[RFC kvm-unit-tests 06/27] arm: Move io_init after vm initialization

Joey Gouly
2023-01-27T11:52:37Z

From: Jean-Philippe Brucker <jean-philippe@linaro.org>

To create shared pages, the NS_SHARED bit must be written into the
idmap. Before VM initializations, idmap hasn't necessarily been created.
To write shared pages, access must be done on a IPA with the NS_SHARED
bit. When the stage-1 MMU is enabled, that bit is set in the PTE. But
when the stage-1 MMU is disabled, then the realm must write to the IPA
with NS_SHARED directly.

To avoid changing the whole virtio infrastructure to support pre-MMU in
a realm, move the IO initialization after MMU enablement.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
---
lib/arm/setup.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/arm/setup.c b/lib/arm/setup.c
index 81052a3d..65d98e97 100644
--- a/lib/arm/setup.c
+++ b/lib/arm/setup.c
@@ -274,9 +274,6 @@ void setup(const void *fdt, phys_addr_t freemem_start)
/* cpu_init must be called before thread_info_init */
thread_info_init(current_thread_info(), 0);

- /* mem_init must be called before io_init */
- io_init();
-
timer_save_state();

ret = dt_get_bootargs(&bootargs);
@@ -292,4 +289,7 @@ void setup(const void *fdt, phys_addr_t freemem_start)

if (!(auxinfo.flags & AUXINFO_MMU_OFF))
setup_vm();
+
+ /* mem_init and setup_vm must be called before io_init */
+ io_init();
}
--
2.17.1