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authorOliver Upton <oupton@google.com>2021-08-18 20:21:32 +0000
committerMarc Zyngier <maz@kernel.org>2021-08-19 09:08:57 +0100
commite10ecb4d6c0761ca545b3946df1707a41f9f845e (patch)
tree62d7304a52743a1e606b1ba475f8595bd47b36fe /arch/arm64/kvm/psci.c
parent6826c6849b46aaa91300201213701eb861af4ba0 (diff)
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 <oupton@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210818202133.1106786-4-oupton@google.com
Diffstat (limited to 'arch/arm64/kvm/psci.c')
-rw-r--r--arch/arm64/kvm/psci.c15
1 files changed, 12 insertions, 3 deletions
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)