linux-kernel - Re: [RFC PATCH v4 7/7] powerpc/powernv/pci-ioda: Add IOMMU_CAP_INTR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <56EA9735.2010401@linux.vnet.ibm.com>
Date:	Thu, 17 Mar 2016 19:38:29 +0800
From:	Yongji Xie <xyjxie@...ux.vnet.ibm.com>
To:	Alex Williamson <alex.williamson@...hat.com>
Cc:	kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-pci@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
	linux-doc@...r.kernel.org, bhelgaas@...gle.com, corbet@....net,
	aik@...abs.ru, benh@...nel.crashing.org, paulus@...ba.org,
	mpe@...erman.id.au, warrier@...ux.vnet.ibm.com,
	zhong@...ux.vnet.ibm.com, nikunj@...ux.vnet.ibm.com
Subject: Re: [RFC PATCH v4 7/7] powerpc/powernv/pci-ioda: Add
 IOMMU_CAP_INTR_REMAP for IODA host bridge

On 2016/3/17 0:32, Alex Williamson wrote:
> On Mon,  7 Mar 2016 15:48:38 +0800
> Yongji Xie <xyjxie@...ux.vnet.ibm.com> wrote:
>
>> This patch adds IOMMU_CAP_INTR_REMAP for IODA host bridge so that
>> we can mmap MSI-X table in vfio driver.
>>
>> Signed-off-by: Yongji Xie <xyjxie@...ux.vnet.ibm.com>
>> ---
>>   arch/powerpc/platforms/powernv/pci-ioda.c |   17 +++++++++++++++++
>>   1 file changed, 17 insertions(+)
>>
>> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>> index f90dc04..f01b9ab 100644
>> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>> @@ -1955,6 +1955,20 @@ static struct iommu_table_ops pnv_ioda2_iommu_ops = {
>>   	.free = pnv_ioda2_table_free,
>>   };
>>   
>> +static bool pnv_ioda_iommu_capable(enum iommu_cap cap)
>> +{
>> +	switch (cap) {
>> +	case IOMMU_CAP_INTR_REMAP:
>> +		return true;
>> +	default:
>> +		return false;
>> +	}
>> +}
>> +
>> +static struct iommu_ops pnv_ioda_iommu_ops = {
>> +	.capable = pnv_ioda_iommu_capable,
>> +};
>> +
>>   static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
>>   				      struct pnv_ioda_pe *pe, unsigned int base,
>>   				      unsigned int segs)
>> @@ -3078,6 +3092,9 @@ static void pnv_pci_ioda_fixup(void)
>>   
>>   	/* Link NPU IODA tables to their PCI devices. */
>>   	pnv_npu_ioda_fixup();
>> +
>> +	/* Add IOMMU_CAP_INTR_REMAP */
>> +	bus_set_iommu(&pci_bus_type, &pnv_ioda_iommu_ops);
>>   }
>>   
>>   /*
>
> Doesn't this set you up for a world of hurt?  bus_set_iommu() calls
> iommu_bus_init() which sets up notifiers, which maybe you don't care
> about, but it also means that iommu_domain_alloc(&pci_bus_type) will
> segfault because you're not providing a domain_alloc callback here.

It seems to be hard to add IOMMU_CAP_INTR_REMAP on
PPC64 platform.

And can we add a new ioctl in vfio_iommu_driver to check
if interrupt remapping is supported so that we can use our
own way to determine that on PPC64 platform?

Thanks,
Yongji Xie