From: Anshuman Khandual <khand...@linux.vnet.ibm.com> SWIOTLB buffer default size (64MB) is not enough for large sequential write operations which eventually leads to kernel crash like here.
virtio-pci 0000:00:05.0: swiotlb buffer is full (sz: 327680 bytes) virtio-pci 0000:00:05.0: DMA: Out of SW-IOMMU space for 327680 bytes Kernel panic - not syncing: DMA: Random memory could be DMA read CPU: 12 PID: 3985 Comm: mkfs.ext4 Not tainted 4.18.0-rc4+ #285 Call Trace: [c0000007d2a27020] [c000000000cfdffc] dump_stack+0xb0/0xf4 (unreliable) [c0000007d2a27060] [c000000000112a98] panic+0x140/0x328 [c0000007d2a270f0] [c0000000001b4f88] swiotlb_full+0x108/0x130 [c0000007d2a27180] [c0000000001b5f6c] swiotlb_map_page+0x25c/0x2c0 [c0000007d2a271e0] [c0000000007bfaf8] vring_map_one_sg.isra.0+0x58/0x70 [c0000007d2a27200] [c0000000007c08dc] virtqueue_add_sgs+0x1bc/0x690 [c0000007d2a272f0] [d0000000042a1280] virtio_queue_rq+0x358/0x4a0 [virtio_blk] [c0000007d2a273d0] [c0000000006b5d68] blk_mq_dispatch_rq_list+0x1f8/0x6d0 .................. Increase the SWIOTLB size to 1GB on Ultravisor based secure guests. Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com> Signed-off-by: Thiago Jung Bauermann <bauer...@linux.ibm.com> --- arch/powerpc/Kconfig | 5 +++++ kernel/dma/swiotlb.c | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 1466d1234723..fee7194ce9e4 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -457,6 +457,11 @@ config PPC_SVM If unsure, say "N". +config SWIOTLB_DEFAULT_SIZE + int "Size of Software I/O TLB buffer (in MiB)" + default "1024" + depends on PPC_SVM + config PPC_TRANSACTIONAL_MEM bool "Transactional Memory support for POWERPC" depends on PPC_BOOK3S_64 diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 04b68d9dffac..32dc67422d8a 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -146,8 +146,13 @@ void swiotlb_set_max_segment(unsigned int val) max_segment = rounddown(val, PAGE_SIZE); } +#ifdef CONFIG_SWIOTLB_DEFAULT_SIZE +#define IO_TLB_DEFAULT_SIZE ((unsigned long) CONFIG_SWIOTLB_DEFAULT_SIZE << 20) +#else /* default to 64MB */ #define IO_TLB_DEFAULT_SIZE (64UL<<20) +#endif + unsigned long swiotlb_size_or_default(void) { unsigned long size; _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu