[PATCH 3/4] KVM: arm64: Enforce reserved bits for PSCI target affinities
From: Oliver Upton <hidden>
Date: 2021-08-18 08:51:15
Also in:
kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Some calls in PSCI take a target affinity argument, defined to be bit-compatible with the affinity fields in MPIDR_EL1. All other bits in the parameter are reserved and must be 0. Return INVALID_PARAMETERS if the guest incorrectly sets a reserved bit. Signed-off-by: Oliver Upton <redacted> --- arch/arm64/kvm/psci.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index db4056ecccfd..bb76be01abd2 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c@@ -59,6 +59,17 @@ 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) +{ + unsigned long mask = MPIDR_HWID_BITMASK; + + if (vcpu_mode_is_32bit(vcpu)) + mask &= ~((u32) 0); + + return !(affinity & ~mask); +} + static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) { struct vcpu_reset_state *reset_state;
@@ -66,9 +77,9 @@ 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 +137,9 @@ 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)
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2.33.0.rc1.237.g0d66db33f3-goog