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BACKPORT: KVM: arm64: Actually prevent SMC64 SYSTEM_RESET2 from AArch32

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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.

Bug: 254441685
Fixes: d43583b890e7 ("KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest")
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220322183538.2757758-3-oupton@google.com
(cherry picked from commit 827c2ab3314814e1c7d873372c0fe0cad50ba1c5)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I5509631734af2f74f9bb37ae32f8e9e73d979fc5
This commit is contained in:
Oliver Upton
2022-03-22 18:35:37 +00:00
committed by Lee Jones
parent 46d726e380
commit b1cad5be29
1 changed files with 9 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
arch/arm64/kvm/psci.c
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@@ -204,10 +204,6 @@ 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:
/*
@@ -275,7 +271,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
break;
}
out:
smccc_set_retval(vcpu, val, 0, 0, 0);
return ret;
}
@@ -395,6 +390,15 @@ 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, vcpu->kvm)) {
case KVM_ARM_PSCI_1_1:
return kvm_psci_1_x_call(vcpu, 1);