From 781bb36add9e43907a16a1303a13808ae53cfa31 Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Fri, 12 Jan 2018 11:22:20 +0100 Subject: [PATCH] bus/pci: forbid IOVA mode if IOMMU address width too small [ upstream commit 54a328f552ff2e0098c3f96f9e32302675f2bcf4 ] Intel VT-d supports different address widths for the IOVAs, from 39 bits to 56 bits. While recent processors support at least 48 bits, VT-d emulation currently only supports 39 bits. It makes DMA mapping to fail in this case when using VA as IOVA mode, as user-space virtual addresses uses up to 47 bits (see kernel's Documentation/x86/x86_64/mm.txt). This patch parses VT-d CAP register value available in sysfs, and forbid VA as IOVA mode if the GAW is 39 bits or unknown. Fixes: f37dfab21c98 ("drivers/net: enable IOVA mode for Intel PMDs") Signed-off-by: Maxime Coquelin Tested-by: Chas Williams --- drivers/bus/pci/linux/pci.c | 90 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 81 insertions(+), 9 deletions(-) diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c index ec31216..74deef3 100644 --- a/drivers/bus/pci/linux/pci.c +++ b/drivers/bus/pci/linux/pci.c @@ -577,4 +577,80 @@ } +#if defined(RTE_ARCH_X86) +static bool +pci_one_device_iommu_support_va(struct rte_pci_device *dev) +{ +#define VTD_CAP_MGAW_SHIFT 16 +#define VTD_CAP_MGAW_MASK (0x3fULL << VTD_CAP_MGAW_SHIFT) +#define X86_VA_WIDTH 47 /* From Documentation/x86/x86_64/mm.txt */ + struct rte_pci_addr *addr = &dev->addr; + char filename[PATH_MAX]; + FILE *fp; + uint64_t mgaw, vtd_cap_reg = 0; + + snprintf(filename, sizeof(filename), + "%s/" PCI_PRI_FMT "/iommu/intel-iommu/cap", + rte_pci_get_sysfs_path(), addr->domain, addr->bus, addr->devid, + addr->function); + if (access(filename, F_OK) == -1) { + /* We don't have an Intel IOMMU, assume VA supported*/ + return true; + } + + /* We have an intel IOMMU */ + fp = fopen(filename, "r"); + if (fp == NULL) { + RTE_LOG(ERR, EAL, "%s(): can't open %s\n", __func__, filename); + return false; + } + + if (fscanf(fp, "%" PRIx64, &vtd_cap_reg) != 1) { + RTE_LOG(ERR, EAL, "%s(): can't read %s\n", __func__, filename); + fclose(fp); + return false; + } + + fclose(fp); + + mgaw = ((vtd_cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) + 1; + if (mgaw < X86_VA_WIDTH) + return false; + + return true; +} +#elif defined(RTE_ARCH_PPC_64) +static bool +pci_one_device_iommu_support_va(__rte_unused struct rte_pci_device *dev) +{ + return false; +} +#else +static bool +pci_one_device_iommu_support_va(__rte_unused struct rte_pci_device *dev) +{ + return true; +} +#endif + +/* + * All devices IOMMUs support VA as IOVA + */ +static bool +pci_devices_iommu_support_va(void) +{ + struct rte_pci_device *dev = NULL; + struct rte_pci_driver *drv = NULL; + + FOREACH_DRIVER_ON_PCIBUS(drv) { + FOREACH_DEVICE_ON_PCIBUS(dev) { + if (!rte_pci_match(drv, dev)) + continue; + if (!pci_one_device_iommu_support_va(dev)) + return false; + } + } + return true; +} + /* * Get iommu class of PCI devices on the bus. @@ -587,10 +663,5 @@ enum rte_iova_mode bool has_iova_va; bool is_bound_uio; - bool spapr_iommu = -#if defined(RTE_ARCH_PPC_64) - true; -#else - false; -#endif + bool iommu_no_va; is_bound = pci_one_device_is_bound(); @@ -600,4 +671,5 @@ enum rte_iova_mode has_iova_va = pci_one_device_has_iova_va(); is_bound_uio = pci_one_device_bound_uio(); + iommu_no_va = !pci_devices_iommu_support_va(); #ifdef VFIO_PRESENT is_vfio_noiommu_enabled = rte_vfio_noiommu_is_enabled() == true ? @@ -606,5 +678,5 @@ enum rte_iova_mode if (has_iova_va && !is_bound_uio && !is_vfio_noiommu_enabled && - !spapr_iommu) + !iommu_no_va) return RTE_IOVA_VA; @@ -615,6 +687,6 @@ enum rte_iova_mode if (is_bound_uio) RTE_LOG(WARNING, EAL, "few device bound to UIO\n"); - if (spapr_iommu) - RTE_LOG(WARNING, EAL, "sPAPR IOMMU does not support IOVA as VA\n"); + if (iommu_no_va) + RTE_LOG(WARNING, EAL, "IOMMU does not support IOVA as VA\n"); } -- 1.8.3.1