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Enabling ssr Inheritance WIP#44

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Enabling ssr Inheritance WIP#44
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@bryanb-h2 bryanb-h2 commented Jun 3, 2026

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Removed dependence on standalone.

@bryanb-h2
Fix stmode test WIP.
7c0e7ac 
Signed-off-by: Bryan Bayerdorffer <bryanb@qti.qualcomm.com>
@bryanb-h2 bryanb-h2 marked this pull request as draft June 3, 2026 15:10
zbelinsk
zbelinsk reviewed Jun 4, 2026
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Comment thread kernel/util/stmode/test/Makefile Outdated
include Makefile.inc
OSLIB=
KERNEL_BUILD_DIR := $(INSTALLPATH)/../build/kernel
CFLAGS += -ffixed-r28 -I$(KERNEL_BUILD_DIR)/include

@zbelinsk zbelinsk Jun 4, 2026

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For readability, maybe convert: CFLAGS/ASFLAGS -> EXTRA_CFLAGS/EXTRA_ASFLAGS, and move include below these lines.

zbelinsk added 3 commits June 8, 2026 06:15
@zbelinsk
stmode test: fix privilege mismatch for monitor-space threads
af21393 
h2_thread_create() hardcodes ssr_um=1 (guest-user mode) for created
threads, but this test runs in monitor space (no BOOT/booter) where
code pages are supervisor-execute-only.  Guest-user threads fault with
Hexagon cause 0x11 (user/guest execute to page with no execute
permission) at their first instruction.

Fix by providing a local override of H2K_thread_create_no_squash that
inherits ssr_guest/ssr_um from the caller (main runs ssr_um=0,
ssr_guest=1) instead of hardcoding 1.  Add linking flag --allow-multiple-definition
so the linker picks test.o over libh2kernel.a for this symbol.

Also:
- Add stmode_extend_bootvm_contexts() to pre-allocate NUM_TEST_THREADS
  extra H2K_thread_context slots into the boot VM free list, so the
  test is self-contained and does not require MAX_BOOT_CONTEXTS=3 at
  kernel build time.
- Add wait_for_threads_to_sleep() using MODECTL_W_BITS to quiesce all
  hw threads into WAIT after h2_hwconfig_hwthreads_mask(-1) before
  calling stmode_begin(); without this, stmode_begin races threads
  coming online and spuriously reports >1 active thread.
- Add MODECTL_E_MASK/MODECTL_W_BITS/MODECTL_W_MASK to max.h.

Signed-off-by: Zeev Belinsky <zbelinsk@qti.qualcomm.com>
@zbelinsk
Update test.c
1de4130 
Signed-off-by: zbelinsk <zbelinsk@qti.qualcomm.com>
@zbelinsk
Update test.c
3d1a0a0 
Signed-off-by: zbelinsk <zbelinsk@qti.qualcomm.com>
bryanb-h2
bryanb-h2 commented Jun 8, 2026
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Can't request changes since this is my PR.

Comment thread kernel/util/stmode/test/test.c Outdated
This is needed because this test runs in monitor space (no BOOT/booter), so pages
are supervisor-execute-only. Created threads must run at the same privilege as
main (ssr_um=0, ssr_guest=1) to be able to execute them without cause-0x11. */
IN_SECTION(".text.misc.create") s32_t H2K_thread_create_no_squash(u32_t pc, u32_t sp, u32_t arg1, u32_t prio, H2K_vmblock_t *vmblock, H2K_thread_context *me)

@bryanb-h2 bryanb-h2 Jun 8, 2026

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Instead of doing all this I think it would actually be ok to just change to 'tmp->ssr_um = me->ssr_um' in the real function. ssr_guest doesn't matter for the test because that is only significant when um == 1. Anything in the normal execution flow that calls thread_create via a trap will have me->ssr_um == 1, so it's safe.
We should document this behavior in kernel/thread/create/create/spec though.

Comment thread kernel/util/stmode/test/test.c Outdated
u32_t tmp;

h2_init(NULL);
#if ARCHV <= 3

@bryanb-h2 bryanb-h2 Jun 8, 2026

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Add a function in kernel/util/hw/hw.h to get ssr.

Comment thread kernel/util/stmode/test/test.c Outdated
any threads. */
static H2K_thread_context extra_contexts[NUM_TEST_THREADS] __attribute__((aligned(32)));

static void stmode_extend_bootvm_contexts(H2K_thread_context *me)

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inline?

Comment thread kernel/util/stmode/test/test.c
H2K_stmode_end();
if ((H2K_get_syscfg() & 0x10) == 0) FAIL("stmode_end didn't ensable gie");

h2_thread_create(test1, &stack1[STACK_SIZE], (void *)1, 0);

@bryanb-h2 bryanb-h2 Jun 8, 2026

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Arguably this should just call H2K_thread_create_no_squash() directly to simplify the test. We can do this here since the test runs in monitor. Makes debugging the test easier.

@bryanb-h2 bryanb-h2 marked this pull request as ready for review June 8, 2026 16:15
@bryanb-h2 bryanb-h2 changed the title Fix stmode test WIP. Fix stmode test. Jun 8, 2026
@bryanb-h2 bryanb-h2 changed the title Fix stmode test. Fix stmode test Jun 8, 2026
zbelinsk added 4 commits June 9, 2026 00:58
@zbelinsk
hw.h: add H2K_get_sgp(); use it in tests instead of raw sgp0 asm
c6acbbe 
Add H2K_get_sgp() to kernel/util/hw/hw.h to return the current thread
context pointer from sgp/sgp0.

Also make stmode_extend_bootvm_contexts(), wait_for_threads_to_sleep() static inlines.

Signed-off-by: Zeev Belinsky <zbelinsk@qti.qualcomm.com>
@zbelinsk
hwconfig: add traps; clean up booter
cb9d100 
Add hwconfig trap handlers and user-facing wrappers for registers that
booter was accessing directly via H2K_* kernel functions:
CCR, SYSCFG, livelock (s35), turkey (s61), duck (s62), chicken (s63),
rgdr (s60).

Replace all H2K_get_*/H2K_set_* calls in booter/booter.c with the new
h2_hwconfig_* trap wrappers. Remove include of hw.h from booter since
it no longer needs kernel-internal register access.

Add SSR_UM_BIT (bit 16) to max.h as a named constant.

Simplify stmode test: remove local H2K_thread_create_no_squash override
and --allow-multiple-definition now that create.ref.c inherits ssr_um
from the caller. Use H2K_get_sgp() instead of raw sgp0 asm. Replace
h2_hwconfig_hwthreads_mask() with H2K_trap_hwconfig_hwthreads_mask().

Signed-off-by: Zeev Belinsky <zbelinsk@qti.qualcomm.com>
@zbelinsk
create: inherit ssr_um from caller; set BOOT_THREAD_SSR ssr_um=1
277445d 
H2K_thread_create_no_squash: change tmp->ssr_um from hardcoded 1 to
me->ssr_um so created threads inherit the caller's user mode bit.

Set SSR_UM_BIT in BOOT_THREAD_SSR so the booter boot thread starts as
guest-user (ssr_um=1), which is required for the inheritance to work
correctly for booter-created VMs.

NOTE: h2_compat/error test is currently failing - needs adaptation.
Signed-off-by: Zeev Belinsky <zbelinsk@qti.qualcomm.com>
@zbelinsk
Update max.h
bc1b035 
Signed-off-by: zbelinsk <zbelinsk@qti.qualcomm.com>
@bryanb-h2 bryanb-h2 added the fail label Jun 10, 2026
@zbelinsk zbelinsk changed the title Fix stmode test Enabling ssr Inheritance Jun 11, 2026
@zbelinsk zbelinsk changed the title Enabling ssr Inheritance Enabling ssr Inheritance WIP Jun 11, 2026
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