* Alexey Perevalov (a.pereva...@samsung.com) wrote:
> On 06/16/2017 08:14 PM, Dr. David Alan Gilbert wrote:
> > * Alexey Perevalov (a.pereva...@samsung.com) wrote:
> > > This patch adds ability to track down already received
> > > pages, it's necessary for calculation vCPU block time in
> > > postcopy migration feature, maybe for restore after
> > > postcopy migration failure.
> > > Also it's necessary to solve shared memory issue in
> > > postcopy livemigration. Information about received pages
> > > will be transferred to the software virtual bridge
> > > (e.g. OVS-VSWITCHD), to avoid fallocate (unmap) for
> > > already received pages. fallocate syscall is required for
> > > remmaped shared memory, due to remmaping itself blocks
> > > ioctl(UFFDIO_COPY, ioctl in this case will end with EEXIT
> > > error (struct page is exists after remmap).
> > >
> > > Bitmap is placed into RAMBlock as another postcopy/precopy
> > > related bitmaps.
> > >
> > > Signed-off-by: Alexey Perevalov <a.pereva...@samsung.com>
> > > ---
> > > include/exec/ram_addr.h | 2 ++
> > > migration/postcopy-ram.c | 11 ++++++++---
> > > migration/ram.c | 33 +++++++++++++++++++++++++++++++++
> > > migration/ram.h | 5 +++++
> > > migration/savevm.c | 1 +
> > > 5 files changed, 49 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
> > > index 140efa8..c2c1dfe 100644
> > > --- a/include/exec/ram_addr.h
> > > +++ b/include/exec/ram_addr.h
> > > @@ -47,6 +47,8 @@ struct RAMBlock {
> > > * of the postcopy phase
> > > */
> > > unsigned long *unsentmap;
> > > + /* bitmap of already received pages in postcopy */
> > > + unsigned long *receivedmap;
> > > };
> > > static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
> > > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> > > index 38a429a..5ac3ed2 100644
> > > --- a/migration/postcopy-ram.c
> > > +++ b/migration/postcopy-ram.c
> > > @@ -562,8 +562,13 @@ int
> > > postcopy_ram_enable_notify(MigrationIncomingState *mis)
> > > }
> > > static int qemu_ufd_copy_ioctl(int userfault_fd, void *host_addr,
> > > - void *from_addr, uint64_t pagesize)
> > > + void *from_addr, uint64_t pagesize, RAMBlock *rb)
> > > {
> > > + /* received page isn't feature of blocktime calculation,
> > > + * it's more general entity, so keep it here,
> > > + * but gup betwean two following operation could be high,
> > > + * and in this case blocktime for such small interval will be lost */
> > > + set_receivedmap_by_addr(host_addr, rb);
> > > if (from_addr) {
> > > struct uffdio_copy copy_struct;
> > > copy_struct.dst = (uint64_t)(uintptr_t)host_addr;
> > > @@ -595,7 +600,7 @@ int postcopy_place_page(MigrationIncomingState *mis,
> > > void *host, void *from,
> > > * which would be slightly cheaper, but we'd have to be careful
> > > * of the order of updating our page state.
> > > */
> > > - if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, from, pagesize)) {
> > > + if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, from, pagesize,
> > > rb)) {
> > In your first patch of the series you changed postcopy_place_page to
> > take a RAMBlock* *rather* than a pagesize; perhaps it would be better
> > to do the same here?
> that's true only for postcopy_place_page where pagesize is getting from
> ramblock,
> but not true for postcopy_place_page_zero, where initially was len =
> getpagesize()
Ah, yes:
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> >
> > Other than that looks pretty good.
> >
> > Dave
> >
> > > int e = errno;
> > > error_report("%s: %s copy host: %p from: %p (size: %zd)",
> > > __func__, strerror(e), host, from, pagesize);
> > > @@ -619,7 +624,7 @@ int postcopy_place_page_zero(MigrationIncomingState
> > > *mis, void *host,
> > > pagesize = qemu_ram_pagesize(rb);
> > > if (pagesize == getpagesize()) {
> > > - if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, 0,
> > > getpagesize())) {
> > > + if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, 0,
> > > getpagesize(), rb)) {
> > > int e = errno;
> > > error_report("%s: %s zero host: %p",
> > > __func__, strerror(e), host);
> > > diff --git a/migration/ram.c b/migration/ram.c
> > > index f50479d..f5ea3c2 100644
> > > --- a/migration/ram.c
> > > +++ b/migration/ram.c
> > > @@ -151,6 +151,34 @@ out:
> > > return ret;
> > > }
> > > +void init_receivedmap(void)
> > > +{
> > > + RAMBlock *rb;
> > > +
> > > + RAMBLOCK_FOREACH(rb) {
> > > + unsigned long pages;
> > > + pages = rb->max_length >> TARGET_PAGE_BITS;
> > > + rb->receivedmap = bitmap_new(pages);
> > > + }
> > > +}
> > > +
> > > +static unsigned long int get_received_bit_offset(void *host_addr,
> > > RAMBlock *rb)
> > > +{
> > > + uint64_t host_addr_offset = (uint64_t)(uintptr_t)(host_addr
> > > + - (void
> > > *)rb->host);
> > > + return host_addr_offset >> TARGET_PAGE_BITS;
> > > +}
> > > +
> > > +int test_receivedmap_by_addr(void *host_addr, RAMBlock *rb)
> > > +{
> > > + return test_bit(get_received_bit_offset(host_addr, rb),
> > > rb->receivedmap);
> > > +}
> > > +
> > > +void set_receivedmap_by_addr(void *host_addr, RAMBlock *rb)
> > > +{
> > > + set_bit_atomic(get_received_bit_offset(host_addr, rb),
> > > rb->receivedmap);
> > > +}
> > > +
> > > /*
> > > * An outstanding page request, on the source, having been received
> > > * and queued
> > > @@ -2324,8 +2352,13 @@ static int ram_load_setup(QEMUFile *f, void
> > > *opaque)
> > > static int ram_load_cleanup(void *opaque)
> > > {
> > > + RAMBlock *rb;
> > > xbzrle_load_cleanup();
> > > compress_threads_load_cleanup();
> > > +
> > > + RAMBLOCK_FOREACH(rb) {
> > > + g_free(rb->receivedmap);
> > > + }
> > > return 0;
> > > }
> > > diff --git a/migration/ram.h b/migration/ram.h
> > > index c081fde..7048ff9 100644
> > > --- a/migration/ram.h
> > > +++ b/migration/ram.h
> > > @@ -52,4 +52,9 @@ int ram_discard_range(const char *block_name, uint64_t
> > > start, size_t length);
> > > int ram_postcopy_incoming_init(MigrationIncomingState *mis);
> > > void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
> > > +
> > > +void init_receivedmap(void);
> > > +int test_receivedmap_by_addr(void *host_addr, RAMBlock *rb);
> > > +void set_receivedmap_by_addr(void *host_addr, RAMBlock *rb);
> > > +
> > > #endif
> > > diff --git a/migration/savevm.c b/migration/savevm.c
> > > index 31158da..668d3bb 100644
> > > --- a/migration/savevm.c
> > > +++ b/migration/savevm.c
> > > @@ -1372,6 +1372,7 @@ static int
> > > loadvm_postcopy_handle_advise(MigrationIncomingState *mis)
> > > return -1;
> > > }
> > > + init_receivedmap();
> > > remote_pagesize_summary = qemu_get_be64(mis->from_src_file);
> > > local_pagesize_summary = ram_pagesize_summary();
> > > --
> > > 1.9.1
> > >
> > --
> > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
> >
> >
> >
>
> --
> Best regards,
> Alexey Perevalov
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
