From e10ecb4d6c0761ca545b3946df1707a41f9f845e Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Wed, 18 Aug 2021 20:21:32 +0000 Subject: KVM: arm64: Enforce reserved bits for PSCI target affinities According to the PSCI specification, ARM DEN 0022D, 5.1.4 "CPU_ON", the CPU_ON function takes a target_cpu argument that is bit-compatible with the affinity fields in MPIDR_EL1. All other bits in the argument are RES0. Note that the same constraints apply to the target_affinity argument for the AFFINITY_INFO call. Enforce the spec by returning INVALID_PARAMS if a guest incorrectly sets a RES0 bit. Signed-off-by: Oliver Upton Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210818202133.1106786-4-oupton@google.com --- arch/arm64/kvm/psci.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'arch/arm64/kvm/psci.c') 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) -- cgit v1.2.3