From: Fuad Tabba <tabba@xxxxxxxxxx>
Add PSCI 1.1 support for protected VMs at EL2.
Signed-off-by: Fuad Tabba <tabba@xxxxxxxxxx>
---
arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 13 +
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 69 +++++-
arch/arm64/kvm/hyp/nvhe/pkvm.c | 320 ++++++++++++++++++++++++-
3 files changed, 399 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
index 33d34cc639ea..c1987115b217 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h
@@ -28,6 +28,15 @@ struct kvm_shadow_vcpu_state {
/* Tracks exit code for the protected guest. */
u32 exit_code;
+ /*
+ * Track the power state transition of a protected vcpu.
+ * Can be in one of three states:
+ * PSCI_0_2_AFFINITY_LEVEL_ON
+ * PSCI_0_2_AFFINITY_LEVEL_OFF
+ * PSCI_0_2_AFFINITY_LEVEL_PENDING
+ */
+ int power_state;
+
/*
* Points to the per-cpu pointer of the cpu where it's loaded, or NULL
* if not loaded.
@@ -101,6 +110,10 @@ bool kvm_handle_pvm_restricted(struct kvm_vcpu *vcpu, u64 *exit_code);
void kvm_reset_pvm_sys_regs(struct kvm_vcpu *vcpu);
int kvm_check_pvm_sysreg_table(void);
+void pkvm_reset_vcpu(struct kvm_shadow_vcpu_state *shadow_state);
+
bool kvm_handle_pvm_hvc64(struct kvm_vcpu *vcpu, u64 *exit_code);
+struct kvm_shadow_vcpu_state *pkvm_mpidr_to_vcpu_state(struct kvm_shadow_vm *vm, unsigned long mpidr);
+
#endif /* __ARM64_KVM_NVHE_PKVM_H__ */
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 26c8709f5494..c4778c7d8c4b 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -21,6 +21,7 @@
#include <nvhe/trap_handler.h>
#include <linux/irqchip/arm-gic-v3.h>
+#include <uapi/linux/psci.h>
#include "../../sys_regs.h"
@@ -46,8 +47,37 @@ static void handle_pvm_entry_wfx(struct kvm_vcpu *host_vcpu, struct kvm_vcpu *sh
static void handle_pvm_entry_hvc64(struct kvm_vcpu *host_vcpu, struct kvm_vcpu *shadow_vcpu)
{
+ u32 psci_fn = smccc_get_function(shadow_vcpu);
u64 ret = READ_ONCE(host_vcpu->arch.ctxt.regs.regs[0]);
+ switch (psci_fn) {
+ case PSCI_0_2_FN_CPU_ON:
+ case PSCI_0_2_FN64_CPU_ON:
+ /*
+ * Check whether the cpu_on request to the host was successful.
+ * If not, reset the vcpu state from ON_PENDING to OFF.
+ * This could happen if this vcpu attempted to turn on the other
+ * vcpu while the other one is in the process of turning itself
+ * off.
+ */
+ if (ret != PSCI_RET_SUCCESS) {
+ unsigned long cpu_id = smccc_get_arg1(shadow_vcpu);
+ struct kvm_shadow_vm *shadow_vm;
+ struct kvm_shadow_vcpu_state *target_vcpu_state;
+
+ shadow_vm = get_shadow_vm(shadow_vcpu);
+ target_vcpu_state = pkvm_mpidr_to_vcpu_state(shadow_vm, cpu_id);
+
+ if (target_vcpu_state && READ_ONCE(target_vcpu_state->power_state) == PSCI_0_2_AFFINITY_LEVEL_ON_PENDING)
+ WRITE_ONCE(target_vcpu_state->power_state, PSCI_0_2_AFFINITY_LEVEL_OFF);
+
+ ret = PSCI_RET_INTERNAL_FAILURE;
+ }
+ break;
+ default:
+ break;
+ }
+
vcpu_set_reg(shadow_vcpu, 0, ret);
}
@@ -206,13 +236,45 @@ static void handle_pvm_exit_sys64(struct kvm_vcpu *host_vcpu, struct kvm_vcpu *s
static void handle_pvm_exit_hvc64(struct kvm_vcpu *host_vcpu, struct kvm_vcpu *shadow_vcpu)
{
- int i;
+ int n, i;
+
+ switch (smccc_get_function(shadow_vcpu)) {
+ /*
+ * CPU_ON takes 3 arguments, however, to wake up the target vcpu the
+ * host only needs to know the target's cpu_id, which is passed as the
+ * first argument. The processing of the reset state is done at hyp.
+ */
+ case PSCI_0_2_FN_CPU_ON:
+ case PSCI_0_2_FN64_CPU_ON:
+ n = 2;
+ break;
+
+ case PSCI_0_2_FN_CPU_OFF:
+ case PSCI_0_2_FN_SYSTEM_OFF:
+ case PSCI_0_2_FN_SYSTEM_RESET:
+ case PSCI_0_2_FN_CPU_SUSPEND:
+ case PSCI_0_2_FN64_CPU_SUSPEND:
+ n = 1;
+ break;
+
+ case PSCI_1_1_FN_SYSTEM_RESET2:
+ case PSCI_1_1_FN64_SYSTEM_RESET2:
+ n = 3;
+ break;
+
+ /*
+ * The rest are either blocked or handled by HYP, so we should
+ * really never be here.
+ */
+ default:
+ BUG();
+ }
WRITE_ONCE(host_vcpu->arch.fault.esr_el2,
shadow_vcpu->arch.fault.esr_el2);
/* Pass the hvc function id (r0) as well as any potential arguments. */
- for (i = 0; i < 8; i++)
+ for (i = 0; i < n; i++)
WRITE_ONCE(host_vcpu->arch.ctxt.regs.regs[i],
vcpu_get_reg(shadow_vcpu, i));
}
@@ -430,6 +492,9 @@ static void flush_shadow_state(struct kvm_shadow_vcpu_state *shadow_state)
shadow_entry_exit_handler_fn ec_handler;
u8 esr_ec;
+ if (READ_ONCE(shadow_state->power_state) == PSCI_0_2_AFFINITY_LEVEL_ON_PENDING)
+ pkvm_reset_vcpu(shadow_state);
+
/*
* If we deal with a non-protected guest and the state is potentially
* dirty (from a host perspective), copy the state back into the shadow.
diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c
index 92e60ebeced5..d44f524c936b 100644
--- a/arch/arm64/kvm/hyp/nvhe/pkvm.c
+++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c
@@ -8,6 +8,7 @@
#include <linux/mm.h>
#include <kvm/arm_hypercalls.h>
+#include <kvm/arm_psci.h>
#include <asm/kvm_emulate.h>
@@ -425,6 +426,27 @@ static int init_ptrauth(struct kvm_vcpu *shadow_vcpu)
return ret;
}
+static int init_shadow_psci(struct kvm_shadow_vm *vm,
+ struct kvm_shadow_vcpu_state *shadow_vcpu_state,
+ struct kvm_vcpu *host_vcpu)
+{
+ struct kvm_vcpu *shadow_vcpu = &shadow_vcpu_state->shadow_vcpu;
+ struct vcpu_reset_state *reset_state = &shadow_vcpu->arch.reset_state;
+
+ if (test_bit(KVM_ARM_VCPU_POWER_OFF, shadow_vcpu->arch.features)) {
+ reset_state->reset = false;
+ shadow_vcpu_state->power_state = PSCI_0_2_AFFINITY_LEVEL_OFF;
+ return 0;
+ }
+
+ reset_state->pc = READ_ONCE(host_vcpu->arch.ctxt.regs.pc);
+ reset_state->r0 = READ_ONCE(host_vcpu->arch.ctxt.regs.regs[0]);
+ reset_state->reset = true;
+ shadow_vcpu_state->power_state = PSCI_0_2_AFFINITY_LEVEL_ON_PENDING;
+
+ return 0;
+}
+
static int init_shadow_structs(struct kvm *kvm, struct kvm_shadow_vm *vm,
struct kvm_vcpu **vcpu_array,
int *last_ran,
@@ -485,6 +507,11 @@ static int init_shadow_structs(struct kvm *kvm, struct kvm_shadow_vm *vm,
pkvm_vcpu_init_traps(shadow_vcpu, host_vcpu);
kvm_reset_pvm_sys_regs(shadow_vcpu);
+
+ /* Must be done after reseting sys registers. */
+ ret = init_shadow_psci(vm, shadow_vcpu_state, host_vcpu);
+ if (ret)
+ return ret;
}
return 0;
@@ -800,6 +827,297 @@ int __pkvm_teardown_shadow(unsigned int shadow_handle)
return err;
}
+/*
+ * This function sets the registers on the vcpu to their architecturally defined
+ * reset values.
+ *
+ * Note: Can only be called by the vcpu on itself, after it has been turned on.
+ */
+void pkvm_reset_vcpu(struct kvm_shadow_vcpu_state *shadow_state)
+{
+ struct kvm_vcpu *vcpu = &shadow_state->shadow_vcpu;
+ struct vcpu_reset_state *reset_state = &vcpu->arch.reset_state;
+
+ WARN_ON(!reset_state->reset);
+
+ init_ptrauth(vcpu);
+
+ kvm_reset_vcpu_core(vcpu);
+ kvm_reset_pvm_sys_regs(vcpu);
+
+ /* Must be done after reseting sys registers. */
+ kvm_reset_vcpu_psci(vcpu, reset_state);
+
+ reset_state->reset = false;
+
+ shadow_state->exit_code = 0;
+
+ WARN_ON(shadow_state->power_state != PSCI_0_2_AFFINITY_LEVEL_ON_PENDING);
+ WRITE_ONCE(vcpu->arch.power_off, false);
+ WRITE_ONCE(shadow_state->power_state, PSCI_0_2_AFFINITY_LEVEL_ON);
+}
+
+struct kvm_shadow_vcpu_state *pkvm_mpidr_to_vcpu_state(struct kvm_shadow_vm *vm, unsigned long mpidr)
+{
+ struct kvm_vcpu *vcpu;
+ int i;
+
+ mpidr &= MPIDR_HWID_BITMASK;
+
+ for (i = 0; i < vm->kvm.created_vcpus; i++) {
+ vcpu = &vm->shadow_vcpu_states[i].shadow_vcpu;
+
+ if (mpidr == kvm_vcpu_get_mpidr_aff(vcpu))
+ return &vm->shadow_vcpu_states[i];
+ }
+
+ return NULL;
+}
+
+/*
+ * Returns true if the hypervisor has handled the PSCI call, and control should
+ * go back to the guest, or false if the host needs to do some additional work
+ * (i.e., wake up the vcpu).
+ */
+static bool pvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
+{
+ struct kvm_shadow_vcpu_state *target_vcpu_state;
+ struct kvm_shadow_vm *vm;
+ struct vcpu_reset_state *reset_state;
+ unsigned long cpu_id;
+ unsigned long hvc_ret_val;
+ int power_state;
+
+ cpu_id = smccc_get_arg1(source_vcpu);
+ if (!kvm_psci_valid_affinity(source_vcpu, cpu_id)) {
+ hvc_ret_val = PSCI_RET_INVALID_PARAMS;
+ goto error;
+ }
+
+ vm = get_shadow_vm(source_vcpu);
+ target_vcpu_state = pkvm_mpidr_to_vcpu_state(vm, cpu_id);
+
+ /* Make sure the caller requested a valid vcpu. */
+ if (!target_vcpu_state) {
+ hvc_ret_val = PSCI_RET_INVALID_PARAMS;
+ goto error;
+ }
+
+ /*
+ * Make sure the requested vcpu is not on to begin with.
+ * Atomic to avoid race between vcpus trying to power on the same vcpu.
+ */
+ power_state = cmpxchg(&target_vcpu_state->power_state,
+ PSCI_0_2_AFFINITY_LEVEL_OFF,
+ PSCI_0_2_AFFINITY_LEVEL_ON_PENDING);
+ switch (power_state) {
+ case PSCI_0_2_AFFINITY_LEVEL_ON_PENDING:
+ hvc_ret_val = PSCI_RET_ON_PENDING;
+ goto error;
+ case PSCI_0_2_AFFINITY_LEVEL_ON:
+ hvc_ret_val = PSCI_RET_ALREADY_ON;
+ goto error;
+ case PSCI_0_2_AFFINITY_LEVEL_OFF:
+ break;
+ default:
+ hvc_ret_val = PSCI_RET_INTERNAL_FAILURE;
+ goto error;
+ }
+
+ reset_state = &target_vcpu_state->shadow_vcpu.arch.reset_state;
+
+ reset_state->pc = smccc_get_arg2(source_vcpu);
+ reset_state->r0 = smccc_get_arg3(source_vcpu);
+
+ /* Propagate caller endianness */
+ reset_state->be = kvm_vcpu_is_be(source_vcpu);
+
+ reset_state->reset = true;
+
+ /*
+ * Return to the host, which should make the KVM_REQ_VCPU_RESET request
+ * as well as kvm_vcpu_wake_up() to schedule the vcpu.
+ */
+ return false;
+
+error:
+ /* If there's an error go back straight to the guest. */
+ smccc_set_retval(source_vcpu, hvc_ret_val, 0, 0, 0);
+ return true;
+}
+
+static bool pvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
+{
+ int i, matching_cpus = 0;
+ unsigned long mpidr;
+ unsigned long target_affinity;
+ unsigned long target_affinity_mask;
+ unsigned long lowest_affinity_level;
+ struct kvm_shadow_vm *vm;
+ unsigned long hvc_ret_val;
+
+ target_affinity = smccc_get_arg1(vcpu);
+ lowest_affinity_level = smccc_get_arg2(vcpu);
+
+ if (!kvm_psci_valid_affinity(vcpu, target_affinity)) {
+ hvc_ret_val = PSCI_RET_INVALID_PARAMS;
+ goto done;
+ }
+
+ /* Determine target affinity mask */
+ target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
+ if (!target_affinity_mask) {
+ hvc_ret_val = PSCI_RET_INVALID_PARAMS;
+ goto done;
+ }
+
+ vm = get_shadow_vm(vcpu);
+
+ /* Ignore other bits of target affinity */
+ target_affinity &= target_affinity_mask;
+
+ hvc_ret_val = PSCI_0_2_AFFINITY_LEVEL_OFF;
+
+ /*
+ * If at least one vcpu matching target affinity is ON then return ON,
+ * then if at least one is PENDING_ON then return PENDING_ON.
+ * Otherwise, return OFF.
+ */
+ for (i = 0; i < vm->kvm.created_vcpus; i++) {
+ struct kvm_shadow_vcpu_state *tmp = &vm->shadow_vcpu_states[i];
+
+ mpidr = kvm_vcpu_get_mpidr_aff(&tmp->shadow_vcpu);
+
+ if ((mpidr & target_affinity_mask) == target_affinity) {
+ int power_state;
+
+ matching_cpus++;
+ power_state = READ_ONCE(tmp->power_state);
+ switch (power_state) {
+ case PSCI_0_2_AFFINITY_LEVEL_ON_PENDING:
+ hvc_ret_val = PSCI_0_2_AFFINITY_LEVEL_ON_PENDING;
+ break;
+ case PSCI_0_2_AFFINITY_LEVEL_ON:
+ hvc_ret_val = PSCI_0_2_AFFINITY_LEVEL_ON;
+ goto done;
+ case PSCI_0_2_AFFINITY_LEVEL_OFF:
+ break;
+ default:
+ hvc_ret_val = PSCI_RET_INTERNAL_FAILURE;
+ goto done;
+ }
+ }
+ }
+
+ if (!matching_cpus)
+ hvc_ret_val = PSCI_RET_INVALID_PARAMS;
+
+done:
+ /* Nothing to be handled by the host. Go back to the guest. */
+ smccc_set_retval(vcpu, hvc_ret_val, 0, 0, 0);
+ return true;
+}
+
+/*
+ * Returns true if the hypervisor has handled the PSCI call, and control should
+ * go back to the guest, or false if the host needs to do some additional work
+ * (e.g., turn off and update vcpu scheduling status).
+ */
+static bool pvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
+{
+ struct kvm_shadow_vcpu_state *vcpu_state = get_shadow_state(vcpu);
+
+ WARN_ON(vcpu->arch.power_off);
+ WARN_ON(vcpu_state->power_state != PSCI_0_2_AFFINITY_LEVEL_ON);
+
+ WRITE_ONCE(vcpu->arch.power_off, true);
+ WRITE_ONCE(vcpu_state->power_state, PSCI_0_2_AFFINITY_LEVEL_OFF);
+
+ /* Return to the host so that it can finish powering off the vcpu. */
+ return false;
+}
+
+static bool pvm_psci_version(struct kvm_vcpu *vcpu)
+{
+ /* Nothing to be handled by the host. Go back to the guest. */
+ smccc_set_retval(vcpu, KVM_ARM_PSCI_1_1, 0, 0, 0);
+ return true;
+}
+
+static bool pvm_psci_not_supported(struct kvm_vcpu *vcpu)
+{
+ /* Nothing to be handled by the host. Go back to the guest. */
+ smccc_set_retval(vcpu, PSCI_RET_NOT_SUPPORTED, 0, 0, 0);
+ return true;
+}
+
+static bool pvm_psci_features(struct kvm_vcpu *vcpu)
+{
+ u32 feature = smccc_get_arg1(vcpu);
+ unsigned long val;
+
+ switch (feature) {
+ case PSCI_0_2_FN_PSCI_VERSION:
+ case PSCI_0_2_FN_CPU_SUSPEND:
+ case PSCI_0_2_FN64_CPU_SUSPEND:
+ case PSCI_0_2_FN_CPU_OFF:
+ case PSCI_0_2_FN_CPU_ON:
+ case PSCI_0_2_FN64_CPU_ON:
+ case PSCI_0_2_FN_AFFINITY_INFO:
+ case PSCI_0_2_FN64_AFFINITY_INFO:
+ case PSCI_0_2_FN_SYSTEM_OFF:
+ case PSCI_0_2_FN_SYSTEM_RESET:
+ case PSCI_1_0_FN_PSCI_FEATURES:
+ case PSCI_1_1_FN_SYSTEM_RESET2:
+ case PSCI_1_1_FN64_SYSTEM_RESET2:
+ case ARM_SMCCC_VERSION_FUNC_ID:
+ val = PSCI_RET_SUCCESS;
+ break;
+ default:
+ val = PSCI_RET_NOT_SUPPORTED;
+ break;
+ }
+
+ /* Nothing to be handled by the host. Go back to the guest. */
+ smccc_set_retval(vcpu, val, 0, 0, 0);
+ return true;
+}
+
+static bool pkvm_handle_psci(struct kvm_vcpu *vcpu)
+{
+ u32 psci_fn = smccc_get_function(vcpu);
+
+ switch (psci_fn) {
+ case PSCI_0_2_FN_CPU_ON:
+ kvm_psci_narrow_to_32bit(vcpu);
+ fallthrough;
+ case PSCI_0_2_FN64_CPU_ON:
+ return pvm_psci_vcpu_on(vcpu);
+ case PSCI_0_2_FN_CPU_OFF:
+ return pvm_psci_vcpu_off(vcpu);
+ case PSCI_0_2_FN_AFFINITY_INFO:
+ kvm_psci_narrow_to_32bit(vcpu);
+ fallthrough;
+ case PSCI_0_2_FN64_AFFINITY_INFO:
+ return pvm_psci_vcpu_affinity_info(vcpu);
+ case PSCI_0_2_FN_PSCI_VERSION:
+ return pvm_psci_version(vcpu);
+ case PSCI_1_0_FN_PSCI_FEATURES:
+ return pvm_psci_features(vcpu);
+ case PSCI_0_2_FN_SYSTEM_RESET:
+ case PSCI_0_2_FN_CPU_SUSPEND:
+ case PSCI_0_2_FN64_CPU_SUSPEND:
+ case PSCI_0_2_FN_SYSTEM_OFF:
+ case PSCI_1_1_FN_SYSTEM_RESET2:
+ case PSCI_1_1_FN64_SYSTEM_RESET2:
+ return false; /* Handled by the host. */
+ default:
+ break;
+ }
+
+ return pvm_psci_not_supported(vcpu);
+}
+
/*
* Handler for protected VM HVC calls.
*
@@ -816,6 +1134,6 @@ bool kvm_handle_pvm_hvc64(struct kvm_vcpu *vcpu, u64 *exit_code)
smccc_set_retval(vcpu, ARM_SMCCC_VERSION_1_1, 0, 0, 0);
return true;
default:
- return false;
+ return pkvm_handle_psci(vcpu);
}
}
--
2.36.1.124.g0e6072fb45-goog
