From 3688fec8923101b3a44acde7f3db59b76f82b838 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Date: Wed, 20 Mar 2024 07:49:05 +0100 Subject: memory: Add Error** argument to .log_global_start() handler MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Modify all .log_global_start() handlers to take an Error** parameter and return a bool. Adapt memory_global_dirty_log_start() to interrupt on the first error the loop on handlers. In such case, a rollback is performed to stop dirty logging on all listeners where it was previously enabled. Cc: Stefano Stabellini Cc: Anthony Perard Cc: Paul Durrant Cc: "Michael S. Tsirkin" Cc: Paolo Bonzini Cc: David Hildenbrand Signed-off-by: Cédric Le Goater Reviewed-by: Peter Xu Link: https://lore.kernel.org/r/20240320064911.545001-10-clg@redhat.com [peterx: modify & enrich the comment for listener_add_address_space() ] Signed-off-by: Peter Xu --- hw/i386/xen/xen-hvm.c | 3 ++- hw/vfio/common.c | 4 +++- hw/virtio/vhost.c | 3 ++- include/exec/memory.h | 5 ++++- system/memory.c | 41 +++++++++++++++++++++++++++++++++++++++-- 5 files changed, 50 insertions(+), 6 deletions(-) diff --git a/hw/i386/xen/xen-hvm.c b/hw/i386/xen/xen-hvm.c index 7745cb3..f6e9a1b 100644 --- a/hw/i386/xen/xen-hvm.c +++ b/hw/i386/xen/xen-hvm.c @@ -457,11 +457,12 @@ static void xen_log_sync(MemoryListener *listener, MemoryRegionSection *section) int128_get64(section->size)); } -static void xen_log_global_start(MemoryListener *listener) +static bool xen_log_global_start(MemoryListener *listener, Error **errp) { if (xen_enabled()) { xen_in_migration = true; } + return true; } static void xen_log_global_stop(MemoryListener *listener) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 011ceaa..8f9cbdc 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -1066,7 +1066,8 @@ out: return ret; } -static void vfio_listener_log_global_start(MemoryListener *listener) +static bool vfio_listener_log_global_start(MemoryListener *listener, + Error **errp) { VFIOContainerBase *bcontainer = container_of(listener, VFIOContainerBase, listener); @@ -1083,6 +1084,7 @@ static void vfio_listener_log_global_start(MemoryListener *listener) ret, strerror(-ret)); vfio_set_migration_error(ret); } + return !ret; } static void vfio_listener_log_global_stop(MemoryListener *listener) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index f50180e..4acd77e 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -1044,7 +1044,7 @@ check_dev_state: return r; } -static void vhost_log_global_start(MemoryListener *listener) +static bool vhost_log_global_start(MemoryListener *listener, Error **errp) { int r; @@ -1052,6 +1052,7 @@ static void vhost_log_global_start(MemoryListener *listener) if (r < 0) { abort(); } + return true; } static void vhost_log_global_stop(MemoryListener *listener) diff --git a/include/exec/memory.h b/include/exec/memory.h index 8626a35..5555567 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -998,8 +998,11 @@ struct MemoryListener { * active at that time. * * @listener: The #MemoryListener. + * @errp: pointer to Error*, to store an error if it happens. + * + * Return: true on success, else false setting @errp with error. */ - void (*log_global_start)(MemoryListener *listener); + bool (*log_global_start)(MemoryListener *listener, Error **errp); /** * @log_global_stop: diff --git a/system/memory.c b/system/memory.c index a229a79..86d6c33 100644 --- a/system/memory.c +++ b/system/memory.c @@ -2914,9 +2914,33 @@ static unsigned int postponed_stop_flags; static VMChangeStateEntry *vmstate_change; static void memory_global_dirty_log_stop_postponed_run(void); +static bool memory_global_dirty_log_do_start(Error **errp) +{ + MemoryListener *listener; + + QTAILQ_FOREACH(listener, &memory_listeners, link) { + if (listener->log_global_start) { + if (!listener->log_global_start(listener, errp)) { + goto err; + } + } + } + return true; + +err: + while ((listener = QTAILQ_PREV(listener, link)) != NULL) { + if (listener->log_global_stop) { + listener->log_global_stop(listener); + } + } + + return false; +} + void memory_global_dirty_log_start(unsigned int flags) { unsigned int old_flags; + Error *local_err = NULL; assert(flags && !(flags & (~GLOBAL_DIRTY_MASK))); @@ -2936,7 +2960,13 @@ void memory_global_dirty_log_start(unsigned int flags) trace_global_dirty_changed(global_dirty_tracking); if (!old_flags) { - MEMORY_LISTENER_CALL_GLOBAL(log_global_start, Forward); + if (!memory_global_dirty_log_do_start(&local_err)) { + global_dirty_tracking &= ~flags; + trace_global_dirty_changed(global_dirty_tracking); + error_report_err(local_err); + return; + } + memory_region_transaction_begin(); memory_region_update_pending = true; memory_region_transaction_commit(); @@ -3014,8 +3044,15 @@ static void listener_add_address_space(MemoryListener *listener, listener->begin(listener); } if (global_dirty_tracking) { + /* + * Currently only VFIO can fail log_global_start(), and it's not + * yet allowed to hotplug any PCI device during migration. So this + * should never fail when invoked, guard it with error_abort. If + * it can start to fail in the future, we need to be able to fail + * the whole listener_add_address_space() and its callers. + */ if (listener->log_global_start) { - listener->log_global_start(listener); + listener->log_global_start(listener, &error_abort); } } -- cgit v1.1