Let hvc_handler return 4 registers rather than just one.
Bug: 132395846
Change-Id: Ibc86ba2f24fdfcb55f08aae48e5769cea31c2cd5
diff --git a/src/arch/aarch64/hypervisor/exceptions.S b/src/arch/aarch64/hypervisor/exceptions.S
index 1c4d642..55de601 100644
--- a/src/arch/aarch64/hypervisor/exceptions.S
+++ b/src/arch/aarch64/hypervisor/exceptions.S
@@ -143,25 +143,43 @@
b.ne slow_sync_lower
/*
+ * Make room for hvc_handler_return on stack, and point x8 (the indirect
+ * result location register in the AAPCS64 standard) to it.
+ * hvc_handler_return is returned this way according to paragraph
+ * 5.4.2.B.3 and section 5.5 because it is larger than 16 bytes.
+ */
+ stp xzr, xzr, [sp, #-16]!
+ stp xzr, xzr, [sp, #-16]!
+ stp xzr, xzr, [sp, #-16]!
+ mov x8, sp
+
+ /*
* Save x29 and x30, which are not saved by the callee, then jump to
* HVC handler.
*/
stp x29, x30, [sp, #-16]!
bl hvc_handler
ldp x29, x30, [sp], #16
- cbnz x1, sync_lower_switch
- /* Zero out all volatile registers (except x0) and return. */
+ /* Get the hvc_handler_return back off the stack. */
+ ldp x0, x1, [sp], #16
+ ldp x2, x3, [sp], #16
+ ldr x4, [sp], #16
+
+ cbnz x4, sync_lower_switch
+
+ /*
+ * Zero out volatile registers (except x0-x3, which contain results) and
+ * return.
+ */
stp xzr, xzr, [sp, #-16]!
- ldp x1, x2, [sp]
- ldp x3, x4, [sp]
- ldp x5, x6, [sp]
- ldp x7, x8, [sp]
- ldp x9, x10, [sp]
- ldp x11, x12, [sp]
- ldp x13, x14, [sp]
- ldp x15, x16, [sp], #16
- mov x17, xzr
+ ldp x4, x5, [sp]
+ ldp x6, x7, [sp]
+ ldp x8, x9, [sp]
+ ldp x10, x11, [sp]
+ ldp x12, x13, [sp]
+ ldp x14, x15, [sp]
+ ldp x16, x17, [sp], #16
/* Restore x18, which was saved on the stack. */
ldr x18, [sp], #16
@@ -261,9 +279,9 @@
/* We'll have to switch, so save volatile state before doing so. */
mrs x18, tpidr_el2
- /* Store zeroes in volatile register storage, except x0. */
- stp x0, xzr, [x18, #VCPU_REGS + 8 * 0]
- stp xzr, xzr, [x18, #VCPU_REGS + 8 * 2]
+ /* Store zeroes in volatile register storage, except x0-x3. */
+ stp x0, x1, [x18, #VCPU_REGS + 8 * 0]
+ stp x2, x3, [x18, #VCPU_REGS + 8 * 2]
stp xzr, xzr, [x18, #VCPU_REGS + 8 * 4]
stp xzr, xzr, [x18, #VCPU_REGS + 8 * 6]
stp xzr, xzr, [x18, #VCPU_REGS + 8 * 8]
@@ -283,7 +301,7 @@
stp x2, x3, [x18, #VCPU_REGS + 8 * 31]
/* Save lazy state, then switch to new vcpu. */
- mov x0, x1
+ mov x0, x4
/* Intentional fallthrough. */
/**
diff --git a/src/arch/aarch64/hypervisor/handler.c b/src/arch/aarch64/hypervisor/handler.c
index 1282b81..d896c80 100644
--- a/src/arch/aarch64/hypervisor/handler.c
+++ b/src/arch/aarch64/hypervisor/handler.c
@@ -50,7 +50,7 @@
#define GET_NEXT_PC_INC(esr) (((esr) & (1u << 25)) ? 4 : 2)
struct hvc_handler_return {
- uintreg_t user_ret;
+ smc_res_t user_ret;
struct vcpu *new;
};
@@ -370,76 +370,77 @@
ret.new = NULL;
- if (psci_handler(current(), arg0, arg1, arg2, arg3, &ret.user_ret,
+ if (psci_handler(current(), arg0, arg1, arg2, arg3, &ret.user_ret.res0,
&ret.new)) {
return ret;
}
- if (spci_handler(arg0, arg1, arg2, arg3, &ret.user_ret, &ret.new)) {
+ if (spci_handler(arg0, arg1, arg2, arg3, &ret.user_ret.res0,
+ &ret.new)) {
update_vi(ret.new);
return ret;
}
switch ((uint32_t)arg0) {
case HF_VM_GET_ID:
- ret.user_ret = api_vm_get_id(current());
+ ret.user_ret.res0 = api_vm_get_id(current());
break;
case HF_VM_GET_COUNT:
- ret.user_ret = api_vm_get_count();
+ ret.user_ret.res0 = api_vm_get_count();
break;
case HF_VCPU_GET_COUNT:
- ret.user_ret = api_vcpu_get_count(arg1, current());
+ ret.user_ret.res0 = api_vcpu_get_count(arg1, current());
break;
case HF_VCPU_RUN:
- ret.user_ret = hf_vcpu_run_return_encode(
+ ret.user_ret.res0 = hf_vcpu_run_return_encode(
api_vcpu_run(arg1, arg2, current(), &ret.new));
break;
case HF_VM_CONFIGURE:
- ret.user_ret = api_vm_configure(ipa_init(arg1), ipa_init(arg2),
- current(), &ret.new);
+ ret.user_ret.res0 = api_vm_configure(
+ ipa_init(arg1), ipa_init(arg2), current(), &ret.new);
break;
case HF_MAILBOX_CLEAR:
- ret.user_ret = api_mailbox_clear(current(), &ret.new);
+ ret.user_ret.res0 = api_mailbox_clear(current(), &ret.new);
break;
case HF_MAILBOX_WRITABLE_GET:
- ret.user_ret = api_mailbox_writable_get(current());
+ ret.user_ret.res0 = api_mailbox_writable_get(current());
break;
case HF_MAILBOX_WAITER_GET:
- ret.user_ret = api_mailbox_waiter_get(arg1, current());
+ ret.user_ret.res0 = api_mailbox_waiter_get(arg1, current());
break;
case HF_INTERRUPT_ENABLE:
- ret.user_ret = api_interrupt_enable(arg1, arg2, current());
+ ret.user_ret.res0 = api_interrupt_enable(arg1, arg2, current());
break;
case HF_INTERRUPT_GET:
- ret.user_ret = api_interrupt_get(current());
+ ret.user_ret.res0 = api_interrupt_get(current());
break;
case HF_INTERRUPT_INJECT:
- ret.user_ret = api_interrupt_inject(arg1, arg2, arg3, current(),
- &ret.new);
+ ret.user_ret.res0 = api_interrupt_inject(arg1, arg2, arg3,
+ current(), &ret.new);
break;
case HF_SHARE_MEMORY:
- ret.user_ret =
+ ret.user_ret.res0 =
api_share_memory(arg1 >> 32, ipa_init(arg2), arg3,
arg1 & 0xffffffff, current());
break;
case HF_DEBUG_LOG:
- ret.user_ret = api_debug_log(arg1, current());
+ ret.user_ret.res0 = api_debug_log(arg1, current());
break;
default:
- ret.user_ret = -1;
+ ret.user_ret.res0 = -1;
}
update_vi(ret.new);
