From 1c0f68252a6a8a793ff3352e3580664d18ec5955 Mon Sep 17 00:00:00 2001 From: Zenghui Yu Date: Mon, 21 Sep 2020 12:51:16 +0800 Subject: [PATCH] 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 Signed-off-by: Zenghui Yu Reviewed-by: Cornelia Huck Signed-off-by: Alex Williamson --- 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++) { -- 2.17.1