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path: root/drivers/pci/controller/vmd.c
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Diffstat (limited to 'drivers/pci/controller/vmd.c')
-rw-r--r--drivers/pci/controller/vmd.c63
1 files changed, 51 insertions, 12 deletions
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 5e80f28f0119..e3fcdfec58b3 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -28,6 +28,7 @@
#define BUS_RESTRICT_CAP(vmcap) (vmcap & 0x1)
#define PCI_REG_VMCONFIG 0x44
#define BUS_RESTRICT_CFG(vmcfg) ((vmcfg >> 8) & 0x3)
+#define VMCONFIG_MSI_REMAP 0x2
#define PCI_REG_VMLOCK 0x70
#define MB2_SHADOW_EN(vmlock) (vmlock & 0x2)
@@ -59,6 +60,13 @@ enum vmd_features {
* be used for MSI remapping
*/
VMD_FEAT_OFFSET_FIRST_VECTOR = (1 << 3),
+
+ /*
+ * Device can bypass remapping MSI-X transactions into its MSI-X table,
+ * avoiding the requirement of a VMD MSI domain for child device
+ * interrupt handling.
+ */
+ VMD_FEAT_CAN_BYPASS_MSI_REMAP = (1 << 4),
};
/*
@@ -306,6 +314,16 @@ static struct msi_domain_info vmd_msi_domain_info = {
.chip = &vmd_msi_controller,
};
+static void vmd_set_msi_remapping(struct vmd_dev *vmd, bool enable)
+{
+ u16 reg;
+
+ pci_read_config_word(vmd->dev, PCI_REG_VMCONFIG, &reg);
+ reg = enable ? (reg & ~VMCONFIG_MSI_REMAP) :
+ (reg | VMCONFIG_MSI_REMAP);
+ pci_write_config_word(vmd->dev, PCI_REG_VMCONFIG, reg);
+}
+
static int vmd_create_irq_domain(struct vmd_dev *vmd)
{
struct fwnode_handle *fn;
@@ -325,6 +343,13 @@ static int vmd_create_irq_domain(struct vmd_dev *vmd)
static void vmd_remove_irq_domain(struct vmd_dev *vmd)
{
+ /*
+ * Some production BIOS won't enable remapping between soft reboots.
+ * Ensure remapping is restored before unloading the driver.
+ */
+ if (!vmd->msix_count)
+ vmd_set_msi_remapping(vmd, true);
+
if (vmd->irq_domain) {
struct fwnode_handle *fn = vmd->irq_domain->fwnode;
@@ -679,15 +704,32 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
sd->node = pcibus_to_node(vmd->dev->bus);
- ret = vmd_create_irq_domain(vmd);
- if (ret)
- return ret;
-
/*
- * Override the irq domain bus token so the domain can be distinguished
- * from a regular PCI/MSI domain.
+ * Currently MSI remapping must be enabled in guest passthrough mode
+ * due to some missing interrupt remapping plumbing. This is probably
+ * acceptable because the guest is usually CPU-limited and MSI
+ * remapping doesn't become a performance bottleneck.
*/
- irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
+ if (!(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) ||
+ offset[0] || offset[1]) {
+ ret = vmd_alloc_irqs(vmd);
+ if (ret)
+ return ret;
+
+ vmd_set_msi_remapping(vmd, true);
+
+ ret = vmd_create_irq_domain(vmd);
+ if (ret)
+ return ret;
+
+ /*
+ * Override the IRQ domain bus token so the domain can be
+ * distinguished from a regular PCI/MSI domain.
+ */
+ irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
+ } else {
+ vmd_set_msi_remapping(vmd, false);
+ }
pci_add_resource(&resources, &vmd->resources[0]);
pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
@@ -753,10 +795,6 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (features & VMD_FEAT_OFFSET_FIRST_VECTOR)
vmd->first_vec = 1;
- err = vmd_alloc_irqs(vmd);
- if (err)
- return err;
-
spin_lock_init(&vmd->cfg_lock);
pci_set_drvdata(dev, vmd);
err = vmd_enable_domain(vmd, features);
@@ -825,7 +863,8 @@ static const struct pci_device_id vmd_ids[] = {
.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP,},
{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_VMD_28C0),
.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW |
- VMD_FEAT_HAS_BUS_RESTRICTIONS,},
+ VMD_FEAT_HAS_BUS_RESTRICTIONS |
+ VMD_FEAT_CAN_BYPASS_MSI_REMAP,},
{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x467f),
.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
VMD_FEAT_HAS_BUS_RESTRICTIONS |