If the __pkvm_prot_finalize hypercall returns an error, we WARN but fail
to propagate the failure code back to kvm_arch_init().
Pass a pointer to a zero-initialised return variable so that failure
to finalise the pKVM protections on a host CPU can be reported back to
KVM.
Cc: Marc Zyngier <m...@kernel.org>
Cc: Quentin Perret <qper...@google.com>
Signed-off-by: Will Deacon <w...@kernel.org>
---
arch/arm64/kvm/arm.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 9506cf88fa0e..13bbf35896cd 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1986,9 +1986,25 @@ static int init_hyp_mode(void)
return err;
}
-static void _kvm_host_prot_finalize(void *discard)
+static void _kvm_host_prot_finalize(void *arg)
{
- WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize));
+ int *err = arg;
+
+ if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize)))
+ WRITE_ONCE(*err, -EINVAL);
+}
+
+static int pkvm_drop_host_privileges(void)
+{
+ int ret = 0;
+
+ /*
+ * Flip the static key upfront as that may no longer be possible
+ * once the host stage 2 is installed.
+ */
+ static_branch_enable(&kvm_protected_mode_initialized);
+ on_each_cpu(_kvm_host_prot_finalize, &ret, 1);
+ return ret;
}
static int finalize_hyp_mode(void)
@@ -2002,15 +2018,7 @@ static int finalize_hyp_mode(void)
* None of other sections should ever be introspected.
*/
kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start);
-
- /*
- * Flip the static key upfront as that may no longer be possible
- * once the host stage 2 is installed.
- */
- static_branch_enable(&kvm_protected_mode_initialized);
- on_each_cpu(_kvm_host_prot_finalize, NULL, 1);
-
- return 0;
+ return pkvm_drop_host_privileges();
}
struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
--
2.33.0.464.g1972c5931b-goog
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