From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-bn3nam01on0051.outbound.protection.outlook.com ([104.47.33.51] helo=NAM01-BN3-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1d0aYF-0003i2-Jc for kexec@lists.infradead.org; Tue, 18 Apr 2017 21:20:45 +0000 From: Tom Lendacky Subject: [PATCH v5 23/32] swiotlb: Add warnings for use of bounce buffers with SME Date: Tue, 18 Apr 2017 16:20:19 -0500 Message-ID: <20170418212019.10190.24034.stgit@tlendack-t1.amdoffice.net> In-Reply-To: <20170418211612.10190.82788.stgit@tlendack-t1.amdoffice.net> References: <20170418211612.10190.82788.stgit@tlendack-t1.amdoffice.net> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Thomas Gleixner , Rik van Riel , Brijesh Singh , Toshimitsu Kani , Arnd Bergmann , Jonathan Corbet , Matt Fleming , Joerg Roedel , Radim =?utf-8?b?S3LEjW3DocWZ?= , Konrad Rzeszutek Wilk , Andrey Ryabinin , Ingo Molnar , "Michael S. Tsirkin" , Andy Lutomirski , "H. Peter Anvin" , Borislav Petkov , Paolo Bonzini , Alexander Potapenko , Dave Young , Larry Woodman , Dmitry Vyukov Add warnings to let the user know when bounce buffers are being used for DMA when SME is active. Since the bounce buffers are not in encrypted memory, these notifications are to allow the user to determine some appropriate action - if necessary. Signed-off-by: Tom Lendacky --- arch/x86/include/asm/mem_encrypt.h | 11 +++++++++++ include/linux/dma-mapping.h | 11 +++++++++++ include/linux/mem_encrypt.h | 6 ++++++ lib/swiotlb.c | 3 +++ 4 files changed, 31 insertions(+) diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h index 0637b4b..b406df2 100644 --- a/arch/x86/include/asm/mem_encrypt.h +++ b/arch/x86/include/asm/mem_encrypt.h @@ -26,6 +26,11 @@ static inline bool sme_active(void) return !!sme_me_mask; } +static inline u64 sme_dma_mask(void) +{ + return ((u64)sme_me_mask << 1) - 1; +} + void __init sme_early_encrypt(resource_size_t paddr, unsigned long size); void __init sme_early_decrypt(resource_size_t paddr, @@ -50,6 +55,12 @@ static inline bool sme_active(void) { return false; } + +static inline u64 sme_dma_mask(void) +{ + return 0ULL; +} + #endif static inline void __init sme_early_encrypt(resource_size_t paddr, diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 0977317..f825870 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -10,6 +10,7 @@ #include #include #include +#include /** * List of possible attributes associated with a DMA mapping. The semantics @@ -577,6 +578,11 @@ static inline int dma_set_mask(struct device *dev, u64 mask) if (!dev->dma_mask || !dma_supported(dev, mask)) return -EIO; + + if (sme_active() && (mask < sme_dma_mask())) + dev_warn_ratelimited(dev, + "SME is active, device will require DMA bounce buffers\n"); + *dev->dma_mask = mask; return 0; } @@ -596,6 +602,11 @@ static inline int dma_set_coherent_mask(struct device *dev, u64 mask) { if (!dma_supported(dev, mask)) return -EIO; + + if (sme_active() && (mask < sme_dma_mask())) + dev_warn_ratelimited(dev, + "SME is active, device will require DMA bounce buffers\n"); + dev->coherent_dma_mask = mask; return 0; } diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h index 3c384d1..000c430 100644 --- a/include/linux/mem_encrypt.h +++ b/include/linux/mem_encrypt.h @@ -28,6 +28,12 @@ static inline bool sme_active(void) { return false; } + +static inline u64 sme_dma_mask(void) +{ + return 0ULL; +} + #endif #endif /* CONFIG_AMD_MEM_ENCRYPT */ diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 74d6557..af3a268 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -509,6 +509,9 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, if (no_iotlb_memory) panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); + WARN_ONCE(sme_active(), + "SME is active and the system is using DMA bounce buffers\n"); + mask = dma_get_seg_boundary(hwdev); tbl_dma_addr &= mask; _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec