Commit-ID: ec941c5ffede4d788b9fc008f9eeca75b9e964f5 Gitweb: http://git.kernel.org/tip/ec941c5ffede4d788b9fc008f9eeca75b9e964f5 Author: Igor Mammedov <imamm...@redhat.com> AuthorDate: Fri, 4 Dec 2015 14:07:06 +0100 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Sun, 6 Dec 2015 12:46:31 +0100
x86/mm/64: Enable SWIOTLB if system has SRAT memory regions above MAX_DMA32_PFN when memory hotplug enabled system is booted with less than 4GB of RAM and then later more RAM is hotplugged 32-bit devices stop functioning with following error: nommu_map_single: overflow 327b4f8c0+1522 of device mask ffffffff the reason for this is that if x86_64 system were booted with RAM less than 4GB, it doesn't enable SWIOTLB and when memory is hotplugged beyond MAX_DMA32_PFN, devices that expect 32-bit addresses can't handle 64-bit addresses. Fix it by tracking max possible PFN when parsing memory affinity structures from SRAT ACPI table and enable SWIOTLB if there is hotpluggable memory regions beyond MAX_DMA32_PFN. It fixes KVM guests when they use emulated devices (reproduces with ata_piix, e1000 and usb devices, RHBZ: 1275941, 1275977, 1271527) It also fixes the HyperV, VMWare with emulated devices which are affected by this issue as well. Signed-off-by: Igor Mammedov <imamm...@redhat.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: akata...@vmware.com Cc: fujita.tomon...@lab.ntt.co.jp Cc: konrad.w...@oracle.com Cc: pbonz...@redhat.com Cc: rev...@redhat.com Cc: r...@redhat.com Link: http://lkml.kernel.org/r/1449234426-273049-3-git-send-email-imamm...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/pci-swiotlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c index adf0392..7c577a1 100644 --- a/arch/x86/kernel/pci-swiotlb.c +++ b/arch/x86/kernel/pci-swiotlb.c @@ -88,7 +88,7 @@ int __init pci_swiotlb_detect_4gb(void) { /* don't initialize swiotlb if iommu=off (no_iommu=1) */ #ifdef CONFIG_X86_64 - if (!no_iommu && max_pfn > MAX_DMA32_PFN) + if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN) swiotlb = 1; #endif return swiotlb; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
