[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <56AB421B.3070004@linux.vnet.ibm.com>
Date: Fri, 29 Jan 2016 18:42:35 +0800
From: Yongji Xie <xyjxie@...ux.vnet.ibm.com>
To: Alex Williamson <alex.williamson@...hat.com>, kvm@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org, linux-doc@...r.kernel.org
Cc: 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 v3 5/5] vfio-pci: Allow to mmap MSI-X table if host
bridge supports filtering of MSIs
On 2016/1/29 6:46, Alex Williamson wrote:
> On Fri, 2016-01-15 at 15:06 +0800, Yongji Xie wrote:
>> Current vfio-pci implementation disallows to mmap MSI-X
>> table in case that user get to touch this directly.
>>
>> But we should allow to mmap these MSI-X tables if the PCI
>> host bridge supports filtering of MSIs.
>>
>> Signed-off-by: Yongji Xie <xyjxie@...ux.vnet.ibm.com>
>> ---
>> drivers/vfio/pci/vfio_pci.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
>> index 11fd0f0..4d68f6a 100644
>> --- a/drivers/vfio/pci/vfio_pci.c
>> +++ b/drivers/vfio/pci/vfio_pci.c
>> @@ -555,7 +555,8 @@ static long vfio_pci_ioctl(void *device_data,
>> IORESOURCE_MEM && !pci_resources_share_page(pdev,
>> info.index)) {
>> info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
>> - if (info.index == vdev->msix_bar) {
>> + if (!pci_host_bridge_msi_filtered_enabled(pdev) &&
>> + info.index == vdev->msix_bar) {
>> ret = msix_sparse_mmap_cap(vdev, &caps);
>> if (ret)
>> return ret;
>> @@ -967,7 +968,8 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
>> if (phys_len < PAGE_SIZE || req_start + req_len > phys_len)
>> return -EINVAL;
>>
>> - if (index == vdev->msix_bar) {
>> + if (!pci_host_bridge_msi_filtered_enabled(pdev) &&
>> + index == vdev->msix_bar) {
>> /*
>> * Disallow mmaps overlapping the MSI-X table; users don't
>> * get to touch this directly. We could find somewhere
> What about read()/write() access, why would we allow mmap() but not
> those?
>
Yes, you are right! I miss the MSI-X table check in vfio_pci_bar_rw().
I will fix it in next version. Thanks.
Regards,
Yongji Xie
Powered by blists - more mailing lists