| 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
| ||
|
Message-ID: <75b17c70-1658-91ea-0992-1be769550943@linux.intel.com>
Date: Tue, 28 Jun 2022 17:10:11 +0800
From: Ethan Zhao <haifeng.zhao@...ux.intel.com>
To: Baolu Lu <baolu.lu@...ux.intel.com>,
Joerg Roedel <joro@...tes.org>,
Jason Gunthorpe <jgg@...dia.com>,
Christoph Hellwig <hch@...radead.org>,
Kevin Tian <kevin.tian@...el.com>,
Ashok Raj <ashok.raj@...el.com>, Will Deacon <will@...nel.org>,
Robin Murphy <robin.murphy@....com>,
Jean-Philippe Brucker <jean-philippe@...aro.com>,
Dave Jiang <dave.jiang@...el.com>,
Vinod Koul <vkoul@...nel.org>
Cc: Eric Auger <eric.auger@...hat.com>, Liu Yi L <yi.l.liu@...el.com>,
Jacob jun Pan <jacob.jun.pan@...el.com>,
iommu@...ts.linux-foundation.org, iommu@...ts.linux.dev,
linux-kernel@...r.kernel.org,
Jean-Philippe Brucker <jean-philippe@...aro.org>
Subject: Re: [PATCH v9 10/11] iommu: Per-domain I/O page fault handling
Hi, Baolu
在 2022/6/28 14:28, Baolu Lu 写道:
> Hi Ethan,
>
> On 2022/6/27 21:03, Ethan Zhao wrote:
>> Hi,
>>
>> 在 2022/6/21 22:43, Lu Baolu 写道:
>>> Tweak the I/O page fault handling framework to route the page faults to
>>> the domain and call the page fault handler retrieved from the domain.
>>> This makes the I/O page fault handling framework possible to serve more
>>> usage scenarios as long as they have an IOMMU domain and install a page
>>> fault handler in it. Some unused functions are also removed to avoid
>>> dead code.
>>>
>>> The iommu_get_domain_for_dev_pasid() which retrieves attached domain
>>> for a {device, PASID} pair is used. It will be used by the page fault
>>> handling framework which knows {device, PASID} reported from the iommu
>>> driver. We have a guarantee that the SVA domain doesn't go away during
>>> IOPF handling, because unbind() waits for pending faults with
>>> iopf_queue_flush_dev() before freeing the domain. Hence, there's no
>>> need
>>> to synchronize life cycle of the iommu domains between the unbind() and
>>> the interrupt threads.
>>>
>>> Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
>>> Reviewed-by: Jean-Philippe Brucker <jean-philippe@...aro.org>
>>> ---
>>> drivers/iommu/io-pgfault.c | 64
>>> +++++---------------------------------
>>> 1 file changed, 7 insertions(+), 57 deletions(-)
>>>
>>> diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c
>>> index aee9e033012f..4f24ec703479 100644
>>> --- a/drivers/iommu/io-pgfault.c
>>> +++ b/drivers/iommu/io-pgfault.c
>>> @@ -69,69 +69,18 @@ static int iopf_complete_group(struct device
>>> *dev, struct iopf_fault *iopf,
>>> return iommu_page_response(dev, &resp);
>>> }
>>> -static enum iommu_page_response_code
>>> -iopf_handle_single(struct iopf_fault *iopf)
>>> -{
>>> - vm_fault_t ret;
>>> - struct mm_struct *mm;
>>> - struct vm_area_struct *vma;
>>> - unsigned int access_flags = 0;
>>> - unsigned int fault_flags = FAULT_FLAG_REMOTE;
>>> - struct iommu_fault_page_request *prm = &iopf->fault.prm;
>>> - enum iommu_page_response_code status = IOMMU_PAGE_RESP_INVALID;
>>> -
>>> - if (!(prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID))
>>> - return status;
>>> -
>>> - mm = iommu_sva_find(prm->pasid);
>>> - if (IS_ERR_OR_NULL(mm))
>>> - return status;
>>> -
>>> - mmap_read_lock(mm);
>>> -
>>> - vma = find_extend_vma(mm, prm->addr);
>>> - if (!vma)
>>> - /* Unmapped area */
>>> - goto out_put_mm;
>>> -
>>> - if (prm->perm & IOMMU_FAULT_PERM_READ)
>>> - access_flags |= VM_READ;
>>> -
>>> - if (prm->perm & IOMMU_FAULT_PERM_WRITE) {
>>> - access_flags |= VM_WRITE;
>>> - fault_flags |= FAULT_FLAG_WRITE;
>>> - }
>>> -
>>> - if (prm->perm & IOMMU_FAULT_PERM_EXEC) {
>>> - access_flags |= VM_EXEC;
>>> - fault_flags |= FAULT_FLAG_INSTRUCTION;
>>> - }
>>> -
>>> - if (!(prm->perm & IOMMU_FAULT_PERM_PRIV))
>>> - fault_flags |= FAULT_FLAG_USER;
>>> -
>>> - if (access_flags & ~vma->vm_flags)
>>> - /* Access fault */
>>> - goto out_put_mm;
>>> -
>>> - ret = handle_mm_fault(vma, prm->addr, fault_flags, NULL);
>>> - status = ret & VM_FAULT_ERROR ? IOMMU_PAGE_RESP_INVALID :
>>> - IOMMU_PAGE_RESP_SUCCESS;
>>> -
>>> -out_put_mm:
>>> - mmap_read_unlock(mm);
>>> - mmput(mm);
>>> -
>>> - return status;
>>> -}
>>> -
>>
>> Once the iopf_handle_single() is removed, the name of
>> iopf_handle_group() looks a little weired
>>
>> and confused, does this group mean the iommu group (domain) ? while I
>> take some minutes to
>
> No. This is not the iommu group. It's page request group defined by the
> PCI SIG spec. Multiple page requests could be put in a group with a
> same group id. All page requests in a group could be responded to device
> in one shot.
Thanks your explaination, understand the concept of PCIe PRG. I meant
do we still have the necessity to mention the "group" here in the name
iopf_handle_group(), which one is better ? iopf_handle_prg() or
iopf_handler(), perhaps none of them ? :)
Thanks，
Ethan
>
> Best regards,
> baolu
>
>>
>> look into the code, oh, means a batch / list / queue of iopfs , and
>> iopf_handle_group() becomes a
>>
>> generic iopf_handler() .
>>
>> Doe it make sense to revise the names of iopf_handle_group(),
>> iopf_complete_group, iopf_group in
>>
>> this patch set ?
>>
>>
>> Thanks,
>>
>> Ethan
>>
>>> static void iopf_handle_group(struct work_struct *work)
>>> {
>>> struct iopf_group *group;
>>> + struct iommu_domain *domain;
>>> struct iopf_fault *iopf, *next;
>>> enum iommu_page_response_code status = IOMMU_PAGE_RESP_SUCCESS;
>>> group = container_of(work, struct iopf_group, work);
>>> + domain = iommu_get_domain_for_dev_pasid(group->dev,
>>> + group->last_fault.fault.prm.pasid);
>>> + if (!domain || !domain->iopf_handler)
>>> + status = IOMMU_PAGE_RESP_INVALID;
>>> list_for_each_entry_safe(iopf, next, &group->faults, list) {
>>> /*
>>> @@ -139,7 +88,8 @@ static void iopf_handle_group(struct work_struct
>>> *work)
>>> * faults in the group if there is an error.
>>> */
>>> if (status == IOMMU_PAGE_RESP_SUCCESS)
>>> - status = iopf_handle_single(iopf);
>>> + status = domain->iopf_handler(&iopf->fault,
>>> + domain->fault_data);
>>> if (!(iopf->fault.prm.flags &
>>> IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE))
>>
>
--
"firm, enduring, strong, and long-lived"
Powered by blists - more mailing lists