Hello Alex,
just reporting below what might be a riscv only oddity (also applies to
patch 41 but easier to report here).
Le 03/01/2024 à 18:33, Alex Bennée a écrit :
With the new plugin register API we can now track changes to register
values. Currently the implementation is fairly dumb which will slow
down if a large number of register values are being tracked. This
could be improved by only instrumenting instructions which mention
registers we are interested in tracking.
Example usage:
./qemu-aarch64 -D plugin.log -d plugin \
-cpu max,sve256=on \
-plugin contrib/plugins/libexeclog.so,reg=sp,reg=z\* \
./tests/tcg/aarch64-linux-user/sha512-sve
will display in the execlog any changes to the stack pointer (sp) and
the SVE Z registers.
Signed-off-by: Alex Bennée <[email protected]>
Cc: Akihiko Odaki <[email protected]>
Based-On: <[email protected]>
+static registers_init(int vcpu_index)
+{
+ GPtrArray *registers = g_ptr_array_new();
+ g_autoptr(GArray) reg_list = qemu_plugin_get_registers(vcpu_index);
+
+ if (reg_list && reg_list->len) {
+ /*
+ * Go through each register in the complete list and
+ * see if we want to track it.
+ */
+ for (int r = 0; r < reg_list->len; r++) {
+ qemu_plugin_reg_descriptor *rd = &g_array_index(
+ reg_list, qemu_plugin_reg_descriptor, r);
riscv csrs are not continously numbered and the dynamically generated gdb xml
seems to follow that scheme.
So the calls to Glib string functions output quite a few assertion
warnings because for the non existing csrs rd->name is NULL (and there
are a bit less than 4000 such cases for rv64g).
Checking for NULL and then continue is a simple way to solve the issue, but
I am not sure this is the proper way to proceed, as it might stand in the
generation of the riscv xml description for gdb.
Cheers,
Frédéric
+ for (int p = 0; p < rmatches->len; p++) {
+ g_autoptr(GPatternSpec) pat =
g_pattern_spec_new(rmatches->pdata[p]);
+ if (g_pattern_match_string(pat, rd->name)) {
+ Register *reg = init_vcpu_register(vcpu_index, rd);
+ g_ptr_array_add(registers, reg);
+ }
+ }
+ }
+ }
+ cpus[num_cpus].registers = registers;
+}
