From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38372) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dLuHl-00075h-Tk for qemu-devel@nongnu.org; Fri, 16 Jun 2017 12:39:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dLuHj-0004yz-AX for qemu-devel@nongnu.org; Fri, 16 Jun 2017 12:39:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50818) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dLuHj-0004yQ-28 for qemu-devel@nongnu.org; Fri, 16 Jun 2017 12:39:47 -0400 Date: Fri, 16 Jun 2017 17:39:39 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170616163938.GD2179@work-vm> References: <1497544575-18628-1-git-send-email-a.perevalov@samsung.com> <1497544575-18628-3-git-send-email-a.perevalov@samsung.com> <20170616084936.GG30118@pxdev.xzpeter.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170616084936.GG30118@pxdev.xzpeter.org> Subject: Re: [Qemu-devel] [PATCH v2 2/3] migration: introduce qemu_ufd_copy_ioctl helper List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: Alexey Perevalov , qemu-devel@nongnu.org, i.maximets@samsung.com, quintela@redhat.com * Peter Xu (peterx@redhat.com) wrote: > On Thu, Jun 15, 2017 at 07:36:14PM +0300, Alexey Perevalov wrote: > > Just for placing auxilary operations inside helper, > > auxilary operations like: track received pages, > > notify about copying operation in futher patches. > > > > Signed-off-by: Alexey Perevalov > > --- > > migration/postcopy-ram.c | 35 ++++++++++++++++++++++------------- > > 1 file changed, 22 insertions(+), 13 deletions(-) > > > > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > > index 743ca6c..38a429a 100644 > > --- a/migration/postcopy-ram.c > > +++ b/migration/postcopy-ram.c > > @@ -561,6 +561,26 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis) > > return 0; > > } > > > > +static int qemu_ufd_copy_ioctl(int userfault_fd, void *host_addr, > > + void *from_addr, uint64_t pagesize) > > +{ > > + if (from_addr) { > > + struct uffdio_copy copy_struct; > > + copy_struct.dst = (uint64_t)(uintptr_t)host_addr; > > + copy_struct.src = (uint64_t)(uintptr_t)from_addr; > > + copy_struct.len = pagesize; > > + copy_struct.mode = 0; > > + return ioctl(userfault_fd, UFFDIO_COPY, ©_struct); > > + } else { > > + struct uffdio_zeropage zero_struct; > > + zero_struct.range.start = (uint64_t)(uintptr_t)host_addr; > > + zero_struct.range.len = pagesize; > > + zero_struct.mode = 0; > > + return ioctl(userfault_fd, UFFDIO_ZEROPAGE, &zero_struct); > > + } > > + return 0; > > Remove this line? Yes, probably should; only minor. > > +} > > + > > /* > > * Place a host page (from) at (host) atomically > > * returns 0 on success > > @@ -568,20 +588,14 @@ int postcopy_ram_enable_notify(MigrationIncomingState *mis) > > int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from, > > RAMBlock *rb) > > { > > - struct uffdio_copy copy_struct; > > size_t pagesize = qemu_ram_pagesize(rb); > > > > - copy_struct.dst = (uint64_t)(uintptr_t)host; > > - copy_struct.src = (uint64_t)(uintptr_t)from; > > - copy_struct.len = pagesize; > > - copy_struct.mode = 0; > > - > > /* copy also acks to the kernel waking the stalled thread up > > * TODO: We can inhibit that ack and only do it if it was requested > > * which would be slightly cheaper, but we'd have to be careful > > * of the order of updating our page state. > > */ > > - if (ioctl(mis->userfault_fd, UFFDIO_COPY, ©_struct)) { > > + if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, from, pagesize)) { > > (hmm I know "from" won't be zero, but naturally if without the context > I would doubt it. Shall we add an assert here? You call.) Doesn't seem worth it. > Besides: > > Reviewed-by: Peter Xu Reviewed-by: Dr. David Alan Gilbert > > Thanks, > > > int e = errno; > > error_report("%s: %s copy host: %p from: %p (size: %zd)", > > __func__, strerror(e), host, from, pagesize); > > @@ -605,12 +619,7 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host, > > > > pagesize = qemu_ram_pagesize(rb); > > if (pagesize == getpagesize()) { > > - struct uffdio_zeropage zero_struct; > > - zero_struct.range.start = (uint64_t)(uintptr_t)host; > > - zero_struct.range.len = getpagesize(); > > - zero_struct.mode = 0; > > - > > - if (ioctl(mis->userfault_fd, UFFDIO_ZEROPAGE, &zero_struct)) { > > + if (qemu_ufd_copy_ioctl(mis->userfault_fd, host, 0, getpagesize())) { > > int e = errno; > > error_report("%s: %s zero host: %p", > > __func__, strerror(e), host); > > -- > > 1.9.1 > > > > -- > Peter Xu -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK