summaryrefslogtreecommitdiffstats
path: root/include/exec
diff options
context:
space:
mode:
authorAndrey Gruzdev2021-01-29 11:14:05 +0100
committerDr. David Alan Gilbert2021-02-08 12:19:51 +0100
commit278e2f551a095b234de74dca9c214d5502a1f72c (patch)
tree0759c7262dc70c647fcfb12fdc9905e81666b022 /include/exec
parentmigration: introduce UFFD-WP low-level interface helpers (diff)
downloadqemu-278e2f551a095b234de74dca9c214d5502a1f72c.tar.gz
qemu-278e2f551a095b234de74dca9c214d5502a1f72c.tar.xz
qemu-278e2f551a095b234de74dca9c214d5502a1f72c.zip
migration: support UFFD write fault processing in ram_save_iterate()
In this particular implementation the same single migration thread is responsible for both normal linear dirty page migration and procesing UFFD page fault events. Processing write faults includes reading UFFD file descriptor, finding respective RAM block and saving faulting page to the migration stream. After page has been saved, write protection can be removed. Since asynchronous version of qemu_put_buffer() is expected to be used to save pages, we also have to flush migraion stream prior to un-protecting saved memory range. Write protection is being removed for any previously protected memory chunk that has hit the migration stream. That's valid for pages from linear page scan along with write fault pages. Signed-off-by: Andrey Gruzdev <andrey.gruzdev@virtuozzo.com> Acked-by: Peter Xu <peterx@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20210129101407.103458-4-andrey.gruzdev@virtuozzo.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> fixup pagefault.address cast for 32bit
Diffstat (limited to 'include/exec')
-rw-r--r--include/exec/memory.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 37096217e7..e58c09f130 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -150,6 +150,13 @@ typedef struct IOMMUTLBEvent {
#define RAM_PMEM (1 << 5)
+/*
+ * UFFDIO_WRITEPROTECT is used on this RAMBlock to
+ * support 'write-tracking' migration type.
+ * Implies ram_state->ram_wt_enabled.
+ */
+#define RAM_UF_WRITEPROTECT (1 << 6)
+
static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
IOMMUNotifierFlag flags,
hwaddr start, hwaddr end,