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-rw-r--r--drivers/vfio/pci/vfio_pci_config.c41
1 files changed, 38 insertions, 3 deletions
diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index f1dde2c..964ff22 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -587,12 +587,46 @@ static int __init init_pci_cap_basic_perm(struct perm_bits *perm)
return 0;
}
+static int vfio_pm_config_write(struct vfio_pci_device *vdev, int pos,
+ int count, struct perm_bits *perm,
+ int offset, __le32 val)
+{
+ count = vfio_default_config_write(vdev, pos, count, perm, offset, val);
+ if (count < 0)
+ return count;
+
+ if (offset == PCI_PM_CTRL) {
+ pci_power_t state;
+
+ switch (le32_to_cpu(val) & PCI_PM_CTRL_STATE_MASK) {
+ case 0:
+ state = PCI_D0;
+ break;
+ case 1:
+ state = PCI_D1;
+ break;
+ case 2:
+ state = PCI_D2;
+ break;
+ case 3:
+ state = PCI_D3hot;
+ break;
+ }
+
+ pci_set_power_state(vdev->pdev, state);
+ }
+
+ return count;
+}
+
/* Permissions for the Power Management capability */
static int __init init_pci_cap_pm_perm(struct perm_bits *perm)
{
if (alloc_perm_bits(perm, pci_cap_length[PCI_CAP_ID_PM]))
return -ENOMEM;
+ perm->writefn = vfio_pm_config_write;
+
/*
* We always virtualize the next field so we can remove
* capabilities from the chain if we want to.
@@ -600,10 +634,11 @@ static int __init init_pci_cap_pm_perm(struct perm_bits *perm)
p_setb(perm, PCI_CAP_LIST_NEXT, (u8)ALL_VIRT, NO_WRITE);
/*
- * Power management is defined *per function*,
- * so we let the user write this
+ * Power management is defined *per function*, so we can let
+ * the user change power state, but we trap and initiate the
+ * change ourselves, so the state bits are read-only.
*/
- p_setd(perm, PCI_PM_CTRL, NO_VIRT, ALL_WRITE);
+ p_setd(perm, PCI_PM_CTRL, NO_VIRT, ~PCI_PM_CTRL_STATE_MASK);
return 0;
}