kernel/linux.git/drivers/pci/controller/vmd.c, branch v6.3

PCI: vmd: Add quirk to configure PCIe ASPM and LTR

2023-02-02T15:02:40+00:00

PCIe ports reserved for VMD use are not visible to BIOS and therefore not configured to enable PCIe ASPM or LTR values (which BIOS will configure if they are not set). Lack of this programming results in high power consumption on laptops as reported in bugzilla. For affected products use pci_enable_link_state to set the allowed link states for devices on the root ports. Also set the LTR value to the maximum value needed for the SoC. This is a workaround for products from Rocket Lake through Alder Lake. Raptor Lake, the latest product at this time, has already implemented LTR configuring in BIOS. Future products will move ASPM configuration back to BIOS as well. As this solution is intended for laptops, support is not added for hotplug or for devices downstream of a switch on the root port. Link: https://bugzilla.kernel.org/show_bug.cgi?id=212355 Link: https://bugzilla.kernel.org/show_bug.cgi?id=215063 Link: https://bugzilla.kernel.org/show_bug.cgi?id=213717 Link: https://lore.kernel.org/r/20230120031522.2304439-5-david.e.box@linux.intel.com Signed-off-by: Michael Bottini Signed-off-by: David E. Box Signed-off-by: Lorenzo Pieralisi Reviewed-by: Jon Derrick Reviewed-by: Nirmal Patel Reviewed-by: Kuppuswamy Sathyanarayanan

PCI: vmd: Create feature grouping for client products

2023-02-02T15:02:34+00:00

Simplify the device ID list by creating a grouping of features shared by client products. Suggested-by: Jon Derrick Link: https://lore.kernel.org/r/20230120031522.2304439-4-david.e.box@linux.intel.com Signed-off-by: David E. Box Signed-off-by: Lorenzo Pieralisi Reviewed-by: Kuppuswamy Sathyanarayanan

PCI: vmd: Use PCI_VDEVICE in device list

2023-02-02T15:01:57+00:00

Use PCI_VDEVICE to simplify the device table. Link: https://lore.kernel.org/r/20230120031522.2304439-3-david.e.box@linux.intel.com Signed-off-by: David E. Box Signed-off-by: Lorenzo Pieralisi Reviewed-by: Jon Derrick Reviewed-by: Nirmal Patel Reviewed-by: Kuppuswamy Sathyanarayanan

PCI: vmd: Fix secondary bus reset for Intel bridges

2022-12-06T10:45:25+00:00

The reset was never applied in the current implementation because Intel Bridges owned by VMD are parentless. Internally, pci_reset_bus() applies a reset to the parent of the PCI device supplied as argument, but in this case it failed because there wasn't a parent. In more detail, this change allows the VMD driver to enumerate NVMe devices in pass-through configurations when guest reboots are performed. There was an attempted to fix this, but later we discovered that the code inside pci_reset_bus() wasn’t triggering secondary bus resets. Therefore, we updated the parameters passed to it, and now NVMe SSDs attached to VMD bridges are properly enumerated in VT-d pass-through scenarios. Link: https://lore.kernel.org/r/20221206001637.4744-1-francisco.munoz.ruiz@linux.intel.com Fixes: 6aab5622296b ("PCI: vmd: Clean up domain before enumeration") Signed-off-by: Francisco Munoz Signed-off-by: Lorenzo Pieralisi Reviewed-by: Nirmal Patel Reviewed-by: Jonathan Derrick

PCI: vmd: Disable MSI remapping after suspend

2022-11-11T11:00:26+00:00

MSI remapping is disabled by VMD driver for Intel's Icelake and newer systems in order to improve performance by setting VMCONFIG_MSI_REMAP. By design VMCONFIG_MSI_REMAP register is cleared by firmware during boot. The same register gets cleared when system is put in S3 power state. VMD driver needs to set this register again in order to avoid interrupt issues with devices behind VMD if MSI remapping was disabled before. Link: https://lore.kernel.org/r/20221109142652.450998-1-nirmal.patel@linux.intel.com Fixes: ee81ee84f873 ("PCI: vmd: Disable MSI-X remapping when possible") Signed-off-by: Nirmal Patel Signed-off-by: Lorenzo Pieralisi Reviewed-by: Francisco Munoz

PCI: vmd: Add DID 8086:7D0B and 8086:AD0B for Intel MTL SKUs

2022-06-28T23:36:12+00:00

Add support for VMD devices in MTL-H/P/U/S/M with bus restriction mode and vector 0 disabled for MSI-X remapping. Link: https://lore.kernel.org/r/20220628221023.190547-1-francisco.munoz.ruiz@linux.intel.com Signed-off-by: Francisco Munoz Signed-off-by: Bjorn Helgaas Reviewed-by: Nirmal Patel

PCI: vmd: Use devm_kasprintf() instead of simple kasprintf()

2022-06-10T14:46:14+00:00

Use devm_kasprintf() instead of simple kasprintf() to free allocated memory automatically when the device is freed. Suggested-by: Srikanth Thokala Link: https://lore.kernel.org/r/20220531132617.20517-1-subramanian.mohan@intel.com Signed-off-by: Subramanian Mohan Signed-off-by: Bjorn Helgaas Acked-by: Nirmal Patel

PCI: vmd: Revert 2565e5b69c44 ("PCI: vmd: Do not disable MSI-X remapping if interrupt remapping is enabled by IOMMU.")

2022-05-12T14:54:14+00:00

Revert 2565e5b69c44 ("PCI: vmd: Do not disable MSI-X remapping if interrupt remapping is enabled by IOMMU.") The commit 2565e5b69c44 was added as a workaround to keep MSI-X remapping enabled if IOMMU enables interrupt remapping. VMD would keep running in low performance mode. There is no dependency between MSI-X remapping by VMD and interrupt remapping by IOMMU. Link: https://lore.kernel.org/r/20220511095707.25403-3-nirmal.patel@linux.intel.com Signed-off-by: Nirmal Patel Signed-off-by: Lorenzo Pieralisi

PCI: vmd: Assign VMD IRQ domain before enumeration

2022-05-12T14:54:14+00:00

During the boot process all the PCI devices are assigned default PCI-MSI IRQ domain including VMD endpoint devices. If interrupt-remapping is enabled by IOMMU, the PCI devices except VMD get new INTEL-IR-MSI IRQ domain. And VMD is supposed to create and assign a separate VMD-MSI IRQ domain for its child devices in order to support MSI-X remapping capabilities. Now when MSI-X remapping in VMD is disabled in order to improve performance, VMD skips VMD-MSI IRQ domain assignment process to its child devices. Thus the devices behind VMD get default PCI-MSI IRQ domain instead of INTEL-IR-MSI IRQ domain when VMD creates root bus and configures child devices. As a result host OS fails to boot and DMAR errors were observed when interrupt remapping was enabled on Intel Icelake CPUs. For instance: DMAR: DRHD: handling fault status reg 2 DMAR: [INTR-REMAP] Request device [0xe2:0x00.0] fault index 0xa00 [fault reason 0x25] Blocked a compatibility format interrupt request To fix this issue, dev_msi_info struct in dev struct maintains correct value of IRQ domain. VMD will use this information to assign proper IRQ domain to its child devices when it doesn't create a separate IRQ domain. Link: https://lore.kernel.org/r/20220511095707.25403-2-nirmal.patel@linux.intel.com Signed-off-by: Nirmal Patel Signed-off-by: Lorenzo Pieralisi

PCI: vmd: Prevent recursive locking on interrupt allocation

2022-02-21T07:26:53+00:00

Tejas reported the following recursive locking issue: swapper/0/1 is trying to acquire lock: ffff8881074fd0a0 (&md->mutex){+.+.}-{3:3}, at: msi_get_virq+0x30/0xc0 but task is already holding lock: ffff8881017cd6a0 (&md->mutex){+.+.}-{3:3}, at: __pci_enable_msi_range+0xf2/0x290 stack backtrace: __mutex_lock+0x9d/0x920 msi_get_virq+0x30/0xc0 pci_irq_vector+0x26/0x30 vmd_msi_init+0xcc/0x210 msi_domain_alloc+0xbf/0x150 msi_domain_alloc_irqs_descs_locked+0x3e/0xb0 __pci_enable_msi_range+0x155/0x290 pci_alloc_irq_vectors_affinity+0xba/0x100 pcie_port_device_register+0x307/0x550 pcie_portdrv_probe+0x3c/0xd0 pci_device_probe+0x95/0x110 This is caused by the VMD MSI code which does a lookup of the Linux interrupt number for an VMD managed MSI[X] vector. The lookup function tries to acquire the already held mutex. Avoid that by caching the Linux interrupt number at initialization time instead of looking it up over and over. Fixes: 82ff8e6b78fc ("PCI/MSI: Use msi_get_virq() in pci_get_vector()") Reported-by: "Surendrakumar Upadhyay, TejaskumarX" Signed-off-by: Thomas Gleixner Tested-by: "Surendrakumar Upadhyay, TejaskumarX" Cc: linux-pci@vger.kernel.org Link: https://lore.kernel.org/r/87a6euub2a.ffs@tglx