From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34548) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YtEEN-00084G-U3 for qemu-devel@nongnu.org; Fri, 15 May 2015 07:56:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YtEEL-0005fF-7N for qemu-devel@nongnu.org; Fri, 15 May 2015 07:56:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33710) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YtEEK-0005f5-W4 for qemu-devel@nongnu.org; Fri, 15 May 2015 07:56:41 -0400 Date: Fri, 15 May 2015 12:56:34 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20150515115633.GE2194@work-vm> References: <1427347774-8960-1-git-send-email-zhang.zhanghailiang@huawei.com> <1427347774-8960-9-git-send-email-zhang.zhanghailiang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1427347774-8960-9-git-send-email-zhang.zhanghailiang@huawei.com> Subject: Re: [Qemu-devel] [RFC PATCH v4 08/28] QEMUSizedBuffer: Introduce two help functions for qsb List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: zhanghailiang Cc: lizhijian@cn.fujitsu.com, quintela@redhat.com, yunhong.jiang@intel.com, eddie.dong@intel.com, peter.huangpeng@huawei.com, qemu-devel@nongnu.org, arei.gonglei@huawei.com, amit.shah@redhat.com, Yang Hongyang , david@gibson.dropbear.id.au * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote: > Introduce two new QEMUSizedBuffer APIs which will be used by COLO to buffer > VM state: > One is qsb_put_buffer(), which put the content of a given QEMUSizedBuffer > into QEMUFile, this is used to send buffered VM state to secondary. > Another is qsb_fill_buffer(), read 'size' bytes of data from the file into > qsb, this is used to get VM state from socket into a buffer. > > Signed-off-by: Yang Hongyang > Signed-off-by: zhanghailiang Reviewed-by: Dr. David Alan Gilbert (I could use these in my postcopy world) Dave > --- > include/migration/qemu-file.h | 3 ++- > migration/qemu-file-buf.c | 58 +++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 60 insertions(+), 1 deletion(-) > > diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h > index 745a850..09a0e2a 100644 > --- a/include/migration/qemu-file.h > +++ b/include/migration/qemu-file.h > @@ -140,7 +140,8 @@ ssize_t qsb_get_buffer(const QEMUSizedBuffer *, off_t start, size_t count, > uint8_t *buf); > ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *buf, > off_t pos, size_t count); > - > +void qsb_put_buffer(QEMUFile *f, QEMUSizedBuffer *qsb, int size); > +int qsb_fill_buffer(QEMUSizedBuffer *qsb, QEMUFile *f, int size); > > /* > * For use on files opened with qemu_bufopen > diff --git a/migration/qemu-file-buf.c b/migration/qemu-file-buf.c > index 16a51a1..686f417 100644 > --- a/migration/qemu-file-buf.c > +++ b/migration/qemu-file-buf.c > @@ -365,6 +365,64 @@ ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *source, > return count; > } > > + > +/** > + * Put the content of a given QEMUSizedBuffer into QEMUFile. > + * > + * @f: A QEMUFile > + * @qsb: A QEMUSizedBuffer > + * @size: size of content to write > + */ > +void qsb_put_buffer(QEMUFile *f, QEMUSizedBuffer *qsb, int size) > +{ > + int i, l; > + > + for (i = 0; i < qsb->n_iov && size > 0; i++) { > + l = MIN(qsb->iov[i].iov_len, size); > + qemu_put_buffer(f, qsb->iov[i].iov_base, l); > + size -= l; > + } > +} > + > +/* > + * Read 'size' bytes of data from the file into qsb. > + * always fill from pos 0 and used after qsb_create(). > + * > + * It will return size bytes unless there was an error, in which case it will > + * return as many as it managed to read (assuming blocking fd's which > + * all current QEMUFile are) > + */ > +int qsb_fill_buffer(QEMUSizedBuffer *qsb, QEMUFile *f, int size) > +{ > + ssize_t rc = qsb_grow(qsb, size); > + int pending = size, i; > + qsb->used = 0; > + uint8_t *buf = NULL; > + > + if (rc < 0) { > + return rc; > + } > + > + for (i = 0; i < qsb->n_iov && pending > 0; i++) { > + int doneone = 0; > + /* read until iov full */ > + while (doneone < qsb->iov[i].iov_len && pending > 0) { > + int readone = 0; > + buf = qsb->iov[i].iov_base; > + readone = qemu_get_buffer(f, buf, > + MIN(qsb->iov[i].iov_len - doneone, pending)); > + if (readone == 0) { > + return qsb->used; > + } > + buf += readone; > + doneone += readone; > + pending -= readone; > + qsb->used += readone; > + } > + } > + return qsb->used; > +} > + > typedef struct QEMUBuffer { > QEMUSizedBuffer *qsb; > QEMUFile *file; > -- > 1.7.12.4 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK