From ae21ee65e8bc228416bbcc8a1da01c56a847a60c Mon Sep 17 00:00:00 2001 From: Allen Kay Date: Wed, 7 Oct 2009 10:27:17 -0700 Subject: PCI: acs p2p upsteram forwarding enabling Note: dom0 checking in v4 has been separated out into 2/2. This patch enables P2P upstream forwarding in ACS capable PCIe switches. It solves two potential problems in virtualization environment where a PCIe device is assigned to a guest domain using a HW iommu such as VT-d: 1) Unintentional failure caused by guest physical address programmed into the device's DMA that happens to match the memory address range of other downstream ports in the same PCIe switch. This causes the PCI transaction to go to the matching downstream port instead of go to the root complex to get translated by VT-d as it should be. 2) Malicious guest software intentionally attacks another downstream PCIe device by programming the DMA address into the assigned device that matches memory address range of the downstream PCIe port. We are in process of implementing device filtering software in KVM/XEN management software to allow device assignment of PCIe devices behind a PCIe switch only if it has ACS capability and with the P2P upstream forwarding bits enabled. This patch is intended to work for both KVM and Xen environments. Signed-off-by: Allen Kay Reviewed-by: Mathew Wilcox Reviewed-by: Chris Wright Signed-off-by: Jesse Barnes --- include/linux/pci_regs.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/linux') diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h index dd0bed4f1cf..d798770f08c 100644 --- a/include/linux/pci_regs.h +++ b/include/linux/pci_regs.h @@ -502,6 +502,7 @@ #define PCI_EXT_CAP_ID_VC 2 #define PCI_EXT_CAP_ID_DSN 3 #define PCI_EXT_CAP_ID_PWR 4 +#define PCI_EXT_CAP_ID_ACS 13 #define PCI_EXT_CAP_ID_ARI 14 #define PCI_EXT_CAP_ID_ATS 15 #define PCI_EXT_CAP_ID_SRIOV 16 @@ -662,4 +663,16 @@ #define PCI_SRIOV_VFM_MO 0x2 /* Active.MigrateOut */ #define PCI_SRIOV_VFM_AV 0x3 /* Active.Available */ +/* Access Control Service */ +#define PCI_ACS_CAP 0x04 /* ACS Capability Register */ +#define PCI_ACS_SV 0x01 /* Source Validation */ +#define PCI_ACS_TB 0x02 /* Translation Blocking */ +#define PCI_ACS_RR 0x04 /* P2P Request Redirect */ +#define PCI_ACS_CR 0x08 /* P2P Completion Redirect */ +#define PCI_ACS_UF 0x10 /* Upstream Forwarding */ +#define PCI_ACS_EC 0x20 /* P2P Egress Control */ +#define PCI_ACS_DT 0x40 /* Direct Translated P2P */ +#define PCI_ACS_CTRL 0x06 /* ACS Control Register */ +#define PCI_ACS_EGRESS_CTL_V 0x08 /* ACS Egress Control Vector */ + #endif /* LINUX_PCI_REGS_H */ -- cgit v1.2.3-70-g09d2