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Commit c7753208 authored by Tom Lendacky's avatar Tom Lendacky Committed by Ingo Molnar
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x86, swiotlb: Add memory encryption support 



Since DMA addresses will effectively look like 48-bit addresses when the
memory encryption mask is set, SWIOTLB is needed if the DMA mask of the
device performing the DMA does not support 48-bits. SWIOTLB will be
initialized to create decrypted bounce buffers for use by these devices.

Signed-off-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/aa2d29b78ae7d508db8881e46a3215231b9327a7.1500319216.git.thomas.lendacky@amd.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 163ea3c8

arch/x86/include/asm/dma-mapping.h

+3 −2
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <asm/io.h>

#include <asm/swiotlb.h>

#include <linux/dma-contiguous.h>

#include <linux/mem_encrypt.h>



#ifdef CONFIG_ISA

# define ISA_DMA_BIT_MASK DMA_BIT_MASK(24)
@@ -57,12 +58,12 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) 


static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)

{

	return paddr;

	return __sme_set(paddr);

}



static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)

{

	return daddr;

	return __sme_clr(daddr);

}

#endif /* CONFIG_X86_DMA_REMAP */

arch/x86/include/asm/mem_encrypt.h

+5 −0
Original line number Diff line number Diff line
@@ -34,6 +34,11 @@ void __init sme_early_init(void); 
void __init sme_encrypt_kernel(void);

void __init sme_enable(void);



/* Architecture __weak replacement functions */

void __init mem_encrypt_init(void);



void swiotlb_set_mem_attributes(void *vaddr, unsigned long size);



#else	/* !CONFIG_AMD_MEM_ENCRYPT */



#define sme_me_mask	0UL

arch/x86/kernel/pci-dma.c

+7 −4
Original line number Diff line number Diff line
@@ -93,18 +93,21 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size, 
	if (gfpflags_allow_blocking(flag)) {

		page = dma_alloc_from_contiguous(dev, count, get_order(size),

						 flag);

		if (page && page_to_phys(page) + size > dma_mask) {

		if (page) {

			addr = phys_to_dma(dev, page_to_phys(page));

			if (addr + size > dma_mask) {

				dma_release_from_contiguous(dev, page, count);

				page = NULL;

			}

		}

	}

	/* fallback */

	if (!page)

		page = alloc_pages_node(dev_to_node(dev), flag, get_order(size));

	if (!page)

		return NULL;



	addr = page_to_phys(page);

	addr = phys_to_dma(dev, page_to_phys(page));

	if (addr + size > dma_mask) {

		__free_pages(page, get_order(size));

arch/x86/kernel/pci-nommu.c

+1 −1
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ static dma_addr_t nommu_map_page(struct device *dev, struct page *page, 
				 enum dma_data_direction dir,

				 unsigned long attrs)

{

	dma_addr_t bus = page_to_phys(page) + offset;

	dma_addr_t bus = phys_to_dma(dev, page_to_phys(page)) + offset;

	WARN_ON(size == 0);

	if (!check_addr("map_single", dev, bus, size))

		return NOMMU_MAPPING_ERROR;

arch/x86/kernel/pci-swiotlb.c

+13 −2
Original line number Diff line number Diff line
@@ -6,12 +6,14 @@ 
#include <linux/swiotlb.h>

#include <linux/bootmem.h>

#include <linux/dma-mapping.h>

#include <linux/mem_encrypt.h>



#include <asm/iommu.h>

#include <asm/swiotlb.h>

#include <asm/dma.h>

#include <asm/xen/swiotlb-xen.h>

#include <asm/iommu_table.h>



int swiotlb __read_mostly;



void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
@@ -79,8 +81,8 @@ IOMMU_INIT_FINISH(pci_swiotlb_detect_override, 
		  pci_swiotlb_late_init);



/*

 * if 4GB or more detected (and iommu=off not set) return 1

 * and set swiotlb to 1.

 * If 4GB or more detected (and iommu=off not set) or if SME is active

 * then set swiotlb to 1 and return 1.

 */

int __init pci_swiotlb_detect_4gb(void)

{
@@ -89,6 +91,15 @@ int __init pci_swiotlb_detect_4gb(void) 
	if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)

		swiotlb = 1;

#endif



	/*

	 * If SME is active then swiotlb will be set to 1 so that bounce

	 * buffers are allocated and used for devices that do not support

	 * the addressing range required for the encryption mask.

	 */

	if (sme_active())

		swiotlb = 1;



	return swiotlb;

}

IOMMU_INIT(pci_swiotlb_detect_4gb,