[PATCH v9 0/7] VMD add second root bus support

[PATCH v9 0/7] VMD add second root bus support

[Szymon Durawa]

This series adds support for a second VMD root bus.

Today the VMD driver can enumerate and manage devices only behind the
first VMD root bus. Starting with Intel Arrow Lake, VMD may expose a
second root bus (BUS1), and devices behind that bus are not discovered
by the current driver.

The hardware model for Intel Arrow Lake VMD is slightly different
from earlier VMD generations:

- CFGBAR, MEMBAR1, and MEMBAR2 are shared by both VMD root buses.
- Root ports on BUS1 have PCI_PRIMARY_BUS hardwired to 0x80.
- Interrupt handling remains based on the existing VMD MSI/MSI-X and
  irq_domain model; this series does not introduce a separate interrupt
  domain for BUS1.

To support that layout, the series first refactors the current code so
resource setup, bus creation, and enumeration are split into helpers.
It then partitions the shared CFGBAR/MEMBAR apertures between BUS0 and
BUS1 and creates a second root bus in its own emulated PCI domain.
Reads of PCI_PRIMARY_BUS from BUS1 root port bridges are emulated to
return the actual root bus number, so PCI core bridge scanning does not
detect a mismatch and lose BUS1 subordinate device discovery. This
replaces the separate workaround patch used in v8.

Patch overview:

- Patches 1-4 extract helper functions for bus enumeration, CFGBAR and
  MEMBAR configuration, and root-bus creation.
- Patch 5 replaces hardcoded resource indices and constants with enums
  and defines.
- Patch 6 converts single-bus state (bus, busn_start, sysdata) into
  per-root-bus arrays.
- Patch 7 adds BUS1 resource partitioning, a separate PCI domain for
  BUS1, PCI_PRIMARY_BUS read emulation for BUS1 root ports, and
  second-root-bus support.

Tested on an Arrow Lake platform with NVMe devices present behind both
VMD root buses. With the series applied, devices behind BUS0 and BUS1
are enumerated and become visible to the kernel.

Changes from v1:
- splitting series into more commits, requested by Bjorn
- adding helper functions, suggested by Bjorn
- minor typos and unclear wording updated, suggested by Bjorn

Changes from v2:
- wording update in commit logs, suggested by Bjorn

Changes from v3:
- using GENMASK() instead of manual bits shifting, suggested by Bjorn
- converting decimal number to hex representation, suggested by Bjorn
- wording update in commit logs, suggested by Bjorn

Changes from v4:
- Update Dan's email address
- Resending the whole series to the correct mailing list

Changes from v5:
- Fixed correctness issues in BUS/resource layout in patches 7 and 8
- Fixed lifetime and use-after-free issues in patches 3 and 7
- Fixed resource tree integrity issues in patch 7
- Fixed error-path leaks across patches 3, 4, and 5
- Fixed allocation failure handling in patch 3
- Note on Sashiko feedback: Pre-existing warnings (unrelated to
  this feature series) were left untouched.

Changes from v6:
- Refactoring the series to align with recent changes in link below:
 https://patchwork.kernel.org/project/linux-pci/patch/20260629165025.268836-1-nirmal.patel@linux.intel.com/
- Fixed double free of the IRQ domain and emulated domain number
- Fixed a race with concurrent readers when modifying sibling pointers
- Fixed the MEMBAR2 split equations in
  vmd_configure_membar1_membar2()
- Fixed hardcoded resource indices in vmd_configure_membar()

Changes from v7:
- wording update in commit logs in patch 8, suggested by Bjorn

Changes from v8:
- Dropped patch 8 ("PCI: vmd: Workaround for hardwired BUS1 bus
  number") along with the issues Sashiko reported against it. The
  hardwired BUS1 primary bus number is now handled in patch 7 by
  emulating PCI_PRIMARY_BUS reads for BUS1 root port bridges in
  vmd_pci_read(), and BUS1 is assigned its own emulated PCI domain.
- Patch 6: sysdata is converted to a per-root-bus array as well.
- Patch 7: Fixed a data race reported by Sashiko where the MEMBAR
  .sibling pointers were assigned manually while the resource tree
  could be walked concurrently. BUS0/BUS1 MEMBAR resources are now
  inserted and removed with request_resource()/release_resource().
- Patch 7: Fixed an issue reported by Sashiko where resizing the CFGBAR
  start address for BUS1 caused vmd_domain_reset() to skip the root
  buses. The reset now starts from busn_start[VMD_BUS_0] and covers
  the whole CFGBAR aperture when BUS1 is present.
- Patch 7: BUS1 setup failures (domain allocation or bus creation) now
  release BUS1 resources and fall back to BUS0 only.

Suggested-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Reviewed-by: Asutosh Pathak <asutosh.pathak@linux.intel.com>
Signed-off-by: Szymon Durawa <szymon.durawa@linux.intel.com>

Szymon Durawa (7):
  PCI: vmd: Add vmd_bus_enumeration() helper function
  PCI: vmd: Add vmd_configure_cfgbar() helper function
  PCI: vmd: Add vmd_configure_membar() and
    vmd_configure_membar1_membar2()
  PCI: vmd: Add vmd_create_bus()
  PCI: vmd: Replace hardcoded values with enum and defines
  PCI: vmd: Convert bus, busn_start and sysdata to an array
  PCI: vmd: Add support for second rootbus under VMD

 drivers/pci/controller/vmd.c | 727 ++++++++++++++++++++++++++++-------
 1 file changed, 592 insertions(+), 135 deletions(-)

-- 
2.43.0

[PATCH v9 1/7] PCI: vmd: Add vmd_bus_enumeration() helper function

[Szymon Durawa]

Move the vmd bus enumeration code to a new helper vmd_bus_enumeration().
No functional changes.

Suggested-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Reviewed-by: Asutosh Pathak <asutosh.pathak@linux.intel.com>
Signed-off-by: Szymon Durawa <szymon.durawa@linux.intel.com>
---
 drivers/pci/controller/vmd.c | 89 ++++++++++++++++++++----------------
 1 file changed, 49 insertions(+), 40 deletions(-)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 241023ecf677..57d5e917dc45 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -905,6 +905,54 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata)
 	return 0;
 }
 
+static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
+{
+	struct pci_bus *child;
+	struct pci_dev *dev;
+	int ret;
+
+	vmd_acpi_begin();
+
+	pci_scan_child_bus(bus);
+	vmd_domain_reset(vmd_from_bus(bus));
+
+	/*
+	 * When Intel VMD is enabled, the OS does not discover the Root Ports
+	 * owned by Intel VMD within the MMCFG space. pci_reset_bus() applies
+	 * a reset to the parent of the PCI device supplied as argument. This
+	 * is why we pass a child device, so the reset can be triggered at
+	 * the Intel bridge level and propagated to all the children in the
+	 * hierarchy.
+	 */
+	list_for_each_entry(child, &bus->children, node) {
+		if (!list_empty(&child->devices)) {
+			dev = list_first_entry(&child->devices, struct pci_dev,
+					       bus_list);
+			ret = pci_reset_bus(dev);
+			if (ret)
+				pci_warn(dev, "can't reset device: %d\n", ret);
+
+			break;
+		}
+	}
+
+	pci_assign_unassigned_bus_resources(bus);
+
+	pci_walk_bus(bus, vmd_pm_enable_quirk, &features);
+
+	/*
+	 * VMD root buses are virtual and don't return true on pci_is_pcie()
+	 * and will fail pcie_bus_configure_settings() early. It can instead be
+	 * run on each of the real root ports.
+	 */
+	list_for_each_entry(child, &bus->children, node)
+		pcie_bus_configure_settings(child);
+
+	pci_bus_add_devices(bus);
+
+	vmd_acpi_end();
+}
+
 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 {
 	struct pci_sysdata *sd = &vmd->sysdata;
@@ -915,8 +963,6 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	resource_size_t offset[2] = {0};
 	resource_size_t membar2_offset = 0x2000;
 	resource_size_t busn_end;
-	struct pci_bus *child;
-	struct pci_dev *dev;
 	bool vmd_in_guest;
 	int ret;
 
@@ -1047,45 +1093,8 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
 			       "domain"), "Can't create symlink to domain\n");
 
-	vmd_acpi_begin();
-
-	pci_scan_child_bus(vmd->bus);
-	vmd_domain_reset(vmd);
+	vmd_bus_enumeration(vmd->bus, features);
 
-	/* When Intel VMD is enabled, the OS does not discover the Root Ports
-	 * owned by Intel VMD within the MMCFG space. pci_reset_bus() applies
-	 * a reset to the parent of the PCI device supplied as argument. This
-	 * is why we pass a child device, so the reset can be triggered at
-	 * the Intel bridge level and propagated to all the children in the
-	 * hierarchy.
-	 */
-	list_for_each_entry(child, &vmd->bus->children, node) {
-		if (!list_empty(&child->devices)) {
-			dev = list_first_entry(&child->devices,
-					       struct pci_dev, bus_list);
-			ret = pci_reset_bus(dev);
-			if (ret)
-				pci_warn(dev, "can't reset device: %d\n", ret);
-
-			break;
-		}
-	}
-
-	pci_assign_unassigned_bus_resources(vmd->bus);
-
-	pci_walk_bus(vmd->bus, vmd_pm_enable_quirk, &features);
-
-	/*
-	 * VMD root buses are virtual and don't return true on pci_is_pcie()
-	 * and will fail pcie_bus_configure_settings() early. It can instead be
-	 * run on each of the real root ports.
-	 */
-	list_for_each_entry(child, &vmd->bus->children, node)
-		pcie_bus_configure_settings(child);
-
-	pci_bus_add_devices(vmd->bus);
-
-	vmd_acpi_end();
 	return 0;
 }
 
-- 
2.43.0

[PATCH v9 2/7] PCI: vmd: Add vmd_configure_cfgbar() helper function

[Szymon Durawa]

Move the VMD CFGBAR initialization code to a new helper
vmd_configure_cfgbar(). No functional changes.

Suggested-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Reviewed-by: Asutosh Pathak <asutosh.pathak@linux.intel.com>
Signed-off-by: Szymon Durawa <szymon.durawa@linux.intel.com>
---
 drivers/pci/controller/vmd.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 57d5e917dc45..2a8c10604c82 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -905,6 +905,22 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata)
 	return 0;
 }
 
+static void vmd_configure_cfgbar(struct vmd_dev *vmd)
+{
+	struct resource *res = &vmd->dev->resource[VMD_CFGBAR];
+	resource_size_t busn_end;
+
+	/* Do not let resource[0] end go out of bound.*/
+	busn_end = vmd->busn_start + (resource_size(res) >> 20) - 1;
+	busn_end = min_t(resource_size_t, busn_end, 0xff);
+	vmd->resources[0] = (struct resource) {
+		.name  = "VMD CFGBAR",
+		.start = vmd->busn_start,
+		.end   = busn_end,
+		.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
+	};
+}
+
 static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 {
 	struct pci_bus *child;
@@ -962,7 +978,6 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	LIST_HEAD(resources);
 	resource_size_t offset[2] = {0};
 	resource_size_t membar2_offset = 0x2000;
-	resource_size_t busn_end;
 	bool vmd_in_guest;
 	int ret;
 
@@ -971,16 +986,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	if (ret)
 		return ret;
 
-	/* Do not let resource[0] end go out of bounds */
-	res = &vmd->dev->resource[VMD_CFGBAR];
-	busn_end = vmd->busn_start + (resource_size(res) >> 20) - 1;
-	busn_end = min_t(resource_size_t, busn_end, 0xff);
-	vmd->resources[0] = (struct resource) {
-		.name  = "VMD CFGBAR",
-		.start = vmd->busn_start,
-		.end   = busn_end,
-		.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
-	};
+	vmd_configure_cfgbar(vmd);
 
 	/*
 	 * If the window is below 4GB, clear IORESOURCE_MEM_64 so we can
-- 
2.43.0

[PATCH v9 3/7] PCI: vmd: Add vmd_configure_membar() and vmd_configure_membar1_membar2()

[Szymon Durawa]

Move the MEMBAR1 and MEMBAR2 registry initialization code to new helpers
vmd_configure_membar() and vmd_configure_membar1_membar2().
The refactor preserves MEMBAR address/offset/flags programming, but
resource name construction is now generated in the helper ("VMD MEMBAR%d")
instead of using two separate string literals.

Suggested-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Reviewed-by: Asutosh Pathak <asutosh.pathak@linux.intel.com>
Signed-off-by: Szymon Durawa <szymon.durawa@linux.intel.com>
---
 drivers/pci/controller/vmd.c | 98 +++++++++++++++++++++++++-----------
 1 file changed, 68 insertions(+), 30 deletions(-)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 2a8c10604c82..ed6d03656885 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -921,6 +921,69 @@ static void vmd_configure_cfgbar(struct vmd_dev *vmd)
 	};
 }
 
+/*
+ * vmd_configure_membar - Configure VMD MemBAR register, which points
+ * to MMIO address assigned by the OS or BIOS.
+ * @vmd: the VMD device
+ * @resource_number: resource buffer number to be filled in
+ * @membar_number: number of the MemBAR
+ * @start_offset: 4K aligned offset applied to start of VMD’s MEMBAR MMIO space
+ * @end_offset: 4K aligned offset applied to end of VMD’s MEMBAR MMIO space
+ *
+ * Function fills resource buffer inside the VMD structure.
+ *
+ * Return: 0 on success, -ENOMEM on allocation failure.
+ */
+static int vmd_configure_membar(struct vmd_dev *vmd, u8 resource_number,
+				u8 membar_number, resource_size_t start_offset,
+				resource_size_t end_offset)
+{
+	char *name;
+	u32 upper_bits;
+	unsigned long flags;
+
+	struct resource *res = &vmd->dev->resource[membar_number];
+
+	upper_bits = upper_32_bits(res->end);
+	flags = res->flags & ~IORESOURCE_SIZEALIGN;
+	if (!upper_bits)
+		flags &= ~IORESOURCE_MEM_64;
+
+	name = devm_kasprintf(&vmd->dev->dev, GFP_KERNEL, "VMD MEMBAR%d",
+			      resource_number);
+	if (!name)
+		return -ENOMEM;
+
+	vmd->resources[resource_number] = (struct resource){
+		.name = name,
+		.start = res->start + start_offset,
+		.end = res->end - end_offset,
+		.flags = flags,
+		.parent = res,
+	};
+
+	return 0;
+}
+
+static int vmd_configure_membar1_membar2(struct vmd_dev *vmd,
+					 resource_size_t mbar2_ofs)
+{
+	int ret;
+
+	ret = vmd_configure_membar(vmd, 1, VMD_MEMBAR1, 0, 0);
+	if (ret)
+		return ret;
+
+	ret = vmd_configure_membar(vmd, 2, VMD_MEMBAR2, mbar2_ofs, 0);
+	if (ret) {
+		devm_kfree(&vmd->dev->dev, (void *)vmd->resources[1].name);
+		memset(&vmd->resources[1], 0, sizeof(vmd->resources[1]));
+		return ret;
+	}
+
+	return 0;
+}
+
 static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 {
 	struct pci_bus *child;
@@ -972,9 +1035,6 @@ static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 {
 	struct pci_sysdata *sd = &vmd->sysdata;
-	struct resource *res;
-	u32 upper_bits;
-	unsigned long flags;
 	LIST_HEAD(resources);
 	resource_size_t offset[2] = {0};
 	resource_size_t membar2_offset = 0x2000;
@@ -1000,36 +1060,14 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	 *
 	 * The only way we could use a 64-bit non-prefetchable MEMBAR is
 	 * if its address is <4GB so that we can convert it to a 32-bit
-	 * resource.  To be visible to the host OS, all VMD endpoints must
+	 * resource. To be visible to the host OS, all VMD endpoints must
 	 * be initially configured by platform BIOS, which includes setting
-	 * up these resources.  We can assume the device is configured
+	 * up these resources. We can assume the device is configured
 	 * according to the platform needs.
 	 */
-	res = &vmd->dev->resource[VMD_MEMBAR1];
-	upper_bits = upper_32_bits(res->end);
-	flags = res->flags & ~IORESOURCE_SIZEALIGN;
-	if (!upper_bits)
-		flags &= ~IORESOURCE_MEM_64;
-	vmd->resources[1] = (struct resource) {
-		.name  = "VMD MEMBAR1",
-		.start = res->start,
-		.end   = res->end,
-		.flags = flags,
-		.parent = res,
-	};
-
-	res = &vmd->dev->resource[VMD_MEMBAR2];
-	upper_bits = upper_32_bits(res->end);
-	flags = res->flags & ~IORESOURCE_SIZEALIGN;
-	if (!upper_bits)
-		flags &= ~IORESOURCE_MEM_64;
-	vmd->resources[2] = (struct resource) {
-		.name  = "VMD MEMBAR2",
-		.start = res->start + membar2_offset,
-		.end   = res->end,
-		.flags = flags,
-		.parent = res,
-	};
+	ret = vmd_configure_membar1_membar2(vmd, membar2_offset);
+	if (ret)
+		return ret;
 
 	/* Non-zero offset means guest/direct assign view. */
 	vmd_in_guest = offset[0] || offset[1];
-- 
2.43.0

[PATCH v9 4/7] PCI: vmd: Add vmd_create_bus()

[Szymon Durawa]

Move the VMD bus initialization code to a new helper vmd_create_bus().
No functional changes.

Suggested-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Reviewed-by: Asutosh Pathak <asutosh.pathak@linux.intel.com>
Signed-off-by: Szymon Durawa <szymon.durawa@linux.intel.com>
---
 drivers/pci/controller/vmd.c | 63 ++++++++++++++++++++++--------------
 1 file changed, 38 insertions(+), 25 deletions(-)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index ed6d03656885..8b59b369f126 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -984,6 +984,40 @@ static int vmd_configure_membar1_membar2(struct vmd_dev *vmd,
 	return 0;
 }
 
+static int vmd_create_bus(struct vmd_dev *vmd, struct pci_sysdata *sd,
+			  resource_size_t *offset, bool vmd_in_guest)
+{
+	LIST_HEAD(resources);
+
+	pci_add_resource(&resources, &vmd->resources[0]);
+	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
+	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
+
+	vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
+				       &vmd_ops, sd, &resources);
+	if (!vmd->bus) {
+		pci_free_resource_list(&resources);
+		return -ENODEV;
+	}
+
+	/*
+	 * Don't copy _OSC control flags from root bridge if running in a VM, as
+	 * they don't reflect the physical root bridge capabilities.
+	 */
+	if (!vmd_in_guest)
+		vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
+					   to_pci_host_bridge(vmd->bus->bridge));
+
+	vmd_attach_resources(vmd);
+	if (vmd->irq_domain)
+		dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
+	else
+		dev_set_msi_domain(&vmd->bus->dev,
+				   dev_get_msi_domain(&vmd->dev->dev));
+
+	return 0;
+}
+
 static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 {
 	struct pci_bus *child;
@@ -1035,7 +1069,6 @@ static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 {
 	struct pci_sysdata *sd = &vmd->sysdata;
-	LIST_HEAD(resources);
 	resource_size_t offset[2] = {0};
 	resource_size_t membar2_offset = 0x2000;
 	bool vmd_in_guest;
@@ -1092,10 +1125,6 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 		vmd_set_msi_remapping(vmd, false);
 	}
 
-	pci_add_resource(&resources, &vmd->resources[0]);
-	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
-	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
-
 	sd->vmd_dev = vmd->dev;
 
 	/*
@@ -1110,30 +1139,14 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 
 	sd->node = pcibus_to_node(vmd->dev->bus);
 
-	vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
-				       &vmd_ops, sd, &resources);
-	if (!vmd->bus) {
+	ret = vmd_create_bus(vmd, sd, offset, vmd_in_guest);
+	if (ret) {
+		pci_err(vmd->dev, "Can't create bus: %d\n", ret);
 		pci_bus_release_emul_domain_nr(sd->domain);
-		pci_free_resource_list(&resources);
 		vmd_remove_irq_domain(vmd);
-		return -ENODEV;
+		return ret;
 	}
 
-	/*
-	 * Don't copy _OSC control flags from root bridge if running in a VM, as
-	 * they don't reflect the physical root bridge capabilities.
-	 */
-	if (!vmd_in_guest)
-		vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
-					 to_pci_host_bridge(vmd->bus->bridge));
-
-	vmd_attach_resources(vmd);
-	if (vmd->irq_domain)
-		dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
-	else
-		dev_set_msi_domain(&vmd->bus->dev,
-				   dev_get_msi_domain(&vmd->dev->dev));
-
 	WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
 			       "domain"), "Can't create symlink to domain\n");
 
-- 
2.43.0

[PATCH v9 5/7] PCI: vmd: Replace hardcoded values with enum and defines

[Szymon Durawa]

Add enum vmd_resource type to replace hardcoded values. Add defines for
vmd bus start number based on VMD restriction value. No functional
changes.

Suggested-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Reviewed-by: Asutosh Pathak <asutosh.pathak@linux.intel.com>
Signed-off-by: Szymon Durawa <szymon.durawa@linux.intel.com>
---
 drivers/pci/controller/vmd.c | 52 +++++++++++++++++++++++-------------
 1 file changed, 34 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 8b59b369f126..f85dd2d7c4af 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -26,6 +26,11 @@
 #define VMD_MEMBAR1	2
 #define VMD_MEMBAR2	4
 
+/* VMD restriction value determines secondary start bus number */
+#define VMD_RESTRICT_0_BUS_START 0x0
+#define VMD_RESTRICT_1_BUS_START 0x80
+#define VMD_RESTRICT_2_BUS_START 0xE0
+
 #define PCI_REG_VMCAP		0x40
 #define BUS_RESTRICT_CAP(vmcap)	(vmcap & 0x1)
 #define PCI_REG_VMCONFIG	0x44
@@ -43,6 +48,13 @@
 #define BASE_ID_REG_28C1		0x2840
 #define MEMBAR2_OFFSET_28C1		0x30d0
 
+enum vmd_resource {
+	VMD_RES_CFGBAR = 0, /* VMD Bus0 Config BAR */
+	VMD_RES_MBAR_1, /* VMD Bus0 Resource MemBAR 1 */
+	VMD_RES_MBAR_2, /* VMD Bus0 Resource MemBAR 2 */
+	VMD_RES_COUNT
+};
+
 enum vmd_features {
 	/*
 	 * Device may contain registers which hint the physical location of the
@@ -150,7 +162,7 @@ struct vmd_dev {
 	struct vmd_irq_list	*irqs;
 
 	struct pci_sysdata	sysdata;
-	struct resource		resources[3];
+	struct resource		resources[VMD_RES_COUNT];
 	struct irq_domain	*irq_domain;
 	struct pci_bus		*bus;
 	u8			busn_start;
@@ -554,7 +566,7 @@ static resource_size_t vmd_cfgbar_ecam_space(struct vmd_dev *vmd)
 	unsigned int ecam_start;
 
 	cfgbar_buses = resource_size(&vmd->dev->resource[VMD_CFGBAR]) >> 20;
-	ecam_start = vmd_bus_to_ecam(vmd, vmd->resources[0].start);
+	ecam_start = vmd_bus_to_ecam(vmd, vmd->resources[VMD_RES_CFGBAR].start);
 	if (ecam_start >= cfgbar_buses)
 		return 0;
 
@@ -562,14 +574,15 @@ static resource_size_t vmd_cfgbar_ecam_space(struct vmd_dev *vmd)
 }
 static void vmd_domain_reset(struct vmd_dev *vmd)
 {
-	u16 bus, max_buses = resource_size(&vmd->resources[0]);
+	u16 bus, max_buses = resource_size(&vmd->resources[VMD_RES_CFGBAR]);
 	u8 dev, functions, fn, hdr_type;
 	unsigned int ecam_bus;
 	char __iomem *base;
 
 	max_buses = min_t(u16, max_buses, vmd_cfgbar_ecam_space(vmd));
 	for (bus = 0; bus < max_buses; bus++) {
-		ecam_bus = vmd_bus_to_ecam(vmd, vmd->resources[0].start + bus);
+		ecam_bus = vmd_bus_to_ecam(vmd, vmd->resources[VMD_RES_CFGBAR].start +
+					   bus);
 		for (dev = 0; dev < 32; dev++) {
 			base = vmd->cfgbar + PCIE_ECAM_OFFSET(ecam_bus,
 						PCI_DEVFN(dev, 0), 0);
@@ -613,8 +626,8 @@ static void vmd_domain_reset(struct vmd_dev *vmd)
 
 static void vmd_attach_resources(struct vmd_dev *vmd)
 {
-	vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
-	vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
+	vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[VMD_RES_MBAR_1];
+	vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[VMD_RES_MBAR_2];
 }
 
 static void vmd_detach_resources(struct vmd_dev *vmd)
@@ -690,14 +703,14 @@ static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 
 		switch (BUS_RESTRICT_CFG(reg)) {
 		case 0:
-			vmd->busn_start = 0;
+			vmd->busn_start = VMD_RESTRICT_0_BUS_START;
 			break;
 		case 1:
-			vmd->busn_start = 128;
+			vmd->busn_start = VMD_RESTRICT_1_BUS_START;
 			break;
 		case 3:
 		case 2:
-			vmd->busn_start = 224;
+			vmd->busn_start = VMD_RESTRICT_2_BUS_START;
 			break;
 		default:
 			pci_err(dev, "Unknown Bus Offset Setting (%d)\n",
@@ -910,10 +923,10 @@ static void vmd_configure_cfgbar(struct vmd_dev *vmd)
 	struct resource *res = &vmd->dev->resource[VMD_CFGBAR];
 	resource_size_t busn_end;
 
-	/* Do not let resource[0] end go out of bound.*/
+	/* Do not let resource[VMD_RES_CFGBAR] end go out of bound.*/
 	busn_end = vmd->busn_start + (resource_size(res) >> 20) - 1;
 	busn_end = min_t(resource_size_t, busn_end, 0xff);
-	vmd->resources[0] = (struct resource) {
+	vmd->resources[VMD_RES_CFGBAR] = (struct resource) {
 		.name  = "VMD CFGBAR",
 		.start = vmd->busn_start,
 		.end   = busn_end,
@@ -970,14 +983,15 @@ static int vmd_configure_membar1_membar2(struct vmd_dev *vmd,
 {
 	int ret;
 
-	ret = vmd_configure_membar(vmd, 1, VMD_MEMBAR1, 0, 0);
+	ret = vmd_configure_membar(vmd, VMD_RES_MBAR_1, VMD_MEMBAR1, 0, 0);
 	if (ret)
 		return ret;
 
-	ret = vmd_configure_membar(vmd, 2, VMD_MEMBAR2, mbar2_ofs, 0);
+	ret = vmd_configure_membar(vmd, VMD_RES_MBAR_2, VMD_MEMBAR2, mbar2_ofs, 0);
 	if (ret) {
-		devm_kfree(&vmd->dev->dev, (void *)vmd->resources[1].name);
-		memset(&vmd->resources[1], 0, sizeof(vmd->resources[1]));
+		devm_kfree(&vmd->dev->dev, (void *)vmd->resources[VMD_RES_MBAR_1].name);
+		memset(&vmd->resources[VMD_RES_MBAR_1], 0,
+		       sizeof(vmd->resources[VMD_RES_MBAR_1]));
 		return ret;
 	}
 
@@ -989,9 +1003,11 @@ static int vmd_create_bus(struct vmd_dev *vmd, struct pci_sysdata *sd,
 {
 	LIST_HEAD(resources);
 
-	pci_add_resource(&resources, &vmd->resources[0]);
-	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
-	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
+	pci_add_resource(&resources, &vmd->resources[VMD_RES_CFGBAR]);
+	pci_add_resource_offset(&resources, &vmd->resources[VMD_RES_MBAR_1],
+				offset[0]);
+	pci_add_resource_offset(&resources, &vmd->resources[VMD_RES_MBAR_2],
+				offset[1]);
 
 	vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
 				       &vmd_ops, sd, &resources);
-- 
2.43.0

[PATCH v9 6/7] PCI: vmd: Convert bus, busn_start and sysdata to an array

[Szymon Durawa]

Convert bus, busn_start and sysdata in vmd_dev struct from scalar
to an array to support multiple VMD buses in the future.
No functional changes.

Suggested-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Reviewed-by: Asutosh Pathak <asutosh.pathak@linux.intel.com>
Signed-off-by: Szymon Durawa <szymon.durawa@linux.intel.com>
---
 drivers/pci/controller/vmd.c | 64 +++++++++++++++++++++---------------
 1 file changed, 37 insertions(+), 27 deletions(-)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index f85dd2d7c4af..1db974ed760f 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -55,6 +55,11 @@ enum vmd_resource {
 	VMD_RES_COUNT
 };
 
+enum vmd_rootbus {
+	VMD_BUS_0 = 0,
+	VMD_BUS_COUNT
+};
+
 enum vmd_features {
 	/*
 	 * Device may contain registers which hint the physical location of the
@@ -161,11 +166,11 @@ struct vmd_dev {
 	int msix_count;
 	struct vmd_irq_list	*irqs;
 
-	struct pci_sysdata	sysdata;
+	struct pci_sysdata	sysdata[VMD_BUS_COUNT];
 	struct resource		resources[VMD_RES_COUNT];
 	struct irq_domain	*irq_domain;
-	struct pci_bus		*bus;
-	u8			busn_start;
+	struct pci_bus		*bus[VMD_BUS_COUNT];
+	u8			busn_start[VMD_BUS_COUNT];
 	u8			first_vec;
 	char			*name;
 	int			instance;
@@ -174,7 +179,10 @@ struct vmd_dev {
 
 static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
 {
-	return container_of(bus->sysdata, struct vmd_dev, sysdata);
+	struct pci_sysdata *sd = bus->sysdata;
+
+	return pci_get_drvdata(sd->vmd_dev);
+
 }
 
 static inline unsigned int index_from_irqs(struct vmd_dev *vmd,
@@ -376,7 +384,7 @@ static int vmd_create_irq_domain(struct vmd_dev *vmd)
 	};
 
 	info.fwnode = irq_domain_alloc_named_id_fwnode("VMD-MSI",
-						       vmd->sysdata.domain);
+						       vmd->sysdata[VMD_BUS_0].domain);
 	if (!info.fwnode)
 		return -ENODEV;
 
@@ -425,7 +433,7 @@ static unsigned int vmd_bus_to_ecam(struct vmd_dev *vmd, unsigned int busnr)
 	if (!!(vmd->features & VMD_FEAT_USE_BIOS_INFO))
 		return busnr;
 
-	return busnr - vmd->busn_start;
+	return busnr - vmd->busn_start[VMD_BUS_0];
 }
 
 static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
@@ -703,14 +711,14 @@ static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 
 		switch (BUS_RESTRICT_CFG(reg)) {
 		case 0:
-			vmd->busn_start = VMD_RESTRICT_0_BUS_START;
+			vmd->busn_start[VMD_BUS_0] = VMD_RESTRICT_0_BUS_START;
 			break;
 		case 1:
-			vmd->busn_start = VMD_RESTRICT_1_BUS_START;
+			vmd->busn_start[VMD_BUS_0] = VMD_RESTRICT_1_BUS_START;
 			break;
 		case 3:
 		case 2:
-			vmd->busn_start = VMD_RESTRICT_2_BUS_START;
+			vmd->busn_start[VMD_BUS_0] = VMD_RESTRICT_2_BUS_START;
 			break;
 		default:
 			pci_err(dev, "Unknown Bus Offset Setting (%d)\n",
@@ -747,7 +755,7 @@ static int vmd_get_bus_info_from_bar4(struct vmd_dev *vmd,
 	bar4_2840 = readq(bar4 + BASE_ID_REG_28C1);
 	base_id = bar4_2840 & 0xFFFFFF;
 	base_bus = base_id >> 8;
-	vmd->busn_start = base_bus;
+	vmd->busn_start[VMD_BUS_0] = base_bus;
 
 	/* Calculate offsets like vmd_get_phys_offsets() does */
 	if (phys1)
@@ -924,11 +932,11 @@ static void vmd_configure_cfgbar(struct vmd_dev *vmd)
 	resource_size_t busn_end;
 
 	/* Do not let resource[VMD_RES_CFGBAR] end go out of bound.*/
-	busn_end = vmd->busn_start + (resource_size(res) >> 20) - 1;
+	busn_end = vmd->busn_start[VMD_BUS_0] + (resource_size(res) >> 20) - 1;
 	busn_end = min_t(resource_size_t, busn_end, 0xff);
 	vmd->resources[VMD_RES_CFGBAR] = (struct resource) {
 		.name  = "VMD CFGBAR",
-		.start = vmd->busn_start,
+		.start = vmd->busn_start[VMD_BUS_0],
 		.end   = busn_end,
 		.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
 	};
@@ -1009,9 +1017,10 @@ static int vmd_create_bus(struct vmd_dev *vmd, struct pci_sysdata *sd,
 	pci_add_resource_offset(&resources, &vmd->resources[VMD_RES_MBAR_2],
 				offset[1]);
 
-	vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
-				       &vmd_ops, sd, &resources);
-	if (!vmd->bus) {
+	vmd->bus[VMD_BUS_0] = pci_create_root_bus(&vmd->dev->dev,
+						  vmd->busn_start[VMD_BUS_0],
+						  &vmd_ops, sd, &resources);
+	if (!vmd->bus[VMD_BUS_0]) {
 		pci_free_resource_list(&resources);
 		return -ENODEV;
 	}
@@ -1022,13 +1031,13 @@ static int vmd_create_bus(struct vmd_dev *vmd, struct pci_sysdata *sd,
 	 */
 	if (!vmd_in_guest)
 		vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
-					   to_pci_host_bridge(vmd->bus->bridge));
+					   to_pci_host_bridge(vmd->bus[VMD_BUS_0]->bridge));
 
 	vmd_attach_resources(vmd);
 	if (vmd->irq_domain)
-		dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
+		dev_set_msi_domain(&vmd->bus[VMD_BUS_0]->dev, vmd->irq_domain);
 	else
-		dev_set_msi_domain(&vmd->bus->dev,
+		dev_set_msi_domain(&vmd->bus[VMD_BUS_0]->dev,
 				   dev_get_msi_domain(&vmd->dev->dev));
 
 	return 0;
@@ -1084,7 +1093,7 @@ static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 
 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 {
-	struct pci_sysdata *sd = &vmd->sysdata;
+	struct pci_sysdata *sd = &vmd->sysdata[VMD_BUS_0];
 	resource_size_t offset[2] = {0};
 	resource_size_t membar2_offset = 0x2000;
 	bool vmd_in_guest;
@@ -1163,10 +1172,11 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 		return ret;
 	}
 
-	WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
-			       "domain"), "Can't create symlink to domain\n");
+	WARN(sysfs_create_link(&vmd->dev->dev.kobj,
+			       &vmd->bus[VMD_BUS_0]->dev.kobj, "domain"),
+	     "Can't create symlink to domain\n");
 
-	vmd_bus_enumeration(vmd->bus, features);
+	vmd_bus_enumeration(vmd->bus[VMD_BUS_0], features);
 
 	return 0;
 }
@@ -1203,7 +1213,7 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		return -ENOMEM;
 
 	vmd->dev = dev;
-	vmd->sysdata.domain = PCI_DOMAIN_NR_NOT_SET;
+	vmd->sysdata[VMD_BUS_0].domain = PCI_DOMAIN_NR_NOT_SET;
 	vmd->features = features;
 	vmd->instance = ida_alloc(&vmd_instance_ida, GFP_KERNEL);
 	if (vmd->instance < 0)
@@ -1243,7 +1253,7 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		goto out_release_instance;
 
 	dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
-		 vmd->sysdata.domain);
+		 vmd->sysdata[VMD_BUS_0].domain);
 	return 0;
 
  out_release_instance:
@@ -1263,14 +1273,14 @@ static void vmd_remove(struct pci_dev *dev)
 {
 	struct vmd_dev *vmd = pci_get_drvdata(dev);
 
-	pci_stop_root_bus(vmd->bus);
+	pci_stop_root_bus(vmd->bus[VMD_BUS_0]);
 	sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
-	pci_remove_root_bus(vmd->bus);
+	pci_remove_root_bus(vmd->bus[VMD_BUS_0]);
 	vmd_cleanup_srcu(vmd);
 	vmd_detach_resources(vmd);
 	vmd_remove_irq_domain(vmd);
 	ida_free(&vmd_instance_ida, vmd->instance);
-	pci_bus_release_emul_domain_nr(vmd->sysdata.domain);
+	pci_bus_release_emul_domain_nr(vmd->sysdata[VMD_BUS_0].domain);
 }
 
 static void vmd_shutdown(struct pci_dev *dev)
-- 
2.43.0

[PATCH v9 7/7] PCI: vmd: Add support for second rootbus under VMD

[Szymon Durawa]

Starting from Intel Arrow Lake, VMD exposes a second root bus (BUS1),
reported via Bus Restriction type 3. BUS0 starts at bus 0xE0 and BUS1
at 0xE1; the subordinate bus ranges for each are provided by firmware
in VMD_BUSRANGE0/1. All three VMD BARs are shared between BUS0 and
BUS1: CFGBAR is split by those bus ranges, and MEMBAR1/MEMBAR2 are
split at the offsets in VMD_MEMBAR1_OFFSET and VMD_MEMBAR2_OFFSET1/2.

Add VMD_FEAT_HAS_BUS1_ROOTBUS for client VMDs and, when restriction
type 3 is reported, create and enumerate a second root bus in its own
emulated PCI domain so that its bus numbers and resources stay
separate from BUS0. A "domain1" sysfs link is added alongside the
existing "domain" link. If the BUS1 domain or root bus cannot be
created, the driver warns and continues with BUS0 only. Restriction
type 3 on a VMD without the feature is now rejected instead of being
treated as type 2.

The root ports on BUS1 have PCI_PRIMARY_BUS hardwired to 0x80. Emulate
reads of that register for Type 1 devices on the BUS1 root bus so it
reports the actual root bus number, and set bus->primary on both root
buses before scanning.

Suggested-by: Nirmal Patel <nirmal.patel@linux.intel.com>
Reviewed-by: Asutosh Pathak <asutosh.pathak@linux.intel.com>
Signed-off-by: Szymon Durawa <szymon.durawa@linux.intel.com>
---
 drivers/pci/controller/vmd.c | 467 +++++++++++++++++++++++++++++++----
 1 file changed, 416 insertions(+), 51 deletions(-)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 1db974ed760f..079fa51f6d07 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -4,6 +4,7 @@
  * Copyright (c) 2015, Intel Corporation.
  */
 
+#include <linux/bitfield.h>
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
@@ -30,6 +31,7 @@
 #define VMD_RESTRICT_0_BUS_START 0x0
 #define VMD_RESTRICT_1_BUS_START 0x80
 #define VMD_RESTRICT_2_BUS_START 0xE0
+#define VMD_RESTRICT_3_BUS_START 0xE1
 
 #define PCI_REG_VMCAP		0x40
 #define BUS_RESTRICT_CAP(vmcap)	(vmcap & 0x1)
@@ -48,15 +50,36 @@
 #define BASE_ID_REG_28C1		0x2840
 #define MEMBAR2_OFFSET_28C1		0x30d0
 
+/* Primary Bus Number for VMD devices on root bus 0 */
+#define VMD_PRIMARY_BUS0    0x00
+/* Primary Bus Number for VMD devices on root bus 1 */
+#define VMD_PRIMARY_BUS1    0x80
+
+#define VMD_BUSRANGE0       0xc8
+#define VMD_BUSRANGE1       0xcc
+#define VMD_MEMBAR1_OFFSET  0xd0
+#define VMD_MEMBAR2_OFFSET1 0xd8
+#define VMD_MEMBAR2_OFFSET2 0xdc
+#define VMD_BUS_END(busr) FIELD_GET(GENMASK(15, 8), busr)
+#define VMD_BUS_START(busr) FIELD_GET(GENMASK(7, 0), busr)
+
+/*
+ * Add VMD resources for BUS1, it will share the same MMIO space with
+ * previous VMD resources.
+ */
 enum vmd_resource {
-	VMD_RES_CFGBAR = 0, /* VMD Bus0 Config BAR */
-	VMD_RES_MBAR_1, /* VMD Bus0 Resource MemBAR 1 */
-	VMD_RES_MBAR_2, /* VMD Bus0 Resource MemBAR 2 */
+	VMD_RES_CFGBAR = 0,  /* VMD Bus0 Config BAR */
+	VMD_RES_MBAR_1,      /* VMD Bus0 Resource MemBAR 1 */
+	VMD_RES_MBAR_2,      /* VMD Bus0 Resource MemBAR 2 */
+	VMD_RES_BUS1_CFGBAR, /* VMD Bus1 Config BAR */
+	VMD_RES_BUS1_MBAR_1, /* VMD Bus1 Resource MemBAR 1 */
+	VMD_RES_BUS1_MBAR_2, /* VMD Bus1 Resource MemBAR 2 */
 	VMD_RES_COUNT
 };
 
 enum vmd_rootbus {
 	VMD_BUS_0 = 0,
+	VMD_BUS_1,
 	VMD_BUS_COUNT
 };
 
@@ -109,6 +132,12 @@ enum vmd_features {
 	 * referred to as MEMBAR2 or MSI-X BAR.
 	 */
 	VMD_FEAT_USE_BIOS_INFO		= (1 << 6),
+
+	/*
+	 * Starting from Intel Arrow Lake, VMD devices have their VMD root ports
+	 * on the additional BUS1 root bus.
+	 */
+	VMD_FEAT_HAS_BUS1_ROOTBUS	= (1 << 7)
 };
 
 #define VMD_BIOS_PM_QUIRK_LTR	0x1003	/* 3145728 ns */
@@ -116,7 +145,8 @@ enum vmd_features {
 #define VMD_FEATS_CLIENT	(VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |	\
 				 VMD_FEAT_HAS_BUS_RESTRICTIONS |	\
 				 VMD_FEAT_OFFSET_FIRST_VECTOR |		\
-				 VMD_FEAT_BIOS_PM_QUIRK)
+				 VMD_FEAT_BIOS_PM_QUIRK |		\
+				 VMD_FEAT_HAS_BUS1_ROOTBUS)
 
 static DEFINE_IDA(vmd_instance_ida);
 
@@ -175,6 +205,7 @@ struct vmd_dev {
 	char			*name;
 	int			instance;
 	unsigned long		features;
+	bool			bus1_rootbus;
 };
 
 static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
@@ -451,6 +482,36 @@ static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
 	return vmd->cfgbar + offset;
 }
 
+static bool vmd_is_bus1_root_bridge(struct vmd_dev *vmd, struct pci_bus *bus,
+				    unsigned int devfn)
+{
+	void __iomem *hdr_addr;
+	u8 hdr_type;
+
+	lockdep_assert_held(&vmd->cfg_lock);
+
+	if (!vmd->bus1_rootbus)
+		return false;
+
+	/* Limit strictly to BUS1 */
+	if (bus->sysdata != &vmd->sysdata[VMD_BUS_1])
+		return false;
+
+	if (!pci_is_root_bus(bus))
+		return false;
+
+	/*
+	 * Offset 0x18 is PCI_PRIMARY_BUS only for Type 1 bridge headers.
+	 * On Type 0 endpoints, 0x18 is BAR2. Only apply the quirk to bridges.
+	 */
+	hdr_addr = vmd_cfg_addr(vmd, bus, devfn, PCI_HEADER_TYPE, 1);
+	if (!hdr_addr)
+		return false;
+
+	hdr_type = readb(hdr_addr) & PCI_HEADER_TYPE_MASK;
+	return hdr_type == PCI_HEADER_TYPE_BRIDGE;
+}
+
 /*
  * CPU may deadlock if config space is not serialized on some versions of this
  * hardware, so all config space access is done under a spinlock.
@@ -460,6 +521,7 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
 {
 	struct vmd_dev *vmd = vmd_from_bus(bus);
 	void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
+	int ret = 0;
 
 	if (!addr)
 		return -EFAULT;
@@ -468,16 +530,34 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
 	switch (len) {
 	case 1:
 		*value = readb(addr);
-		return 0;
+		break;
 	case 2:
 		*value = readw(addr);
-		return 0;
+		break;
 	case 4:
 		*value = readl(addr);
-		return 0;
+		break;
 	default:
-		return -EINVAL;
+		ret = -EINVAL;
+		break;
 	}
+
+	/*
+	 * Quirk: Hardware PCIe root port bridges on BUS1 have
+	 * PCI_PRIMARY_BUS hardwired to 0x80 (VMD_PRIMARY_BUS1).
+	 *
+	 * Emulate the primary bus number to match the actual allocated
+	 * root bus number. This prevents the PCI core from detecting a
+	 * bus mismatch without needing synthetic bus ranges.
+	 */
+	if (!ret && reg <= PCI_PRIMARY_BUS && reg + len > PCI_PRIMARY_BUS &&
+	    vmd_is_bus1_root_bridge(vmd, bus, devfn)) {
+		u8 *buf = (u8 *)value;
+
+		buf[PCI_PRIMARY_BUS - reg] = bus->number;
+	}
+
+	return ret;
 }
 
 /*
@@ -574,12 +654,19 @@ static resource_size_t vmd_cfgbar_ecam_space(struct vmd_dev *vmd)
 	unsigned int ecam_start;
 
 	cfgbar_buses = resource_size(&vmd->dev->resource[VMD_CFGBAR]) >> 20;
-	ecam_start = vmd_bus_to_ecam(vmd, vmd->resources[VMD_RES_CFGBAR].start);
+
+	if (vmd->bus1_rootbus)
+		/* BUS1 splits the aperture, so reset scans start from BUS0. */
+		ecam_start = vmd_bus_to_ecam(vmd, vmd->busn_start[VMD_BUS_0]);
+	else
+		ecam_start = vmd_bus_to_ecam(vmd, vmd->resources[VMD_RES_CFGBAR].start);
+
 	if (ecam_start >= cfgbar_buses)
 		return 0;
 
 	return cfgbar_buses - ecam_start;
 }
+
 static void vmd_domain_reset(struct vmd_dev *vmd)
 {
 	u16 bus, max_buses = resource_size(&vmd->resources[VMD_RES_CFGBAR]);
@@ -587,10 +674,13 @@ static void vmd_domain_reset(struct vmd_dev *vmd)
 	unsigned int ecam_bus;
 	char __iomem *base;
 
+	if (vmd->bus1_rootbus)
+		max_buses = resource_size(&vmd->dev->resource[VMD_CFGBAR]) >> 20;
+
 	max_buses = min_t(u16, max_buses, vmd_cfgbar_ecam_space(vmd));
 	for (bus = 0; bus < max_buses; bus++) {
-		ecam_bus = vmd_bus_to_ecam(vmd, vmd->resources[VMD_RES_CFGBAR].start +
-					   bus);
+		/* Calculate the ECAM bus nr starting from the first bus of VMD_BUS_0 */
+		ecam_bus = vmd_bus_to_ecam(vmd, vmd->busn_start[VMD_BUS_0] + bus);
 		for (dev = 0; dev < 32; dev++) {
 			base = vmd->cfgbar + PCIE_ECAM_OFFSET(ecam_bus,
 						PCI_DEVFN(dev, 0), 0);
@@ -632,16 +722,53 @@ static void vmd_domain_reset(struct vmd_dev *vmd)
 	}
 }
 
-static void vmd_attach_resources(struct vmd_dev *vmd)
+static int vmd_attach_resources(struct vmd_dev *vmd)
 {
-	vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[VMD_RES_MBAR_1];
-	vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[VMD_RES_MBAR_2];
+	int ret;
+
+	ret = request_resource(&vmd->dev->resource[VMD_MEMBAR1],
+			       &vmd->resources[VMD_RES_MBAR_1]);
+	if (ret)
+		return ret;
+
+	ret = request_resource(&vmd->dev->resource[VMD_MEMBAR2],
+			       &vmd->resources[VMD_RES_MBAR_2]);
+	if (ret) {
+		release_resource(&vmd->resources[VMD_RES_MBAR_1]);
+		return ret;
+	}
+
+	if (vmd->bus1_rootbus && vmd->sysdata[VMD_BUS_1].domain >= 0) {
+		ret = request_resource(&vmd->dev->resource[VMD_MEMBAR1],
+				       &vmd->resources[VMD_RES_BUS1_MBAR_1]);
+		if (ret) {
+			release_resource(&vmd->resources[VMD_RES_MBAR_1]);
+			release_resource(&vmd->resources[VMD_RES_MBAR_2]);
+			return ret;
+		}
+
+		ret = request_resource(&vmd->dev->resource[VMD_MEMBAR2],
+				       &vmd->resources[VMD_RES_BUS1_MBAR_2]);
+		if (ret) {
+			release_resource(&vmd->resources[VMD_RES_MBAR_1]);
+			release_resource(&vmd->resources[VMD_RES_MBAR_2]);
+			release_resource(&vmd->resources[VMD_RES_BUS1_MBAR_1]);
+			return ret;
+		}
+	}
+
+	return 0;
 }
 
 static void vmd_detach_resources(struct vmd_dev *vmd)
 {
-	vmd->dev->resource[VMD_MEMBAR1].child = NULL;
-	vmd->dev->resource[VMD_MEMBAR2].child = NULL;
+	if (vmd->bus1_rootbus && vmd->sysdata[VMD_BUS_1].domain >= 0) {
+		release_resource(&vmd->resources[VMD_RES_BUS1_MBAR_2]);
+		release_resource(&vmd->resources[VMD_RES_BUS1_MBAR_1]);
+	}
+
+	release_resource(&vmd->resources[VMD_RES_MBAR_2]);
+	release_resource(&vmd->resources[VMD_RES_MBAR_1]);
 }
 
 static int vmd_get_phys_offsets(struct vmd_dev *vmd, bool native_hint,
@@ -698,7 +825,7 @@ static int vmd_get_phys_offsets(struct vmd_dev *vmd, bool native_hint,
 	return 0;
 }
 
-static int vmd_get_bus_number_start(struct vmd_dev *vmd)
+static int vmd_get_bus_number_start(struct vmd_dev *vmd, unsigned long features)
 {
 	struct pci_dev *dev = vmd->dev;
 	u16 reg;
@@ -716,10 +843,27 @@ static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 		case 1:
 			vmd->busn_start[VMD_BUS_0] = VMD_RESTRICT_1_BUS_START;
 			break;
-		case 3:
 		case 2:
 			vmd->busn_start[VMD_BUS_0] = VMD_RESTRICT_2_BUS_START;
 			break;
+		case 3:
+			if (!(features & VMD_FEAT_HAS_BUS1_ROOTBUS)) {
+				pci_err(dev, "VMD Bus Restriction detected type %d, but BUS1 root bus is not supported, aborting.\n",
+					BUS_RESTRICT_CFG(reg));
+				return -ENODEV;
+			}
+
+			/*
+			 * Per Intel VMD specification (e.g., Arrow Lake-S):
+			 * - VMD (on root bus 0) secondary bus start number: 0xE0
+			 *	(devices span 0xE2..0xF0 via VMD_BUSRANGE0).
+			 * - VMD (on root bus 1) secondary bus start number: 0xE1
+			 *	(devices span 0xF1..0xFF via VMD_BUSRANGE1).
+			 */
+			vmd->busn_start[VMD_BUS_0] = VMD_RESTRICT_2_BUS_START;
+			vmd->busn_start[VMD_BUS_1] = VMD_RESTRICT_3_BUS_START;
+			vmd->bus1_rootbus = true;
+			break;
 		default:
 			pci_err(dev, "Unknown Bus Offset Setting (%d)\n",
 				BUS_RESTRICT_CFG(reg));
@@ -859,7 +1003,7 @@ static int vmd_prepare_offsets_and_bus(struct vmd_dev *vmd,
 	 * limits the bus range to between 0-127, 128-255, or 224-255.
 	 */
 	if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) {
-		ret = vmd_get_bus_number_start(vmd);
+		ret = vmd_get_bus_number_start(vmd, features);
 		if (ret)
 			return ret;
 	}
@@ -926,7 +1070,7 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata)
 	return 0;
 }
 
-static void vmd_configure_cfgbar(struct vmd_dev *vmd)
+static int vmd_configure_cfgbar(struct vmd_dev *vmd)
 {
 	struct resource *res = &vmd->dev->resource[VMD_CFGBAR];
 	resource_size_t busn_end;
@@ -940,6 +1084,62 @@ static void vmd_configure_cfgbar(struct vmd_dev *vmd)
 		.end   = busn_end,
 		.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
 	};
+
+	if (vmd->bus1_rootbus) {
+		int ret;
+		u16 bus0_range = 0;
+		u16 bus1_range = 0;
+		u8 bus0_start, bus0_end;
+		u8 bus1_start, bus1_end;
+
+		ret = pci_read_config_word(vmd->dev, VMD_BUSRANGE0, &bus0_range);
+		if (ret) {
+			pci_err(vmd->dev, "Failed to read VMD_BUSRANGE0: %d\n", ret);
+			return -EIO;
+		}
+
+		ret = pci_read_config_word(vmd->dev, VMD_BUSRANGE1, &bus1_range);
+		if (ret) {
+			pci_err(vmd->dev, "Failed to read VMD_BUSRANGE1: %d\n", ret);
+			return -EIO;
+		}
+
+		bus0_start = VMD_BUS_START(bus0_range);
+		bus0_end = VMD_BUS_END(bus0_range);
+		bus1_start = VMD_BUS_START(bus1_range);
+		bus1_end = VMD_BUS_END(bus1_range);
+
+		if (bus0_start > bus0_end || bus1_start > bus1_end) {
+			pci_err(vmd->dev,
+				"Invalid bus range(s): BUS0 [%02x-%02x], BUS1 [%02x-%02x]\n",
+				bus0_start, bus0_end, bus1_start, bus1_end);
+			return -EINVAL;
+		}
+
+		if (!(bus0_end < bus1_start || bus1_end < bus0_start)) {
+			pci_err(vmd->dev,
+				"Overlapping bus ranges: BUS0 [%02x-%02x], BUS1 [%02x-%02x]\n",
+				bus0_start, bus0_end, bus1_start, bus1_end);
+			return -EINVAL;
+		}
+
+		/*
+		 * Resize BUS0 CFGBAR range to make space for BUS1
+		 * owned devices by adjusting range end with value stored in
+		 * VMD_BUSRANGE0 register.
+		 */
+		vmd->resources[VMD_RES_CFGBAR].start = bus0_start;
+		vmd->resources[VMD_RES_CFGBAR].end = bus0_end;
+
+		vmd->resources[VMD_RES_BUS1_CFGBAR] = (struct resource){
+			.name = "VMD CFGBAR BUS1",
+			.start = bus1_start,
+			.end = bus1_end,
+			.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
+		};
+	}
+
+	return 0;
 }
 
 /*
@@ -970,8 +1170,9 @@ static int vmd_configure_membar(struct vmd_dev *vmd, u8 resource_number,
 	if (!upper_bits)
 		flags &= ~IORESOURCE_MEM_64;
 
-	name = devm_kasprintf(&vmd->dev->dev, GFP_KERNEL, "VMD MEMBAR%d",
-			      resource_number);
+	name = devm_kasprintf(&vmd->dev->dev, GFP_KERNEL, "VMD MEMBAR%d %s",
+			      membar_number / 2,
+			      resource_number > VMD_RES_MBAR_2 ? "BUS1" : "");
 	if (!name)
 		return -ENOMEM;
 
@@ -991,55 +1192,132 @@ static int vmd_configure_membar1_membar2(struct vmd_dev *vmd,
 {
 	int ret;
 
-	ret = vmd_configure_membar(vmd, VMD_RES_MBAR_1, VMD_MEMBAR1, 0, 0);
-	if (ret)
-		return ret;
+	if (vmd->bus1_rootbus) {
+		u32 reg = 0;
+		u32 bus1_mbar1_ofs = 0;
+		u64 bus1_mbar2_ofs = 0;
+		resource_size_t mbar1_sz, mbar2_sz;
 
-	ret = vmd_configure_membar(vmd, VMD_RES_MBAR_2, VMD_MEMBAR2, mbar2_ofs, 0);
-	if (ret) {
-		devm_kfree(&vmd->dev->dev, (void *)vmd->resources[VMD_RES_MBAR_1].name);
-		memset(&vmd->resources[VMD_RES_MBAR_1], 0,
-		       sizeof(vmd->resources[VMD_RES_MBAR_1]));
-		return ret;
+		mbar1_sz = resource_size(&vmd->dev->resource[VMD_MEMBAR1]);
+		mbar2_sz = resource_size(&vmd->dev->resource[VMD_MEMBAR2]);
+
+		ret = pci_read_config_dword(vmd->dev, VMD_MEMBAR1_OFFSET,
+					    &bus1_mbar1_ofs);
+		if (ret)
+			return -EIO;
+
+		ret = pci_read_config_dword(vmd->dev, VMD_MEMBAR2_OFFSET1, &reg);
+		if (ret)
+			return -EIO;
+		bus1_mbar2_ofs = reg;
+
+		ret = pci_read_config_dword(vmd->dev, VMD_MEMBAR2_OFFSET2, &reg);
+		if (ret)
+			return -EIO;
+		bus1_mbar2_ofs |= (u64)reg << 32;
+
+		if (!bus1_mbar1_ofs || bus1_mbar1_ofs >= mbar1_sz) {
+			pci_err(vmd->dev, "Invalid MEMBAR1 offset %#llx (BAR size %#llx)\n",
+				(unsigned long long)bus1_mbar1_ofs,
+				(unsigned long long)mbar1_sz);
+			return -EINVAL;
+		}
+
+		if (!bus1_mbar2_ofs || mbar2_ofs >= mbar2_sz ||
+		    bus1_mbar2_ofs <= mbar2_ofs || bus1_mbar2_ofs >= mbar2_sz) {
+			pci_err(vmd->dev,
+				"Invalid MEMBAR2 split %#llx (shadow offset %#llx, BAR size %#llx)\n",
+				(unsigned long long)bus1_mbar2_ofs,
+				(unsigned long long)mbar2_ofs,
+				(unsigned long long)mbar2_sz);
+			return -EINVAL;
+		}
+
+		/*
+		 * Resize BUS MEMBAR1 and MEMBAR2 ranges to make space
+		 * for BUS1 owned devices by adjusting range end with values
+		 * stored in VMD_MEMBAR1_OFFSET and VMD_MEMBAR2_OFFSET registers
+		 */
+		ret = vmd_configure_membar(vmd, VMD_RES_MBAR_1, VMD_MEMBAR1, 0,
+					   mbar1_sz - bus1_mbar1_ofs);
+		if (ret)
+			return ret;
+
+		ret = vmd_configure_membar(vmd, VMD_RES_MBAR_2, VMD_MEMBAR2,
+					   mbar2_ofs, mbar2_sz - bus1_mbar2_ofs);
+		if (ret)
+			return ret;
+
+		ret = vmd_configure_membar(vmd, VMD_RES_BUS1_MBAR_1, VMD_MEMBAR1,
+					   bus1_mbar1_ofs, 0);
+		if (ret)
+			return ret;
+
+		ret = vmd_configure_membar(vmd, VMD_RES_BUS1_MBAR_2, VMD_MEMBAR2,
+					   bus1_mbar2_ofs, 0);
+		if (ret)
+			return ret;
+	} else {
+		ret = vmd_configure_membar(vmd, VMD_RES_MBAR_1, VMD_MEMBAR1, 0, 0);
+		if (ret)
+			return ret;
+
+		ret = vmd_configure_membar(vmd, VMD_RES_MBAR_2, VMD_MEMBAR2,
+					   mbar2_ofs, 0);
+		if (ret)
+			return ret;
 	}
 
 	return 0;
 }
 
-static int vmd_create_bus(struct vmd_dev *vmd, struct pci_sysdata *sd,
-			  resource_size_t *offset, bool vmd_in_guest)
+static int vmd_create_bus(struct vmd_dev *vmd, enum vmd_rootbus bus_number,
+			  struct pci_sysdata *sd, resource_size_t *offset,
+			  bool vmd_in_guest, u8 primary)
 {
+	u8 cfgbar = bus_number * 3;
+	u8 membar1 = cfgbar + 1;
+	u8 membar2 = cfgbar + 2;
+	struct pci_bus *vmd_bus;
 	LIST_HEAD(resources);
 
-	pci_add_resource(&resources, &vmd->resources[VMD_RES_CFGBAR]);
-	pci_add_resource_offset(&resources, &vmd->resources[VMD_RES_MBAR_1],
+	pci_add_resource(&resources, &vmd->resources[cfgbar]);
+	pci_add_resource_offset(&resources, &vmd->resources[membar1],
 				offset[0]);
-	pci_add_resource_offset(&resources, &vmd->resources[VMD_RES_MBAR_2],
+	pci_add_resource_offset(&resources, &vmd->resources[membar2],
 				offset[1]);
 
-	vmd->bus[VMD_BUS_0] = pci_create_root_bus(&vmd->dev->dev,
-						  vmd->busn_start[VMD_BUS_0],
-						  &vmd_ops, sd, &resources);
-	if (!vmd->bus[VMD_BUS_0]) {
+	vmd_bus = pci_create_root_bus(&vmd->dev->dev,
+				      vmd->busn_start[bus_number], &vmd_ops, sd,
+				      &resources);
+
+	if (!vmd_bus) {
 		pci_free_resource_list(&resources);
 		return -ENODEV;
 	}
 
+	/*
+	 * pci_create_root_bus() does not initialise bus->primary.
+	 * Set it here before any scanning so bridge traversal logic
+	 * sees the correct upstream bus number from the start.
+	 */
+	vmd_bus->primary = primary;
+
 	/*
 	 * Don't copy _OSC control flags from root bridge if running in a VM, as
 	 * they don't reflect the physical root bridge capabilities.
 	 */
 	if (!vmd_in_guest)
 		vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
-					   to_pci_host_bridge(vmd->bus[VMD_BUS_0]->bridge));
-
-	vmd_attach_resources(vmd);
+					   to_pci_host_bridge(vmd_bus->bridge));
 	if (vmd->irq_domain)
-		dev_set_msi_domain(&vmd->bus[VMD_BUS_0]->dev, vmd->irq_domain);
+		dev_set_msi_domain(&vmd_bus->dev, vmd->irq_domain);
 	else
-		dev_set_msi_domain(&vmd->bus[VMD_BUS_0]->dev,
+		dev_set_msi_domain(&vmd_bus->dev,
 				   dev_get_msi_domain(&vmd->dev->dev));
 
+	vmd->bus[bus_number] = vmd_bus;
+
 	return 0;
 }
 
@@ -1052,7 +1330,15 @@ static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 	vmd_acpi_begin();
 
 	pci_scan_child_bus(bus);
-	vmd_domain_reset(vmd_from_bus(bus));
+
+	/*
+	 * vmd_domain_reset() walks the full VMD CFGBAR aperture, so a single
+	 * invocation from BUS0 resets bridge windows for the whole VMD domain,
+	 * including BUS1. Running it again during BUS1 enumeration would
+	 * re-clobber windows already assigned for BUS0.
+	 */
+	if (bus->primary == VMD_PRIMARY_BUS0)
+		vmd_domain_reset(vmd_from_bus(bus));
 
 	/*
 	 * When Intel VMD is enabled, the OS does not discover the Root Ports
@@ -1091,6 +1377,16 @@ static void vmd_bus_enumeration(struct pci_bus *bus, unsigned long features)
 	vmd_acpi_end();
 }
 
+/* Drop BUS1 configuration and continue with BUS0 only. */
+static void vmd_disable_bus1(struct vmd_dev *vmd)
+{
+	vmd->resources[VMD_RES_BUS1_CFGBAR] = (struct resource){};
+	vmd->resources[VMD_RES_BUS1_MBAR_1] = (struct resource){};
+	vmd->resources[VMD_RES_BUS1_MBAR_2] = (struct resource){};
+	vmd->sysdata[VMD_BUS_1].domain = PCI_DOMAIN_NR_NOT_SET;
+	vmd->bus[VMD_BUS_1] = NULL;
+}
+
 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 {
 	struct pci_sysdata *sd = &vmd->sysdata[VMD_BUS_0];
@@ -1104,7 +1400,9 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 	if (ret)
 		return ret;
 
-	vmd_configure_cfgbar(vmd);
+	ret = vmd_configure_cfgbar(vmd);
+	if (ret)
+		return ret;
 
 	/*
 	 * If the window is below 4GB, clear IORESOURCE_MEM_64 so we can
@@ -1164,11 +1462,38 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 
 	sd->node = pcibus_to_node(vmd->dev->bus);
 
-	ret = vmd_create_bus(vmd, sd, offset, vmd_in_guest);
+	if (vmd->bus1_rootbus) {
+		vmd->sysdata[VMD_BUS_1].vmd_dev = vmd->dev;
+		vmd->sysdata[VMD_BUS_1].node = pcibus_to_node(vmd->dev->bus);
+		vmd->sysdata[VMD_BUS_1].domain = pci_bus_find_emul_domain_nr(0, 0x10000, INT_MAX);
+		if (vmd->sysdata[VMD_BUS_1].domain < 0) {
+			pci_warn(vmd->dev,
+				 "Can't allocate BUS1 domain: %d, continuing with BUS0 only\n",
+				 vmd->sysdata[VMD_BUS_1].domain);
+			vmd_disable_bus1(vmd);
+		}
+	}
+
+	ret = vmd_attach_resources(vmd);
+	if (ret) {
+		pci_bus_release_emul_domain_nr(sd->domain);
+		if (vmd->bus1_rootbus && vmd->sysdata[VMD_BUS_1].domain >= 0)
+			pci_bus_release_emul_domain_nr(vmd->sysdata[VMD_BUS_1].domain);
+
+		vmd_remove_irq_domain(vmd);
+		return ret;
+	}
+
+	ret = vmd_create_bus(vmd, VMD_BUS_0, sd, offset, vmd_in_guest,
+			     VMD_PRIMARY_BUS0);
 	if (ret) {
 		pci_err(vmd->dev, "Can't create bus: %d\n", ret);
 		pci_bus_release_emul_domain_nr(sd->domain);
+		if (vmd->bus1_rootbus && vmd->sysdata[VMD_BUS_1].domain >= 0)
+			pci_bus_release_emul_domain_nr(vmd->sysdata[VMD_BUS_1].domain);
+
 		vmd_remove_irq_domain(vmd);
+		vmd_detach_resources(vmd);
 		return ret;
 	}
 
@@ -1176,8 +1501,33 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
 			       &vmd->bus[VMD_BUS_0]->dev.kobj, "domain"),
 	     "Can't create symlink to domain\n");
 
+	if (vmd->bus1_rootbus && vmd->sysdata[VMD_BUS_1].domain >= 0) {
+		ret = vmd_create_bus(vmd, VMD_BUS_1, &vmd->sysdata[VMD_BUS_1], offset,
+				     vmd_in_guest, VMD_PRIMARY_BUS1);
+		if (ret) {
+			pci_warn(vmd->dev,
+				 "Can't create BUS1: %d, continuing with BUS0 only\n",
+				 ret);
+
+			release_resource(&vmd->resources[VMD_RES_BUS1_MBAR_2]);
+			release_resource(&vmd->resources[VMD_RES_BUS1_MBAR_1]);
+			pci_bus_release_emul_domain_nr(vmd->sysdata[VMD_BUS_1].domain);
+			vmd_disable_bus1(vmd);
+		}
+
+		if (vmd->bus1_rootbus && vmd->sysdata[VMD_BUS_1].domain >= 0) {
+			WARN(sysfs_create_link(&vmd->dev->dev.kobj,
+					       &vmd->bus[VMD_BUS_1]->dev.kobj,
+					       "domain1"),
+			     "Can't create symlink to domain1\n");
+		}
+	}
+
 	vmd_bus_enumeration(vmd->bus[VMD_BUS_0], features);
 
+	if (vmd->bus1_rootbus && vmd->sysdata[VMD_BUS_1].domain >= 0)
+		vmd_bus_enumeration(vmd->bus[VMD_BUS_1], features);
+
 	return 0;
 }
 
@@ -1214,6 +1564,7 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 
 	vmd->dev = dev;
 	vmd->sysdata[VMD_BUS_0].domain = PCI_DOMAIN_NR_NOT_SET;
+	vmd->sysdata[VMD_BUS_1].domain = PCI_DOMAIN_NR_NOT_SET;
 	vmd->features = features;
 	vmd->instance = ida_alloc(&vmd_instance_ida, GFP_KERNEL);
 	if (vmd->instance < 0)
@@ -1252,8 +1603,14 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	if (err)
 		goto out_release_instance;
 
-	dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
-		 vmd->sysdata[VMD_BUS_0].domain);
+	if (vmd->bus1_rootbus && vmd->sysdata[VMD_BUS_1].domain >= 0)
+		dev_info(&vmd->dev->dev, "Bound to PCI domains %04x and %04x\n",
+			 vmd->sysdata[VMD_BUS_0].domain,
+			 vmd->sysdata[VMD_BUS_1].domain);
+	else
+		dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
+			 vmd->sysdata[VMD_BUS_0].domain);
+
 	return 0;
 
  out_release_instance:
@@ -1276,6 +1633,14 @@ static void vmd_remove(struct pci_dev *dev)
 	pci_stop_root_bus(vmd->bus[VMD_BUS_0]);
 	sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
 	pci_remove_root_bus(vmd->bus[VMD_BUS_0]);
+
+	if (vmd->bus1_rootbus && vmd->bus[VMD_BUS_1]) {
+		pci_stop_root_bus(vmd->bus[VMD_BUS_1]);
+		sysfs_remove_link(&vmd->dev->dev.kobj, "domain1");
+		pci_remove_root_bus(vmd->bus[VMD_BUS_1]);
+		pci_bus_release_emul_domain_nr(vmd->sysdata[VMD_BUS_1].domain);
+	}
+
 	vmd_cleanup_srcu(vmd);
 	vmd_detach_resources(vmd);
 	vmd_remove_irq_domain(vmd);
@@ -1376,4 +1741,4 @@ module_pci_driver(vmd_drv);
 MODULE_AUTHOR("Intel Corporation");
 MODULE_DESCRIPTION("Volume Management Device driver");
 MODULE_LICENSE("GPL v2");
-MODULE_VERSION("0.6");
+MODULE_VERSION("0.7");
-- 
2.43.0