return (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_end) -
diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
index edeac2380591..04dd68835b3f 100644
--- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
+++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
@@ -342,44 +342,6 @@ int vgic_v2_parse_attr(struct kvm_device *dev, struct kvm_device_attr *attr,
return 0;
}
-/* unlocks vcpus from @vcpu_lock_idx and smaller */
-static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx)
-{
- struct kvm_vcpu *tmp_vcpu;
-
- for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
- tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
- mutex_unlock(&tmp_vcpu->mutex);
- }
-}
-
-void unlock_all_vcpus(struct kvm *kvm)
-{
- unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1);
-}
-
-/* Returns true if all vcpus were locked, false otherwise */
-bool lock_all_vcpus(struct kvm *kvm)
-{
- struct kvm_vcpu *tmp_vcpu;
- unsigned long c;
-
- /*
- * Any time a vcpu is run, vcpu_load is called which tries to grab the
- * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
- * that no other VCPUs are run and fiddle with the vgic state while we
- * access it.
- */
- kvm_for_each_vcpu(c, tmp_vcpu, kvm) {
- if (!mutex_trylock(&tmp_vcpu->mutex)) {
- unlock_vcpus(kvm, c - 1);
- return false;
- }
- }
-
- return true;
-}
-
/**
* vgic_v2_attr_regs_access - allows user space to access VGIC v2 state
*
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index 7f7f3c5ed85a..f9923beedd27 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -273,9 +273,6 @@ int vgic_init(struct kvm *kvm);
void vgic_debug_init(struct kvm *kvm);
void vgic_debug_destroy(struct kvm *kvm);
-bool lock_all_vcpus(struct kvm *kvm);
-void unlock_all_vcpus(struct kvm *kvm);
-
static inline int vgic_v3_max_apr_idx(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *cpu_if = &vcpu->arch.vgic_cpu;
--
2.34.1
