* [PATCH v2 1/2] vfio/pci: Remove redundant declaration of vfio_pci_driver
@ 2020-09-21 4:51 Zenghui Yu
2020-09-21 4:51 ` [PATCH v2 2/2] vfio/pci: Don't regenerate vconfig for all BARs if !bardirty Zenghui Yu
0 siblings, 1 reply; 4+ messages in thread
From: Zenghui Yu @ 2020-09-21 4:51 UTC (permalink / raw)
To: kvm, linux-kernel; +Cc: alex.williamson, cohuck, wanghaibin.wang, Zenghui Yu
It was added by commit 137e5531351d ("vfio/pci: Add sriov_configure
support") but duplicates a forward declaration earlier in the file.
Remove it.
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
---
* From v1:
- Clarify the commit message per Alex's suggestion.
- Add Cornelia's R-b tag.
drivers/vfio/pci/vfio_pci.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 1ab1f5cda4ac..da68e2f86622 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1862,7 +1862,6 @@ static const struct vfio_device_ops vfio_pci_ops = {
static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev);
static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck);
-static struct pci_driver vfio_pci_driver;
static int vfio_pci_bus_notifier(struct notifier_block *nb,
unsigned long action, void *data)
--
2.19.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v2 2/2] vfio/pci: Don't regenerate vconfig for all BARs if !bardirty
2020-09-21 4:51 [PATCH v2 1/2] vfio/pci: Remove redundant declaration of vfio_pci_driver Zenghui Yu
@ 2020-09-21 4:51 ` Zenghui Yu
2020-09-21 10:21 ` Cornelia Huck
0 siblings, 1 reply; 4+ messages in thread
From: Zenghui Yu @ 2020-09-21 4:51 UTC (permalink / raw)
To: kvm, linux-kernel; +Cc: alex.williamson, cohuck, wanghaibin.wang, Zenghui Yu
Now we regenerate vconfig for all the BARs via vfio_bar_fixup(), every time
any offset of any of them are read. Though BARs aren't re-read regularly,
the regeneration can be avoid if no BARs had been written since they were
last read, in which case the vdev->bardirty is false.
Let's predicate the vfio_bar_fixup() on the bardirty so that it can return
immediately if !bardirty.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
---
* From v1:
- Per Alex's suggestion, let vfio_bar_fixup() test vdev->bardirty to
avoid doing work if bardirty is false, instead of removing it entirely.
- Rewrite the commit message.
drivers/vfio/pci/vfio_pci_config.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index d98843feddce..5e02ba07e8e8 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -467,6 +467,9 @@ static void vfio_bar_fixup(struct vfio_pci_device *vdev)
__le32 *vbar;
u64 mask;
+ if (!vdev->bardirty)
+ return;
+
vbar = (__le32 *)&vdev->vconfig[PCI_BASE_ADDRESS_0];
for (i = 0; i < PCI_STD_NUM_BARS; i++, vbar++) {
--
2.19.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2 2/2] vfio/pci: Don't regenerate vconfig for all BARs if !bardirty
2020-09-21 4:51 ` [PATCH v2 2/2] vfio/pci: Don't regenerate vconfig for all BARs if !bardirty Zenghui Yu
@ 2020-09-21 10:21 ` Cornelia Huck
2020-09-21 11:28 ` Zenghui Yu
0 siblings, 1 reply; 4+ messages in thread
From: Cornelia Huck @ 2020-09-21 10:21 UTC (permalink / raw)
To: Zenghui Yu; +Cc: kvm, linux-kernel, alex.williamson, wanghaibin.wang
On Mon, 21 Sep 2020 12:51:16 +0800
Zenghui Yu <yuzenghui@huawei.com> wrote:
> Now we regenerate vconfig for all the BARs via vfio_bar_fixup(), every time
> any offset of any of them are read. Though BARs aren't re-read regularly,
> the regeneration can be avoid if no BARs had been written since they were
s/avoid/avoided/
> last read, in which case the vdev->bardirty is false.
s/the//
>
> Let's predicate the vfio_bar_fixup() on the bardirty so that it can return
> immediately if !bardirty.
Maybe
"Let's return immediately in vfio_bar_fixup() if bardirty is false." ?
>
> Suggested-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
> ---
> * From v1:
> - Per Alex's suggestion, let vfio_bar_fixup() test vdev->bardirty to
> avoid doing work if bardirty is false, instead of removing it entirely.
> - Rewrite the commit message.
>
> drivers/vfio/pci/vfio_pci_config.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
> index d98843feddce..5e02ba07e8e8 100644
> --- a/drivers/vfio/pci/vfio_pci_config.c
> +++ b/drivers/vfio/pci/vfio_pci_config.c
> @@ -467,6 +467,9 @@ static void vfio_bar_fixup(struct vfio_pci_device *vdev)
> __le32 *vbar;
> u64 mask;
>
> + if (!vdev->bardirty)
Finally, bardirty can actually affect something :)
> + return;
> +
> vbar = (__le32 *)&vdev->vconfig[PCI_BASE_ADDRESS_0];
>
> for (i = 0; i < PCI_STD_NUM_BARS; i++, vbar++) {
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 2/2] vfio/pci: Don't regenerate vconfig for all BARs if !bardirty
2020-09-21 10:21 ` Cornelia Huck
@ 2020-09-21 11:28 ` Zenghui Yu
0 siblings, 0 replies; 4+ messages in thread
From: Zenghui Yu @ 2020-09-21 11:28 UTC (permalink / raw)
To: Cornelia Huck; +Cc: kvm, linux-kernel, alex.williamson, wanghaibin.wang
Hi Cornelia,
On 2020/9/21 18:21, Cornelia Huck wrote:
> On Mon, 21 Sep 2020 12:51:16 +0800
> Zenghui Yu <yuzenghui@huawei.com> wrote:
>
>> Now we regenerate vconfig for all the BARs via vfio_bar_fixup(), every time
>> any offset of any of them are read. Though BARs aren't re-read regularly,
>> the regeneration can be avoid if no BARs had been written since they were
>
> s/avoid/avoided/
>
>> last read, in which case the vdev->bardirty is false.
>
> s/the//
>
>>
>> Let's predicate the vfio_bar_fixup() on the bardirty so that it can return
>> immediately if !bardirty.
>
> Maybe
>
> "Let's return immediately in vfio_bar_fixup() if bardirty is false." ?
Yes.
>>
>> Suggested-by: Alex Williamson <alex.williamson@redhat.com>
>> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
>> ---
>> * From v1:
>> - Per Alex's suggestion, let vfio_bar_fixup() test vdev->bardirty to
>> avoid doing work if bardirty is false, instead of removing it entirely.
>> - Rewrite the commit message.
>>
>> drivers/vfio/pci/vfio_pci_config.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
>> index d98843feddce..5e02ba07e8e8 100644
>> --- a/drivers/vfio/pci/vfio_pci_config.c
>> +++ b/drivers/vfio/pci/vfio_pci_config.c
>> @@ -467,6 +467,9 @@ static void vfio_bar_fixup(struct vfio_pci_device *vdev)
>> __le32 *vbar;
>> u64 mask;
>>
>> + if (!vdev->bardirty)
>
> Finally, bardirty can actually affect something :)
>
>> + return;
>> +
>> vbar = (__le32 *)&vdev->vconfig[PCI_BASE_ADDRESS_0];
>>
>> for (i = 0; i < PCI_STD_NUM_BARS; i++, vbar++) {
>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Thanks for you review! I think Alex can help fix the commit message when
applying? Otherwise I can send a v3.
Thanks,
Zenghui
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-09-21 11:28 UTC | newest]
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2020-09-21 4:51 [PATCH v2 1/2] vfio/pci: Remove redundant declaration of vfio_pci_driver Zenghui Yu
2020-09-21 4:51 ` [PATCH v2 2/2] vfio/pci: Don't regenerate vconfig for all BARs if !bardirty Zenghui Yu
2020-09-21 10:21 ` Cornelia Huck
2020-09-21 11:28 ` Zenghui Yu
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