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From: Thiago Jung Bauermann <bauerman@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Anshuman Khandual <anshuman.linux@gmail.com>,
	Alexey Kardashevskiy <aik@ozlabs.ru>,
	Mike Anderson <andmike@linux.ibm.com>,
	Ram Pai <linuxram@us.ibm.com>,
	linux-kernel@vger.kernel.org,
	Claudio Carvalho <cclaudio@linux.ibm.com>,
	Paul Mackerras <paulus@samba.org>, Christoph Hellwig <hch@lst.de>,
	Thiago Jung Bauermann <bauerman@linux.ibm.com>,
	Anshuman Khandual <khandual@linux.vnet.ibm.com>
Subject: [PATCH 11/12] powerpc/pseries/svm: Force SWIOTLB for secure guests
Date: Tue, 21 May 2019 01:49:11 -0300
Message-ID: <20190521044912.1375-12-bauerman@linux.ibm.com> (raw)
In-Reply-To: <20190521044912.1375-1-bauerman@linux.ibm.com>

From: Anshuman Khandual <khandual@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 <khandual@linux.vnet.ibm.com>
[ Use ARCH_HAS_MEM_ENCRYPT hooks to share swiotlb memory pool. ]
Signed-off-by: Thiago Jung Bauermann <bauerman@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)
 


  parent reply index

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-21  4:49 [PATCH 00/12] Secure Virtual Machine Enablement Thiago Jung Bauermann
2019-05-21  4:49 ` [PATCH 01/12] powerpc/pseries: Introduce option to build secure virtual machines Thiago Jung Bauermann
2019-05-21  4:49 ` [RFC PATCH 02/12] powerpc: Add support for adding an ESM blob to the zImage wrapper Thiago Jung Bauermann
2019-05-21  5:13   ` Christoph Hellwig
2019-05-21 15:09     ` Ram Pai
2019-05-21 23:15     ` Paul Mackerras
2019-05-21  4:49 ` [RFC PATCH 03/12] powerpc/prom_init: Add the ESM call to prom_init Thiago Jung Bauermann
2019-06-26  7:44   ` Alexey Kardashevskiy
2019-06-28 22:33     ` Thiago Jung Bauermann
2019-07-01  3:13       ` Alexey Kardashevskiy
2019-05-21  4:49 ` [PATCH 04/12] powerpc/pseries/svm: Add helpers for UV_SHARE_PAGE and UV_UNSHARE_PAGE Thiago Jung Bauermann
2019-05-21  4:49 ` [PATCH 05/12] powerpc/pseries: Add and use LPPACA_SIZE constant Thiago Jung Bauermann
2019-05-21  4:49 ` [PATCH 06/12] powerpc/pseries/svm: Use shared memory for LPPACA structures Thiago Jung Bauermann
2019-05-21  4:49 ` [PATCH 07/12] powerpc/pseries/svm: Use shared memory for Debug Trace Log (DTL) Thiago Jung Bauermann
2019-05-21  4:49 ` [PATCH 08/12] powerpc/pseries/svm: Export guest SVM status to user space via sysfs Thiago Jung Bauermann
2019-05-21  4:49 ` [PATCH 09/12] powerpc/pseries/svm: Disable doorbells in SVM guests Thiago Jung Bauermann
2019-05-21  4:49 ` [PATCH 10/12] powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests Thiago Jung Bauermann
2019-05-21  4:49 ` Thiago Jung Bauermann [this message]
2019-05-21  5:15   ` [PATCH 11/12] powerpc/pseries/svm: Force SWIOTLB for " Christoph Hellwig
2019-05-23  5:15     ` Thiago Jung Bauermann
2019-05-21  4:49 ` [PATCH 12/12] powerpc/configs: Enable secure guest support in pseries and ppc64 defconfigs Thiago Jung Bauermann
2019-06-07 14:47   ` [RFC PATCH 1/1] powerpc/pseries/svm: Unshare all pages before kexecing a new kernel Ram Pai
2019-06-01 17:11 ` [PATCH 00/12] Secure Virtual Machine Enablement Thiago Jung Bauermann

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