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author | Marc Zyngier <maz@kernel.org> | 2021-08-20 12:23:02 +0100 |
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committer | Marc Zyngier <maz@kernel.org> | 2021-08-20 12:23:02 +0100 |
commit | 78bc117095cc30408e2131e81757a6659ac4b002 (patch) | |
tree | d34bd6cb153cb54c44fa03b7bdc592eaeab7ea2d /arch/arm64 | |
parent | cf0c7125d5783f93b78921845d4b101c65a7998b (diff) | |
parent | cb97cf95c44021278b7637731bc0928026bc29ab (diff) | |
download | linux-stable-78bc117095cc30408e2131e81757a6659ac4b002.tar.gz linux-stable-78bc117095cc30408e2131e81757a6659ac4b002.tar.bz2 linux-stable-78bc117095cc30408e2131e81757a6659ac4b002.zip |
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: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64')
-rw-r--r-- | arch/arm64/kvm/arm.c | 8 | ||||
-rw-r--r-- | arch/arm64/kvm/psci.c | 15 | ||||
-rw-r--r-- | arch/arm64/kvm/reset.c | 16 |
3 files changed, 30 insertions, 9 deletions
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index fd9a6bcf797f..1decdec70102 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1216,6 +1216,14 @@ long kvm_arch_vcpu_ioctl(struct file *filp, if (copy_from_user(®, 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, ®); else diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index db4056ecccfd..74c47d420253 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -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) diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 08fd487d5f95..5ce36b0a3343 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -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 */ |