Instead of print it to STDERR, bring the error upwards so that it can be
reported via QMP responses.
E.g.:
{ "execute": "migrate-set-capabilities" ,
"arguments": { "capabilities":
[ { "capability": "postcopy-ram", "state": true } ] } }
{ "error":
{ "class": "GenericError",
"desc": "Postcopy is not supported: Host backend files need to be TMPFS
or HUGETLBFS only" } }
Signed-off-by: Peter Xu <pet...@redhat.com>
---
migration/migration.c | 9 +++---
migration/postcopy-ram.c | 61 ++++++++++++++++++++++------------------
migration/postcopy-ram.h | 3 +-
migration/savevm.c | 3 +-
4 files changed, 42 insertions(+), 34 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index bda4789193..ac15fa6092 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1313,6 +1313,7 @@ static bool migrate_caps_check(bool *cap_list,
MigrationCapabilityStatusList *cap;
bool old_postcopy_cap;
MigrationIncomingState *mis = migration_incoming_get_current();
+ Error *local_err = NULL;
old_postcopy_cap = cap_list[MIGRATION_CAPABILITY_POSTCOPY_RAM];
@@ -1344,11 +1345,9 @@ static bool migrate_caps_check(bool *cap_list,
* special support.
*/
if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) &&
- !postcopy_ram_supported_by_host(mis)) {
- /* postcopy_ram_supported_by_host will have emitted a more
- * detailed message
- */
- error_setg(errp, "Postcopy is not supported");
+ !postcopy_ram_supported_by_host(mis, &local_err)) {
+ error_propagate_prepend(errp, local_err,
+ "Postcopy is not supported: ");
return false;
}
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index bbb8af61ae..0713ddeeef 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -282,11 +282,14 @@ static bool request_ufd_features(int ufd, uint64_t
features)
return true;
}
-static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis)
+static bool ufd_check_and_apply(int ufd, MigrationIncomingState *mis,
+ Error **errp)
{
uint64_t asked_features = 0;
static uint64_t supported_features;
+ assert(errp);
+
/*
* it's not possible to
* request UFFD_API twice per one fd
@@ -294,7 +297,7 @@ static bool ufd_check_and_apply(int ufd,
MigrationIncomingState *mis)
*/
if (!supported_features) {
if (!receive_ufd_features(&supported_features)) {
- error_report("%s failed", __func__);
+ error_setg(errp, "Userfault feature detection failed");
return false;
}
}
@@ -316,8 +319,7 @@ static bool ufd_check_and_apply(int ufd,
MigrationIncomingState *mis)
* userfault file descriptor
*/
if (!request_ufd_features(ufd, asked_features)) {
- error_report("%s failed: features %" PRIu64, __func__,
- asked_features);
+ error_setg(errp, "Failed features %" PRIu64, asked_features);
return false;
}
@@ -328,7 +330,8 @@ static bool ufd_check_and_apply(int ufd,
MigrationIncomingState *mis)
have_hp = supported_features & UFFD_FEATURE_MISSING_HUGETLBFS;
#endif
if (!have_hp) {
- error_report("Userfault on this host does not support huge pages");
+ error_setg(errp,
+ "Userfault on this host does not support huge pages");
return false;
}
}
@@ -337,7 +340,7 @@ static bool ufd_check_and_apply(int ufd,
MigrationIncomingState *mis)
/* Callback from postcopy_ram_supported_by_host block iterator.
*/
-static int test_ramblock_postcopiable(RAMBlock *rb)
+static int test_ramblock_postcopiable(RAMBlock *rb, Error **errp)
{
const char *block_name = qemu_ram_get_idstr(rb);
ram_addr_t length = qemu_ram_get_used_length(rb);
@@ -345,16 +348,18 @@ static int test_ramblock_postcopiable(RAMBlock *rb)
QemuFsType fs;
if (length % pagesize) {
- error_report("Postcopy requires RAM blocks to be a page size multiple,"
- " block %s is 0x" RAM_ADDR_FMT " bytes with a "
- "page size of 0x%zx", block_name, length, pagesize);
+ error_setg(errp,
+ "Postcopy requires RAM blocks to be a page size multiple,"
+ " block %s is 0x" RAM_ADDR_FMT " bytes with a "
+ "page size of 0x%zx", block_name, length, pagesize);
return 1;
}
if (rb->fd >= 0) {
fs = qemu_fd_getfs(rb->fd);
if (fs != QEMU_FS_TYPE_TMPFS && fs != QEMU_FS_TYPE_HUGETLBFS) {
- error_report("Host backend files need to be TMPFS or HUGETLBFS
only");
+ error_setg(errp,
+ "Host backend files need to be TMPFS or HUGETLBFS
only");
return 1;
}
}
@@ -367,7 +372,8 @@ static int test_ramblock_postcopiable(RAMBlock *rb)
* normally fine since if the postcopy succeeds it gets turned back on at the
* end.
*/
-bool postcopy_ram_supported_by_host(MigrationIncomingState *mis)
+bool postcopy_ram_supported_by_host(MigrationIncomingState *mis,
+ Error **errp)
{
long pagesize = qemu_real_host_page_size();
int ufd = -1;
@@ -376,29 +382,28 @@ bool
postcopy_ram_supported_by_host(MigrationIncomingState *mis)
struct uffdio_register reg_struct;
struct uffdio_range range_struct;
uint64_t feature_mask;
- Error *local_err = NULL;
RAMBlock *block;
+ assert(errp);
+
if (qemu_target_page_size() > pagesize) {
- error_report("Target page size bigger than host page size");
+ error_setg(errp, "Target page size bigger than host page size");
goto out;
}
ufd = uffd_open(O_CLOEXEC);
if (ufd == -1) {
- error_report("%s: userfaultfd not available: %s", __func__,
- strerror(errno));
+ error_setg(errp, "Userfaultfd not available: %s", strerror(errno));
goto out;
}
/* Give devices a chance to object */
- if (postcopy_notify(POSTCOPY_NOTIFY_PROBE, &local_err)) {
- error_report_err(local_err);
+ if (postcopy_notify(POSTCOPY_NOTIFY_PROBE, errp)) {
goto out;
}
/* Version and features check */
- if (!ufd_check_and_apply(ufd, mis)) {
+ if (!ufd_check_and_apply(ufd, mis, errp)) {
goto out;
}
@@ -416,7 +421,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState
*mis)
* affect in reality, or we can revisit.
*/
RAMBLOCK_FOREACH(block) {
- if (test_ramblock_postcopiable(block)) {
+ if (test_ramblock_postcopiable(block, errp)) {
goto out;
}
}
@@ -426,7 +431,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState
*mis)
* it was enabled.
*/
if (munlockall()) {
- error_report("%s: munlockall: %s", __func__, strerror(errno));
+ error_setg(errp, "munlockall() failed: %s", strerror(errno));
goto out;
}
@@ -438,8 +443,7 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState
*mis)
testarea = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE |
MAP_ANONYMOUS, -1, 0);
if (testarea == MAP_FAILED) {
- error_report("%s: Failed to map test area: %s", __func__,
- strerror(errno));
+ error_setg(errp, "Failed to map test area: %s", strerror(errno));
goto out;
}
g_assert(QEMU_PTR_IS_ALIGNED(testarea, pagesize));
@@ -449,14 +453,14 @@ bool
postcopy_ram_supported_by_host(MigrationIncomingState *mis)
reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
if (ioctl(ufd, UFFDIO_REGISTER, ®_struct)) {
- error_report("%s userfault register: %s", __func__, strerror(errno));
+ error_setg(errp, "UFFDIO_REGISTER failed: %s", strerror(errno));
goto out;
}
range_struct.start = (uintptr_t)testarea;
range_struct.len = pagesize;
if (ioctl(ufd, UFFDIO_UNREGISTER, &range_struct)) {
- error_report("%s userfault unregister: %s", __func__, strerror(errno));
+ error_setg(errp, "UFFDIO_UNREGISTER failed: %s", strerror(errno));
goto out;
}
@@ -464,8 +468,8 @@ bool postcopy_ram_supported_by_host(MigrationIncomingState
*mis)
(__u64)1 << _UFFDIO_COPY |
(__u64)1 << _UFFDIO_ZEROPAGE;
if ((reg_struct.ioctls & feature_mask) != feature_mask) {
- error_report("Missing userfault map features: %" PRIx64,
- (uint64_t)(~reg_struct.ioctls & feature_mask));
+ error_setg(errp, "Missing userfault map features: %" PRIx64,
+ (uint64_t)(~reg_struct.ioctls & feature_mask));
goto out;
}
@@ -1187,6 +1191,8 @@ static int
postcopy_temp_pages_setup(MigrationIncomingState *mis)
int postcopy_ram_incoming_setup(MigrationIncomingState *mis)
{
+ Error *local_err = NULL;
+
/* Open the fd for the kernel to give us userfaults */
mis->userfault_fd = uffd_open(O_CLOEXEC | O_NONBLOCK);
if (mis->userfault_fd == -1) {
@@ -1199,7 +1205,8 @@ int postcopy_ram_incoming_setup(MigrationIncomingState
*mis)
* Although the host check already tested the API, we need to
* do the check again as an ABI handshake on the new fd.
*/
- if (!ufd_check_and_apply(mis->userfault_fd, mis)) {
+ if (!ufd_check_and_apply(mis->userfault_fd, mis, &local_err)) {
+ error_report_err(local_err);
return -1;
}
diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index b4867a32d5..442ab89752 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -14,7 +14,8 @@
#define QEMU_POSTCOPY_RAM_H
/* Return true if the host supports everything we need to do postcopy-ram */
-bool postcopy_ram_supported_by_host(MigrationIncomingState *mis);
+bool postcopy_ram_supported_by_host(MigrationIncomingState *mis,
+ Error **errp);
/*
* Make all of RAM sensitive to accesses to areas that haven't yet been written
diff --git a/migration/savevm.c b/migration/savevm.c
index aa54a67fda..0d61ab6c19 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1752,7 +1752,8 @@ static int
loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
return -EINVAL;
}
- if (!postcopy_ram_supported_by_host(mis)) {
+ if (!postcopy_ram_supported_by_host(mis, &local_err)) {
+ error_report_err(local_err);
postcopy_state_set(POSTCOPY_INCOMING_NONE);
return -1;
}
--
2.39.1
