hw/cxl: Check for multiple mappings of memory backends.

Similar protection to that provided for -numa memdev=x
to make sure that memory used to back a type3 device is not also mapped
as normal RAM, or for multiple type3 devices.

This is an easy footgun to remove and seems multiple people have
run into it.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20240705113956.941732-4-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Jonathan Cameron 2024-07-05 12:39:56 +01:00 committed by Michael S. Tsirkin
parent b7dbfe4f47
commit 9de2049c95

View File

@ -737,6 +737,11 @@ static bool cxl_setup_memory(CXLType3Dev *ct3d, Error **errp)
error_setg(errp, "volatile memdev must have backing device");
return false;
}
if (host_memory_backend_is_mapped(ct3d->hostvmem)) {
error_setg(errp, "memory backend %s can't be used multiple times.",
object_get_canonical_path_component(OBJECT(ct3d->hostvmem)));
return false;
}
memory_region_set_nonvolatile(vmr, false);
memory_region_set_enabled(vmr, true);
host_memory_backend_set_mapped(ct3d->hostvmem, true);
@ -760,6 +765,11 @@ static bool cxl_setup_memory(CXLType3Dev *ct3d, Error **errp)
error_setg(errp, "persistent memdev must have backing device");
return false;
}
if (host_memory_backend_is_mapped(ct3d->hostpmem)) {
error_setg(errp, "memory backend %s can't be used multiple times.",
object_get_canonical_path_component(OBJECT(ct3d->hostpmem)));
return false;
}
memory_region_set_nonvolatile(pmr, true);
memory_region_set_enabled(pmr, true);
host_memory_backend_set_mapped(ct3d->hostpmem, true);
@ -790,6 +800,11 @@ static bool cxl_setup_memory(CXLType3Dev *ct3d, Error **errp)
return false;
}
if (host_memory_backend_is_mapped(ct3d->dc.host_dc)) {
error_setg(errp, "memory backend %s can't be used multiple times.",
object_get_canonical_path_component(OBJECT(ct3d->dc.host_dc)));
return false;
}
/*
* Set DC regions as volatile for now, non-volatile support can
* be added in the future if needed.