* Alexey Perevalov (a.pereva...@samsung.com) wrote: > On 05/31/2017 08:54 PM, Dr. David Alan Gilbert wrote: > > * Alexey Perevalov (a.pereva...@samsung.com) wrote: > > > That tiny refactoring is necessary to be able to set > > > UFFD_FEATURE_THREAD_ID while requesting features, and then > > > to create downtime context in case when kernel supports it. > > > > > > Signed-off-by: Alexey Perevalov <a.pereva...@samsung.com> > > > --- > > > migration/migration.c | 2 +- > > > migration/postcopy-ram.c | 10 +++++----- > > > migration/postcopy-ram.h | 2 +- > > > migration/savevm.c | 2 +- > > > 4 files changed, 8 insertions(+), 8 deletions(-) > > > > > > diff --git a/migration/migration.c b/migration/migration.c > > > index 0304c01..d735976 100644 > > > --- a/migration/migration.c > > > +++ b/migration/migration.c > > > @@ -789,7 +789,7 @@ void > > > qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, > > > * special support. > > > */ > > > if (!old_postcopy_cap && runstate_check(RUN_STATE_INMIGRATE) && > > > - !postcopy_ram_supported_by_host()) { > > > + !postcopy_ram_supported_by_host(NULL)) { > > Why is that NULL rather than migration_incoming_get_current()? > > That's on the destination. > In current implementation, AFAIU, > migrate-set-capabilities with postcopy-ram argument should be done on source > machine only, > and it's not required on destination. And it is unnecessary requirement to > support userfaultfd on > source and check it there.
Note the 'runstate_check(RUN_STATE_INMIGRATE)' - this check is made on the destination. While it's not strictly necessary for the management layer to do a migrate_set_capability postcopy-ram on the destination, it does it anyway to check the destination is capable of postcopy before it starts migration. Dave > > > > > Dave > > > > > /* postcopy_ram_supported_by_host will have emitted a more > > > * detailed message > > > */ > > > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > > > index a0489f6..4adab36 100644 > > > --- a/migration/postcopy-ram.c > > > +++ b/migration/postcopy-ram.c > > > @@ -59,7 +59,7 @@ struct PostcopyDiscardState { > > > #include <sys/eventfd.h> > > > #include <linux/userfaultfd.h> > > > -static bool ufd_version_check(int ufd) > > > +static bool ufd_version_check(int ufd, MigrationIncomingState *mis) > > > { > > > struct uffdio_api api_struct; > > > uint64_t ioctl_mask; > > > @@ -112,7 +112,7 @@ static int test_range_shared(const char *block_name, > > > void *host_addr, > > > * normally fine since if the postcopy succeeds it gets turned back on > > > at the > > > * end. > > > */ > > > -bool postcopy_ram_supported_by_host(void) > > > +bool postcopy_ram_supported_by_host(MigrationIncomingState *mis) > > > { > > > long pagesize = getpagesize(); > > > int ufd = -1; > > > @@ -135,7 +135,7 @@ bool postcopy_ram_supported_by_host(void) > > > } > > > /* Version and features check */ > > > - if (!ufd_version_check(ufd)) { > > > + if (!ufd_version_check(ufd, mis)) { > > > goto out; > > > } > > > @@ -512,7 +512,7 @@ int postcopy_ram_enable_notify(MigrationIncomingState > > > *mis) > > > * Although the host check already tested the API, we need to > > > * do the check again as an ABI handshake on the new fd. > > > */ > > > - if (!ufd_version_check(mis->userfault_fd)) { > > > + if (!ufd_version_check(mis->userfault_fd, mis)) { > > > return -1; > > > } > > > @@ -650,7 +650,7 @@ void *postcopy_get_tmp_page(MigrationIncomingState > > > *mis) > > > #else > > > /* No target OS support, stubs just fail */ > > > -bool postcopy_ram_supported_by_host(void) > > > +bool postcopy_ram_supported_by_host(MigrationIncomingState *mis) > > > { > > > error_report("%s: No OS support", __func__); > > > return false; > > > diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h > > > index 52d51e8..587a8b8 100644 > > > --- a/migration/postcopy-ram.h > > > +++ b/migration/postcopy-ram.h > > > @@ -14,7 +14,7 @@ > > > #define QEMU_POSTCOPY_RAM_H > > > /* Return true if the host supports everything we need to do > > > postcopy-ram */ > > > -bool postcopy_ram_supported_by_host(void); > > > +bool postcopy_ram_supported_by_host(MigrationIncomingState *mis); > > > /* > > > * Make all of RAM sensitive to accesses to areas that haven't yet been > > > written > > > diff --git a/migration/savevm.c b/migration/savevm.c > > > index f5e8194..61a6df7 100644 > > > --- a/migration/savevm.c > > > +++ b/migration/savevm.c > > > @@ -1356,7 +1356,7 @@ static int > > > loadvm_postcopy_handle_advise(MigrationIncomingState *mis) > > > return -1; > > > } > > > - if (!postcopy_ram_supported_by_host()) { > > > + if (!postcopy_ram_supported_by_host(mis)) { > > > postcopy_state_set(POSTCOPY_INCOMING_NONE); > > > return -1; > > > } > > > -- > > > 1.8.3.1 > > > > > -- > > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK > > > > > > > > -- > Best regards, > Alexey Perevalov -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK