fix: abort EL0 partition for system register access
This patch fixes a bug, leading to a crash, when SPMC triages a trap
due to system register access by EL0 partition.
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
Change-Id: Ic9a0e635e2caa46fa3a47ac12ac6130dd4fa3355
diff --git a/src/arch/aarch64/hypervisor/exceptions.S b/src/arch/aarch64/hypervisor/exceptions.S
index 753e149..04bfb98 100644
--- a/src/arch/aarch64/hypervisor/exceptions.S
+++ b/src/arch/aarch64/hypervisor/exceptions.S
@@ -283,6 +283,9 @@
mrs x0, esr_el2
bl handle_system_register_access
+ /* Switch vCPU if requested by handler. */
+ cbnz x0, vcpu_switch
+
/* Continue running the same vCPU. */
mrs x0, tpidr_el2
b vcpu_restore_nonvolatile_and_run
diff --git a/src/arch/aarch64/hypervisor/handler.c b/src/arch/aarch64/hypervisor/handler.c
index 94a535d..7e55fc9 100644
--- a/src/arch/aarch64/hypervisor/handler.c
+++ b/src/arch/aarch64/hypervisor/handler.c
@@ -1250,11 +1250,12 @@
* Handles EC = 011000, MSR, MRS instruction traps.
* Returns non-null ONLY if the access failed and the vCPU is changing.
*/
-void handle_system_register_access(uintreg_t esr_el2)
+struct vcpu *handle_system_register_access(uintreg_t esr_el2)
{
struct vcpu *vcpu = current();
ffa_id_t vm_id = vcpu->vm->id;
uintreg_t ec = GET_ESR_EC(esr_el2);
+ bool is_el0_partition = vcpu->vm->el0_partition;
CHECK(ec == EC_MSR);
/*
@@ -1264,28 +1265,36 @@
if (debug_el1_is_register_access(esr_el2)) {
if (!debug_el1_process_access(vcpu, vm_id, esr_el2)) {
inject_el1_sysreg_trap_exception(vcpu, esr_el2);
- return;
+ return NULL;
}
} else if (perfmon_is_register_access(esr_el2)) {
if (!perfmon_process_access(vcpu, vm_id, esr_el2)) {
inject_el1_sysreg_trap_exception(vcpu, esr_el2);
- return;
+ return NULL;
}
} else if (feature_id_is_register_access(esr_el2)) {
if (!feature_id_process_access(vcpu, esr_el2)) {
inject_el1_sysreg_trap_exception(vcpu, esr_el2);
- return;
+ return NULL;
}
} else if (el1_physical_timer_is_register_access(esr_el2)) {
if (!el1_physical_timer_process_access(vcpu, esr_el2)) {
inject_el1_sysreg_trap_exception(vcpu, esr_el2);
- return;
+ return NULL;
}
} else {
+ if (is_el0_partition) {
+ dlog_warning(
+ "Unexpected system register access by EL0 "
+ "partition\n");
+ return api_abort(vcpu);
+ }
+
inject_el1_sysreg_trap_exception(vcpu, esr_el2);
- return;
+ return NULL;
}
/* Instruction was fulfilled. Skip it and run the next one. */
vcpu->regs.pc += GET_NEXT_PC_INC(esr_el2);
+ return NULL;
}