| Message ID | 1457336918-3893-6-git-send-email-xyjxie@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 7 Mar 2016 15:48:36 +0800 Yongji Xie <xyjxie@linux.vnet.ibm.com> wrote: > Current vfio-pci implementation disallows to mmap > sub-page(size < PAGE_SIZE) MMIO BARs because these BARs' mmio > page may be shared with other BARs. > > But we should allow to mmap these sub-page MMIO BARs if PCI > resource allocator can make sure these BARs' mmio page will > not be shared with other BARs. > > Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> > --- > drivers/vfio/pci/vfio_pci.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > index 1ce1d36..49d7a69 100644 > --- a/drivers/vfio/pci/vfio_pci.c > +++ b/drivers/vfio/pci/vfio_pci.c > @@ -589,7 +589,8 @@ static long vfio_pci_ioctl(void *device_data, > VFIO_REGION_INFO_FLAG_WRITE; > if (IS_ENABLED(CONFIG_VFIO_PCI_MMAP) && > pci_resource_flags(pdev, info.index) & > - IORESOURCE_MEM && info.size >= PAGE_SIZE) { > + IORESOURCE_MEM && !pci_resources_share_page(pdev, > + info.index)) { this would be a preferable line wrap: IORESOURCE_MEM && !pci_resources_share_page(pdev, info.index)) { > info.flags |= VFIO_REGION_INFO_FLAG_MMAP; > if (info.index == vdev->msix_bar) { > ret = msix_sparse_mmap_cap(vdev, &caps); > @@ -1016,6 +1017,10 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma) > return -EINVAL; > > phys_len = pci_resource_len(pdev, index); > + > + if (!pci_resources_share_page(pdev, index)) > + phys_len = PAGE_ALIGN(phys_len); > + > req_len = vma->vm_end - vma->vm_start; > pgoff = vma->vm_pgoff & > ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1); -- 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
On 2016/3/17 0:30, Alex Williamson wrote: > On Mon, 7 Mar 2016 15:48:36 +0800 > Yongji Xie <xyjxie@linux.vnet.ibm.com> wrote: > >> Current vfio-pci implementation disallows to mmap >> sub-page(size < PAGE_SIZE) MMIO BARs because these BARs' mmio >> page may be shared with other BARs. >> >> But we should allow to mmap these sub-page MMIO BARs if PCI >> resource allocator can make sure these BARs' mmio page will >> not be shared with other BARs. >> >> Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> >> --- >> drivers/vfio/pci/vfio_pci.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c >> index 1ce1d36..49d7a69 100644 >> --- a/drivers/vfio/pci/vfio_pci.c >> +++ b/drivers/vfio/pci/vfio_pci.c >> @@ -589,7 +589,8 @@ static long vfio_pci_ioctl(void *device_data, >> VFIO_REGION_INFO_FLAG_WRITE; >> if (IS_ENABLED(CONFIG_VFIO_PCI_MMAP) && >> pci_resource_flags(pdev, info.index) & >> - IORESOURCE_MEM && info.size >= PAGE_SIZE) { >> + IORESOURCE_MEM && !pci_resources_share_page(pdev, >> + info.index)) { > this would be a preferable line wrap: > > IORESOURCE_MEM && > !pci_resources_share_page(pdev, info.index)) { OK. I'll fix it. Thanks, Yongji Xie -- 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
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index 1ce1d36..49d7a69 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -589,7 +589,8 @@ static long vfio_pci_ioctl(void *device_data, VFIO_REGION_INFO_FLAG_WRITE; if (IS_ENABLED(CONFIG_VFIO_PCI_MMAP) && pci_resource_flags(pdev, info.index) & - IORESOURCE_MEM && info.size >= PAGE_SIZE) { + IORESOURCE_MEM && !pci_resources_share_page(pdev, + info.index)) { info.flags |= VFIO_REGION_INFO_FLAG_MMAP; if (info.index == vdev->msix_bar) { ret = msix_sparse_mmap_cap(vdev, &caps); @@ -1016,6 +1017,10 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma) return -EINVAL; phys_len = pci_resource_len(pdev, index); + + if (!pci_resources_share_page(pdev, index)) + phys_len = PAGE_ALIGN(phys_len); + req_len = vma->vm_end - vma->vm_start; pgoff = vma->vm_pgoff & ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
Current vfio-pci implementation disallows to mmap sub-page(size < PAGE_SIZE) MMIO BARs because these BARs' mmio page may be shared with other BARs. But we should allow to mmap these sub-page MMIO BARs if PCI resource allocator can make sure these BARs' mmio page will not be shared with other BARs. Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com> --- drivers/vfio/pci/vfio_pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)