From: Anshuman Khandual <khand...@linux.vnet.ibm.com> SWIOTLB checks range of incoming CPU addresses to be bounced and sees if the device can access it through its DMA window without requiring bouncing. In such cases it just chooses to skip bouncing. But for cases like secure guests on powerpc platform all addresses need to be bounced into the shared pool of memory because the host cannot access it otherwise. Hence the need to do the bouncing is not related to device's DMA window and use of bounce buffers is forced by setting swiotlb_force.
Also, connect the shared memory conversion functions into the ARCH_HAS_MEM_ENCRYPT hooks and call swiotlb_update_mem_attributes() to convert SWIOTLB's memory pool to shared memory. Signed-off-by: Anshuman Khandual <khand...@linux.vnet.ibm.com> [ Use ARCH_HAS_MEM_ENCRYPT hooks to share swiotlb memory pool. ] Signed-off-by: Thiago Jung Bauermann <bauer...@linux.ibm.com> --- arch/powerpc/include/asm/mem_encrypt.h | 19 +++++++++++ arch/powerpc/platforms/pseries/Kconfig | 5 +++ arch/powerpc/platforms/pseries/svm.c | 45 ++++++++++++++++++++++++++ 3 files changed, 69 insertions(+) diff --git a/arch/powerpc/include/asm/mem_encrypt.h b/arch/powerpc/include/asm/mem_encrypt.h new file mode 100644 index 000000000000..45d5e4d0e6e0 --- /dev/null +++ b/arch/powerpc/include/asm/mem_encrypt.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * SVM helper functions + * + * Copyright 2019 IBM Corporation + */ + +#ifndef _ASM_POWERPC_MEM_ENCRYPT_H +#define _ASM_POWERPC_MEM_ENCRYPT_H + +#define sme_me_mask 0ULL + +static inline bool sme_active(void) { return false; } +static inline bool sev_active(void) { return false; } + +int set_memory_encrypted(unsigned long addr, int numpages); +int set_memory_decrypted(unsigned long addr, int numpages); + +#endif /* _ASM_POWERPC_MEM_ENCRYPT_H */ diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index 82c16aa4f1ce..41b10f3bc729 100644 --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -145,9 +145,14 @@ config PAPR_SCM help Enable access to hypervisor provided storage class memory. +config ARCH_HAS_MEM_ENCRYPT + def_bool n + config PPC_SVM bool "Secure virtual machine (SVM) support for POWER" depends on PPC_PSERIES + select SWIOTLB + select ARCH_HAS_MEM_ENCRYPT default n help Support secure guests on POWER. There are certain POWER platforms which diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c index c508196f7c83..618622d636d5 100644 --- a/arch/powerpc/platforms/pseries/svm.c +++ b/arch/powerpc/platforms/pseries/svm.c @@ -7,8 +7,53 @@ */ #include <linux/mm.h> +#include <asm/machdep.h> +#include <asm/svm.h> +#include <asm/swiotlb.h> #include <asm/ultravisor.h> +static int __init init_svm(void) +{ + if (!is_secure_guest()) + return 0; + + /* Don't release the SWIOTLB buffer. */ + ppc_swiotlb_enable = 1; + + /* + * Since the guest memory is inaccessible to the host, devices always + * need to use the SWIOTLB buffer for DMA even if dma_capable() says + * otherwise. + */ + swiotlb_force = SWIOTLB_FORCE; + + /* Share the SWIOTLB buffer with the host. */ + swiotlb_update_mem_attributes(); + + return 0; +} +machine_early_initcall(pseries, init_svm); + +int set_memory_encrypted(unsigned long addr, int numpages) +{ + if (!PAGE_ALIGNED(addr)) + return -EINVAL; + + uv_unshare_page(PHYS_PFN(__pa(addr)), numpages); + + return 0; +} + +int set_memory_decrypted(unsigned long addr, int numpages) +{ + if (!PAGE_ALIGNED(addr)) + return -EINVAL; + + uv_share_page(PHYS_PFN(__pa(addr)), numpages); + + return 0; +} + /* There's one dispatch log per CPU. */ #define NR_DTL_PAGE (DISPATCH_LOG_BYTES * CONFIG_NR_CPUS / PAGE_SIZE)