The new parameter takes a list of devices separated by a semicolon. Each device specified will have its iommu_passthrough bit in struct device set. This is very similar to the existing 'disable_acs_redir' parameter.
Signed-off-by: Lu Baolu <[email protected]> --- .../admin-guide/kernel-parameters.txt | 5 +++ drivers/pci/pci.c | 34 +++++++++++++++++++ drivers/pci/pci.h | 1 + drivers/pci/probe.c | 2 ++ 4 files changed, 42 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index ade4e6ec23e0..d3edc2cb6696 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3583,6 +3583,11 @@ may put more devices in an IOMMU group. force_floating [S390] Force usage of floating interrupts. nomio [S390] Do not use MIO instructions. + iommu_passthrough=<pci_dev>[; ...] + Specify one or more PCI devices (in the format + specified above) separated by semicolons. + Each device specified will bypass IOMMU DMA + translation. pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management. diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 90dbd7c70371..05bf3f4acc36 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6401,6 +6401,37 @@ void __weak pci_fixup_cardbus(struct pci_bus *bus) } EXPORT_SYMBOL(pci_fixup_cardbus); +static const char *iommu_passthrough_param; +bool pci_iommu_passthrough_match(struct pci_dev *dev) +{ + int ret = 0; + const char *p = iommu_passthrough_param; + + if (!p) + return false; + + while (*p) { + ret = pci_dev_str_match(dev, p, &p); + if (ret < 0) { + pr_info_once("PCI: Can't parse iommu_passthrough parameter: %s\n", + iommu_passthrough_param); + + break; + } else if (ret == 1) { + pci_info(dev, "PCI: IOMMU passthrough\n"); + return true; + } + + if (*p != ';' && *p != ',') { + /* End of param or invalid format */ + break; + } + p++; + } + + return false; +} + static int __init pci_setup(char *str) { while (str) { @@ -6462,6 +6493,8 @@ static int __init pci_setup(char *str) pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); } else if (!strncmp(str, "disable_acs_redir=", 18)) { disable_acs_redir_param = str + 18; + } else if (!strncmp(str, "iommu_passthrough=", 18)) { + iommu_passthrough_param = str + 18; } else { pr_err("PCI: Unknown option `%s'\n", str); } @@ -6486,6 +6519,7 @@ static int __init pci_realloc_setup_params(void) resource_alignment_param = kstrdup(resource_alignment_param, GFP_KERNEL); disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL); + iommu_passthrough_param = kstrdup(iommu_passthrough_param, GFP_KERNEL); return 0; } diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index a0a53bd05a0b..95f6af06aba6 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -288,6 +288,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev); void pci_disable_bridge_window(struct pci_dev *dev); struct pci_bus *pci_bus_get(struct pci_bus *bus); void pci_bus_put(struct pci_bus *bus); +bool pci_iommu_passthrough_match(struct pci_dev *dev); /* PCIe link information */ #define PCIE_SPEED2STR(speed) \ diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 512cb4312ddd..4c571ee75621 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2404,6 +2404,8 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) dev->state_saved = false; + dev->dev.iommu_passthrough = pci_iommu_passthrough_match(dev); + pci_init_capabilities(dev); /* -- 2.17.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
