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target/arm/machine: Fix detection of unknown incoming cpregs

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Currently the check of cpreg index matches fail to detect
a situation where the length of both arrays is same but
- destination has an extra register not found in the incoming stream (idx1)
- source has an extra register not found in the destination (idx2)
  where idx1 < = idx2
Normally this should fail but it does not.

Fix the logic to scan all indexes.

Fixes: 721fae1253 ("target-arm: Convert TCG to using (index,value) list for cp migration")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20260304101625.1962633-8-eric.auger@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Eric Auger
2026-03-06 09:01:12 +00:00
committed by Peter Maydell
parent e25c63c3b3
commit dbfed8d808
1 changed files with 49 additions and 12 deletions
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61
target/arm/machine.c
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@@ -1057,6 +1057,35 @@ static gchar *print_register_name(uint64_t kvm_regidx)
}
}
/*
* Handle the situation where @kvmidx is on destination but not
* in the incoming stream. This never fails the migration.
*/
static void handle_cpreg_missing_in_incoming_stream(ARMCPU *cpu, uint64_t kvmidx)
{
g_autofree gchar *name = print_register_name(kvmidx);
warn_report("%s: %s "
"expected by the destination but not in the incoming stream: "
"skip it", __func__, name);
}
/*
* Handle the situation where @kvmidx is in the incoming stream
* but not on destination. This currently fails the migration but
* we plan to accomodate some exceptions, hence the boolean returned value.
*/
static bool handle_cpreg_only_in_incoming_stream(ARMCPU *cpu, uint64_t kvmidx)
{
g_autofree gchar *name = print_register_name(kvmidx);
bool fail = true;
error_report("%s: %s in the incoming stream but unknown on the "
"destination: fail migration", __func__, name);
return fail;
}
static int cpu_post_load(void *opaque, int version_id)
{
ARMCPU *cpu = opaque;
@@ -1096,21 +1125,12 @@ static int cpu_post_load(void *opaque, int version_id)
for (i = 0, v = 0; i < cpu->cpreg_array_len
&& v < cpu->cpreg_vmstate_array_len;) {
if (cpu->cpreg_vmstate_indexes[v] > cpu->cpreg_indexes[i]) {
g_autofree gchar *name = print_register_name(cpu->cpreg_indexes[i]);
warn_report("%s: %s "
"expected by the destination but not in the incoming stream: "
"skip it", __func__, name);
i++;
handle_cpreg_missing_in_incoming_stream(cpu, cpu->cpreg_indexes[i++]);
continue;
}
if (cpu->cpreg_vmstate_indexes[v] < cpu->cpreg_indexes[i]) {
g_autofree gchar *name = print_register_name(cpu->cpreg_vmstate_indexes[v]);
error_report("%s: %s in the incoming stream but unknown on the destination: "
"fail migration", __func__, name);
v++;
fail = true;
fail = handle_cpreg_only_in_incoming_stream(cpu,
cpu->cpreg_vmstate_indexes[v++]);
continue;
}
/* matching register, copy the value over */
@@ -1118,6 +1138,23 @@ static int cpu_post_load(void *opaque, int version_id)
i++;
v++;
}
/*
* if we have reached the end of the incoming array but there are
* still regs in cpreg, continue parsing the regs which are missing
* in the input stream
*/
for ( ; i < cpu->cpreg_array_len; i++) {
handle_cpreg_missing_in_incoming_stream(cpu, cpu->cpreg_indexes[i]);
}
/*
* if we have reached the end of the cpreg array but there are
* still regs in the input stream, continue parsing the vmstate array
*/
for ( ; v < cpu->cpreg_vmstate_array_len; v++) {
fail = handle_cpreg_only_in_incoming_stream(cpu,
cpu->cpreg_vmstate_indexes[v]);
}
if (fail) {
return -1;
}