From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Graf Date: Wed, 28 May 2014 00:44:05 +0000 Subject: Re: [PATCH v7 3/3] drivers/vfio: EEH support for VFIO PCI device Message-Id: <53853155.60809@suse.de> List-Id: References: <1401180052-6060-1-git-send-email-gwshan@linux.vnet.ibm.com> <1401180052-6060-4-git-send-email-gwshan@linux.vnet.ibm.com> <1401214527.3289.611.camel@ul30vt.home> <5385166A.5060404@suse.de> <1401237575.3289.676.camel@ul30vt.home> In-Reply-To: <1401237575.3289.676.camel@ul30vt.home> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Alex Williamson Cc: aik@ozlabs.ru, Gavin Shan , kvm-ppc@vger.kernel.org, qiudayu@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org On 28.05.14 02:39, Alex Williamson wrote: > On Wed, 2014-05-28 at 00:49 +0200, Alexander Graf wrote: >> On 27.05.14 20:15, Alex Williamson wrote: >>> On Tue, 2014-05-27 at 18:40 +1000, Gavin Shan wrote: >>>> The patch adds new IOCTL commands for sPAPR VFIO container device >>>> to support EEH functionality for PCI devices, which have been passed >>>> through from host to somebody else via VFIO. >>>> >>>> Signed-off-by: Gavin Shan >>>> --- >>>> Documentation/vfio.txt | 92 ++++++++++++++++++++++++++++++++++++- >>>> drivers/vfio/pci/Makefile | 1 + >>>> drivers/vfio/pci/vfio_pci.c | 20 +++++--- >>>> drivers/vfio/pci/vfio_pci_eeh.c | 46 +++++++++++++++++++ >>>> drivers/vfio/pci/vfio_pci_private.h | 5 ++ >>>> drivers/vfio/vfio_iommu_spapr_tce.c | 85 ++++++++++++++++++++++++++++++++++ >>>> include/uapi/linux/vfio.h | 66 ++++++++++++++++++++++++++ >>>> 7 files changed, 308 insertions(+), 7 deletions(-) >>>> create mode 100644 drivers/vfio/pci/vfio_pci_eeh.c >> [...] >> >>>> + >>>> + return ret; >>>> +} >>>> + >>>> static long tce_iommu_ioctl(void *iommu_data, >>>> unsigned int cmd, unsigned long arg) >>>> { >>>> @@ -283,6 +363,11 @@ static long tce_iommu_ioctl(void *iommu_data, >>>> tce_iommu_disable(container); >>>> mutex_unlock(&container->lock); >>>> return 0; >>>> + case VFIO_EEH_PE_SET_OPTION: >>>> + case VFIO_EEH_PE_GET_STATE: >>>> + case VFIO_EEH_PE_RESET: >>>> + case VFIO_EEH_PE_CONFIGURE: >>>> + return tce_iommu_eeh_ioctl(iommu_data, cmd, arg); >>> This is where it would have really made sense to have a single >>> VFIO_EEH_OP ioctl with a data structure passed to indicate the sub-op. >>> AlexG, are you really attached to splitting these out into separate >>> ioctls? >> I don't see the problem. We need to forward 4 ioctls to a separate piece >> of code, so we forward 4 ioctls to a separate piece of code :). Putting >> them into one ioctl just moves the switch() into another function. > And uses an extra 3 ioctl numbers and gives us extra things to update if > we ever need to add more ioctls, etc. ioctl numbers are an address > space, how much address space do we really want to give to EEH? It's > not a big difference, but I don't think it's completely even either. > Thanks, Yes, that's the point. I by far prefer to have you push back on anyone who introduces useless ioctls rather than have a separate EEH number space that people can just throw anything in they like ;). Alex From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) (using TLSv1 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 8E6141A0547 for ; Wed, 28 May 2014 10:44:12 +1000 (EST) Message-ID: <53853155.60809@suse.de> Date: Wed, 28 May 2014 02:44:05 +0200 From: Alexander Graf MIME-Version: 1.0 To: Alex Williamson Subject: Re: [PATCH v7 3/3] drivers/vfio: EEH support for VFIO PCI device References: <1401180052-6060-1-git-send-email-gwshan@linux.vnet.ibm.com> <1401180052-6060-4-git-send-email-gwshan@linux.vnet.ibm.com> <1401214527.3289.611.camel@ul30vt.home> <5385166A.5060404@suse.de> <1401237575.3289.676.camel@ul30vt.home> In-Reply-To: <1401237575.3289.676.camel@ul30vt.home> Content-Type: text/plain; charset=UTF-8; format=flowed Cc: aik@ozlabs.ru, Gavin Shan , kvm-ppc@vger.kernel.org, qiudayu@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 28.05.14 02:39, Alex Williamson wrote: > On Wed, 2014-05-28 at 00:49 +0200, Alexander Graf wrote: >> On 27.05.14 20:15, Alex Williamson wrote: >>> On Tue, 2014-05-27 at 18:40 +1000, Gavin Shan wrote: >>>> The patch adds new IOCTL commands for sPAPR VFIO container device >>>> to support EEH functionality for PCI devices, which have been passed >>>> through from host to somebody else via VFIO. >>>> >>>> Signed-off-by: Gavin Shan >>>> --- >>>> Documentation/vfio.txt | 92 ++++++++++++++++++++++++++++++++++++- >>>> drivers/vfio/pci/Makefile | 1 + >>>> drivers/vfio/pci/vfio_pci.c | 20 +++++--- >>>> drivers/vfio/pci/vfio_pci_eeh.c | 46 +++++++++++++++++++ >>>> drivers/vfio/pci/vfio_pci_private.h | 5 ++ >>>> drivers/vfio/vfio_iommu_spapr_tce.c | 85 ++++++++++++++++++++++++++++++++++ >>>> include/uapi/linux/vfio.h | 66 ++++++++++++++++++++++++++ >>>> 7 files changed, 308 insertions(+), 7 deletions(-) >>>> create mode 100644 drivers/vfio/pci/vfio_pci_eeh.c >> [...] >> >>>> + >>>> + return ret; >>>> +} >>>> + >>>> static long tce_iommu_ioctl(void *iommu_data, >>>> unsigned int cmd, unsigned long arg) >>>> { >>>> @@ -283,6 +363,11 @@ static long tce_iommu_ioctl(void *iommu_data, >>>> tce_iommu_disable(container); >>>> mutex_unlock(&container->lock); >>>> return 0; >>>> + case VFIO_EEH_PE_SET_OPTION: >>>> + case VFIO_EEH_PE_GET_STATE: >>>> + case VFIO_EEH_PE_RESET: >>>> + case VFIO_EEH_PE_CONFIGURE: >>>> + return tce_iommu_eeh_ioctl(iommu_data, cmd, arg); >>> This is where it would have really made sense to have a single >>> VFIO_EEH_OP ioctl with a data structure passed to indicate the sub-op. >>> AlexG, are you really attached to splitting these out into separate >>> ioctls? >> I don't see the problem. We need to forward 4 ioctls to a separate piece >> of code, so we forward 4 ioctls to a separate piece of code :). Putting >> them into one ioctl just moves the switch() into another function. > And uses an extra 3 ioctl numbers and gives us extra things to update if > we ever need to add more ioctls, etc. ioctl numbers are an address > space, how much address space do we really want to give to EEH? It's > not a big difference, but I don't think it's completely even either. > Thanks, Yes, that's the point. I by far prefer to have you push back on anyone who introduces useless ioctls rather than have a separate EEH number space that people can just throw anything in they like ;). Alex