Commit 1c0f6825 authored Sep 21, 2020 by Zenghui Yu Committed by Alex Williamson Sep 21, 2020

vfio/pci: Don't regenerate vconfig for all BARs if !bardirty

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 avoided if no BARs had been written
since they were last read, in which case vdev->bardirty is false.

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>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

parent ba4f184e

drivers/vfio/pci/vfio_pci_config.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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++) {