From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51518) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aNmyj-0007lK-FL for qemu-devel@nongnu.org; Mon, 25 Jan 2016 14:39:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aNmye-0000F2-AP for qemu-devel@nongnu.org; Mon, 25 Jan 2016 14:39:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60056) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aNmye-0000Es-2p for qemu-devel@nongnu.org; Mon, 25 Jan 2016 14:39:04 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id 7F8278F861 for ; Mon, 25 Jan 2016 19:39:03 +0000 (UTC) Date: Mon, 25 Jan 2016 19:38:59 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20160125193858.GI2464@work-vm> References: <1452599056-27357-1-git-send-email-berrange@redhat.com> <1452599056-27357-9-git-send-email-berrange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1452599056-27357-9-git-send-email-berrange@redhat.com> Subject: Re: [Qemu-devel] [PATCH v1 08/22] migration: convert post-copy to use QIOChannelBuffer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: Amit Shah , qemu-devel@nongnu.org, Juan Quintela * Daniel P. Berrange (berrange@redhat.com) wrote: > The post-copy code does some I/O to/from an intermediate > in-memory buffer rather than direct to the underlying > I/O channel. Switch this code to use QIOChannelBuffer > instead of QEMUSizedBuffer. > > Signed-off-by: Daniel P. Berrange > --- > docs/migration.txt | 4 ++-- > include/sysemu/sysemu.h | 2 +- > migration/migration.c | 15 +++++++-------- > migration/savevm.c | 41 +++++++++++++---------------------------- > 4 files changed, 23 insertions(+), 39 deletions(-) > > diff --git a/docs/migration.txt b/docs/migration.txt > index fda8d61..11703de 100644 > --- a/docs/migration.txt > +++ b/docs/migration.txt > @@ -403,8 +403,8 @@ listen thread: --- page -- page -- page -- page -- page -- > > On receipt of CMD_PACKAGED (1) > All the data associated with the package - the ( ... ) section in the > -diagram - is read into memory (into a QEMUSizedBuffer), and the main thread > -recurses into qemu_loadvm_state_main to process the contents of the package (2) > +diagram - is read into memory, and the main thread recurses into > +qemu_loadvm_state_main to process the contents of the package (2) > which contains commands (3,6) and devices (4...) > > On receipt of 'postcopy listen' - 3 -(i.e. the 1st command in the package) > diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h > index 3bb8897..0f59912 100644 > --- a/include/sysemu/sysemu.h > +++ b/include/sysemu/sysemu.h > @@ -120,7 +120,7 @@ void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command, > uint16_t len, uint8_t *data); > void qemu_savevm_send_ping(QEMUFile *f, uint32_t value); > void qemu_savevm_send_open_return_path(QEMUFile *f); > -int qemu_savevm_send_packaged(QEMUFile *f, const QEMUSizedBuffer *qsb); > +int qemu_savevm_send_packaged(QEMUFile *f, const char *buf, size_t len); > void qemu_savevm_send_postcopy_advise(QEMUFile *f); > void qemu_savevm_send_postcopy_listen(QEMUFile *f); > void qemu_savevm_send_postcopy_run(QEMUFile *f); > diff --git a/migration/migration.c b/migration/migration.c > index 715f069..e921b20 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -33,6 +33,7 @@ > #include "qom/cpu.h" > #include "exec/memory.h" > #include "exec/address-spaces.h" > +#include "io/channel-buffer.h" > > #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */ > > @@ -1401,7 +1402,8 @@ static int await_return_path_close_on_source(MigrationState *ms) > static int postcopy_start(MigrationState *ms, bool *old_vm_running) > { > int ret; > - const QEMUSizedBuffer *qsb; > + QIOChannelBuffer *bioc; > + QEMUFile *fb; > int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); > migrate_set_state(ms, MIGRATION_STATUS_ACTIVE, > MIGRATION_STATUS_POSTCOPY_ACTIVE); > @@ -1456,11 +1458,9 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running) > * So we wrap the device state up in a package with a length at the start; > * to do this we use a qemu_buf to hold the whole of the device state. > */ > - QEMUFile *fb = qemu_bufopen("w", NULL); > - if (!fb) { > - error_report("Failed to create buffered file"); > - goto fail; > - } > + bioc = qio_channel_buffer_new(4096); > + fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc)); Why is that _input ? Also, what's your naming converntion; my 'qsb' was just an abbreviation of (Q)EMU(S)ized(B)uffer; what's a bioc? > + object_unref(OBJECT(bioc)); > > /* > * Make sure the receiver can get incoming pages before we send the rest > @@ -1474,10 +1474,9 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running) > qemu_savevm_send_postcopy_run(fb); > > /* <><> end of stuff going into the package */ > - qsb = qemu_buf_get(fb); > > /* Now send that blob */ > - if (qemu_savevm_send_packaged(ms->file, qsb)) { > + if (qemu_savevm_send_packaged(ms->file, bioc->data, bioc->usage)) { > goto fail_closefb; > } > qemu_fclose(fb); > diff --git a/migration/savevm.c b/migration/savevm.c > index 0ad1b93..f2e1880 100644 > --- a/migration/savevm.c > +++ b/migration/savevm.c > @@ -50,6 +50,7 @@ > #include "qemu/iov.h" > #include "block/snapshot.h" > #include "block/qapi.h" > +#include "io/channel-buffer.h" > > > #ifndef ETH_P_RARP > @@ -760,10 +761,8 @@ void qemu_savevm_send_open_return_path(QEMUFile *f) > * 0 on success > * -ve on error > */ > -int qemu_savevm_send_packaged(QEMUFile *f, const QEMUSizedBuffer *qsb) > +int qemu_savevm_send_packaged(QEMUFile *f, const char *buf, size_t len) > { > - size_t cur_iov; > - size_t len = qsb_get_length(qsb); > uint32_t tmp; > > if (len > MAX_VM_CMD_PACKAGED_SIZE) { > @@ -777,18 +776,7 @@ int qemu_savevm_send_packaged(QEMUFile *f, const QEMUSizedBuffer *qsb) > trace_qemu_savevm_send_packaged(); > qemu_savevm_command_send(f, MIG_CMD_PACKAGED, 4, (uint8_t *)&tmp); > > - /* all the data follows (concatinating the iov's) */ > - for (cur_iov = 0; cur_iov < qsb->n_iov; cur_iov++) { > - /* The iov entries are partially filled */ > - size_t towrite = MIN(qsb->iov[cur_iov].iov_len, len); > - len -= towrite; > - > - if (!towrite) { > - break; > - } > - > - qemu_put_buffer(f, qsb->iov[cur_iov].iov_base, towrite); > - } > + qemu_put_buffer(f, (const uint8_t *)buf, len); > > return 0; > } > @@ -1548,9 +1536,8 @@ static int loadvm_postcopy_handle_run(MigrationIncomingState *mis) > static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis) > { > int ret; > - uint8_t *buffer; > uint32_t length; > - QEMUSizedBuffer *qsb; > + QIOChannelBuffer *bioc; > > length = qemu_get_be32(mis->from_src_file); > trace_loadvm_handle_cmd_packaged(length); > @@ -1559,28 +1546,26 @@ static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis) > error_report("Unreasonably large packaged state: %u", length); > return -1; > } > - buffer = g_malloc0(length); > - ret = qemu_get_buffer(mis->from_src_file, buffer, (int)length); > + > + bioc = qio_channel_buffer_new(length); > + ret = qemu_get_buffer(mis->from_src_file, > + (uint8_t *)bioc->data, > + (int)length); Actually, qemu_get_buffer takes a size_t now; so you can fix that at the same time. > if (ret != length) { > - g_free(buffer); > + object_unref(OBJECT(bioc)); > error_report("CMD_PACKAGED: Buffer receive fail ret=%d length=%d\n", > ret, length); > return (ret < 0) ? ret : -EAGAIN; > } > + bioc->usage += length; I'm a bit surprised you've not wrapped feeding the data into the qio_channel_buffer up a bit rather than having the callers prod at it's buffer/usage elements directly. Dave > trace_loadvm_handle_cmd_packaged_received(ret); > > - /* Setup a dummy QEMUFile that actually reads from the buffer */ > - qsb = qsb_create(buffer, length); > - g_free(buffer); /* Because qsb_create copies */ > - if (!qsb) { > - error_report("Unable to create qsb"); > - } > - QEMUFile *packf = qemu_bufopen("r", qsb); > + QEMUFile *packf = qemu_fopen_channel_input(QIO_CHANNEL(bioc)); > > ret = qemu_loadvm_state_main(packf, mis); > trace_loadvm_handle_cmd_packaged_main(ret); > qemu_fclose(packf); > - qsb_free(qsb); > + object_unref(OBJECT(bioc)); > > return ret; > } > -- > 2.5.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK