On 2/25/25 10:46, Alex Bennée wrote:
From: Igor Mammedov <imamm...@redhat.com>
that will enable assert_cpu_is_self when QEMU is configured with
--enable-debug
without need for manual patching DEBUG_TLB_GATE define.
Need to manually path DEBUG_TLB_GATE define to enable assert,
let regression caused by [1] creep in unnoticed.
1) 30933c4fb4f3d ("tcg/cputlb: remove other-cpu capability from TLB flushing")
Signed-off-by: Igor Mammedov <imamm...@redhat.com>
Suggested-by: Alex Bennée <alex.ben...@linaro.org>
Message-Id: <20250207162048.1890669-5-imamm...@redhat.com>
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
---
accel/tcg/cputlb.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index fc16a576f0..65b04b1055 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -73,11 +73,8 @@
} \
} while (0)
-#define assert_cpu_is_self(cpu) do { \
- if (DEBUG_TLB_GATE) { \
- g_assert(!(cpu)->created || qemu_cpu_is_self(cpu)); \
- } \
- } while (0)
+#define assert_cpu_is_self(cpu) \
+ tcg_debug_assert(!(cpu)->created || qemu_cpu_is_self(cpu))
I think this check is just wrong or incomplete.
The intent here is to check that we're not attempting to modify the softmmu tlb
asynchronously while a cpu is running.
(0) A synchronous flush to the current cpu is (obviously?) ok.
(1) A flush to a cpu that is not yet created is (or should be) a no-op.
Not checked here are any of the other reasons a flush might be ok:
(2) The system as a whole is stopped, on the way in from migration/vmload.
(3) The cpu is offline, on the way in from poweroff/reset.
If we decide that {1, 2, 3} are too complicated to check, then perhaps the solution to
queue flushes to the cpu's workqueue is the appropriate solution. But so far all I see is
that we have an incomplete check, and no ready explanation for why that check can't be
improved.
r~
