[PATCH v6 9/9] KVM: arm/arm64: vgic-its: Implement KVM_DEV_ARM_ITS_CTRL_RESET

Eric Auger
2017-10-26T15:23:13Z

On reset we clear the valid bits of GITS_CBASER and GITS_BASER<n>.
We also clear command queue registers and free the cache (device,
collection, and lpi lists).

As we need to take the same locks as save/restore functions, we
create a vgic_its_ctrl() wrapper that handles KVM_DEV_ARM_VGIC_GRP_CTRL
group functions.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v5 -> v6:
- Rework the locking and create vgic_its_ctrl

v2 -> v3:
- added Christoffer's R-b
---
arch/arm/include/uapi/asm/kvm.h | 1 +
arch/arm64/include/uapi/asm/kvm.h | 1 +
virt/kvm/arm/vgic/vgic-its.c | 105 ++++++++++++++++++++------------------
3 files changed, 58 insertions(+), 49 deletions(-)

diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
index 5db2d4c..7ef0c06 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -215,6 +215,7 @@ struct kvm_arch_memory_slot {
#define KVM_DEV_ARM_ITS_SAVE_TABLES 1
#define KVM_DEV_ARM_ITS_RESTORE_TABLES 2
#define KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES 3
+#define KVM_DEV_ARM_ITS_CTRL_RESET 4

/* KVM_IRQ_LINE irq field index values */
#define KVM_ARM_IRQ_TYPE_SHIFT 24
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 9f3ca24..b5306ce 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -227,6 +227,7 @@ struct kvm_arch_memory_slot {
#define KVM_DEV_ARM_ITS_SAVE_TABLES 1
#define KVM_DEV_ARM_ITS_RESTORE_TABLES 2
#define KVM_DEV_ARM_VGIC_SAVE_PENDING_TABLES 3
+#define KVM_DEV_ARM_ITS_CTRL_RESET 4

/* Device Control API on vcpu fd */
#define KVM_ARM_VCPU_PMU_V3_CTRL 0
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 2a92d4d..09a459b 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -2301,29 +2301,13 @@ static int vgic_its_restore_collection_table(struct vgic_its *its)
*/
static int vgic_its_save_tables_v0(struct vgic_its *its)
{
- struct kvm *kvm = its->dev->kvm;
int ret;

- mutex_lock(&kvm->lock);
- mutex_lock(&its->its_lock);
-
- if (!lock_all_vcpus(kvm)) {
- mutex_unlock(&its->its_lock);
- mutex_unlock(&kvm->lock);
- return -EBUSY;
- }
-
ret = vgic_its_save_device_tables(its);
if (ret)
- goto out;
-
- ret = vgic_its_save_collection_table(its);
+ return ret;

-out:
- unlock_all_vcpus(kvm);
- mutex_unlock(&its->its_lock);
- mutex_unlock(&kvm->lock);
- return ret;
+ return vgic_its_save_collection_table(its);
}

/**
@@ -2333,29 +2317,13 @@ static int vgic_its_save_tables_v0(struct vgic_its *its)
*/
static int vgic_its_restore_tables_v0(struct vgic_its *its)
{
- struct kvm *kvm = its->dev->kvm;
int ret;

- mutex_lock(&kvm->lock);
- mutex_lock(&its->its_lock);
-
- if (!lock_all_vcpus(kvm)) {
- mutex_unlock(&its->its_lock);
- mutex_unlock(&kvm->lock);
- return -EBUSY;
- }
-
ret = vgic_its_restore_collection_table(its);
if (ret)
- goto out;
-
- ret = vgic_its_restore_device_tables(its);
-out:
- unlock_all_vcpus(kvm);
- mutex_unlock(&its->its_lock);
- mutex_unlock(&kvm->lock);
+ return ret;

- return ret;
+ return vgic_its_restore_device_tables(its);
}

static int vgic_its_commit_v0(struct vgic_its *its)
@@ -2374,6 +2342,19 @@ static int vgic_its_commit_v0(struct vgic_its *its)
return 0;
}

+static void vgic_its_reset(struct kvm *kvm, struct vgic_its *its)
+{
+ /* We need to keep the ABI specific field values */
+ its->baser_coll_table &= ~GITS_BASER_VALID;
+ its->baser_device_table &= ~GITS_BASER_VALID;
+ its->cbaser = 0;
+ its->creadr = 0;
+ its->cwriter = 0;
+ its->enabled = 0;
+ vgic_its_free_device_list(kvm, its);
+ vgic_its_free_collection_list(kvm, its);
+}
+
static int vgic_its_has_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
@@ -2388,6 +2369,8 @@ static int vgic_its_has_attr(struct kvm_device *dev,
switch (attr->attr) {
case KVM_DEV_ARM_VGIC_CTRL_INIT:
return 0;
+ case KVM_DEV_ARM_ITS_CTRL_RESET:
+ return 0;
case KVM_DEV_ARM_ITS_SAVE_TABLES:
return 0;
case KVM_DEV_ARM_ITS_RESTORE_TABLES:
@@ -2400,6 +2383,41 @@ static int vgic_its_has_attr(struct kvm_device *dev,
return -ENXIO;
}

+static int vgic_its_ctrl(struct kvm *kvm, struct vgic_its *its, u64 attr)
+{
+ const struct vgic_its_abi *abi = vgic_its_get_abi(its);
+ int ret = 0;
+
+ if (attr == KVM_DEV_ARM_VGIC_CTRL_INIT) /* Nothing to do */
+ return 0;
+
+ mutex_lock(&kvm->lock);
+ mutex_lock(&its->its_lock);
+
+ if (!lock_all_vcpus(kvm)) {
+ mutex_unlock(&its->its_lock);
+ mutex_unlock(&kvm->lock);
+ return -EBUSY;
+ }
+
+ switch (attr) {
+ case KVM_DEV_ARM_ITS_CTRL_RESET:
+ vgic_its_reset(kvm, its);
+ break;
+ case KVM_DEV_ARM_ITS_SAVE_TABLES:
+ ret = abi->save_tables(its);
+ break;
+ case KVM_DEV_ARM_ITS_RESTORE_TABLES:
+ ret = abi->restore_tables(its);
+ break;
+ }
+
+ unlock_all_vcpus(kvm);
+ mutex_unlock(&its->its_lock);
+ mutex_unlock(&kvm->lock);
+ return ret;
+}
+
static int vgic_its_set_attr(struct kvm_device *dev,
struct kvm_device_attr *attr)
{
@@ -2425,19 +2443,8 @@ static int vgic_its_set_attr(struct kvm_device *dev,

return vgic_register_its_iodev(dev->kvm, its, addr);
}
- case KVM_DEV_ARM_VGIC_GRP_CTRL: {
- const struct vgic_its_abi *abi = vgic_its_get_abi(its);
-
- switch (attr->attr) {
- case KVM_DEV_ARM_VGIC_CTRL_INIT:
- /* Nothing to do */
- return 0;
- case KVM_DEV_ARM_ITS_SAVE_TABLES:
- return abi->save_tables(its);
- case KVM_DEV_ARM_ITS_RESTORE_TABLES:
- return abi->restore_tables(its);
- }
- }
+ case KVM_DEV_ARM_VGIC_GRP_CTRL:
+ return vgic_its_ctrl(dev->kvm, its, attr->attr);
case KVM_DEV_ARM_VGIC_GRP_ITS_REGS: {
u64 __user *uaddr = (u64 __user *)(long)attr->addr;
u64 reg;
--
2.5.5