diff mbox series

[1/2] PCI: Add support for VF Resizable Bar extended cap

Message ID 20211215141626.3090807-2-michal.winiarski@intel.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show
Series PCI: VF resizable BAR | expand

Commit Message

Michał Winiarski Dec. 15, 2021, 2:16 p.m. UTC 
Similar to regular resizable BAR, VF BAR can also be resized.
The structures are very similar, which means we can reuse most of the
implementation. See PCIe r4.0, sec 9.3.7.4.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
---
 drivers/pci/pci.c             | 25 +++++++++++++++--
 drivers/pci/setup-res.c       | 53 ++++++++++++++++++++++++++++++++---
 include/uapi/linux/pci_regs.h |  1 +
 3 files changed, 72 insertions(+), 7 deletions(-)

Comments

Krzysztof Wilczyński Dec. 16, 2021, 12:21 a.m. UTC | #1 
Hi Michał,

[...]
> +static int pci_memory_decoding(struct pci_dev *dev)
> +{
> +	u16 cmd;
> +
> +	pci_read_config_word(dev, PCI_COMMAND, &cmd);
> +	if (cmd & PCI_COMMAND_MEMORY)
> +		return -EBUSY;
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PCI_IOV
> +static int pci_vf_memory_decoding(struct pci_dev *dev)
> +{
> +	u16 cmd;
> +
> +	pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_CTRL, &cmd);
> +	if (cmd & PCI_SRIOV_CTRL_MSE)
> +		return -EBUSY;
> +
> +	return 0;
> +}
> +#endif
> +
>  int pci_resize_resource(struct pci_dev *dev, int resno, int size)
>  {
>  	struct resource *res = dev->resource + resno;
>  	struct pci_host_bridge *host;
>  	int old, ret;
>  	u32 sizes;
> -	u16 cmd;
>  
>  	/* Check if we must preserve the firmware's resource assignment */
>  	host = pci_find_host_bridge(dev->bus);
> @@ -424,9 +447,14 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size)
>  	if (!(res->flags & IORESOURCE_UNSET))
>  		return -EBUSY;
>  
> -	pci_read_config_word(dev, PCI_COMMAND, &cmd);
> -	if (cmd & PCI_COMMAND_MEMORY)
> -		return -EBUSY;
> +#ifdef CONFIG_PCI_IOV
> +	if (resno >= PCI_IOV_RESOURCES)
> +		ret = pci_vf_memory_decoding(dev);
> +	else
> +#endif
> +	ret = pci_memory_decoding(dev);
> +	if (ret)
> +		return ret;

The above else works, however, it does trip our static analysis tools, and
lack of the indentation makes it slightly confusing to read, at least at
the first glance.  Thus, I wonder whether it would be possible to combine
the pci_vf_memory_decoding() and pci_memory_decoding() somehow neatly into
a private helper that takes a boolean to indicate whether it's a VF or not.
Then, we could drop the if-statement, since some of the logic could live
within the helper.

What do you think?

	Krzysztof
Christian König Dec. 16, 2021, 7:50 a.m. UTC | #2 
Am 15.12.21 um 15:16 schrieb Michał Winiarski:
> Similar to regular resizable BAR, VF BAR can also be resized.
> The structures are very similar, which means we can reuse most of the
> implementation. See PCIe r4.0, sec 9.3.7.4.
>
> Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
> ---
>   drivers/pci/pci.c             | 25 +++++++++++++++--
>   drivers/pci/setup-res.c       | 53 ++++++++++++++++++++++++++++++++---
>   include/uapi/linux/pci_regs.h |  1 +
>   3 files changed, 72 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 3d2fb394986a4..89448c5104e46 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -1682,12 +1682,15 @@ static void pci_restore_config_space(struct pci_dev *pdev)
>   	}
>   }
>   
> -static void pci_restore_rebar_state(struct pci_dev *pdev)
> +static void __pci_restore_rebar_state(struct pci_dev *pdev, int cap)
>   {
>   	unsigned int pos, nbars, i;
>   	u32 ctrl;
>   
> -	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
> +	if (WARN_ON(cap != PCI_EXT_CAP_ID_REBAR && cap != PCI_EXT_CAP_ID_VF_REBAR))
> +		return;
> +
> +	pos = pci_find_ext_capability(pdev, cap);
>   	if (!pos)
>   		return;
>   
> @@ -1709,6 +1712,14 @@ static void pci_restore_rebar_state(struct pci_dev *pdev)
>   	}
>   }
>   
> +static void pci_restore_rebar_state(struct pci_dev *pdev)
> +{
> +	__pci_restore_rebar_state(pdev, PCI_EXT_CAP_ID_REBAR);
> +#ifdef CONFIG_PCI_IOV
> +	__pci_restore_rebar_state(pdev, PCI_EXT_CAP_ID_VF_REBAR);
> +#endif
> +}
> +

It's probably cleaner to let the caller specify the capability to 
restore directly.

>   /**
>    * pci_restore_state - Restore the saved state of a PCI device
>    * @dev: PCI device that we're dealing with
> @@ -3639,10 +3650,18 @@ void pci_acs_init(struct pci_dev *dev)
>    */
>   static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
>   {
> +	int cap = PCI_EXT_CAP_ID_REBAR;
>   	unsigned int pos, nbars, i;
>   	u32 ctrl;
>   
> -	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
> +#ifdef CONFIG_PCI_IOV
> +	if (bar >= PCI_IOV_RESOURCES) {
> +		cap = PCI_EXT_CAP_ID_VF_REBAR;
> +		bar -= PCI_IOV_RESOURCES;
> +	}
> +#endif
> +
> +	pos = pci_find_ext_capability(pdev, cap);
>   	if (!pos)
>   		return -ENOTSUPP;
>   
> diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
> index 7f1acb3918d0c..1946e52e7678a 100644
> --- a/drivers/pci/setup-res.c
> +++ b/drivers/pci/setup-res.c
> @@ -407,13 +407,36 @@ void pci_release_resource(struct pci_dev *dev, int resno)
>   }
>   EXPORT_SYMBOL(pci_release_resource);
>   
> +static int pci_memory_decoding(struct pci_dev *dev)
> +{
> +	u16 cmd;
> +
> +	pci_read_config_word(dev, PCI_COMMAND, &cmd);
> +	if (cmd & PCI_COMMAND_MEMORY)
> +		return -EBUSY;
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PCI_IOV
> +static int pci_vf_memory_decoding(struct pci_dev *dev)
> +{
> +	u16 cmd;
> +
> +	pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_CTRL, &cmd);
> +	if (cmd & PCI_SRIOV_CTRL_MSE)
> +		return -EBUSY;
> +
> +	return 0;
> +}
> +#endif
> +
>   int pci_resize_resource(struct pci_dev *dev, int resno, int size)
>   {
>   	struct resource *res = dev->resource + resno;
>   	struct pci_host_bridge *host;
>   	int old, ret;
>   	u32 sizes;
> -	u16 cmd;
>   
>   	/* Check if we must preserve the firmware's resource assignment */
>   	host = pci_find_host_bridge(dev->bus);
> @@ -424,9 +447,14 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size)
>   	if (!(res->flags & IORESOURCE_UNSET))
>   		return -EBUSY;
>   
> -	pci_read_config_word(dev, PCI_COMMAND, &cmd);
> -	if (cmd & PCI_COMMAND_MEMORY)
> -		return -EBUSY;
> +#ifdef CONFIG_PCI_IOV
> +	if (resno >= PCI_IOV_RESOURCES)
> +		ret = pci_vf_memory_decoding(dev);
> +	else
> +#endif
> +	ret = pci_memory_decoding(dev);
> +	if (ret)
> +		return ret;

Way to many #ifdef spread around inside the code, please restructure that.

For example concentrating the logic in a single function should help:

static int pci_check_decoding_disabled(..., inr resno)
{

#ifdef CONFIG_PCI_IOV
	if (resno...
		return -EBUSY;
	else
		return 0;
#endif

	if (...)
		return -EBUSY;
	return 0;

}

>   
>   	sizes = pci_rebar_get_possible_sizes(dev, resno);
>   	if (!sizes)
> @@ -445,6 +473,14 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size)
>   
>   	res->end = res->start + pci_rebar_size_to_bytes(size) - 1;
>   
> +#ifdef CONFIG_PCI_IOV
> +	if (resno >= PCI_IOV_RESOURCES) {
> +		dev->sriov->barsz[resno - PCI_IOV_RESOURCES] = pci_rebar_size_to_bytes(size);
> +		res->end = res->start +
> +			resource_size(res) * pci_sriov_get_totalvfs(dev) - 1;
> +	}
> +#endif
> +
>   	/* Check if the new config works by trying to assign everything. */
>   	if (dev->bus->self) {
>   		ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
> @@ -456,6 +492,15 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size)
>   error_resize:
>   	pci_rebar_set_size(dev, resno, old);
>   	res->end = res->start + pci_rebar_size_to_bytes(old) - 1;
> +
> +#ifdef CONFIG_PCI_IOV
> +	if (resno >= PCI_IOV_RESOURCES) {
> +		dev->sriov->barsz[resno - PCI_IOV_RESOURCES] = pci_rebar_size_to_bytes(old);
> +		res->end = res->start +
> +			pci_rebar_size_to_bytes(old) * pci_sriov_get_totalvfs(dev) - 1;
> +	}
> +#endif
> +

Looks like this deserves it's own function.

Regards,
Christian.

>   	return ret;
>   }
>   EXPORT_SYMBOL(pci_resize_resource);
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index ff6ccbc6efe96..7f5726d23b038 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -734,6 +734,7 @@
>   #define PCI_EXT_CAP_ID_L1SS	0x1E	/* L1 PM Substates */
>   #define PCI_EXT_CAP_ID_PTM	0x1F	/* Precision Time Measurement */
>   #define PCI_EXT_CAP_ID_DVSEC	0x23	/* Designated Vendor-Specific */
> +#define PCI_EXT_CAP_ID_VF_REBAR	0x24	/* VF Resizable BAR */
>   #define PCI_EXT_CAP_ID_DLF	0x25	/* Data Link Feature */
>   #define PCI_EXT_CAP_ID_PL_16GT	0x26	/* Physical Layer 16.0 GT/s */
>   #define PCI_EXT_CAP_ID_MAX	PCI_EXT_CAP_ID_PL_16GT
Michał Winiarski Dec. 17, 2021, 10:58 a.m. UTC | #3 
On 16.12.2021 08:50, Christian König wrote:
> 
> 
> Am 15.12.21 um 15:16 schrieb Michał Winiarski:
>> Similar to regular resizable BAR, VF BAR can also be resized.
>> The structures are very similar, which means we can reuse most of the
>> implementation. See PCIe r4.0, sec 9.3.7.4.
>>
>> Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
>> ---
>>   drivers/pci/pci.c             | 25 +++++++++++++++--
>>   drivers/pci/setup-res.c       | 53 ++++++++++++++++++++++++++++++++---
>>   include/uapi/linux/pci_regs.h |  1 +
>>   3 files changed, 72 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index 3d2fb394986a4..89448c5104e46 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -1682,12 +1682,15 @@ static void pci_restore_config_space(struct 
>> pci_dev *pdev)
>>       }
>>   }
>> -static void pci_restore_rebar_state(struct pci_dev *pdev)
>> +static void __pci_restore_rebar_state(struct pci_dev *pdev, int cap)
>>   {
>>       unsigned int pos, nbars, i;
>>       u32 ctrl;
>> -    pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
>> +    if (WARN_ON(cap != PCI_EXT_CAP_ID_REBAR && cap != 
>> PCI_EXT_CAP_ID_VF_REBAR))
>> +        return;
>> +
>> +    pos = pci_find_ext_capability(pdev, cap);
>>       if (!pos)
>>           return;
>> @@ -1709,6 +1712,14 @@ static void pci_restore_rebar_state(struct 
>> pci_dev *pdev)
>>       }
>>   }
>> +static void pci_restore_rebar_state(struct pci_dev *pdev)
>> +{
>> +    __pci_restore_rebar_state(pdev, PCI_EXT_CAP_ID_REBAR);
>> +#ifdef CONFIG_PCI_IOV
>> +    __pci_restore_rebar_state(pdev, PCI_EXT_CAP_ID_VF_REBAR);
>> +#endif
>> +}
>> +
> 
> It's probably cleaner to let the caller specify the capability to 
> restore directly.

Ok - I'll go with:
pci_restore_rebar_state(dev);
pci_restore_vf_rebar_state(dev);

in pci_restore_state() (where pci_restore_vf_rebar_state() will be 
"no-op" if there's no CONFIG_PCI_IOV).

> 
>>   /**
>>    * pci_restore_state - Restore the saved state of a PCI device
>>    * @dev: PCI device that we're dealing with
>> @@ -3639,10 +3650,18 @@ void pci_acs_init(struct pci_dev *dev)
>>    */
>>   static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
>>   {
>> +    int cap = PCI_EXT_CAP_ID_REBAR;
>>       unsigned int pos, nbars, i;
>>       u32 ctrl;
>> -    pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
>> +#ifdef CONFIG_PCI_IOV
>> +    if (bar >= PCI_IOV_RESOURCES) {
>> +        cap = PCI_EXT_CAP_ID_VF_REBAR;
>> +        bar -= PCI_IOV_RESOURCES;
>> +    }
>> +#endif
>> +
>> +    pos = pci_find_ext_capability(pdev, cap);
>>       if (!pos)
>>           return -ENOTSUPP;
>> diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
>> index 7f1acb3918d0c..1946e52e7678a 100644
>> --- a/drivers/pci/setup-res.c
>> +++ b/drivers/pci/setup-res.c
>> @@ -407,13 +407,36 @@ void pci_release_resource(struct pci_dev *dev, 
>> int resno)
>>   }
>>   EXPORT_SYMBOL(pci_release_resource);
>> +static int pci_memory_decoding(struct pci_dev *dev)
>> +{
>> +    u16 cmd;
>> +
>> +    pci_read_config_word(dev, PCI_COMMAND, &cmd);
>> +    if (cmd & PCI_COMMAND_MEMORY)
>> +        return -EBUSY;
>> +
>> +    return 0;
>> +}
>> +
>> +#ifdef CONFIG_PCI_IOV
>> +static int pci_vf_memory_decoding(struct pci_dev *dev)
>> +{
>> +    u16 cmd;
>> +
>> +    pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_CTRL, &cmd);
>> +    if (cmd & PCI_SRIOV_CTRL_MSE)
>> +        return -EBUSY;
>> +
>> +    return 0;
>> +}
>> +#endif
>> +
>>   int pci_resize_resource(struct pci_dev *dev, int resno, int size)
>>   {
>>       struct resource *res = dev->resource + resno;
>>       struct pci_host_bridge *host;
>>       int old, ret;
>>       u32 sizes;
>> -    u16 cmd;
>>       /* Check if we must preserve the firmware's resource assignment */
>>       host = pci_find_host_bridge(dev->bus);
>> @@ -424,9 +447,14 @@ int pci_resize_resource(struct pci_dev *dev, int 
>> resno, int size)
>>       if (!(res->flags & IORESOURCE_UNSET))
>>           return -EBUSY;
>> -    pci_read_config_word(dev, PCI_COMMAND, &cmd);
>> -    if (cmd & PCI_COMMAND_MEMORY)
>> -        return -EBUSY;
>> +#ifdef CONFIG_PCI_IOV
>> +    if (resno >= PCI_IOV_RESOURCES)
>> +        ret = pci_vf_memory_decoding(dev);
>> +    else
>> +#endif
>> +    ret = pci_memory_decoding(dev);
>> +    if (ret)
>> +        return ret;
> 
> Way to many #ifdef spread around inside the code, please restructure that.
> 
> For example concentrating the logic in a single function should help:
> 
> static int pci_check_decoding_disabled(..., inr resno)
> {
> 
> #ifdef CONFIG_PCI_IOV
>      if (resno...
>          return -EBUSY;
>      else
>          return 0;
> #endif
> 
>      if (...)
>          return -EBUSY;
>      return 0;
> 
> }
> 

Ok.

>>       sizes = pci_rebar_get_possible_sizes(dev, resno);
>>       if (!sizes)
>> @@ -445,6 +473,14 @@ int pci_resize_resource(struct pci_dev *dev, int 
>> resno, int size)
>>       res->end = res->start + pci_rebar_size_to_bytes(size) - 1;
>> +#ifdef CONFIG_PCI_IOV
>> +    if (resno >= PCI_IOV_RESOURCES) {
>> +        dev->sriov->barsz[resno - PCI_IOV_RESOURCES] = 
>> pci_rebar_size_to_bytes(size);
>> +        res->end = res->start +
>> +            resource_size(res) * pci_sriov_get_totalvfs(dev) - 1;
>> +    }
>> +#endif
>> +
>>       /* Check if the new config works by trying to assign everything. */
>>       if (dev->bus->self) {
>>           ret = pci_reassign_bridge_resources(dev->bus->self, 
>> res->flags);
>> @@ -456,6 +492,15 @@ int pci_resize_resource(struct pci_dev *dev, int 
>> resno, int size)
>>   error_resize:
>>       pci_rebar_set_size(dev, resno, old);
>>       res->end = res->start + pci_rebar_size_to_bytes(old) - 1;
>> +
>> +#ifdef CONFIG_PCI_IOV
>> +    if (resno >= PCI_IOV_RESOURCES) {
>> +        dev->sriov->barsz[resno - PCI_IOV_RESOURCES] = 
>> pci_rebar_size_to_bytes(old);
>> +        res->end = res->start +
>> +            pci_rebar_size_to_bytes(old) * 
>> pci_sriov_get_totalvfs(dev) - 1;
>> +    }
>> +#endif
>> +
> 
> Looks like this deserves it's own function.

I'll extract the whole "restore after failed resize" to separate 
function (for both native and IOV).

Thanks!
-Michał

> 
> Regards,
> Christian.
> 
>>       return ret;
>>   }
>>   EXPORT_SYMBOL(pci_resize_resource);
>> diff --git a/include/uapi/linux/pci_regs.h 
>> b/include/uapi/linux/pci_regs.h
>> index ff6ccbc6efe96..7f5726d23b038 100644
>> --- a/include/uapi/linux/pci_regs.h
>> +++ b/include/uapi/linux/pci_regs.h
>> @@ -734,6 +734,7 @@
>>   #define PCI_EXT_CAP_ID_L1SS    0x1E    /* L1 PM Substates */
>>   #define PCI_EXT_CAP_ID_PTM    0x1F    /* Precision Time Measurement */
>>   #define PCI_EXT_CAP_ID_DVSEC    0x23    /* Designated 
>> Vendor-Specific */
>> +#define PCI_EXT_CAP_ID_VF_REBAR    0x24    /* VF Resizable BAR */
>>   #define PCI_EXT_CAP_ID_DLF    0x25    /* Data Link Feature */
>>   #define PCI_EXT_CAP_ID_PL_16GT    0x26    /* Physical Layer 16.0 
>> GT/s */
>>   #define PCI_EXT_CAP_ID_MAX    PCI_EXT_CAP_ID_PL_16GT
>
Michał Winiarski Dec. 17, 2021, 12:38 p.m. UTC | #4 
On 16.12.2021 01:21, Krzysztof Wilczyński wrote:
> Hi Michał,
> 
> [...]
>> +static int pci_memory_decoding(struct pci_dev *dev)
>> +{
>> +	u16 cmd;
>> +
>> +	pci_read_config_word(dev, PCI_COMMAND, &cmd);
>> +	if (cmd & PCI_COMMAND_MEMORY)
>> +		return -EBUSY;
>> +
>> +	return 0;
>> +}
>> +
>> +#ifdef CONFIG_PCI_IOV
>> +static int pci_vf_memory_decoding(struct pci_dev *dev)
>> +{
>> +	u16 cmd;
>> +
>> +	pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_CTRL, &cmd);
>> +	if (cmd & PCI_SRIOV_CTRL_MSE)
>> +		return -EBUSY;
>> +
>> +	return 0;
>> +}
>> +#endif
>> +
>>   int pci_resize_resource(struct pci_dev *dev, int resno, int size)
>>   {
>>   	struct resource *res = dev->resource + resno;
>>   	struct pci_host_bridge *host;
>>   	int old, ret;
>>   	u32 sizes;
>> -	u16 cmd;
>>   
>>   	/* Check if we must preserve the firmware's resource assignment */
>>   	host = pci_find_host_bridge(dev->bus);
>> @@ -424,9 +447,14 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size)
>>   	if (!(res->flags & IORESOURCE_UNSET))
>>   		return -EBUSY;
>>   
>> -	pci_read_config_word(dev, PCI_COMMAND, &cmd);
>> -	if (cmd & PCI_COMMAND_MEMORY)
>> -		return -EBUSY;
>> +#ifdef CONFIG_PCI_IOV
>> +	if (resno >= PCI_IOV_RESOURCES)
>> +		ret = pci_vf_memory_decoding(dev);
>> +	else
>> +#endif
>> +	ret = pci_memory_decoding(dev);
>> +	if (ret)
>> +		return ret;
> 
> The above else works, however, it does trip our static analysis tools, and
> lack of the indentation makes it slightly confusing to read, at least at
> the first glance.  Thus, I wonder whether it would be possible to combine
> the pci_vf_memory_decoding() and pci_memory_decoding() somehow neatly into
> a private helper that takes a boolean to indicate whether it's a VF or not.
> Then, we could drop the if-statement, since some of the logic could live
> within the helper.
> 
> What do you think?

Sure - implementing a helper in a way that Christian suggested (the 
helper still takes resno though) should also take care of that.

Thanks
-Michał

> 
> 	Krzysztof
diff mbox series

Patch

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 3d2fb394986a4..89448c5104e46 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1682,12 +1682,15 @@  static void pci_restore_config_space(struct pci_dev *pdev)
 	}
 }
 
-static void pci_restore_rebar_state(struct pci_dev *pdev)
+static void __pci_restore_rebar_state(struct pci_dev *pdev, int cap)
 {
 	unsigned int pos, nbars, i;
 	u32 ctrl;
 
-	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
+	if (WARN_ON(cap != PCI_EXT_CAP_ID_REBAR && cap != PCI_EXT_CAP_ID_VF_REBAR))
+		return;
+
+	pos = pci_find_ext_capability(pdev, cap);
 	if (!pos)
 		return;
 
@@ -1709,6 +1712,14 @@  static void pci_restore_rebar_state(struct pci_dev *pdev)
 	}
 }
 
+static void pci_restore_rebar_state(struct pci_dev *pdev)
+{
+	__pci_restore_rebar_state(pdev, PCI_EXT_CAP_ID_REBAR);
+#ifdef CONFIG_PCI_IOV
+	__pci_restore_rebar_state(pdev, PCI_EXT_CAP_ID_VF_REBAR);
+#endif
+}
+
 /**
  * pci_restore_state - Restore the saved state of a PCI device
  * @dev: PCI device that we're dealing with
@@ -3639,10 +3650,18 @@  void pci_acs_init(struct pci_dev *dev)
  */
 static int pci_rebar_find_pos(struct pci_dev *pdev, int bar)
 {
+	int cap = PCI_EXT_CAP_ID_REBAR;
 	unsigned int pos, nbars, i;
 	u32 ctrl;
 
-	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR);
+#ifdef CONFIG_PCI_IOV
+	if (bar >= PCI_IOV_RESOURCES) {
+		cap = PCI_EXT_CAP_ID_VF_REBAR;
+		bar -= PCI_IOV_RESOURCES;
+	}
+#endif
+
+	pos = pci_find_ext_capability(pdev, cap);
 	if (!pos)
 		return -ENOTSUPP;
 
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 7f1acb3918d0c..1946e52e7678a 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -407,13 +407,36 @@  void pci_release_resource(struct pci_dev *dev, int resno)
 }
 EXPORT_SYMBOL(pci_release_resource);
 
+static int pci_memory_decoding(struct pci_dev *dev)
+{
+	u16 cmd;
+
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	if (cmd & PCI_COMMAND_MEMORY)
+		return -EBUSY;
+
+	return 0;
+}
+
+#ifdef CONFIG_PCI_IOV
+static int pci_vf_memory_decoding(struct pci_dev *dev)
+{
+	u16 cmd;
+
+	pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_CTRL, &cmd);
+	if (cmd & PCI_SRIOV_CTRL_MSE)
+		return -EBUSY;
+
+	return 0;
+}
+#endif
+
 int pci_resize_resource(struct pci_dev *dev, int resno, int size)
 {
 	struct resource *res = dev->resource + resno;
 	struct pci_host_bridge *host;
 	int old, ret;
 	u32 sizes;
-	u16 cmd;
 
 	/* Check if we must preserve the firmware's resource assignment */
 	host = pci_find_host_bridge(dev->bus);
@@ -424,9 +447,14 @@  int pci_resize_resource(struct pci_dev *dev, int resno, int size)
 	if (!(res->flags & IORESOURCE_UNSET))
 		return -EBUSY;
 
-	pci_read_config_word(dev, PCI_COMMAND, &cmd);
-	if (cmd & PCI_COMMAND_MEMORY)
-		return -EBUSY;
+#ifdef CONFIG_PCI_IOV
+	if (resno >= PCI_IOV_RESOURCES)
+		ret = pci_vf_memory_decoding(dev);
+	else
+#endif
+	ret = pci_memory_decoding(dev);
+	if (ret)
+		return ret;
 
 	sizes = pci_rebar_get_possible_sizes(dev, resno);
 	if (!sizes)
@@ -445,6 +473,14 @@  int pci_resize_resource(struct pci_dev *dev, int resno, int size)
 
 	res->end = res->start + pci_rebar_size_to_bytes(size) - 1;
 
+#ifdef CONFIG_PCI_IOV
+	if (resno >= PCI_IOV_RESOURCES) {
+		dev->sriov->barsz[resno - PCI_IOV_RESOURCES] = pci_rebar_size_to_bytes(size);
+		res->end = res->start +
+			resource_size(res) * pci_sriov_get_totalvfs(dev) - 1;
+	}
+#endif
+
 	/* Check if the new config works by trying to assign everything. */
 	if (dev->bus->self) {
 		ret = pci_reassign_bridge_resources(dev->bus->self, res->flags);
@@ -456,6 +492,15 @@  int pci_resize_resource(struct pci_dev *dev, int resno, int size)
 error_resize:
 	pci_rebar_set_size(dev, resno, old);
 	res->end = res->start + pci_rebar_size_to_bytes(old) - 1;
+
+#ifdef CONFIG_PCI_IOV
+	if (resno >= PCI_IOV_RESOURCES) {
+		dev->sriov->barsz[resno - PCI_IOV_RESOURCES] = pci_rebar_size_to_bytes(old);
+		res->end = res->start +
+			pci_rebar_size_to_bytes(old) * pci_sriov_get_totalvfs(dev) - 1;
+	}
+#endif
+
 	return ret;
 }
 EXPORT_SYMBOL(pci_resize_resource);
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index ff6ccbc6efe96..7f5726d23b038 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -734,6 +734,7 @@ 
 #define PCI_EXT_CAP_ID_L1SS	0x1E	/* L1 PM Substates */
 #define PCI_EXT_CAP_ID_PTM	0x1F	/* Precision Time Measurement */
 #define PCI_EXT_CAP_ID_DVSEC	0x23	/* Designated Vendor-Specific */
+#define PCI_EXT_CAP_ID_VF_REBAR	0x24	/* VF Resizable BAR */
 #define PCI_EXT_CAP_ID_DLF	0x25	/* Data Link Feature */
 #define PCI_EXT_CAP_ID_PL_16GT	0x26	/* Physical Layer 16.0 GT/s */
 #define PCI_EXT_CAP_ID_MAX	PCI_EXT_CAP_ID_PL_16GT