From: Michal Privoznik <mprivozn@redhat.com>

QEMU can't really do live dumps of guest memory. It's because
inside of dump_init() the vm_stop() is called basically
unconditionally (the only condition is whether vCPUs are
running). Hence, there is no way for us to do live dumps and thus
honor VIR_DUMP_LIVE flag. Instead of silently pretending the flag
works, reject it with appropriate error message.

Resolves: https://gitlab.com/libvirt/libvirt/-/issues/646
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 src/qemu/qemu_driver.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index aef313ae9c..b3b0ee66f8 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -3162,7 +3162,7 @@ qemuDomainCoreDumpWithFormat(virDomainPtr dom,
     int ret = -1;
     virObjectEvent *event = NULL;
 
-    virCheckFlags(VIR_DUMP_LIVE | VIR_DUMP_CRASH |
+    virCheckFlags(VIR_DUMP_CRASH |
                   VIR_DUMP_BYPASS_CACHE | VIR_DUMP_RESET |
                   VIR_DUMP_MEMORY_ONLY, -1);
 
-- 
2.49.0

On Tue, Jun 03, 2025 at 10:03:12AM +0200, Michal Privoznik via Devel wrote:
> From: Michal Privoznik <mprivozn@redhat.com>
> 
> QEMU can't really do live dumps of guest memory. It's because
> inside of dump_init() the vm_stop() is called basically
> unconditionally (the only condition is whether vCPUs are
> running). Hence, there is no way for us to do live dumps and thus
> honor VIR_DUMP_LIVE flag. Instead of silently pretending the flag
> works, reject it with appropriate error message.
> 
> Resolves: https://gitlab.com/libvirt/libvirt/-/issues/646
> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
> ---
>  src/qemu/qemu_driver.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>


With regards,
Daniel
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