On 10.05.19 00:34, Halil Pasic wrote:
On Wed, 8 May 2019 15:15:40 +0200
Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> wrote:
On Fri, 26 Apr 2019 20:32:39 +0200
Halil Pasic <pasic@xxxxxxxxxxxxx> wrote:
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@xxxxxxxxxxxxx>
---
arch/s390/Kconfig | 4 +++
arch/s390/include/asm/mem_encrypt.h | 18 +++++++++++++
arch/s390/mm/init.c | 50
+++++++++++++++++++++++++++++++++++++ 3 files changed, 72
insertions(+) create mode 100644 arch/s390/include/asm/mem_encrypt.h
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 1c3fcf19c3af..5500d05d4d53 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
@@ -191,6 +194,7 @@ config S390
select ARCH_HAS_SCALED_CPUTIME
select VIRT_TO_BUS
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
This is rather ugly, but I understand why it's there
Nod.
+
+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 3e82f66d5c61..7e3cbd15dcfa 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);
@@ -126,6 +130,50 @@ 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 all pages shared, (swiotlb, dma_free) */
this is a copypaste typo, I think? (should be UNshared?)
also, it doesn't make ALL pages unshared, but only those specified in
the parameters
Right a copy paste error. Needs correction. The all was meant like all
pages in the range specified by the arguments. But it is better changed
since it turned out to be confusing.
with this fixed:
Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Thanks!
+ for (i = 0; i < numpages; ++i) {
+ uv_remove_shared(addr);
+ addr += PAGE_SIZE;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(set_memory_encrypted);
+
+int set_memory_decrypted(unsigned long addr, int numpages)
+{
+ int i;
+ /* make all pages shared (swiotlb, dma_alloca) */
same here with ALL
+ for (i = 0; i < numpages; ++i) {
+ uv_set_shared(addr);
+ addr += PAGE_SIZE;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(set_memory_decrypted);
+
+/* are we a protected virtualization guest? */
+bool sev_active(void)
this is also ugly. the correct solution would be probably to refactor
everything, including all the AMD SEV code.... let's not go there
Nod. Maybe later.
+{
+ return is_prot_virt_guest();
+}
+EXPORT_SYMBOL_GPL(sev_active);
+
+/* protected virtualization */
+static void pv_init(void)
+{
+ if (!sev_active())
can't you just use is_prot_virt_guest here?
Sure! I guess it would be less confusing. It is something I did not
remember to change when the interface for this provided by uv.h went
from sketchy to nice.
integrated in v2
Michael
Thanks again!
Regards,
Halil
+ 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);
@@ -134,6 +182,8 @@ 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();
--
Mit freundlichen Grüßen / Kind regards
Michael Müller
IBM Deutschland Research & Development GmbH
Vorsitzender des Aufsichtsrats: Matthias Hartmann
Geschäftsführung: Dirk Wittkopp
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