The SMCCC does not allow the SMC64 calling convention to be used from
AArch32. While KVM checks to see if the calling convention is allowed in
PSCI_1_0_FN_PSCI_FEATURES, it does not actually prevent calls to
unadvertised PSCI v1.0+ functions.
Hoist the check to see if the requested function is allowed into
kvm_psci_call(), thereby preventing SMC64 calls from AArch32 for all
PSCI versions.
Fixes: d43583b890e7 ("KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest")
Acked-by: Will Deacon <will@xxxxxxxxxx>
Reviewed-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx>
---
arch/arm64/kvm/psci.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index cd3ee947485f..d24ccc77500b 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -232,10 +232,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
unsigned long val;
int ret = 1;
- val = kvm_psci_check_allowed_function(vcpu, psci_fn);
- if (val)
- goto out;
-
switch (psci_fn) {
case PSCI_0_2_FN_PSCI_VERSION:
/*
@@ -303,7 +299,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
break;
}
-out:
smccc_set_retval(vcpu, val, 0, 0, 0);
return ret;
}
@@ -423,6 +418,15 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
*/
int kvm_psci_call(struct kvm_vcpu *vcpu)
{
+ u32 psci_fn = smccc_get_function(vcpu);
+ unsigned long val;
+
+ val = kvm_psci_check_allowed_function(vcpu, psci_fn);
+ if (val) {
+ smccc_set_retval(vcpu, val, 0, 0, 0);
+ return 1;
+ }
+
switch (kvm_psci_version(vcpu)) {
case KVM_ARM_PSCI_1_1:
return kvm_psci_1_x_call(vcpu, 1);
--
2.35.1.894.gb6a874cedc-goog
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