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| Started by | Alexander Duyck <alexander.duyck@gmail.com> |
|---|---|
| First post | 2015-10-27 06:50 +0100 |
| Last post | 2015-10-29 04:40 +0100 |
| Articles | 4 — 2 participants |
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Re: [PATCH v2] iov: restore NumVFs register to 0 before return from virtfn_max_buses() Alexander Duyck <alexander.duyck@gmail.com> - 2015-10-27 06:50 +0100
Re: [PATCH v2] iov: restore NumVFs register to 0 before return from virtfn_max_buses() ethan zhao <ethan.zhao@oracle.com> - 2015-10-27 10:30 +0100
Re: [PATCH v2] iov: restore NumVFs register to 0 before return from virtfn_max_buses() Alexander Duyck <alexander.duyck@gmail.com> - 2015-10-27 16:20 +0100
Re: [PATCH v2] iov: restore NumVFs register to 0 before return from virtfn_max_buses() ethan zhao <ethan.zhao@oracle.com> - 2015-10-29 04:40 +0100
| From | Alexander Duyck <alexander.duyck@gmail.com> |
|---|---|
| Date | 2015-10-27 06:50 +0100 |
| Subject | Re: [PATCH v2] iov: restore NumVFs register to 0 before return from virtfn_max_buses() |
| Message-ID | <qo5iW-1kk-7@gated-at.bofh.it> |
On 10/15/2015 10:16 AM, Bjorn Helgaas wrote:
> Hi Ethan,
>
> On Wed, Sep 16, 2015 at 12:19:53PM +0900, Ethan Zhao wrote:
>> After commit 4449f079722c ("PCI: Calculate maximum number of buses
>> required for VFs"),the initial value of NumVFs register was left to
>> non-zero after sriov_init() and no VFs was enabled in device driver.
>> this changed the behaviour of kernel exported by lspci and sysfs etc.
>> so this patch restore the NumVFs register to zero after the
>> calculation of max_VF_buses was done and before return from
>> virtfn_max_buses().
>>
>> Tested on stable 4.1 and passed building on stable 4.3-rc1
>>
>> Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
>> Tested-by: Sriharsha Yadagudde <sriharsha.devdas@oracle.com>
> Can you test the patch below? I'm trying to avoid touching
> PCI_SRIOV_NUM_VF in more than one place, and I think it's OK to set it
> and test offset/stride at the end, instead of setting NUM_VF to zero,
> testing offset/stride, computing max_bus, then setting NUM_VF to zero
> again.
>
> Bjorn
>
>
> commit 8e20e89658f23b8d16b1e21810e9f63c8625129c
> Author: Bjorn Helgaas <bhelgaas@google.com>
> Date: Thu Oct 15 11:31:21 2015 -0500
>
> PCI: Set SR-IOV NumVFs to zero after enumeration
>
> The enumeration path should leave NumVFs set to zero. But after
> 4449f079722c ("PCI: Calculate maximum number of buses required for VFs"),
> we call virtfn_max_buses() in the enumeration path, which changes NumVFs.
> This NumVFs change is visible via lspci and sysfs until a driver enables
> SR-IOV.
>
> Set NumVFs to zero after virtfn_max_buses() computes the maximum number of
> buses.
>
> Fixes: 4449f079722c ("PCI: Calculate maximum number of buses required for VFs")
> Based-on-patch-by: Ethan Zhao <ethan.zhao@oracle.com>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
>
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index ee0ebff..0202ab0 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -384,7 +384,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
> int rc;
> int nres;
> u32 pgsz;
> - u16 ctrl, total, offset, stride;
> + u16 ctrl, total;
> struct pci_sriov *iov;
> struct resource *res;
> struct pci_dev *pdev;
> @@ -414,11 +414,6 @@ static int sriov_init(struct pci_dev *dev, int pos)
>
> found:
> pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
> - pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0);
> - pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
> - pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
> - if (!offset || (total > 1 && !stride))
> - return -EIO;
>
> pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
> i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
> @@ -456,8 +451,6 @@ found:
> iov->nres = nres;
> iov->ctrl = ctrl;
> iov->total_VFs = total;
> - iov->offset = offset;
> - iov->stride = stride;
> iov->pgsz = pgsz;
> iov->self = dev;
> pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
> @@ -475,6 +468,11 @@ found:
> dev->sriov = iov;
> dev->is_physfn = 1;
> iov->max_VF_buses = virtfn_max_buses(dev);
> + pci_iov_set_numvfs(dev, 0);
> + if (!iov->offset || (total > 1 && !iov->stride)) {
> + rc = -EIO;
> + goto failed;
> + }
>
> return 0;
>
You might want to reorder this a bit. The problem is offset and stride
can be 0 if numvfs is 0. So you should probably test offset and stride
first, and then reset numvfs to 0.
- Alex
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| From | ethan zhao <ethan.zhao@oracle.com> |
|---|---|
| Date | 2015-10-27 10:30 +0100 |
| Message-ID | <qo8JQ-3sW-3@gated-at.bofh.it> |
| In reply to | #1256473 |
Alexander,
On 2015/10/27 13:48, Alexander Duyck wrote:
> On 10/15/2015 10:16 AM, Bjorn Helgaas wrote:
>> Hi Ethan,
>>
>> On Wed, Sep 16, 2015 at 12:19:53PM +0900, Ethan Zhao wrote:
>>> After commit 4449f079722c ("PCI: Calculate maximum number of buses
>>> required for VFs"),the initial value of NumVFs register was left to
>>> non-zero after sriov_init() and no VFs was enabled in device driver.
>>> this changed the behaviour of kernel exported by lspci and sysfs etc.
>>> so this patch restore the NumVFs register to zero after the
>>> calculation of max_VF_buses was done and before return from
>>> virtfn_max_buses().
>>>
>>> Tested on stable 4.1 and passed building on stable 4.3-rc1
>>>
>>> Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
>>> Tested-by: Sriharsha Yadagudde <sriharsha.devdas@oracle.com>
>> Can you test the patch below? I'm trying to avoid touching
>> PCI_SRIOV_NUM_VF in more than one place, and I think it's OK to set it
>> and test offset/stride at the end, instead of setting NUM_VF to zero,
>> testing offset/stride, computing max_bus, then setting NUM_VF to zero
>> again.
>>
>> Bjorn
>>
>>
>> commit 8e20e89658f23b8d16b1e21810e9f63c8625129c
>> Author: Bjorn Helgaas <bhelgaas@google.com>
>> Date: Thu Oct 15 11:31:21 2015 -0500
>>
>> PCI: Set SR-IOV NumVFs to zero after enumeration
>> The enumeration path should leave NumVFs set to zero. But
>> after
>> 4449f079722c ("PCI: Calculate maximum number of buses required
>> for VFs"),
>> we call virtfn_max_buses() in the enumeration path, which
>> changes NumVFs.
>> This NumVFs change is visible via lspci and sysfs until a driver
>> enables
>> SR-IOV.
>> Set NumVFs to zero after virtfn_max_buses() computes the
>> maximum number of
>> buses.
>> Fixes: 4449f079722c ("PCI: Calculate maximum number of
>> buses required for VFs")
>> Based-on-patch-by: Ethan Zhao <ethan.zhao@oracle.com>
>> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
>>
>> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
>> index ee0ebff..0202ab0 100644
>> --- a/drivers/pci/iov.c
>> +++ b/drivers/pci/iov.c
>> @@ -384,7 +384,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
>> int rc;
>> int nres;
>> u32 pgsz;
>> - u16 ctrl, total, offset, stride;
>> + u16 ctrl, total;
>> struct pci_sriov *iov;
>> struct resource *res;
>> struct pci_dev *pdev;
>> @@ -414,11 +414,6 @@ static int sriov_init(struct pci_dev *dev, int pos)
>> found:
>> pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
>> - pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0);
>> - pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
>> - pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
>> - if (!offset || (total > 1 && !stride))
>> - return -EIO;
>> pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
>> i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
>> @@ -456,8 +451,6 @@ found:
>> iov->nres = nres;
>> iov->ctrl = ctrl;
>> iov->total_VFs = total;
>> - iov->offset = offset;
>> - iov->stride = stride;
>> iov->pgsz = pgsz;
>> iov->self = dev;
>> pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
>> @@ -475,6 +468,11 @@ found:
>> dev->sriov = iov;
>> dev->is_physfn = 1;
>> iov->max_VF_buses = virtfn_max_buses(dev);
>> + pci_iov_set_numvfs(dev, 0);
>> + if (!iov->offset || (total > 1 && !iov->stride)) {
>> + rc = -EIO;
>> + goto failed;
>> + }
>> return 0;
>
> You might want to reorder this a bit. The problem is offset and
> stride can be 0 if numvfs is 0. So you should probably test offset
> and stride
Yes, the spec says "Note: First VF Offset is unused if NumVFs is 0. If
NumVFs is greater than 0, First VF Offset must
25 not be zero. "
> first, and then reset numvfs to 0.
Why test it before reset numvfs ?
Thanks,
Ethan
>
> - Alex
>
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| From | Alexander Duyck <alexander.duyck@gmail.com> |
|---|---|
| Date | 2015-10-27 16:20 +0100 |
| Message-ID | <qoecy-6N1-15@gated-at.bofh.it> |
| In reply to | #1256607 |
On 10/27/2015 02:28 AM, ethan zhao wrote:
> Alexander,
> On 2015/10/27 13:48, Alexander Duyck wrote:
>> On 10/15/2015 10:16 AM, Bjorn Helgaas wrote:
>>> Hi Ethan,
>>>
>>> On Wed, Sep 16, 2015 at 12:19:53PM +0900, Ethan Zhao wrote:
>>>> After commit 4449f079722c ("PCI: Calculate maximum number of buses
>>>> required for VFs"),the initial value of NumVFs register was left to
>>>> non-zero after sriov_init() and no VFs was enabled in device driver.
>>>> this changed the behaviour of kernel exported by lspci and sysfs etc.
>>>> so this patch restore the NumVFs register to zero after the
>>>> calculation of max_VF_buses was done and before return from
>>>> virtfn_max_buses().
>>>>
>>>> Tested on stable 4.1 and passed building on stable 4.3-rc1
>>>>
>>>> Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
>>>> Tested-by: Sriharsha Yadagudde <sriharsha.devdas@oracle.com>
>>> Can you test the patch below? I'm trying to avoid touching
>>> PCI_SRIOV_NUM_VF in more than one place, and I think it's OK to set it
>>> and test offset/stride at the end, instead of setting NUM_VF to zero,
>>> testing offset/stride, computing max_bus, then setting NUM_VF to zero
>>> again.
>>>
>>> Bjorn
>>>
>>>
>>> commit 8e20e89658f23b8d16b1e21810e9f63c8625129c
>>> Author: Bjorn Helgaas <bhelgaas@google.com>
>>> Date: Thu Oct 15 11:31:21 2015 -0500
>>>
>>> PCI: Set SR-IOV NumVFs to zero after enumeration
>>> The enumeration path should leave NumVFs set to zero. But
>>> after
>>> 4449f079722c ("PCI: Calculate maximum number of buses required
>>> for VFs"),
>>> we call virtfn_max_buses() in the enumeration path, which
>>> changes NumVFs.
>>> This NumVFs change is visible via lspci and sysfs until a
>>> driver enables
>>> SR-IOV.
>>> Set NumVFs to zero after virtfn_max_buses() computes the
>>> maximum number of
>>> buses.
>>> Fixes: 4449f079722c ("PCI: Calculate maximum number of
>>> buses required for VFs")
>>> Based-on-patch-by: Ethan Zhao <ethan.zhao@oracle.com>
>>> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
>>>
>>> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
>>> index ee0ebff..0202ab0 100644
>>> --- a/drivers/pci/iov.c
>>> +++ b/drivers/pci/iov.c
>>> @@ -384,7 +384,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
>>> int rc;
>>> int nres;
>>> u32 pgsz;
>>> - u16 ctrl, total, offset, stride;
>>> + u16 ctrl, total;
>>> struct pci_sriov *iov;
>>> struct resource *res;
>>> struct pci_dev *pdev;
>>> @@ -414,11 +414,6 @@ static int sriov_init(struct pci_dev *dev, int
>>> pos)
>>> found:
>>> pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
>>> - pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0);
>>> - pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
>>> - pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
>>> - if (!offset || (total > 1 && !stride))
>>> - return -EIO;
>>> pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
>>> i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
>>> @@ -456,8 +451,6 @@ found:
>>> iov->nres = nres;
>>> iov->ctrl = ctrl;
>>> iov->total_VFs = total;
>>> - iov->offset = offset;
>>> - iov->stride = stride;
>>> iov->pgsz = pgsz;
>>> iov->self = dev;
>>> pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
>>> @@ -475,6 +468,11 @@ found:
>>> dev->sriov = iov;
>>> dev->is_physfn = 1;
>>> iov->max_VF_buses = virtfn_max_buses(dev);
>>> + pci_iov_set_numvfs(dev, 0);
>>> + if (!iov->offset || (total > 1 && !iov->stride)) {
>>> + rc = -EIO;
>>> + goto failed;
>>> + }
>>> return 0;
>>
>> You might want to reorder this a bit. The problem is offset and
>> stride can be 0 if numvfs is 0. So you should probably test offset
>> and stride
> Yes, the spec says "Note: First VF Offset is unused if NumVFs is 0.
> If NumVFs is greater than 0, First VF Offset must
> 25 not be zero. "
>> first, and then reset numvfs to 0.
> Why test it before reset numvfs ?
Because pci_iov_set_numvfs will end up resetting offset and stride based
on the values when it writes the 0 into numvfs. As such testing it
after the reset could give you invalid values since offset and stride
can be 0 when numvfs is 0.
Actually maybe I will go over this and submit a couple patches myself.
Looking over things it seems like the code has gotten a bit silly since
virtfn_max_busses looks like it is iterating over VFs and that doesn't
make much sense when offset and stride are both positive values so it
should just be a matter of computing the bus of the last VF.
- Alex
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| From | ethan zhao <ethan.zhao@oracle.com> |
|---|---|
| Date | 2015-10-29 04:40 +0100 |
| Message-ID | <qoMee-3kT-3@gated-at.bofh.it> |
| In reply to | #1256844 |
Alex,
On 2015/10/27 23:15, Alexander Duyck wrote:
> On 10/27/2015 02:28 AM, ethan zhao wrote:
>> Alexander,
>> On 2015/10/27 13:48, Alexander Duyck wrote:
>>> On 10/15/2015 10:16 AM, Bjorn Helgaas wrote:
>>>> Hi Ethan,
>>>>
>>>> On Wed, Sep 16, 2015 at 12:19:53PM +0900, Ethan Zhao wrote:
>>>>> After commit 4449f079722c ("PCI: Calculate maximum number of buses
>>>>> required for VFs"),the initial value of NumVFs register was left to
>>>>> non-zero after sriov_init() and no VFs was enabled in device driver.
>>>>> this changed the behaviour of kernel exported by lspci and sysfs etc.
>>>>> so this patch restore the NumVFs register to zero after the
>>>>> calculation of max_VF_buses was done and before return from
>>>>> virtfn_max_buses().
>>>>>
>>>>> Tested on stable 4.1 and passed building on stable 4.3-rc1
>>>>>
>>>>> Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
>>>>> Tested-by: Sriharsha Yadagudde <sriharsha.devdas@oracle.com>
>>>> Can you test the patch below? I'm trying to avoid touching
>>>> PCI_SRIOV_NUM_VF in more than one place, and I think it's OK to set it
>>>> and test offset/stride at the end, instead of setting NUM_VF to zero,
>>>> testing offset/stride, computing max_bus, then setting NUM_VF to zero
>>>> again.
>>>>
>>>> Bjorn
>>>>
>>>>
>>>> commit 8e20e89658f23b8d16b1e21810e9f63c8625129c
>>>> Author: Bjorn Helgaas <bhelgaas@google.com>
>>>> Date: Thu Oct 15 11:31:21 2015 -0500
>>>>
>>>> PCI: Set SR-IOV NumVFs to zero after enumeration
>>>> The enumeration path should leave NumVFs set to zero. But
>>>> after
>>>> 4449f079722c ("PCI: Calculate maximum number of buses required
>>>> for VFs"),
>>>> we call virtfn_max_buses() in the enumeration path, which
>>>> changes NumVFs.
>>>> This NumVFs change is visible via lspci and sysfs until a
>>>> driver enables
>>>> SR-IOV.
>>>> Set NumVFs to zero after virtfn_max_buses() computes the
>>>> maximum number of
>>>> buses.
>>>> Fixes: 4449f079722c ("PCI: Calculate maximum number of
>>>> buses required for VFs")
>>>> Based-on-patch-by: Ethan Zhao <ethan.zhao@oracle.com>
>>>> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
>>>>
>>>> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
>>>> index ee0ebff..0202ab0 100644
>>>> --- a/drivers/pci/iov.c
>>>> +++ b/drivers/pci/iov.c
>>>> @@ -384,7 +384,7 @@ static int sriov_init(struct pci_dev *dev, int
>>>> pos)
>>>> int rc;
>>>> int nres;
>>>> u32 pgsz;
>>>> - u16 ctrl, total, offset, stride;
>>>> + u16 ctrl, total;
>>>> struct pci_sriov *iov;
>>>> struct resource *res;
>>>> struct pci_dev *pdev;
>>>> @@ -414,11 +414,6 @@ static int sriov_init(struct pci_dev *dev, int
>>>> pos)
>>>> found:
>>>> pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
>>>> - pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0);
>>>> - pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
>>>> - pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
>>>> - if (!offset || (total > 1 && !stride))
>>>> - return -EIO;
>>>> pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
>>>> i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
>>>> @@ -456,8 +451,6 @@ found:
>>>> iov->nres = nres;
>>>> iov->ctrl = ctrl;
>>>> iov->total_VFs = total;
>>>> - iov->offset = offset;
>>>> - iov->stride = stride;
>>>> iov->pgsz = pgsz;
>>>> iov->self = dev;
>>>> pci_read_config_dword(dev, pos + PCI_SRIOV_CAP, &iov->cap);
>>>> @@ -475,6 +468,11 @@ found:
>>>> dev->sriov = iov;
>>>> dev->is_physfn = 1;
>>>> iov->max_VF_buses = virtfn_max_buses(dev);
>>>> + pci_iov_set_numvfs(dev, 0);
>>>> + if (!iov->offset || (total > 1 && !iov->stride)) {
>>>> + rc = -EIO;
>>>> + goto failed;
>>>> + }
>>>> return 0;
>>>
>>> You might want to reorder this a bit. The problem is offset and
>>> stride can be 0 if numvfs is 0. So you should probably test offset
>>> and stride
>> Yes, the spec says "Note: First VF Offset is unused if NumVFs is 0.
>> If NumVFs is greater than 0, First VF Offset must
>> 25 not be zero. "
>>> first, and then reset numvfs to 0.
>> Why test it before reset numvfs ?
>
> Because pci_iov_set_numvfs will end up resetting offset and stride
> based on the values when it writes the 0 into numvfs. As such
Seems virtfn_max_buses() never call pci_iov_set_numvfs() with 0, so no
need to check it before the last resetting to 0 ?
> testing it after the reset could give you invalid values since offset
> and stride can be 0 when numvfs is 0.
>
> Actually maybe I will go over this and submit a couple patches
> myself. Looking over things it seems like the code has gotten a bit
> silly since virtfn_max_busses looks like it is iterating over VFs and
> that doesn't make much sense when offset and stride are both positive
so far it works at least. :>
Thanks,
Ethan
> values so it should just be a matter of computing the bus of the last VF.
>
> - Alex
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