From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH 0/6] Save state error handling (kill off no_migrate) Date: Mon, 8 Nov 2010 13:40:43 +0200 Message-ID: <20101108114043.GB1075@redhat.com> References: <20101006204546.32127.70109.stgit@s20.home> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org, cam@cs.ualberta.ca, quintela@redhat.com, anthony@codemonkey.ws To: Alex Williamson Return-path: Received: from mx1.redhat.com ([209.132.183.28]:4734 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754712Ab0KHLkw (ORCPT ); Mon, 8 Nov 2010 06:40:52 -0500 Content-Disposition: inline In-Reply-To: <20101006204546.32127.70109.stgit@s20.home> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Oct 06, 2010 at 02:58:57PM -0600, Alex Williamson wrote: > Our code paths for saving or migrating a VM are full of functions that > return void, leaving no opportunity for a device to cancel a migration, > either from error or incompatibility. The ivshmem driver attempted to > solve this with a no_migrate flag on the save state entry. I think the > more generic and flexible way to solve this is to allow driver save > functions to fail. This series implements that and converts ivshmem > to uses a set_params function to NAK migration much earlier in the > processes. This touches a lot of files, but bulk of those changes are > simply s/void/int/ and tacking a "return 0" to the end of functions. > Thanks, > > Alex Well error handling is always tricky: it seems easier to require save handlers to never fail. So there's a bunch of code here but what exactly is the benefit? Since save handlers have no idea what does the remote do, what is the compatibility you mention? > --- > > Alex Williamson (6): > savevm: Remove register_device_unmigratable() > savevm: Allow set_params and save_live_state to error > virtio: Allow virtio_save() errors > pci: Allow pci_device_save() to return error > savevm: Allow vmsd->pre_save to return error > savevm: Allow SaveStateHandler() to return error > > > block-migration.c | 4 +- > hw/adb.c | 8 +++- > hw/ads7846.c | 4 +- > hw/arm_gic.c | 4 +- > hw/arm_timer.c | 6 ++- > hw/armv7m_nvic.c | 4 +- > hw/cuda.c | 4 +- > hw/fdc.c | 3 + > hw/g364fb.c | 4 +- > hw/grackle_pci.c | 4 +- > hw/gt64xxx.c | 4 +- > hw/heathrow_pic.c | 4 +- > hw/hpet.c | 3 + > hw/hw.h | 12 ++---- > hw/i2c.c | 3 + > hw/ide/core.c | 4 +- > hw/ivshmem.c | 30 +++++++++++---- > hw/lsi53c895a.c | 4 +- > hw/m48t59.c | 4 +- > hw/mac_dbdma.c | 4 +- > hw/mac_nvram.c | 4 +- > hw/max111x.c | 4 +- > hw/mipsnet.c | 4 +- > hw/mst_fpga.c | 3 + > hw/nand.c | 3 + > hw/openpic.c | 4 +- > hw/pci.c | 9 +++- > hw/pci.h | 2 - > hw/piix4.c | 4 +- > hw/pl011.c | 4 +- > hw/pl022.c | 4 +- > hw/pl061.c | 4 +- > hw/ppc4xx_pci.c | 11 ++++- > hw/ppce500_pci.c | 11 ++++- > hw/pxa2xx.c | 28 ++++++++++---- > hw/pxa2xx_dma.c | 4 +- > hw/pxa2xx_gpio.c | 4 +- > hw/pxa2xx_keypad.c | 3 + > hw/pxa2xx_lcd.c | 4 +- > hw/pxa2xx_mmci.c | 4 +- > hw/pxa2xx_pic.c | 4 +- > hw/pxa2xx_timer.c | 4 +- > hw/rc4030.c | 4 +- > hw/rtl8139.c | 4 +- > hw/serial.c | 3 + > hw/spitz.c | 14 +++++-- > hw/ssd0323.c | 4 +- > hw/ssi-sd.c | 4 +- > hw/stellaris.c | 20 +++++++--- > hw/stellaris_enet.c | 4 +- > hw/stellaris_input.c | 4 +- > hw/syborg_fb.c | 4 +- > hw/syborg_interrupt.c | 3 + > hw/syborg_keyboard.c | 3 + > hw/syborg_pointer.c | 3 + > hw/syborg_rtc.c | 4 +- > hw/syborg_serial.c | 4 +- > hw/syborg_timer.c | 4 +- > hw/tsc2005.c | 4 +- > hw/tsc210x.c | 4 +- > hw/twl92230.c | 3 + > hw/unin_pci.c | 4 +- > hw/usb-uhci.c | 3 + > hw/virtio-balloon.c | 9 +++- > hw/virtio-blk.c | 10 ++++- > hw/virtio-net.c | 11 ++++- > hw/virtio-pci.c | 10 ++++- > hw/virtio-serial-bus.c | 10 ++++- > hw/virtio.c | 14 +++++-- > hw/virtio.h | 4 +- > hw/wm8750.c | 3 + > hw/zaurus.c | 4 +- > qemu-common.h | 2 - > savevm.c | 88 +++++++++++++++++++------------------------ > slirp/slirp.c | 6 ++- > target-arm/machine.c | 3 + > target-cris/machine.c | 3 + > target-i386/machine.c | 7 ++- > target-microblaze/machine.c | 3 + > target-mips/machine.c | 3 + > target-ppc/machine.c | 3 + > target-s390x/machine.c | 3 + > target-sparc/machine.c | 3 + > 83 files changed, 365 insertions(+), 181 deletions(-) > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html