@@ -66,10 +66,19 @@ void __hyp_set_vectors(phys_addr_t phys_vector_base);
void __hyp_reset_vectors(void);
DECLARE_STATIC_KEY_FALSE(kvm_protected_mode);
+DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
/* Reports the availability of HYP mode */
static inline bool is_hyp_mode_available(void)
{
+ /*
+ * If KVM protected mode is initialized, all CPUs must have been booted
+ * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
+ */
+ if (IS_ENABLED(CONFIG_KVM) &&
+ static_branch_likely(&kvm_protected_mode_initialized))
+ return true;
+
return (__boot_cpu_mode[0] == BOOT_CPU_MODE_EL2 &&
__boot_cpu_mode[1] == BOOT_CPU_MODE_EL2);
}
@@ -77,6 +86,14 @@ static inline bool is_hyp_mode_available(void)
/* Check if the bootloader has booted CPUs in different modes */
static inline bool is_hyp_mode_mismatched(void)
{
+ /*
+ * If KVM protected mode is initialized, all CPUs must have been booted
+ * in EL2. Avoid checking __boot_cpu_mode as CPUs now come up in EL1.
+ */
+ if (IS_ENABLED(CONFIG_KVM) &&
+ static_branch_likely(&kvm_protected_mode_initialized))
+ return false;
+
return __boot_cpu_mode[0] != __boot_cpu_mode[1];
}
@@ -48,6 +48,7 @@ __asm__(".arch_extension virt");
#endif
DEFINE_STATIC_KEY_FALSE(kvm_protected_mode);
+DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
@@ -1838,12 +1839,14 @@ int kvm_arch_init(void *opaque)
if (err)
goto out_hyp;
- if (is_kvm_protected_mode())
+ if (is_kvm_protected_mode()) {
+ static_branch_enable(&kvm_protected_mode_initialized);
kvm_info("Protected nVHE mode initialized successfully\n");
- else if (in_hyp_mode)
+ } else if (in_hyp_mode) {
kvm_info("VHE mode initialized successfully\n");
- else
+ } else {
kvm_info("Hyp mode initialized successfully\n");
+ }
return 0;
With protected nVHE hyp code interception host's PSCI CPU_ON/OFF/SUSPEND SMCs, from the host's perspective new CPUs start booting in EL1 while previously they would have booted in EL2. The kernel logic which keeps track of the mode CPUs were booted in needs to be adjusted to account for this fact. Add a static key enabled if KVM protected nVHE initialization is successful. When the key is enabled, is_hyp_mode_available continues to report `true` because its users either treat it a check whether KVM will be / has been initialized, or whether stub HVCs can be made (eg. hibernate). is_hyp_mode_mismatched is changed to report `false` when the key is enabled. That's because all cores' modes matched at the point of KVM init and KVM will not allow cores not present at init to boot. That said, the function is never used after KVM is initialized. Signed-off-by: David Brazdil <dbrazdil@google.com> --- arch/arm64/include/asm/virt.h | 17 +++++++++++++++++ arch/arm64/kvm/arm.c | 9 ++++++--- 2 files changed, 23 insertions(+), 3 deletions(-)