From 54bd63570484167cb13edf81e31fff107b879981 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 15 Jun 2017 10:36:22 +0200 Subject: [PATCH] iommu/amd: Suppress IO_PAGE_FAULTs in kdump kernel When booting into a kdump kernel, suppress IO_PAGE_FAULTs by default for all devices. But allow the faults again when a domain is assigned to a device. Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 3 ++- drivers/iommu/amd_iommu_init.c | 9 +++++++++ drivers/iommu/amd_iommu_types.h | 1 + 3 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 6498f5baa7ea..95ee360a5199 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -2078,7 +2078,8 @@ static void set_dte_entry(u16 devid, struct protection_domain *domain, bool ats) flags |= tmp; } - flags &= ~(0xffffUL); + + flags &= ~(DTE_FLAG_SA | 0xffffULL); flags |= domain->id; amd_iommu_dev_table[devid].data[1] = flags; diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index 3fa7e3b35507..cf7896550e75 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -1900,6 +1901,14 @@ static void init_device_table_dma(void) for (devid = 0; devid <= amd_iommu_last_bdf; ++devid) { set_dev_entry_bit(devid, DEV_ENTRY_VALID); set_dev_entry_bit(devid, DEV_ENTRY_TRANSLATION); + /* + * In kdump kernels in-flight DMA from the old kernel might + * cause IO_PAGE_FAULTs. There are no reports that a kdump + * actually failed because of that, so just disable fault + * reporting in the hardware to get rid of the messages + */ + if (is_kdump_kernel()) + set_dev_entry_bit(devid, DEV_ENTRY_NO_PAGE_FAULT); } } diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h index 6960d7db2fab..294a409e283b 100644 --- a/drivers/iommu/amd_iommu_types.h +++ b/drivers/iommu/amd_iommu_types.h @@ -322,6 +322,7 @@ #define IOMMU_PTE_IW (1ULL << 62) #define DTE_FLAG_IOTLB (1ULL << 32) +#define DTE_FLAG_SA (1ULL << 34) #define DTE_FLAG_GV (1ULL << 55) #define DTE_FLAG_MASK (0x3ffULL << 32) #define DTE_GLX_SHIFT (56) -- 2.20.1