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-rw-r--r--arch/arm/kvm/psci.c235
1 files changed, 216 insertions, 19 deletions
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 448f60e8d23c..09cf37737ee2 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -27,6 +27,36 @@
* as described in ARM document number ARM DEN 0022A.
*/
+#define AFFINITY_MASK(level) ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1)
+
+static unsigned long psci_affinity_mask(unsigned long affinity_level)
+{
+ if (affinity_level <= 3)
+ return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level);
+
+ return 0;
+}
+
+static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu)
+{
+ /*
+ * NOTE: For simplicity, we make VCPU suspend emulation to be
+ * same-as WFI (Wait-for-interrupt) emulation.
+ *
+ * This means for KVM the wakeup events are interrupts and
+ * this is consistent with intended use of StateID as described
+ * in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A).
+ *
+ * Further, we also treat power-down request to be same as
+ * stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2
+ * specification (ARM DEN 0022A). This means all suspend states
+ * for KVM will preserve the register state.
+ */
+ kvm_vcpu_block(vcpu);
+
+ return PSCI_RET_SUCCESS;
+}
+
static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
{
vcpu->arch.pause = true;
@@ -38,6 +68,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
struct kvm_vcpu *vcpu = NULL, *tmp;
wait_queue_head_t *wq;
unsigned long cpu_id;
+ unsigned long context_id;
unsigned long mpidr;
phys_addr_t target_pc;
int i;
@@ -58,10 +89,17 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
* Make sure the caller requested a valid CPU and that the CPU is
* turned off.
*/
- if (!vcpu || !vcpu->arch.pause)
- return KVM_PSCI_RET_INVAL;
+ if (!vcpu)
+ return PSCI_RET_INVALID_PARAMS;
+ if (!vcpu->arch.pause) {
+ if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
+ return PSCI_RET_ALREADY_ON;
+ else
+ return PSCI_RET_INVALID_PARAMS;
+ }
target_pc = *vcpu_reg(source_vcpu, 2);
+ context_id = *vcpu_reg(source_vcpu, 3);
kvm_reset_vcpu(vcpu);
@@ -76,26 +114,160 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
kvm_vcpu_set_be(vcpu);
*vcpu_pc(vcpu) = target_pc;
+ /*
+ * NOTE: We always update r0 (or x0) because for PSCI v0.1
+ * the general puspose registers are undefined upon CPU_ON.
+ */
+ *vcpu_reg(vcpu, 0) = context_id;
vcpu->arch.pause = false;
smp_mb(); /* Make sure the above is visible */
wq = kvm_arch_vcpu_wq(vcpu);
wake_up_interruptible(wq);
- return KVM_PSCI_RET_SUCCESS;
+ return PSCI_RET_SUCCESS;
}
-/**
- * kvm_psci_call - handle PSCI call if r0 value is in range
- * @vcpu: Pointer to the VCPU struct
- *
- * Handle PSCI calls from guests through traps from HVC instructions.
- * The calling convention is similar to SMC calls to the secure world where
- * the function number is placed in r0 and this function returns true if the
- * function number specified in r0 is withing the PSCI range, and false
- * otherwise.
- */
-bool kvm_psci_call(struct kvm_vcpu *vcpu)
+static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
+{
+ int i;
+ unsigned long mpidr;
+ unsigned long target_affinity;
+ unsigned long target_affinity_mask;
+ unsigned long lowest_affinity_level;
+ struct kvm *kvm = vcpu->kvm;
+ struct kvm_vcpu *tmp;
+
+ target_affinity = *vcpu_reg(vcpu, 1);
+ lowest_affinity_level = *vcpu_reg(vcpu, 2);
+
+ /* Determine target affinity mask */
+ target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
+ if (!target_affinity_mask)
+ return PSCI_RET_INVALID_PARAMS;
+
+ /* Ignore other bits of target affinity */
+ target_affinity &= target_affinity_mask;
+
+ /*
+ * If one or more VCPU matching target affinity are running
+ * then ON else OFF
+ */
+ kvm_for_each_vcpu(i, tmp, kvm) {
+ mpidr = kvm_vcpu_get_mpidr(tmp);
+ if (((mpidr & target_affinity_mask) == target_affinity) &&
+ !tmp->arch.pause) {
+ return PSCI_0_2_AFFINITY_LEVEL_ON;
+ }
+ }
+
+ return PSCI_0_2_AFFINITY_LEVEL_OFF;
+}
+
+static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
+{
+ memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
+ vcpu->run->system_event.type = type;
+ vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
+}
+
+static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
+{
+ kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
+}
+
+static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
+{
+ kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
+}
+
+int kvm_psci_version(struct kvm_vcpu *vcpu)
+{
+ if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
+ return KVM_ARM_PSCI_0_2;
+
+ return KVM_ARM_PSCI_0_1;
+}
+
+static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
+{
+ int ret = 1;
+ unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
+ unsigned long val;
+
+ switch (psci_fn) {
+ case PSCI_0_2_FN_PSCI_VERSION:
+ /*
+ * Bits[31:16] = Major Version = 0
+ * Bits[15:0] = Minor Version = 2
+ */
+ val = 2;
+ break;
+ case PSCI_0_2_FN_CPU_SUSPEND:
+ case PSCI_0_2_FN64_CPU_SUSPEND:
+ val = kvm_psci_vcpu_suspend(vcpu);
+ break;
+ case PSCI_0_2_FN_CPU_OFF:
+ kvm_psci_vcpu_off(vcpu);
+ val = PSCI_RET_SUCCESS;
+ break;
+ case PSCI_0_2_FN_CPU_ON:
+ case PSCI_0_2_FN64_CPU_ON:
+ val = kvm_psci_vcpu_on(vcpu);
+ break;
+ case PSCI_0_2_FN_AFFINITY_INFO:
+ case PSCI_0_2_FN64_AFFINITY_INFO:
+ val = kvm_psci_vcpu_affinity_info(vcpu);
+ break;
+ case PSCI_0_2_FN_MIGRATE:
+ case PSCI_0_2_FN64_MIGRATE:
+ val = PSCI_RET_NOT_SUPPORTED;
+ break;
+ case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
+ /*
+ * Trusted OS is MP hence does not require migration
+ * or
+ * Trusted OS is not present
+ */
+ val = PSCI_0_2_TOS_MP;
+ break;
+ case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
+ case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
+ val = PSCI_RET_NOT_SUPPORTED;
+ break;
+ case PSCI_0_2_FN_SYSTEM_OFF:
+ kvm_psci_system_off(vcpu);
+ /*
+ * We should'nt be going back to guest VCPU after
+ * receiving SYSTEM_OFF request.
+ *
+ * If user space accidently/deliberately resumes
+ * guest VCPU after SYSTEM_OFF request then guest
+ * VCPU should see internal failure from PSCI return
+ * value. To achieve this, we preload r0 (or x0) with
+ * PSCI return value INTERNAL_FAILURE.
+ */
+ val = PSCI_RET_INTERNAL_FAILURE;
+ ret = 0;
+ break;
+ case PSCI_0_2_FN_SYSTEM_RESET:
+ kvm_psci_system_reset(vcpu);
+ /*
+ * Same reason as SYSTEM_OFF for preloading r0 (or x0)
+ * with PSCI return value INTERNAL_FAILURE.
+ */
+ val = PSCI_RET_INTERNAL_FAILURE;
+ ret = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ *vcpu_reg(vcpu, 0) = val;
+ return ret;
+}
+
+static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
{
unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
unsigned long val;
@@ -103,20 +275,45 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu)
switch (psci_fn) {
case KVM_PSCI_FN_CPU_OFF:
kvm_psci_vcpu_off(vcpu);
- val = KVM_PSCI_RET_SUCCESS;
+ val = PSCI_RET_SUCCESS;
break;
case KVM_PSCI_FN_CPU_ON:
val = kvm_psci_vcpu_on(vcpu);
break;
case KVM_PSCI_FN_CPU_SUSPEND:
case KVM_PSCI_FN_MIGRATE:
- val = KVM_PSCI_RET_NI;
+ val = PSCI_RET_NOT_SUPPORTED;
break;
-
default:
- return false;
+ return -EINVAL;
}
*vcpu_reg(vcpu, 0) = val;
- return true;
+ return 1;
+}
+
+/**
+ * kvm_psci_call - handle PSCI call if r0 value is in range
+ * @vcpu: Pointer to the VCPU struct
+ *
+ * Handle PSCI calls from guests through traps from HVC instructions.
+ * The calling convention is similar to SMC calls to the secure world
+ * where the function number is placed in r0.
+ *
+ * This function returns: > 0 (success), 0 (success but exit to user
+ * space), and < 0 (errors)
+ *
+ * Errors:
+ * -EINVAL: Unrecognized PSCI function
+ */
+int kvm_psci_call(struct kvm_vcpu *vcpu)
+{
+ switch (kvm_psci_version(vcpu)) {
+ case KVM_ARM_PSCI_0_2:
+ return kvm_psci_0_2_call(vcpu);
+ case KVM_ARM_PSCI_0_1:
+ return kvm_psci_0_1_call(vcpu);
+ default:
+ return -EINVAL;
+ };
}