Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754088AbbFSHxw (ORCPT ); Fri, 19 Jun 2015 03:53:52 -0400 Received: from mail-qc0-f174.google.com ([209.85.216.174]:35824 "EHLO mail-qc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753795AbbFSHxo (ORCPT ); Fri, 19 Jun 2015 03:53:44 -0400 MIME-Version: 1.0 X-Originating-IP: [80.15.154.113] In-Reply-To: <1434644277.3700.41.camel@redhat.com> References: <1434359385-19916-1-git-send-email-eric.auger@linaro.org> <1434580294.5628.135.camel@redhat.com> <1434644277.3700.41.camel@redhat.com> Date: Fri, 19 Jun 2015 09:53:43 +0200 Message-ID: Subject: Re: [PATCH v4 0/4] VFIO platform reset From: Baptiste Reynal To: Alex Williamson Cc: Eric Auger , eric.auger@st.com, "moderated list:ARM SMMU DRIVER" , open list , patches@linaro.org, Christoffer Dall , Christian Pinto , Daniel Raho Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5870 Lines: 144 [1-4/4] Acked-by: Baptiste Reynal Tested-by: Baptiste Reynal Reviewed-by: Baptiste Reynal On Thu, Jun 18, 2015 at 6:17 PM, Alex Williamson wrote: > On Thu, 2015-06-18 at 17:23 +0200, Baptiste Reynal wrote: >> Hello everyone, >> >> I tested and reviewed the patches, everything's fine for me. > > Hi Baptiste, > > Would you like to provide a Sign-off/Ack/Review tag for the series then? > >> I agree to be maintainer of vfio platform drivers, though I don't >> think the volume of patches about VFIO will justify a new mailing >> list. > > Ok, I'll officially post the patch for MAINTAINERS then. Until someone > complains, we'll continue to use the kvm list. Thanks, > > Alex > >> On Thu, Jun 18, 2015 at 12:31 AM, Alex Williamson >> wrote: >> > On Mon, 2015-06-15 at 11:09 +0200, Eric Auger wrote: >> >> In situations where the userspace driver is stopped abnormally and the >> >> VFIO platform device is released, the assigned HW device currently is >> >> left running. As a consequence the HW device might continue issuing IRQs >> >> and performing DMA accesses. >> >> >> >> On release, no physical IRQ handler is setup anymore. Also the DMA buffers >> >> are unmapped leading to IOMMU aborts. So there is no serious consequence. >> >> >> >> However when assigning that HW device again to another userspace driver, >> >> this latter might face some unexpected IRQs and DMA accesses, which are >> >> the result of the previous assignment. >> >> >> >> In virtualization use-case, a VM newly granted with that HW device may be >> >> impacted by the assignment of that device to a previous VM: >> >> - IRQs may be injected very early when booting the new guest, even before >> >> the guest driver has initialized leading to possible driver state >> >> inconsistency. >> >> - DMA accesses may hit the newly mapped VM address space at addresses that >> >> may jeopardize the integrity of the newly installed VM. >> >> >> >> Obviously the criticity depends on the assigned HW device. >> >> >> >> As opposed to PCI, there is no standard mechanism to reset the platform >> >> device. >> >> >> >> This series proposes to implement device specific reset functions in >> >> separate in-kernel vfio reset modules. The vfio-platform driver holds >> >> a whitelist of implemented triplets (compat string, module name, >> >> reset function name). When the vfio-platform driver is probed it identifies >> >> the fellow reset module/function matching the compat string of the >> >> device, if any, and forces the load of this reset module. >> >> >> >> A first reset module is provided: the vfio-platform-calxedaxgmac >> >> module which implements a basic reset for the Calxeda xgmac. >> >> >> >> The series can be found at >> >> https://git.linaro.org/people/eric.auger/linux.git/shortlog/refs/heads/v4.1-rc8-reset-v4 >> >> >> >> History: >> >> v3 -> v4: >> >> - fix the commit message of "VFIO: platform: add reset struct and lookup table" >> > >> > Baptiste, >> > >> > Any comments? Should we also add something like this to MAINTAINERS >> > before we go much further? >> > >> > diff --git a/MAINTAINERS b/MAINTAINERS >> > index d8afd29..c6bf7f6 100644 >> > --- a/MAINTAINERS >> > +++ b/MAINTAINERS >> > @@ -10545,6 +10545,12 @@ F: drivers/vfio/ >> > F: include/linux/vfio.h >> > F: include/uapi/linux/vfio.h >> > >> > +VFIO PLATFORM DRIVER >> > +M: Baptiste Reynal >> > +L: kvm@vger.kernel.org >> > +S: Maintained >> > +F: drivers/vfio/platform/ >> > + >> > VIDEOBUF2 FRAMEWORK >> > M: Pawel Osciak >> > M: Marek Szyprowski >> > >> > I'm not sure what you want to be the primary list, maybe it's time to >> > ask for a vfio list. Thanks, >> > Alex >> > >> >> >> >> v2 -> v3: >> >> - remove void module_init/exit functions in calxeda reset module >> >> - remove enum vfio_platform_reset_type >> >> - for reset lookup, use ARRAY_SIZE >> >> - in reset put use symbol_put_addr >> >> >> >> v1 -> v2: >> >> - much simplified compared to v1 although principle of external modules is >> >> kept: removed mechanism of dynamic registration of reset functions >> >> - list is replaced by whitelist lookup table >> >> - name of the reset function also stored in the lookup table >> >> - autoload of reset modules >> >> >> >> RFC -> PATCH v1: >> >> - solution now based on a lookup list instead of specialized driver >> >> >> >> >> >> Eric Auger (4): >> >> VFIO: platform: add reset struct and lookup table >> >> VFIO: platform: add reset callback >> >> VFIO: platform: populate the reset function on probe >> >> VFIO: platform: Calxeda xgmac reset module >> >> >> >> drivers/vfio/platform/Kconfig | 2 + >> >> drivers/vfio/platform/Makefile | 2 + >> >> drivers/vfio/platform/reset/Kconfig | 7 ++ >> >> drivers/vfio/platform/reset/Makefile | 5 ++ >> >> .../platform/reset/vfio_platform_calxedaxgmac.c | 86 ++++++++++++++++++++++ >> >> drivers/vfio/platform/vfio_platform_common.c | 60 ++++++++++++++- >> >> drivers/vfio/platform/vfio_platform_private.h | 7 ++ >> >> 7 files changed, 166 insertions(+), 3 deletions(-) >> >> create mode 100644 drivers/vfio/platform/reset/Kconfig >> >> create mode 100644 drivers/vfio/platform/reset/Makefile >> >> create mode 100644 drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c >> >> >> > >> > >> > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/