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From: Halil Pasic <pasic@linux.ibm.com>
To: kvm@vger.kernel.org, linux-s390@vger.kernel.org,
	Cornelia Huck <cohuck@redhat.com>,
	Sebastian Ott <sebott@linux.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Halil Pasic <pasic@linux.ibm.com>,
	virtualization@lists.linux-foundation.org,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Christoph Hellwig <hch@infradead.org>,
	Thomas Huth <thuth@redhat.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Viktor Mihajlovski <mihajlov@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	Michael Mueller <mimu@linux.ibm.com>,
	Claudio Imbrenda <imbrenda@linux.ibm.com>,
	Farhan Ali <alifm@linux.ibm.com>,
	Eric Farman <farman@linux.ibm.com>,
	"Jason J. Herne" <jjherne@linux.ibm.com>
Subject: [PATCH v5 1/8] s390/mm: force swiotlb for protected virtualization
Date: Wed, 12 Jun 2019 13:12:29 +0200
Message-ID: <20190612111236.99538-2-pasic@linux.ibm.com> (raw)
In-Reply-To: <20190612111236.99538-1-pasic@linux.ibm.com>

On s390, protected virtualization guests have to use bounced I/O
buffers.  That requires some plumbing.

Let us make sure, any device that uses DMA API with direct ops correctly
is spared from the problems, that a hypervisor attempting I/O to a
non-shared page would bring.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 arch/s390/Kconfig                   |  4 +++
 arch/s390/include/asm/mem_encrypt.h | 18 +++++++++++
 arch/s390/mm/init.c                 | 47 +++++++++++++++++++++++++++++
 3 files changed, 69 insertions(+)
 create mode 100644 arch/s390/include/asm/mem_encrypt.h

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 109243fdb6ec..88d8355b7bf7 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -1,4 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
+config ARCH_HAS_MEM_ENCRYPT
+        def_bool y
+
 config MMU
 	def_bool y
 
@@ -187,6 +190,7 @@ config S390
 	select VIRT_CPU_ACCOUNTING
 	select ARCH_HAS_SCALED_CPUTIME
 	select HAVE_NMI
+	select SWIOTLB
 
 
 config SCHED_OMIT_FRAME_POINTER
diff --git a/arch/s390/include/asm/mem_encrypt.h b/arch/s390/include/asm/mem_encrypt.h
new file mode 100644
index 000000000000..0898c09a888c
--- /dev/null
+++ b/arch/s390/include/asm/mem_encrypt.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef S390_MEM_ENCRYPT_H__
+#define S390_MEM_ENCRYPT_H__
+
+#ifndef __ASSEMBLY__
+
+#define sme_me_mask	0ULL
+
+static inline bool sme_active(void) { return false; }
+extern bool sev_active(void);
+
+int set_memory_encrypted(unsigned long addr, int numpages);
+int set_memory_decrypted(unsigned long addr, int numpages);
+
+#endif	/* __ASSEMBLY__ */
+
+#endif	/* S390_MEM_ENCRYPT_H__ */
+
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 14d1eae9fe43..f0bee6af3960 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -18,6 +18,7 @@
 #include <linux/mman.h>
 #include <linux/mm.h>
 #include <linux/swap.h>
+#include <linux/swiotlb.h>
 #include <linux/smp.h>
 #include <linux/init.h>
 #include <linux/pagemap.h>
@@ -29,6 +30,7 @@
 #include <linux/export.h>
 #include <linux/cma.h>
 #include <linux/gfp.h>
+#include <linux/dma-mapping.h>
 #include <asm/processor.h>
 #include <linux/uaccess.h>
 #include <asm/pgtable.h>
@@ -42,6 +44,8 @@
 #include <asm/sclp.h>
 #include <asm/set_memory.h>
 #include <asm/kasan.h>
+#include <asm/dma-mapping.h>
+#include <asm/uv.h>
 
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 
@@ -128,6 +132,47 @@ void mark_rodata_ro(void)
 	pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
 }
 
+int set_memory_encrypted(unsigned long addr, int numpages)
+{
+	int i;
+
+	/* make specified pages unshared, (swiotlb, dma_free) */
+	for (i = 0; i < numpages; ++i) {
+		uv_remove_shared(addr);
+		addr += PAGE_SIZE;
+	}
+	return 0;
+}
+
+int set_memory_decrypted(unsigned long addr, int numpages)
+{
+	int i;
+	/* make specified pages shared (swiotlb, dma_alloca) */
+	for (i = 0; i < numpages; ++i) {
+		uv_set_shared(addr);
+		addr += PAGE_SIZE;
+	}
+	return 0;
+}
+
+/* are we a protected virtualization guest? */
+bool sev_active(void)
+{
+	return is_prot_virt_guest();
+}
+
+/* protected virtualization */
+static void pv_init(void)
+{
+	if (!is_prot_virt_guest())
+		return;
+
+	/* make sure bounce buffers are shared */
+	swiotlb_init(1);
+	swiotlb_update_mem_attributes();
+	swiotlb_force = SWIOTLB_FORCE;
+}
+
 void __init mem_init(void)
 {
 	cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
@@ -136,6 +181,8 @@ void __init mem_init(void)
 	set_max_mapnr(max_low_pfn);
         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 
+	pv_init();
+
 	/* Setup guest page hinting */
 	cmma_init();
 
-- 
2.17.1


  reply index

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-12 11:12 [PATCH v5 0/8] s390: virtio: support " Halil Pasic
2019-06-12 11:12 ` Halil Pasic [this message]
2019-06-13  8:09   ` [PATCH v5 1/8] s390/mm: force swiotlb for " Michael Mueller
2019-07-11 21:48   ` Thiago Jung Bauermann
2019-06-12 11:12 ` [PATCH v5 2/8] s390/cio: introduce DMA pools to cio Halil Pasic
2019-06-12 14:23   ` Cornelia Huck
2019-06-13  8:13   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 3/8] s390/cio: add basic protected virtualization support Halil Pasic
2019-06-13  8:21   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 4/8] s390/airq: use DMA memory for adapter interrupts Halil Pasic
2019-06-12 14:35   ` Cornelia Huck
2019-06-12 15:11     ` Halil Pasic
2019-06-13  8:25   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 5/8] virtio/s390: use cacheline aligned airq bit vectors Halil Pasic
2019-06-13  8:27   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 6/8] virtio/s390: add indirection to indicators access Halil Pasic
2019-06-13  8:29   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 7/8] virtio/s390: use DMA memory for ccw I/O and classic notifiers Halil Pasic
2019-06-13  8:32   ` Michael Mueller
2019-06-12 11:12 ` [PATCH v5 8/8] virtio/s390: make airq summary indicators DMA Halil Pasic
2019-06-13  8:35   ` Michael Mueller
2019-06-13  9:11 ` [PATCH v5 0/8] s390: virtio: support protected virtualization Michael Mueller
2019-06-13 11:14   ` Halil Pasic
2019-06-13 11:17     ` Michael Mueller

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