Commit 78bc1170 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

Merge branch kvm-arm64/psci/cpu_on into kvmarm-master/next 



PSCI fixes from Oliver Upton:
- Plug race on reset
- Ensure that a pending reset is applied before userspace accesses
- Reject PSCI requests with illegal affinity bits

* kvm-arm64/psci/cpu_on:
  selftests: KVM: Introduce psci_cpu_on_test
  KVM: arm64: Enforce reserved bits for PSCI target affinities
  KVM: arm64: Handle PSCI resets before userspace touches vCPU state
  KVM: arm64: Fix read-side race on updates to vcpu reset state

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parents cf0c7125 cb97cf95

arch/arm64/kvm/arm.c

+8 −0
Original line number Diff line number Diff line
@@ -1216,6 +1216,14 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
		if (copy_from_user(&reg, argp, sizeof(reg)))

			break;



		/*

		 * We could owe a reset due to PSCI. Handle the pending reset

		 * here to ensure userspace register accesses are ordered after

		 * the reset.

		 */

		if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))

			kvm_reset_vcpu(vcpu);



		if (ioctl == KVM_SET_ONE_REG)

			r = kvm_arm_set_reg(vcpu, &reg);

		else

arch/arm64/kvm/psci.c

+12 −3
Original line number Diff line number Diff line
@@ -59,6 +59,12 @@ static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) 
	kvm_vcpu_kick(vcpu);

}



static inline bool kvm_psci_valid_affinity(struct kvm_vcpu *vcpu,

					   unsigned long affinity)

{

	return !(affinity & ~MPIDR_HWID_BITMASK);

}



static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)

{

	struct vcpu_reset_state *reset_state;
@@ -66,9 +72,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) 
	struct kvm_vcpu *vcpu = NULL;

	unsigned long cpu_id;



	cpu_id = smccc_get_arg1(source_vcpu) & MPIDR_HWID_BITMASK;

	if (vcpu_mode_is_32bit(source_vcpu))

		cpu_id &= ~((u32) 0);

	cpu_id = smccc_get_arg1(source_vcpu);

	if (!kvm_psci_valid_affinity(source_vcpu, cpu_id))

		return PSCI_RET_INVALID_PARAMS;



	vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id);
@@ -126,6 +132,9 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) 
	target_affinity = smccc_get_arg1(vcpu);

	lowest_affinity_level = smccc_get_arg2(vcpu);



	if (!kvm_psci_valid_affinity(vcpu, target_affinity))

		return PSCI_RET_INVALID_PARAMS;



	/* Determine target affinity mask */

	target_affinity_mask = psci_affinity_mask(lowest_affinity_level);

	if (!target_affinity_mask)

arch/arm64/kvm/reset.c

+10 −6
Original line number Diff line number Diff line
@@ -210,10 +210,16 @@ static bool vcpu_allowed_register_width(struct kvm_vcpu *vcpu) 
 */

int kvm_reset_vcpu(struct kvm_vcpu *vcpu)

{

	struct vcpu_reset_state reset_state;

	int ret;

	bool loaded;

	u32 pstate;



	mutex_lock(&vcpu->kvm->lock);

	reset_state = vcpu->arch.reset_state;

	WRITE_ONCE(vcpu->arch.reset_state.reset, false);

	mutex_unlock(&vcpu->kvm->lock);



	/* Reset PMU outside of the non-preemptible section */

	kvm_pmu_vcpu_reset(vcpu);
@@ -276,8 +282,8 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) 
	 * Additional reset state handling that PSCI may have imposed on us.

	 * Must be done after all the sys_reg reset.

	 */

	if (vcpu->arch.reset_state.reset) {

		unsigned long target_pc = vcpu->arch.reset_state.pc;

	if (reset_state.reset) {

		unsigned long target_pc = reset_state.pc;



		/* Gracefully handle Thumb2 entry point */

		if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
@@ -286,13 +292,11 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu) 
		}



		/* Propagate caller endianness */

		if (vcpu->arch.reset_state.be)

		if (reset_state.be)

			kvm_vcpu_set_be(vcpu);



		*vcpu_pc(vcpu) = target_pc;

		vcpu_set_reg(vcpu, 0, vcpu->arch.reset_state.r0);



		vcpu->arch.reset_state.reset = false;

		vcpu_set_reg(vcpu, 0, reset_state.r0);

	}



	/* Reset timer */

tools/testing/selftests/kvm/.gitignore

+1 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0-only

/aarch64/debug-exceptions

/aarch64/get-reg-list

/aarch64/psci_cpu_on_test

/aarch64/vgic_init

/s390x/memop

/s390x/resets

tools/testing/selftests/kvm/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -86,6 +86,7 @@ TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test 


TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions

TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list

TEST_GEN_PROGS_aarch64 += aarch64/psci_cpu_on_test

TEST_GEN_PROGS_aarch64 += aarch64/vgic_init

TEST_GEN_PROGS_aarch64 += demand_paging_test

TEST_GEN_PROGS_aarch64 += dirty_log_test