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* [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64
@ 2016-06-07 16:06 Julien Grall
  2016-06-07 16:06 ` [PATCH v3 01/16] xen/arm: Makefile: Sort the entries alphabetically Julien Grall
                   ` (15 more replies)
  0 siblings, 16 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

Hello,

Some of the processor errata will require to modify code sequence. As those
modifications may impact the performance, they should only be enabled on
affected cores. Furthermore, Xen may also want to take advantage of
new hardware features coming up with v8.1 and v8.2.

The first part of the series adds the alternative infrastructure, most of
the code is based on Linux v4.6-rc3. The rest of the series implements
errata for Cortex-A57 and Cortex-A53.

A branch with all the patches can be found here:

git://xenbits.xen.org/people/julieng/xen-unstable.git branch alternative-v3

For all the changes, see in each patch.

Yours sincerely,

Julien Grall (16):
  xen/arm: Makefile: Sort the entries alphabetically
  xen/arm: Include the header asm-arm/system.h in asm-arm/page.h
  xen/arm: Add macros to handle the MIDR
  xen/arm: Add cpu_hwcap bitmap
  xen/arm64: Add an helper to invalidate all instruction caches
  xen/arm: arm64: Move the define BRK_BUG_FRAME into a separate header
  xen/arm: arm64: Reserve a brk immediate to fault on purpose
  xen/arm: arm64: Add helpers to decode and encode branch instructions
  xen/arm: Introduce alternative runtime patching
  xen/arm: cpufeature: Provide an helper to check if a capability is
    supported
  xen/arm: Detect silicon revision and set cap bits accordingly
  xen/arm: Document the errata implemented in Xen
  xen/arm: arm64: Add Cortex-A53 cache errata workaround
  xen/arm: arm64: Add cortex-A57 erratum 832075 workaround
  xen/arm: traps: Don't inject a fault if the translation VA -> IPA
    fails
  xen/arm: arm64: Document Cortex-A57 erratum 834220

 docs/misc/arm/silicon-errata.txt  |  50 +++++++++
 xen/arch/arm/Kconfig              |  96 +++++++++++++++++
 xen/arch/arm/Makefile             |  43 ++++----
 xen/arch/arm/alternative.c        | 221 ++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/arm32/Makefile       |   9 +-
 xen/arch/arm/arm64/Makefile       |  13 ++-
 xen/arch/arm/arm64/cache.S        |   2 +
 xen/arch/arm/arm64/insn.c         | 219 +++++++++++++++++++++++++++++++++++++
 xen/arch/arm/cpuerrata.c          |  52 +++++++++
 xen/arch/arm/cpufeature.c         |  50 +++++++++
 xen/arch/arm/platforms/Makefile   |   2 +-
 xen/arch/arm/setup.c              |  10 ++
 xen/arch/arm/smpboot.c            |   3 +
 xen/arch/arm/traps.c              |  15 ++-
 xen/arch/arm/xen.lds.S            |  10 ++
 xen/include/asm-arm/alternative.h | 165 ++++++++++++++++++++++++++++
 xen/include/asm-arm/arm64/brk.h   |  39 +++++++
 xen/include/asm-arm/arm64/bug.h   |   5 +-
 xen/include/asm-arm/arm64/insn.h  |  88 +++++++++++++++
 xen/include/asm-arm/arm64/io.h    |  21 +++-
 xen/include/asm-arm/arm64/page.h  |  13 ++-
 xen/include/asm-arm/cpuerrata.h   |   6 ++
 xen/include/asm-arm/cpufeature.h  |  47 ++++++++
 xen/include/asm-arm/insn.h        |  20 ++++
 xen/include/asm-arm/page.h        |   1 +
 xen/include/asm-arm/processor.h   |  43 +++++++-
 26 files changed, 1198 insertions(+), 45 deletions(-)
 create mode 100644 docs/misc/arm/silicon-errata.txt
 create mode 100644 xen/arch/arm/alternative.c
 create mode 100644 xen/arch/arm/arm64/insn.c
 create mode 100644 xen/arch/arm/cpuerrata.c
 create mode 100644 xen/arch/arm/cpufeature.c
 create mode 100644 xen/include/asm-arm/alternative.h
 create mode 100644 xen/include/asm-arm/arm64/brk.h
 create mode 100644 xen/include/asm-arm/arm64/insn.h
 create mode 100644 xen/include/asm-arm/cpuerrata.h
 create mode 100644 xen/include/asm-arm/insn.h

-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 01/16] xen/arm: Makefile: Sort the entries alphabetically
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 02/16] xen/arm: Include the header asm-arm/system.h in asm-arm/page.h Julien Grall
                   ` (14 subsequent siblings)
  15 siblings, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v3:
        - Rebase on staging (conflict with s/xsplice/livepatch).

    Changes in v2:
        - Add Stefano's acked-by
---
 xen/arch/arm/Makefile           | 40 +++++++++++++++++++++-------------------
 xen/arch/arm/arm32/Makefile     |  9 ++++-----
 xen/arch/arm/arm64/Makefile     | 12 +++++-------
 xen/arch/arm/platforms/Makefile |  2 +-
 4 files changed, 31 insertions(+), 32 deletions(-)

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index af4d0e1..bd93013 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -4,43 +4,45 @@ subdir-y += platforms
 subdir-$(CONFIG_ARM_64) += efi
 subdir-$(CONFIG_ACPI) += acpi
 
-obj-$(EARLY_PRINTK) += early_printk.o
+obj-y += bootfdt.o
 obj-y += cpu.o
+obj-y += decode.o
+obj-y += device.o
 obj-y += domain.o
-obj-y += psci.o
-obj-y += vpsci.o
-obj-y += domctl.o
-obj-y += sysctl.o
 obj-y += domain_build.o
-obj-y += gic.o gic-v2.o
+obj-y += domctl.o
+obj-$(EARLY_PRINTK) += early_printk.o
+obj-y += gic.o
+obj-y += gic-v2.o
 obj-$(CONFIG_HAS_GICV3) += gic-v3.o
+obj-y += guestcopy.o
+obj-y += hvm.o
 obj-y += io.o
 obj-y += irq.o
 obj-y += kernel.o
+obj-$(CONFIG_LIVEPATCH) += livepatch.o
 obj-y += mm.o
 obj-y += p2m.o
 obj-y += percpu.o
-obj-y += guestcopy.o
-obj-y += physdev.o
 obj-y += platform.o
 obj-y += platform_hypercall.o
+obj-y += physdev.o
+obj-y += processor.o
+obj-y += psci.o
 obj-y += setup.o
-obj-y += bootfdt.o
-obj-y += time.o
-obj-y += smpboot.o
-obj-y += smp.o
 obj-y += shutdown.o
+obj-y += smc.o
+obj-y += smp.o
+obj-y += smpboot.o
+obj-y += sysctl.o
+obj-y += time.o
 obj-y += traps.o
-obj-y += vgic.o vgic-v2.o
+obj-y += vgic.o
+obj-y += vgic-v2.o
 obj-$(CONFIG_ARM_64) += vgic-v3.o
 obj-y += vtimer.o
+obj-y += vpsci.o
 obj-y += vuart.o
-obj-y += hvm.o
-obj-y += device.o
-obj-y += decode.o
-obj-y += processor.o
-obj-y += smc.o
-obj-$(CONFIG_LIVEPATCH) += livepatch.o
 
 #obj-bin-y += ....o
 
diff --git a/xen/arch/arm/arm32/Makefile b/xen/arch/arm/arm32/Makefile
index df0e7de..b20db64 100644
--- a/xen/arch/arm/arm32/Makefile
+++ b/xen/arch/arm/arm32/Makefile
@@ -1,12 +1,11 @@
 subdir-y += lib
 
+obj-$(EARLY_PRINTK) += debug.o
+obj-y += domctl.o
+obj-y += domain.o
 obj-y += entry.o
 obj-y += proc-v7.o proc-caxx.o
-
+obj-y += smpboot.o
 obj-y += traps.o
-obj-y += domain.o
 obj-y += vfp.o
-obj-y += smpboot.o
-obj-y += domctl.o
 
-obj-$(EARLY_PRINTK) += debug.o
diff --git a/xen/arch/arm/arm64/Makefile b/xen/arch/arm/arm64/Makefile
index c7243f5..39c6ac6 100644
--- a/xen/arch/arm/arm64/Makefile
+++ b/xen/arch/arm/arm64/Makefile
@@ -1,12 +1,10 @@
 subdir-y += lib
 
+obj-y += cache.o
+obj-$(EARLY_PRINTK) += debug.o
+obj-y += domctl.o
+obj-y += domain.o
 obj-y += entry.o
-
+obj-y += smpboot.o
 obj-y += traps.o
-obj-y += domain.o
 obj-y += vfp.o
-obj-y += smpboot.o
-obj-y += domctl.o
-obj-y += cache.o
-
-obj-$(EARLY_PRINTK) += debug.o
diff --git a/xen/arch/arm/platforms/Makefile b/xen/arch/arm/platforms/Makefile
index 3689eec..49fa683 100644
--- a/xen/arch/arm/platforms/Makefile
+++ b/xen/arch/arm/platforms/Makefile
@@ -3,8 +3,8 @@ obj-$(CONFIG_ARM_32) += brcm.o
 obj-$(CONFIG_ARM_32) += exynos5.o
 obj-$(CONFIG_ARM_32) += midway.o
 obj-$(CONFIG_ARM_32) += omap5.o
-obj-$(CONFIG_ARM_32) += sunxi.o
 obj-$(CONFIG_ARM_32) += rcar2.o
 obj-$(CONFIG_ARM_64) += seattle.o
+obj-$(CONFIG_ARM_32) += sunxi.o
 obj-$(CONFIG_ARM_64) += xgene-storm.o
 obj-$(CONFIG_ARM_64) += xilinx-zynqmp.o
-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 02/16] xen/arm: Include the header asm-arm/system.h in asm-arm/page.h
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
  2016-06-07 16:06 ` [PATCH v3 01/16] xen/arm: Makefile: Sort the entries alphabetically Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 03/16] xen/arm: Add macros to handle the MIDR Julien Grall
                   ` (13 subsequent siblings)
  15 siblings, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

The header asm-arm/page.h makes use of the macro dsb defined in the header
asm-arm/system.h. Currently, the includer has to specify both of them.

This can be avoided by including asm-arm/system.h in asm-arm/page.h.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v2:
        - Add Stefano's acked-by
---
 xen/include/asm-arm/page.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xen/include/asm-arm/page.h b/xen/include/asm-arm/page.h
index a94e978..05d9f82 100644
--- a/xen/include/asm-arm/page.h
+++ b/xen/include/asm-arm/page.h
@@ -84,6 +84,7 @@
 #include <xen/errno.h>
 #include <xen/types.h>
 #include <xen/lib.h>
+#include <asm/system.h>
 
 /* WARNING!  Unlike the Intel pagetable code, where l1 is the lowest
  * level and l4 is the root of the trie, the ARM pagetables follow ARM's
-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 03/16] xen/arm: Add macros to handle the MIDR
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
  2016-06-07 16:06 ` [PATCH v3 01/16] xen/arm: Makefile: Sort the entries alphabetically Julien Grall
  2016-06-07 16:06 ` [PATCH v3 02/16] xen/arm: Include the header asm-arm/system.h in asm-arm/page.h Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 04/16] xen/arm: Add cpu_hwcap bitmap Julien Grall
                   ` (12 subsequent siblings)
  15 siblings, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

Add new macros to easily get different parts of the register and to
check if a given MIDR match a CPU model range. The latter will be really
useful to handle errata later.

The macros have been imported from the header
arch/arm64/include/asm/cputype.h in Linux v4.6-rc3.

Also remove MIDR_MASK which is unused.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v2:
        - Add Stefano's acked-by
---
 xen/include/asm-arm/processor.h | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
index 284ad6a..dba9b9a 100644
--- a/xen/include/asm-arm/processor.h
+++ b/xen/include/asm-arm/processor.h
@@ -9,7 +9,40 @@
 #include <public/arch-arm.h>
 
 /* MIDR Main ID Register */
-#define MIDR_MASK    0xff0ffff0
+#define MIDR_REVISION_MASK      0xf
+#define MIDR_RESIVION(midr)     ((midr) & MIDR_REVISION_MASK)
+#define MIDR_PARTNUM_SHIFT      4
+#define MIDR_PARTNUM_MASK       (0xfff << MIDR_PARTNUM_SHIFT)
+#define MIDR_PARTNUM(midr) \
+    (((midr) & MIDR_PARTNUM_MASK) >> MIDR_PARTNUM_SHIFT)
+#define MIDR_ARCHITECTURE_SHIFT 16
+#define MIDR_ARCHITECTURE_MASK  (0xf << MIDR_ARCHITECTURE_SHIFT)
+#define MIDR_ARCHITECTURE(midr) \
+    (((midr) & MIDR_ARCHITECTURE_MASK) >> MIDR_ARCHITECTURE_SHIFT)
+#define MIDR_VARIANT_SHIFT      20
+#define MIDR_VARIANT_MASK       (0xf << MIDR_VARIANT_SHIFT)
+#define MIDR_VARIANT(midr) \
+    (((midr) & MIDR_VARIANT_MASK) >> MIDR_VARIANT_SHIFT)
+#define MIDR_IMPLEMENTOR_SHIFT  24
+#define MIDR_IMPLEMENTOR_MASK   (0xff << MIDR_IMPLEMENTOR_SHIFT)
+#define MIDR_IMPLEMENTOR(midr) \
+    (((midr) & MIDR_IMPLEMENTOR_MASK) >> MIDR_IMPLEMENTOR_SHIFT)
+
+#define MIDR_CPU_MODEL(imp, partnum)            \
+    (((imp)     << MIDR_IMPLEMENTOR_SHIFT) |    \
+     (0xf       << MIDR_ARCHITECTURE_SHIFT) |   \
+     ((partnum) << MIDR_PARTNUM_SHIFT))
+
+#define MIDR_CPU_MODEL_MASK \
+     (MIDR_IMPLEMENTOR_MASK | MIDR_PARTNUM_MASK | MIDR_ARCHITECTURE_MASK)
+
+#define MIDR_IS_CPU_MODEL_RANGE(midr, model, rv_min, rv_max)            \
+({                                                                      \
+        u32 _model = (midr) & MIDR_CPU_MODEL_MASK;                      \
+        u32 _rv = (midr) & (MIDR_REVISION_MASK | MIDR_VARIANT_MASK);    \
+                                                                        \
+        _model == (model) && _rv >= (rv_min) && _rv <= (rv_max);        \
+})
 
 /* MPIDR Multiprocessor Affinity Register */
 #define _MPIDR_UP           (30)
-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 04/16] xen/arm: Add cpu_hwcap bitmap
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (2 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 03/16] xen/arm: Add macros to handle the MIDR Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 05/16] xen/arm64: Add an helper to invalidate all instruction caches Julien Grall
                   ` (11 subsequent siblings)
  15 siblings, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

This will be used to know if a feature, which Xen cares, is available accross
all the CPUs.

This code is a light version of arch/arm64/kernel/cpufeature.c from
Linux v4.6-rc3.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v3:
        - Add Stefano's reviewed-by
---
 xen/arch/arm/Makefile            |  1 +
 xen/arch/arm/cpufeature.c        | 34 ++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/cpufeature.h | 29 +++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+)
 create mode 100644 xen/arch/arm/cpufeature.c

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index bd93013..b95d924 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -6,6 +6,7 @@ subdir-$(CONFIG_ACPI) += acpi
 
 obj-y += bootfdt.o
 obj-y += cpu.o
+obj-y += cpufeature.o
 obj-y += decode.o
 obj-y += device.o
 obj-y += domain.o
diff --git a/xen/arch/arm/cpufeature.c b/xen/arch/arm/cpufeature.c
new file mode 100644
index 0000000..7a1b56b
--- /dev/null
+++ b/xen/arch/arm/cpufeature.c
@@ -0,0 +1,34 @@
+/*
+ * Contains CPU feature definitions
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <xen/config.h>
+#include <xen/types.h>
+#include <xen/init.h>
+#include <xen/smp.h>
+#include <asm/cpufeature.h>
+
+DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS);
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
index 7b519cd..2bebad1 100644
--- a/xen/include/asm-arm/cpufeature.h
+++ b/xen/include/asm-arm/cpufeature.h
@@ -35,6 +35,35 @@
 #endif
 #define cpu_has_security  (boot_cpu_feature32(security) > 0)
 
+#define ARM_NCAPS           0
+
+#ifndef __ASSEMBLY__
+
+#include <xen/types.h>
+#include <xen/lib.h>
+#include <xen/bitops.h>
+
+extern DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS);
+
+static inline bool_t cpus_have_cap(unsigned int num)
+{
+    if ( num >= ARM_NCAPS )
+        return 0;
+
+    return test_bit(num, cpu_hwcaps);
+}
+
+static inline void cpus_set_cap(unsigned int num)
+{
+    if (num >= ARM_NCAPS)
+        printk(XENLOG_WARNING "Attempt to set an illegal CPU capability (%d >= %d)\n",
+               num, ARM_NCAPS);
+    else
+        __set_bit(num, cpu_hwcaps);
+}
+
+#endif /* __ASSEMBLY__ */
+
 #endif
 /*
  * Local variables:
-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 05/16] xen/arm64: Add an helper to invalidate all instruction caches
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (3 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 04/16] xen/arm: Add cpu_hwcap bitmap Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 06/16] xen/arm: arm64: Move the define BRK_BUG_FRAME into a separate header Julien Grall
                   ` (10 subsequent siblings)
  15 siblings, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v2:
        - Add Stefano's acked-by
---
 xen/include/asm-arm/arm64/page.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/xen/include/asm-arm/arm64/page.h b/xen/include/asm-arm/arm64/page.h
index 29a32cf..fbdc8fb 100644
--- a/xen/include/asm-arm/arm64/page.h
+++ b/xen/include/asm-arm/arm64/page.h
@@ -24,6 +24,12 @@ static inline void write_pte(lpae_t *p, lpae_t pte)
  * inline asm operand) */
 #define __clean_and_invalidate_dcache_one(R) "dc  civac, %" #R ";"
 
+/* Invalidate all instruction caches in Inner Shareable domain to PoU */
+static inline void invalidate_icache(void)
+{
+    asm volatile ("ic ialluis");
+}
+
 /*
  * Flush all hypervisor mappings from the TLB of the local processor.
  *
-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 06/16] xen/arm: arm64: Move the define BRK_BUG_FRAME into a separate header
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (4 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 05/16] xen/arm64: Add an helper to invalidate all instruction caches Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 07/16] xen/arm: arm64: Reserve a brk immediate to fault on purpose Julien Grall
                   ` (9 subsequent siblings)
  15 siblings, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

New immediates will be defined in the future. To keep track of the
immediates allocated, gather all of them in a separate header.

Also rename BRK_BUG_FRAME to BKR_BUG_FRAME_IMM.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v2:
        - Add Stefano's reviewed-by
---
 xen/arch/arm/traps.c            |  2 +-
 xen/include/asm-arm/arm64/brk.h | 26 ++++++++++++++++++++++++++
 xen/include/asm-arm/arm64/bug.h |  5 ++---
 3 files changed, 29 insertions(+), 4 deletions(-)
 create mode 100644 xen/include/asm-arm/arm64/brk.h

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index aa3e3c2..a4eedca 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -1203,7 +1203,7 @@ static void do_trap_brk(struct cpu_user_regs *regs, const union hsr hsr)
 
     switch (hsr.brk.comment)
     {
-    case BRK_BUG_FRAME:
+    case BRK_BUG_FRAME_IMM:
         if ( do_bug_frame(regs, regs->pc) )
             goto die;
 
diff --git a/xen/include/asm-arm/arm64/brk.h b/xen/include/asm-arm/arm64/brk.h
new file mode 100644
index 0000000..7867b07
--- /dev/null
+++ b/xen/include/asm-arm/arm64/brk.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2016 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_ARM_ARM64_BRK
+#define __ASM_ARM_ARM64_BRK
+
+/*
+ * #imm16 values used for BRK instruction generation
+ * 0x001: xen-mode BUG() and WARN() traps
+ */
+#define BRK_BUG_FRAME_IMM   1
+
+#endif /* !__ASM_ARM_ARM64_BRK */
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/asm-arm/arm64/bug.h b/xen/include/asm-arm/arm64/bug.h
index 42b0e4f..59f664d 100644
--- a/xen/include/asm-arm/arm64/bug.h
+++ b/xen/include/asm-arm/arm64/bug.h
@@ -2,9 +2,8 @@
 #define __ARM_ARM64_BUG_H__
 
 #include <xen/stringify.h>
+#include <asm/arm64/brk.h>
 
-#define BRK_BUG_FRAME 1
-
-#define BUG_INSTR "brk " __stringify(BRK_BUG_FRAME)
+#define BUG_INSTR "brk " __stringify(BRK_BUG_FRAME_IMM)
 
 #endif /* __ARM_ARM64_BUG_H__ */
-- 
1.9.1


_______________________________________________
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Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 07/16] xen/arm: arm64: Reserve a brk immediate to fault on purpose
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (5 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 06/16] xen/arm: arm64: Move the define BRK_BUG_FRAME into a separate header Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 08/16] xen/arm: arm64: Add helpers to decode and encode branch instructions Julien Grall
                   ` (8 subsequent siblings)
  15 siblings, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

It may not possible to return a proper error when encoding an
instruction. Instead, a handcrafted instruction will be returned.

Also, provide the encoding for the faulting instruction.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v2:
        - Add Stefano's acked-by
---
 xen/include/asm-arm/arm64/brk.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/xen/include/asm-arm/arm64/brk.h b/xen/include/asm-arm/arm64/brk.h
index 7867b07..04442c4 100644
--- a/xen/include/asm-arm/arm64/brk.h
+++ b/xen/include/asm-arm/arm64/brk.h
@@ -12,8 +12,21 @@
 /*
  * #imm16 values used for BRK instruction generation
  * 0x001: xen-mode BUG() and WARN() traps
+ * 0x002: for triggering a fault on purpose (reserved)
  */
 #define BRK_BUG_FRAME_IMM   1
+#define BRK_FAULT_IMM       2
+
+/*
+ * BRK instruction encoding
+ * The #imm16 value should be placed at bits[20:5] within BRK ins
+ */
+#define AARCH64_BREAK_MON 0xd4200000
+
+/*
+ * BRK instruction for provoking a fault on purpose
+ */
+#define AARCH64_BREAK_FAULT (AARCH64_BREAK_MON | (BRK_FAULT_IMM << 5))
 
 #endif /* !__ASM_ARM_ARM64_BRK */
 /*
-- 
1.9.1


_______________________________________________
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http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 08/16] xen/arm: arm64: Add helpers to decode and encode branch instructions
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (6 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 07/16] xen/arm: arm64: Reserve a brk immediate to fault on purpose Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching Julien Grall
                   ` (7 subsequent siblings)
  15 siblings, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

We may need to update branch instruction when patching Xen.

The code has been imported from the files arch/arm64/kernel/insn.c
and arch/arm64/include/asm/insn.h in Linux v4.6.

Note that only the necessary helpers have been imported.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v3:
        - Add Stefano's acked-by

    Changes in v2:
        - Re-sync with Linux v4.6
        - Drop any reference to arm32
---
 xen/arch/arm/arm64/Makefile      |   1 +
 xen/arch/arm/arm64/insn.c        | 219 +++++++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/arm64/insn.h |  72 +++++++++++++
 xen/include/asm-arm/insn.h       |  20 ++++
 4 files changed, 312 insertions(+)
 create mode 100644 xen/arch/arm/arm64/insn.c
 create mode 100644 xen/include/asm-arm/arm64/insn.h
 create mode 100644 xen/include/asm-arm/insn.h

diff --git a/xen/arch/arm/arm64/Makefile b/xen/arch/arm/arm64/Makefile
index 39c6ac6..c1fa43f 100644
--- a/xen/arch/arm/arm64/Makefile
+++ b/xen/arch/arm/arm64/Makefile
@@ -5,6 +5,7 @@ obj-$(EARLY_PRINTK) += debug.o
 obj-y += domctl.o
 obj-y += domain.o
 obj-y += entry.o
+obj-y += insn.o
 obj-y += smpboot.o
 obj-y += traps.o
 obj-y += vfp.o
diff --git a/xen/arch/arm/arm64/insn.c b/xen/arch/arm/arm64/insn.c
new file mode 100644
index 0000000..12b4d96
--- /dev/null
+++ b/xen/arch/arm/arm64/insn.c
@@ -0,0 +1,219 @@
+/*
+ * Based on Linux v4.6 arch/arm64/kernel.ins.c
+ *
+ * Copyright (C) 2013 Huawei Ltd.
+ * Author: Jiang Liu <liuj97@gmail.com>
+ *
+ * Copyright (C) 2014-2016 Zi Shen Lim <zlim.lnx@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <xen/config.h>
+#include <xen/types.h>
+#include <xen/lib.h>
+#include <xen/errno.h>
+#include <xen/sizes.h>
+#include <xen/bitops.h>
+#include <asm/insn.h>
+#include <asm/arm64/insn.h>
+
+#define __kprobes
+#define pr_err(fmt, ...) printk(XENLOG_ERR fmt, ## __VA_ARGS__)
+
+bool aarch64_insn_is_branch_imm(u32 insn)
+{
+	return (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn) ||
+		aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn) ||
+		aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
+		aarch64_insn_is_bcond(insn));
+}
+
+static int __kprobes aarch64_get_imm_shift_mask(enum aarch64_insn_imm_type type,
+						u32 *maskp, int *shiftp)
+{
+	u32 mask;
+	int shift;
+
+	switch (type) {
+	case AARCH64_INSN_IMM_26:
+		mask = BIT(26) - 1;
+		shift = 0;
+		break;
+	case AARCH64_INSN_IMM_19:
+		mask = BIT(19) - 1;
+		shift = 5;
+		break;
+	case AARCH64_INSN_IMM_16:
+		mask = BIT(16) - 1;
+		shift = 5;
+		break;
+	case AARCH64_INSN_IMM_14:
+		mask = BIT(14) - 1;
+		shift = 5;
+		break;
+	case AARCH64_INSN_IMM_12:
+		mask = BIT(12) - 1;
+		shift = 10;
+		break;
+	case AARCH64_INSN_IMM_9:
+		mask = BIT(9) - 1;
+		shift = 12;
+		break;
+	case AARCH64_INSN_IMM_7:
+		mask = BIT(7) - 1;
+		shift = 15;
+		break;
+	case AARCH64_INSN_IMM_6:
+	case AARCH64_INSN_IMM_S:
+		mask = BIT(6) - 1;
+		shift = 10;
+		break;
+	case AARCH64_INSN_IMM_R:
+		mask = BIT(6) - 1;
+		shift = 16;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	*maskp = mask;
+	*shiftp = shift;
+
+	return 0;
+}
+
+#define ADR_IMM_HILOSPLIT	2
+#define ADR_IMM_SIZE		SZ_2M
+#define ADR_IMM_LOMASK		((1 << ADR_IMM_HILOSPLIT) - 1)
+#define ADR_IMM_HIMASK		((ADR_IMM_SIZE >> ADR_IMM_HILOSPLIT) - 1)
+#define ADR_IMM_LOSHIFT		29
+#define ADR_IMM_HISHIFT		5
+
+u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn)
+{
+	u32 immlo, immhi, mask;
+	int shift;
+
+	switch (type) {
+	case AARCH64_INSN_IMM_ADR:
+		shift = 0;
+		immlo = (insn >> ADR_IMM_LOSHIFT) & ADR_IMM_LOMASK;
+		immhi = (insn >> ADR_IMM_HISHIFT) & ADR_IMM_HIMASK;
+		insn = (immhi << ADR_IMM_HILOSPLIT) | immlo;
+		mask = ADR_IMM_SIZE - 1;
+		break;
+	default:
+		if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
+			pr_err("aarch64_insn_decode_immediate: unknown immediate encoding %d\n",
+			       type);
+			return 0;
+		}
+	}
+
+	return (insn >> shift) & mask;
+}
+
+u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
+				  u32 insn, u64 imm)
+{
+	u32 immlo, immhi, mask;
+	int shift;
+
+	if (insn == AARCH64_BREAK_FAULT)
+		return AARCH64_BREAK_FAULT;
+
+	switch (type) {
+	case AARCH64_INSN_IMM_ADR:
+		shift = 0;
+		immlo = (imm & ADR_IMM_LOMASK) << ADR_IMM_LOSHIFT;
+		imm >>= ADR_IMM_HILOSPLIT;
+		immhi = (imm & ADR_IMM_HIMASK) << ADR_IMM_HISHIFT;
+		imm = immlo | immhi;
+		mask = ((ADR_IMM_LOMASK << ADR_IMM_LOSHIFT) |
+			(ADR_IMM_HIMASK << ADR_IMM_HISHIFT));
+		break;
+	default:
+		if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
+			pr_err("aarch64_insn_encode_immediate: unknown immediate encoding %d\n",
+			       type);
+			return AARCH64_BREAK_FAULT;
+		}
+	}
+
+	/* Update the immediate field. */
+	insn &= ~(mask << shift);
+	insn |= (imm & mask) << shift;
+
+	return insn;
+}
+
+/*
+ * Decode the imm field of a branch, and return the byte offset as a
+ * signed value (so it can be used when computing a new branch
+ * target).
+ */
+s32 aarch64_get_branch_offset(u32 insn)
+{
+	s32 imm;
+
+	if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn)) {
+		imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_26, insn);
+		return (imm << 6) >> 4;
+	}
+
+	if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
+	    aarch64_insn_is_bcond(insn)) {
+		imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_19, insn);
+		return (imm << 13) >> 11;
+	}
+
+	if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn)) {
+		imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_14, insn);
+		return (imm << 18) >> 16;
+	}
+
+	/* Unhandled instruction */
+	BUG();
+}
+
+/*
+ * Encode the displacement of a branch in the imm field and return the
+ * updated instruction.
+ */
+u32 aarch64_set_branch_offset(u32 insn, s32 offset)
+{
+	if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn))
+		return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
+						     offset >> 2);
+
+	if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
+	    aarch64_insn_is_bcond(insn))
+		return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
+						     offset >> 2);
+
+	if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn))
+		return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_14, insn,
+						     offset >> 2);
+
+	/* Unhandled instruction */
+	BUG();
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 8
+ * indent-tabs-mode: t
+ * End:
+ */
diff --git a/xen/include/asm-arm/arm64/insn.h b/xen/include/asm-arm/arm64/insn.h
new file mode 100644
index 0000000..cfcdbe9
--- /dev/null
+++ b/xen/include/asm-arm/arm64/insn.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2013 Huawei Ltd.
+ * Author: Jiang Liu <liuj97@gmail.com>
+ *
+ * Copyright (C) 2014 Zi Shen Lim <zlim.lnx@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __ARCH_ARM_ARM64_INSN
+#define __ARCH_ARM_ARM64_INSN
+
+#include <xen/config.h>
+#include <xen/types.h>
+#include <xen/stdbool.h>
+
+enum aarch64_insn_imm_type {
+	AARCH64_INSN_IMM_ADR,
+	AARCH64_INSN_IMM_26,
+	AARCH64_INSN_IMM_19,
+	AARCH64_INSN_IMM_16,
+	AARCH64_INSN_IMM_14,
+	AARCH64_INSN_IMM_12,
+	AARCH64_INSN_IMM_9,
+	AARCH64_INSN_IMM_7,
+	AARCH64_INSN_IMM_6,
+	AARCH64_INSN_IMM_S,
+	AARCH64_INSN_IMM_R,
+	AARCH64_INSN_IMM_MAX
+};
+
+#define	__AARCH64_INSN_FUNCS(abbr, mask, val)	\
+static always_inline bool_t aarch64_insn_is_##abbr(u32 code) \
+{ return (code & (mask)) == (val); } \
+static always_inline u32 aarch64_insn_get_##abbr##_value(void) \
+{ return (val); }
+
+__AARCH64_INSN_FUNCS(b,		0xFC000000, 0x14000000)
+__AARCH64_INSN_FUNCS(bl,	0xFC000000, 0x94000000)
+__AARCH64_INSN_FUNCS(cbz,	0x7F000000, 0x34000000)
+__AARCH64_INSN_FUNCS(cbnz,	0x7F000000, 0x35000000)
+__AARCH64_INSN_FUNCS(tbz,	0x7F000000, 0x36000000)
+__AARCH64_INSN_FUNCS(tbnz,	0x7F000000, 0x37000000)
+__AARCH64_INSN_FUNCS(bcond,	0xFF000010, 0x54000000)
+
+bool aarch64_insn_is_branch_imm(u32 insn);
+
+u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn);
+u32 aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
+				  u32 insn, u64 imm);
+
+s32 aarch64_get_branch_offset(u32 insn);
+u32 aarch64_set_branch_offset(u32 insn, s32 offset);
+
+#endif /* !__ARCH_ARM_ARM64_INSN */
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 8
+ * indent-tabs-mode: t
+ * End:
+ */
diff --git a/xen/include/asm-arm/insn.h b/xen/include/asm-arm/insn.h
new file mode 100644
index 0000000..a205ceb
--- /dev/null
+++ b/xen/include/asm-arm/insn.h
@@ -0,0 +1,20 @@
+#ifndef __ARCH_ARM_INSN
+#define __ARCH_ARM_INSN
+
+#include <xen/types.h>
+
+#if defined(CONFIG_ARM_64)
+# include <asm/arm64/insn.h>
+#else
+# error "unknown ARM variant"
+#endif
+
+#endif /* !__ARCH_ARM_INSN */
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 8
+ * indent-tabs-mode: t
+ * End:
+ */
-- 
1.9.1


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (7 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 08/16] xen/arm: arm64: Add helpers to decode and encode branch instructions Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 17:24   ` Konrad Rzeszutek Wilk
  2016-06-09 13:33   ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 10/16] xen/arm: cpufeature: Provide an helper to check if a capability is supported Julien Grall
                   ` (6 subsequent siblings)
  15 siblings, 2 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

Some of the processor erratum will require to modify code sequence.
As those modifications may impact the performance, they should only
be enabled on affected cores. Furthermore, Xen may also want to take
advantage of new hardware features coming up with v8.1 and v8.2.

This patch adds an infrastructure to patch Xen during boot time
depending on the "features" available on the platform.

This code is based on the file arch/arm64/kernel/alternative.c in
Linux 4.6-rc3. Any references to arm64 have been dropped to make the
code as generic as possible.

When Xen is creating the page tables, all the executable sections
(.text and .init.text) will be marked read-only and then enforced by
setting SCTLR.WNX.

Whilst it might be possible to mark those entries read-only after
Xen has been patched, we would need extra care to avoid possible
TLBs conflicts (see D4-1732 in ARM DDI 0487A.i) as all
physical CPUs will be running.

All the physical CPUs have to be brought up before patching Xen because
each cores may have different errata/features which require code
patching. The only way to find them is to probe system registers on
each CPU.

To avoid extra complexity, it is possible to create a temporary
writeable mapping with vmap. This mapping will be used to write the
new instructions.

Lastly, runtime patching is currently not necessary for ARM32. So the
code is only enabled for ARM64.

Signed-off-by: Julien Grall <julien.grall@arm.com>

---
    Changes in v2:
        - Use hard tabs in Kconfig
        - Update the copyright year
        - Update the commit message to explain the extra mapping

    Changes in v3:
        - .altinstr_replacement should live in init.text
        - Add a comment to explain when apply_alternatives_all should be
        called.
---
 xen/arch/arm/Kconfig              |   5 +
 xen/arch/arm/Makefile             |   1 +
 xen/arch/arm/alternative.c        | 221 ++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/setup.c              |   7 ++
 xen/arch/arm/xen.lds.S            |  10 ++
 xen/include/asm-arm/alternative.h | 165 ++++++++++++++++++++++++++++
 xen/include/asm-arm/arm64/insn.h  |  16 +++
 7 files changed, 425 insertions(+)
 create mode 100644 xen/arch/arm/alternative.c
 create mode 100644 xen/include/asm-arm/alternative.h

diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 6231cd5..0141bd9 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -14,6 +14,7 @@ config ARM_64
 	def_bool y
 	depends on 64BIT
 	select HAS_GICV3
+	select ALTERNATIVE
 
 config ARM
 	def_bool y
@@ -46,6 +47,10 @@ config ACPI
 config HAS_GICV3
 	bool
 
+# Select ALTERNATIVE if the architecture supports runtime patching
+config ALTERNATIVE
+	bool
+
 endmenu
 
 source "common/Kconfig"
diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index b95d924..67ccc43 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -4,6 +4,7 @@ subdir-y += platforms
 subdir-$(CONFIG_ARM_64) += efi
 subdir-$(CONFIG_ACPI) += acpi
 
+obj-$(CONFIG_ALTERNATIVE) += alternative.o
 obj-y += bootfdt.o
 obj-y += cpu.o
 obj-y += cpufeature.o
diff --git a/xen/arch/arm/alternative.c b/xen/arch/arm/alternative.c
new file mode 100644
index 0000000..d00f98e
--- /dev/null
+++ b/xen/arch/arm/alternative.c
@@ -0,0 +1,221 @@
+/*
+ * alternative runtime patching
+ * inspired by the x86 version
+ *
+ * Copyright (C) 2014-2016 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <xen/config.h>
+#include <xen/init.h>
+#include <xen/types.h>
+#include <xen/kernel.h>
+#include <xen/mm.h>
+#include <xen/vmap.h>
+#include <xen/smp.h>
+#include <xen/stop_machine.h>
+#include <asm/alternative.h>
+#include <asm/atomic.h>
+#include <asm/byteorder.h>
+#include <asm/cpufeature.h>
+#include <asm/insn.h>
+#include <asm/page.h>
+
+#define __ALT_PTR(a,f)      (u32 *)((void *)&(a)->f + (a)->f)
+#define ALT_ORIG_PTR(a)     __ALT_PTR(a, orig_offset)
+#define ALT_REPL_PTR(a)     __ALT_PTR(a, alt_offset)
+
+extern const struct alt_instr __alt_instructions[], __alt_instructions_end[];
+
+struct alt_region {
+    const struct alt_instr *begin;
+    const struct alt_instr *end;
+};
+
+/*
+ * Check if the target PC is within an alternative block.
+ */
+static bool_t branch_insn_requires_update(const struct alt_instr *alt,
+                                          unsigned long pc)
+{
+    unsigned long replptr;
+
+    if ( is_active_kernel_text(pc) )
+        return 1;
+
+    replptr = (unsigned long)ALT_REPL_PTR(alt);
+    if ( pc >= replptr && pc <= (replptr + alt->alt_len) )
+        return 0;
+
+    /*
+     * Branching into *another* alternate sequence is doomed, and
+     * we're not even trying to fix it up.
+     */
+    BUG();
+}
+
+static u32 get_alt_insn(const struct alt_instr *alt,
+                        const u32 *insnptr, const u32 *altinsnptr)
+{
+    u32 insn;
+
+    insn = le32_to_cpu(*altinsnptr);
+
+    if ( insn_is_branch_imm(insn) )
+    {
+        s32 offset = insn_get_branch_offset(insn);
+        unsigned long target;
+
+        target = (unsigned long)altinsnptr + offset;
+
+        /*
+         * If we're branching inside the alternate sequence,
+         * do not rewrite the instruction, as it is already
+         * correct. Otherwise, generate the new instruction.
+         */
+        if ( branch_insn_requires_update(alt, target) )
+        {
+            offset = target - (unsigned long)insnptr;
+            insn = insn_set_branch_offset(insn, offset);
+        }
+    }
+
+    return insn;
+}
+
+static int __apply_alternatives(const struct alt_region *region)
+{
+    const struct alt_instr *alt;
+    const u32 *origptr, *replptr;
+    u32 *writeptr, *writemap;
+    mfn_t text_mfn = _mfn(virt_to_mfn(_stext));
+    unsigned int text_order = get_order_from_bytes(_end - _start);
+
+    printk("Patching kernel code\n");
+
+    /*
+     * The text section is read-only. So re-map Xen to be able to patch
+     * the code.
+     */
+    writemap = __vmap(&text_mfn, 1 << text_order, 1, 1, PAGE_HYPERVISOR,
+                      VMAP_DEFAULT);
+    if ( !writemap )
+    {
+        printk("alternatives: Unable to map the text section\n");
+        return -ENOMEM;
+    }
+
+    for ( alt = region->begin; alt < region->end; alt++ )
+    {
+        u32 insn;
+        int i, nr_inst;
+
+        if ( !cpus_have_cap(alt->cpufeature) )
+            continue;
+
+        BUG_ON(alt->alt_len != alt->orig_len);
+
+        origptr = ALT_ORIG_PTR(alt);
+        writeptr = origptr - (u32 *)_start + writemap;
+        replptr = ALT_REPL_PTR(alt);
+
+        nr_inst = alt->alt_len / sizeof(insn);
+
+        for ( i = 0; i < nr_inst; i++ )
+        {
+            insn = get_alt_insn(alt, origptr + i, replptr + i);
+            *(writeptr + i) = cpu_to_le32(insn);
+        }
+
+        /* Ensure the new instructions reached the memory and nuke */
+        clean_and_invalidate_dcache_va_range(writeptr,
+                                             (sizeof (*writeptr) * nr_inst));
+    }
+
+    /* Nuke the instruction cache */
+    invalidate_icache();
+
+    vunmap(writemap);
+
+    return 0;
+}
+
+/*
+ * We might be patching the stop_machine state machine, so implement a
+ * really simple polling protocol here.
+ */
+static int __apply_alternatives_multi_stop(void *unused)
+{
+    static int patched = 0;
+    struct alt_region region = {
+        .begin = __alt_instructions,
+        .end = __alt_instructions_end,
+    };
+
+    /* We always have a CPU 0 at this point (__init) */
+    if ( smp_processor_id() )
+    {
+        while ( !read_atomic(&patched) )
+            cpu_relax();
+        isb();
+    }
+    else
+    {
+        int ret;
+
+        BUG_ON(patched);
+        ret = __apply_alternatives(&region);
+        /* The patching is not expected to fail during boot. */
+        BUG_ON(ret != 0);
+
+        /* Barriers provided by the cache flushing */
+        write_atomic(&patched, 1);
+    }
+
+    return 0;
+}
+
+/*
+ * This function should only be called during boot and before CPU0 jump
+ * into the idle_loop.
+ */
+void __init apply_alternatives_all(void)
+{
+    int ret;
+
+	/* better not try code patching on a live SMP system */
+    ret = stop_machine_run(__apply_alternatives_multi_stop, NULL, NR_CPUS);
+
+    /* stop_machine_run should never fail at this stage of the boot */
+    BUG_ON(ret);
+}
+
+int apply_alternatives(void *start, size_t length)
+{
+    struct alt_region region = {
+        .begin = start,
+        .end = start + length,
+    };
+
+    return __apply_alternatives(&region);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 9bc11c4..01e2900 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -38,6 +38,7 @@
 #include <xen/vmap.h>
 #include <xen/libfdt/libfdt.h>
 #include <xen/acpi.h>
+#include <asm/alternative.h>
 #include <asm/page.h>
 #include <asm/current.h>
 #include <asm/setup.h>
@@ -835,6 +836,12 @@ void __init start_xen(unsigned long boot_phys_offset,
 
     do_initcalls();
 
+    /*
+     * It needs to be called after do_initcalls to be able to use
+     * stop_machine (tasklets initialized via an initcall).
+     */
+    apply_alternatives_all();
+
     /* Create initial domain 0. */
     /* The vGIC for DOM0 is exactly emulating the hardware GIC */
     config.gic_version = XEN_DOMCTL_CONFIG_GIC_NATIVE;
diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
index 1f010bd..495f9d8 100644
--- a/xen/arch/arm/xen.lds.S
+++ b/xen/arch/arm/xen.lds.S
@@ -129,6 +129,9 @@ SECTIONS
        _sinittext = .;
        *(.init.text)
        _einittext = .;
+#ifdef CONFIG_ALTERNATIVE
+       *(.altinstr_replacement)
+#endif
   } :text
   . = ALIGN(PAGE_SIZE);
   .init.data : {
@@ -167,6 +170,13 @@ SECTIONS
        *(.xsm_initcall.init)
        __xsm_initcall_end = .;
   } :text
+#ifdef CONFIG_ALTERNATIVE
+  .init.alternatives : {
+      __alt_instructions = .;
+      *(.altinstructions)
+      __alt_instructions_end = .;
+  }
+#endif
   __init_end_efi = .;
   . = ALIGN(STACK_SIZE);
   __init_end = .;
diff --git a/xen/include/asm-arm/alternative.h b/xen/include/asm-arm/alternative.h
new file mode 100644
index 0000000..7e3a610
--- /dev/null
+++ b/xen/include/asm-arm/alternative.h
@@ -0,0 +1,165 @@
+#ifndef __ASM_ALTERNATIVE_H
+#define __ASM_ALTERNATIVE_H
+
+#include <asm/cpufeature.h>
+#include <xen/config.h>
+#include <xen/kconfig.h>
+
+#ifdef CONFIG_ALTERNATIVE
+
+#ifndef __ASSEMBLY__
+
+#include <xen/init.h>
+#include <xen/types.h>
+#include <xen/stringify.h>
+
+struct alt_instr {
+	s32 orig_offset;	/* offset to original instruction */
+	s32 alt_offset;		/* offset to replacement instruction */
+	u16 cpufeature;		/* cpufeature bit set for replacement */
+	u8  orig_len;		/* size of original instruction(s) */
+	u8  alt_len;		/* size of new instruction(s), <= orig_len */
+};
+
+void __init apply_alternatives_all(void);
+int apply_alternatives(void *start, size_t length);
+
+#define ALTINSTR_ENTRY(feature)						      \
+	" .word 661b - .\n"				/* label           */ \
+	" .word 663f - .\n"				/* new instruction */ \
+	" .hword " __stringify(feature) "\n"		/* feature bit     */ \
+	" .byte 662b-661b\n"				/* source len      */ \
+	" .byte 664f-663f\n"				/* replacement len */
+
+/*
+ * alternative assembly primitive:
+ *
+ * If any of these .org directive fail, it means that insn1 and insn2
+ * don't have the same length. This used to be written as
+ *
+ * .if ((664b-663b) != (662b-661b))
+ * 	.error "Alternatives instruction length mismatch"
+ * .endif
+ *
+ * but most assemblers die if insn1 or insn2 have a .inst. This should
+ * be fixed in a binutils release posterior to 2.25.51.0.2 (anything
+ * containing commit 4e4d08cf7399b606 or c1baaddf8861).
+ */
+#define __ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg_enabled)	\
+	".if "__stringify(cfg_enabled)" == 1\n"				\
+	"661:\n\t"							\
+	oldinstr "\n"							\
+	"662:\n"							\
+	".pushsection .altinstructions,\"a\"\n"				\
+	ALTINSTR_ENTRY(feature)						\
+	".popsection\n"							\
+	".pushsection .altinstr_replacement, \"a\"\n"			\
+	"663:\n\t"							\
+	newinstr "\n"							\
+	"664:\n\t"							\
+	".popsection\n\t"						\
+	".org	. - (664b-663b) + (662b-661b)\n\t"			\
+	".org	. - (662b-661b) + (664b-663b)\n"			\
+	".endif\n"
+
+#define _ALTERNATIVE_CFG(oldinstr, newinstr, feature, cfg, ...)	\
+	__ALTERNATIVE_CFG(oldinstr, newinstr, feature, IS_ENABLED(cfg))
+
+#else
+
+#include <asm/asm_defns.h>
+
+.macro altinstruction_entry orig_offset alt_offset feature orig_len alt_len
+	.word \orig_offset - .
+	.word \alt_offset - .
+	.hword \feature
+	.byte \orig_len
+	.byte \alt_len
+.endm
+
+.macro alternative_insn insn1, insn2, cap, enable = 1
+	.if \enable
+661:	\insn1
+662:	.pushsection .altinstructions, "a"
+	altinstruction_entry 661b, 663f, \cap, 662b-661b, 664f-663f
+	.popsection
+	.pushsection .altinstr_replacement, "ax"
+663:	\insn2
+664:	.popsection
+	.org	. - (664b-663b) + (662b-661b)
+	.org	. - (662b-661b) + (664b-663b)
+	.endif
+.endm
+
+/*
+ * Begin an alternative code sequence.
+ *
+ * The code that follows this macro will be assembled and linked as
+ * normal. There are no restrictions on this code.
+ */
+.macro alternative_if_not cap, enable = 1
+	.if \enable
+	.pushsection .altinstructions, "a"
+	altinstruction_entry 661f, 663f, \cap, 662f-661f, 664f-663f
+	.popsection
+661:
+	.endif
+.endm
+
+/*
+ * Provide the alternative code sequence.
+ *
+ * The code that follows this macro is assembled into a special
+ * section to be used for dynamic patching. Code that follows this
+ * macro must:
+ *
+ * 1. Be exactly the same length (in bytes) as the default code
+ *    sequence.
+ *
+ * 2. Not contain a branch target that is used outside of the
+ *    alternative sequence it is defined in (branches into an
+ *    alternative sequence are not fixed up).
+ */
+.macro alternative_else
+662:	.pushsection .altinstr_replacement, "ax"
+663:
+.endm
+
+/*
+ * Complete an alternative code sequence.
+ */
+.macro alternative_endif
+664:	.popsection
+	.org	. - (664b-663b) + (662b-661b)
+	.org	. - (662b-661b) + (664b-663b)
+.endm
+
+#define _ALTERNATIVE_CFG(insn1, insn2, cap, cfg, ...)	\
+	alternative_insn insn1, insn2, cap, IS_ENABLED(cfg)
+
+#endif  /*  __ASSEMBLY__  */
+
+/*
+ * Usage: asm(ALTERNATIVE(oldinstr, newinstr, feature));
+ *
+ * Usage: asm(ALTERNATIVE(oldinstr, newinstr, feature, CONFIG_FOO));
+ * N.B. If CONFIG_FOO is specified, but not selected, the whole block
+ *      will be omitted, including oldinstr.
+ */
+#define ALTERNATIVE(oldinstr, newinstr, ...)   \
+	_ALTERNATIVE_CFG(oldinstr, newinstr, __VA_ARGS__, 1)
+
+#else /* !CONFIG_ALTERNATIVE */
+
+static inline void apply_alternatives_all(void)
+{
+}
+
+int apply_alternatives(void *start, size_t lenght)
+{
+    return 0;
+}
+
+#endif
+
+#endif /* __ASM_ALTERNATIVE_H */
diff --git a/xen/include/asm-arm/arm64/insn.h b/xen/include/asm-arm/arm64/insn.h
index cfcdbe9..6ce37be 100644
--- a/xen/include/asm-arm/arm64/insn.h
+++ b/xen/include/asm-arm/arm64/insn.h
@@ -61,6 +61,22 @@ u32 aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
 s32 aarch64_get_branch_offset(u32 insn);
 u32 aarch64_set_branch_offset(u32 insn, s32 offset);
 
+/* Wrapper for common code */
+static inline bool insn_is_branch_imm(u32 insn)
+{
+    return aarch64_insn_is_branch_imm(insn);
+}
+
+static inline s32 insn_get_branch_offset(u32 insn)
+{
+    return aarch64_get_branch_offset(insn);
+}
+
+static inline u32 insn_set_branch_offset(u32 insn, s32 offset)
+{
+    return aarch64_set_branch_offset(insn, offset);
+}
+
 #endif /* !__ARCH_ARM_ARM64_INSN */
 /*
  * Local variables:
-- 
1.9.1


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 10/16] xen/arm: cpufeature: Provide an helper to check if a capability is supported
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (8 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-22  9:59   ` Stefano Stabellini
  2016-06-07 16:06 ` [PATCH v3 11/16] xen/arm: Detect silicon revision and set cap bits accordingly Julien Grall
                   ` (5 subsequent siblings)
  15 siblings, 1 reply; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

The CPU capabilities will be set depending on the value found in the CPU
registers. This patch provides a generic to go through a set of capabilities
and find which one should be enabled.

The parameter "info" is used to display the kind of capability updated (e.g
workaround, feature...).

Signed-off-by: Julien Grall <julien.grall@arm.com>

---
    Changes in v3:
         - Patch added. The code was previously part of "Detect
         silicon...".
---
 xen/arch/arm/cpufeature.c        | 16 ++++++++++++++++
 xen/include/asm-arm/cpufeature.h |  9 +++++++++
 2 files changed, 25 insertions(+)

diff --git a/xen/arch/arm/cpufeature.c b/xen/arch/arm/cpufeature.c
index 7a1b56b..088625b 100644
--- a/xen/arch/arm/cpufeature.c
+++ b/xen/arch/arm/cpufeature.c
@@ -24,6 +24,22 @@
 
 DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS);
 
+void update_cpu_capabilities(const struct arm_cpu_capabilities *caps,
+                             const char *info)
+{
+    int i;
+
+    for ( i = 0; caps[i].matches; i++ )
+    {
+        if ( !caps[i].matches(&caps[i]) )
+            continue;
+
+        if ( !cpus_have_cap(caps[i].capability) && caps[i].desc )
+            printk(XENLOG_INFO "%s: %s\n", info, caps[i].desc);
+        cpus_set_cap(caps[i].capability);
+    }
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
index 2bebad1..be2414c 100644
--- a/xen/include/asm-arm/cpufeature.h
+++ b/xen/include/asm-arm/cpufeature.h
@@ -62,6 +62,15 @@ static inline void cpus_set_cap(unsigned int num)
         __set_bit(num, cpu_hwcaps);
 }
 
+struct arm_cpu_capabilities {
+    const char *desc;
+    u16 capability;
+    bool_t (*matches)(const struct arm_cpu_capabilities *);
+};
+
+void update_cpu_capabilities(const struct arm_cpu_capabilities *caps,
+                             const char *info);
+
 #endif /* __ASSEMBLY__ */
 
 #endif
-- 
1.9.1


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 11/16] xen/arm: Detect silicon revision and set cap bits accordingly
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (9 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 10/16] xen/arm: cpufeature: Provide an helper to check if a capability is supported Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-22 10:00   ` Stefano Stabellini
  2016-06-07 16:06 ` [PATCH v3 12/16] xen/arm: Document the errata implemented in Xen Julien Grall
                   ` (4 subsequent siblings)
  15 siblings, 1 reply; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

After each CPU has been started, we iterate through a list of CPU
errata to detect CPUs which need from hypervisor code patches.

For each bug there is a function which check if that a particular CPU is
affected. This needs to be done on every CPUs to cover heterogenous
system properly.

If a certain erratum has been detected, the capability bit will be set.
In the case the erratum requires code patching, this will be triggered
by the call to apply_alternatives.

The code is based on the file arch/arm64/kernel/cpu_errata.c in Linux
v4.6-rc3.

Signed-off-by: Julien Grall <julien.grall@arm.com>

---
    Changes in v3:
        - Move update_cpu_capabilities in a separate patch
        - Update the commit message to mention that workaround may
        not require code patching.

    Changes in v2:
        - Use XENLOG_INFO for the loglevel of the message
---
 xen/arch/arm/Makefile            |  1 +
 xen/arch/arm/cpuerrata.c         | 26 ++++++++++++++++++++++++++
 xen/arch/arm/setup.c             |  3 +++
 xen/arch/arm/smpboot.c           |  3 +++
 xen/include/asm-arm/cpuerrata.h  |  6 ++++++
 xen/include/asm-arm/cpufeature.h |  6 ++++++
 6 files changed, 45 insertions(+)
 create mode 100644 xen/arch/arm/cpuerrata.c
 create mode 100644 xen/include/asm-arm/cpuerrata.h

diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
index 67ccc43..a90ecf3 100644
--- a/xen/arch/arm/Makefile
+++ b/xen/arch/arm/Makefile
@@ -7,6 +7,7 @@ subdir-$(CONFIG_ACPI) += acpi
 obj-$(CONFIG_ALTERNATIVE) += alternative.o
 obj-y += bootfdt.o
 obj-y += cpu.o
+obj-y += cpuerrata.o
 obj-y += cpufeature.o
 obj-y += decode.o
 obj-y += device.o
diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
new file mode 100644
index 0000000..52d39f8
--- /dev/null
+++ b/xen/arch/arm/cpuerrata.c
@@ -0,0 +1,26 @@
+#include <xen/config.h>
+#include <asm/cpufeature.h>
+#include <asm/cpuerrata.h>
+
+#define MIDR_RANGE(model, min, max)     \
+    .matches = is_affected_midr_range,  \
+    .midr_model = model,                \
+    .midr_range_min = min,              \
+    .midr_range_max = max
+
+static bool_t __maybe_unused
+is_affected_midr_range(const struct arm_cpu_capabilities *entry)
+{
+    return MIDR_IS_CPU_MODEL_RANGE(boot_cpu_data.midr.bits, entry->midr_model,
+                                   entry->midr_range_min,
+                                   entry->midr_range_max);
+}
+
+static const struct arm_cpu_capabilities arm_errata[] = {
+    {},
+};
+
+void check_local_cpu_errata(void)
+{
+    update_cpu_capabilities(arm_errata, "enabled workaround for");
+}
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 01e2900..6e34bea 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -43,6 +43,7 @@
 #include <asm/current.h>
 #include <asm/setup.h>
 #include <asm/gic.h>
+#include <asm/cpuerrata.h>
 #include <asm/cpufeature.h>
 #include <asm/platform.h>
 #include <asm/procinfo.h>
@@ -171,6 +172,8 @@ static void __init processor_id(void)
     }
 
     processor_setup();
+
+    check_local_cpu_errata();
 }
 
 void dt_unreserved_regions(paddr_t s, paddr_t e,
diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
index ba83406..fdd11b5 100644
--- a/xen/arch/arm/smpboot.c
+++ b/xen/arch/arm/smpboot.c
@@ -29,6 +29,7 @@
 #include <xen/timer.h>
 #include <xen/irq.h>
 #include <xen/console.h>
+#include <asm/cpuerrata.h>
 #include <asm/gic.h>
 #include <asm/psci.h>
 #include <asm/acpi.h>
@@ -317,6 +318,8 @@ void start_secondary(unsigned long boot_phys_offset,
     local_irq_enable();
     local_abort_enable();
 
+    check_local_cpu_errata();
+
     printk(XENLOG_DEBUG "CPU %u booted.\n", smp_processor_id());
 
     startup_cpu_idle_loop();
diff --git a/xen/include/asm-arm/cpuerrata.h b/xen/include/asm-arm/cpuerrata.h
new file mode 100644
index 0000000..8ffd7ba
--- /dev/null
+++ b/xen/include/asm-arm/cpuerrata.h
@@ -0,0 +1,6 @@
+#ifndef __ARM_CPUERRATA_H
+#define __ARM_CPUERRATA_H
+
+void check_local_cpu_errata(void);
+
+#endif /* __ARM_CPUERRATA_H */
diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
index be2414c..fb57295 100644
--- a/xen/include/asm-arm/cpufeature.h
+++ b/xen/include/asm-arm/cpufeature.h
@@ -66,6 +66,12 @@ struct arm_cpu_capabilities {
     const char *desc;
     u16 capability;
     bool_t (*matches)(const struct arm_cpu_capabilities *);
+    union {
+        struct {    /* To be used for eratum handling only */
+            u32 midr_model;
+            u32 midr_range_min, midr_range_max;
+        };
+    };
 };
 
 void update_cpu_capabilities(const struct arm_cpu_capabilities *caps,
-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 12/16] xen/arm: Document the errata implemented in Xen
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (10 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 11/16] xen/arm: Detect silicon revision and set cap bits accordingly Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-22 10:03   ` Stefano Stabellini
  2016-06-07 16:06 ` [PATCH v3 13/16] xen/arm: arm64: Add Cortex-A53 cache errata workaround Julien Grall
                   ` (3 subsequent siblings)
  15 siblings, 1 reply; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

The new document will help to keep track of each erratum Xen is able to
handle.

The text is based on the Linux doc in Documents/arm64/silicon-errata.txt.

Also list the current errata that Xen is aware of.

Signed-off-by: Julien Grall <julien.grall@arm.com>

---
    Changes in v3:
        - Fix grammar in the commit message
        - s/Linux/Xen/
        - Mention that runtime patching is only supported by ARM64
---
 docs/misc/arm/silicon-errata.txt | 45 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 docs/misc/arm/silicon-errata.txt

diff --git a/docs/misc/arm/silicon-errata.txt b/docs/misc/arm/silicon-errata.txt
new file mode 100644
index 0000000..374a63a
--- /dev/null
+++ b/docs/misc/arm/silicon-errata.txt
@@ -0,0 +1,45 @@
+                Silicon Errata and Software Workarounds
+                =======================================
+
+It is an unfortunate fact of life that hardware is often produced with
+so-called "errata", which can cause it to deviate from the architecture
+under specific circumstances.  For hardware produced by ARM, these
+errata are broadly classified into the following categories:
+
+  Category A: A critical error without a viable workaround.
+  Category B: A significant or critical error with an acceptable
+              workaround.
+  Category C: A minor error that is not expected to occur under normal
+              operation.
+
+For more information, consult one of the "Software Developers Errata
+Notice" documents available on infocenter.arm.com (registration
+required).
+
+As far as Xen is concerned, Category B errata may require some special
+treatment in the hypervisor. For example, avoiding a particular sequence
+of code, or configuring the processor in a particular way. A less common
+situation may require similar actions in order to declassify a Category A
+erratum into a Category C erratum. These are collectively known as
+"software workarounds" and are only required in the minority of cases
+(e.g. those cases that both require a non-secure workaround *and* can
+be triggered by Xen).
+
+For software workarounds that may adversely impact systems unaffected by
+the erratum in question, a Kconfig entry is added under "ARM errata
+workarounds via the alternatives framework". These are enabled by default
+and patched in at runtime when an affected CPU is detected. Note that
+runtime patching is only supported by ARM64. For less-intrusive workarounds,
+a Kconfig option is not available and the code is structured (preferably
+with a comment) in such a way that the erratum will not be hit.
+
+This approach can make it slightly onerous to determine exactly which
+errata are worked around in an arbitrary hypervisor source tree, so this
+file acts as a registry of software workarounds in the Xen hypervisor and
+will be updated when new workarounds are committed and backported to
+stable hypervisors.
+
+| Implementor    | Component       | Erratum ID      | Kconfig                 |
++----------------+-----------------+-----------------+-------------------------+
+| ARM            | Cortex-A15      | #766422         | N/A                     |
+| ARM            | Cortex-A57      | #852523         | N/A                     |
-- 
1.9.1


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http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 13/16] xen/arm: arm64: Add Cortex-A53 cache errata workaround
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (11 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 12/16] xen/arm: Document the errata implemented in Xen Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-22 10:04   ` Stefano Stabellini
  2016-06-07 16:06 ` [PATCH v3 14/16] xen/arm: arm64: Add cortex-A57 erratum 832075 workaround Julien Grall
                   ` (2 subsequent siblings)
  15 siblings, 1 reply; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

The ARM errata 819472, 827319 and 824069 define the same workaround for
these hardware issues in certain Cortex-A53 parts.

The cache instructions "dc cvac" and "dc cvau" need to be upgraded to
"dc civac".

Use the alternative framework to replace those instructions only on
affected cores.

Whilst the errata affect cache instructions issued at any exception
level, it is not necessary to trap EL1/EL0 data cache instructions
access in order to upgrade them. Indeed the data cache corruption would
always be at the address used by the data cache instructions. Note that
this address could point to a shared memory between guests and the
hypervisors, however all the information present in it are be validated
before any use.

Therefore a malicious guest could only hurt itself. Note that all the
guests should implement/enable the workaround for the affected cores.

Signed-off-by: Julien Grall <julien.grall@arm.com>

---
    Changes in v3:
        - Remove conflict introduced whilst rebasing this series
---
 docs/misc/arm/silicon-errata.txt |  3 ++
 xen/arch/arm/Kconfig             | 71 ++++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/arm64/cache.S       |  2 ++
 xen/arch/arm/cpuerrata.c         | 17 ++++++++++
 xen/include/asm-arm/arm64/page.h |  7 +++-
 xen/include/asm-arm/cpufeature.h |  4 ++-
 xen/include/asm-arm/processor.h  |  6 ++++
 7 files changed, 108 insertions(+), 2 deletions(-)

diff --git a/docs/misc/arm/silicon-errata.txt b/docs/misc/arm/silicon-errata.txt
index 374a63a..fe9f52e 100644
--- a/docs/misc/arm/silicon-errata.txt
+++ b/docs/misc/arm/silicon-errata.txt
@@ -42,4 +42,7 @@ stable hypervisors.
 | Implementor    | Component       | Erratum ID      | Kconfig                 |
 +----------------+-----------------+-----------------+-------------------------+
 | ARM            | Cortex-A15      | #766422         | N/A                     |
+| ARM            | Cortex-A53      | #827319         | ARM64_ERRATUM_827319    |
+| ARM            | Cortex-A53      | #824069         | ARM64_ERRATUM_824069    |
+| ARM            | Cortex-A53      | #819472         | ARM64_ERRATUM_819472    |
 | ARM            | Cortex-A57      | #852523         | N/A                     |
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 0141bd9..a473d9c 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -53,6 +53,77 @@ config ALTERNATIVE
 
 endmenu
 
+menu "ARM errata workaround via the alternative framework"
+	depends on ALTERNATIVE
+
+config ARM64_ERRATUM_827319
+	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
+	default y
+	depends on ARM_64
+	help
+	  This option adds an alternative code sequence to work around ARM
+	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
+	  master interface and an L2 cache.
+
+	  Under certain conditions this erratum can cause a clean line eviction
+	  to occur at the same time as another transaction to the same address
+	  on the AMBA 5 CHI interface, which can cause data corruption if the
+	  interconnect reorders the two transactions.
+
+	  The workaround promotes data cache clean instructions to
+	  data cache clean-and-invalidate.
+	  Please note that this does not necessarily enable the workaround,
+	  as it depends on the alternative framework, which will only patch
+	  the kernel if an affected CPU is detected.
+
+	  If unsure, say Y.
+
+config ARM64_ERRATUM_824069
+	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
+	default y
+	depends on ARM_64
+	help
+	  This option adds an alternative code sequence to work around ARM
+	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
+	  to a coherent interconnect.
+
+	  If a Cortex-A53 processor is executing a store or prefetch for
+	  write instruction at the same time as a processor in another
+	  cluster is executing a cache maintenance operation to the same
+	  address, then this erratum might cause a clean cache line to be
+	  incorrectly marked as dirty.
+
+	  The workaround promotes data cache clean instructions to
+	  data cache clean-and-invalidate.
+	  Please note that this option does not necessarily enable the
+	  workaround, as it depends on the alternative framework, which will
+	  only patch the kernel if an affected CPU is detected.
+
+	  If unsure, say Y.
+
+config ARM64_ERRATUM_819472
+	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
+	default y
+	depends on ARM_64
+	help
+	  This option adds an alternative code sequence to work around ARM
+	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
+	  present when it is connected to a coherent interconnect.
+
+	  If the processor is executing a load and store exclusive sequence at
+	  the same time as a processor in another cluster is executing a cache
+	  maintenance operation to the same address, then this erratum might
+	  cause data corruption.
+
+	  The workaround promotes data cache clean instructions to
+	  data cache clean-and-invalidate.
+	  Please note that this does not necessarily enable the workaround,
+	  as it depends on the alternative framework, which will only patch
+	  the kernel if an affected CPU is detected.
+
+	  If unsure, say Y.
+endmenu
+
 source "common/Kconfig"
 
 source "drivers/Kconfig"
diff --git a/xen/arch/arm/arm64/cache.S b/xen/arch/arm/arm64/cache.S
index eff4e16..9a88a2b 100644
--- a/xen/arch/arm/arm64/cache.S
+++ b/xen/arch/arm/arm64/cache.S
@@ -19,6 +19,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <asm/alternative.h>
+
 /*
  * dcache_line_size - get the minimum D-cache line size from the CTR register.
  */
diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
index 52d39f8..211b520 100644
--- a/xen/arch/arm/cpuerrata.c
+++ b/xen/arch/arm/cpuerrata.c
@@ -17,6 +17,23 @@ is_affected_midr_range(const struct arm_cpu_capabilities *entry)
 }
 
 static const struct arm_cpu_capabilities arm_errata[] = {
+#if defined(CONFIG_ARM64_ERRATUM_827319) || \
+    defined(CONFIG_ARM64_ERRATUM_824069)
+    {
+        /* Cortex-A53 r0p[012] */
+        .desc = "ARM errata 827319, 824069",
+        .capability = ARM64_WORKAROUND_CLEAN_CACHE,
+        MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x02),
+    },
+#endif
+#ifdef CONFIG_ARM64_ERRATUM_819472
+    {
+        /* Cortex-A53 r0[01] */
+        .desc = "ARM erratum 819472",
+        .capability = ARM64_WORKAROUND_CLEAN_CACHE,
+        MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x01),
+    },
+#endif
     {},
 };
 
diff --git a/xen/include/asm-arm/arm64/page.h b/xen/include/asm-arm/arm64/page.h
index fbdc8fb..79ef7bd 100644
--- a/xen/include/asm-arm/arm64/page.h
+++ b/xen/include/asm-arm/arm64/page.h
@@ -3,6 +3,8 @@
 
 #ifndef __ASSEMBLY__
 
+#include <asm/alternative.h>
+
 /* Write a pagetable entry */
 static inline void write_pte(lpae_t *p, lpae_t pte)
 {
@@ -18,7 +20,10 @@ static inline void write_pte(lpae_t *p, lpae_t pte)
 #define __invalidate_dcache_one(R) "dc ivac, %" #R ";"
 
 /* Inline ASM to flush dcache on register R (may be an inline asm operand) */
-#define __clean_dcache_one(R) "dc cvac, %" #R ";"
+#define __clean_dcache_one(R)                   \
+    ALTERNATIVE("dc cvac, %" #R ";",            \
+                "dc civac, %" #R ";",           \
+                ARM64_WORKAROUND_CLEAN_CACHE)   \
 
 /* Inline ASM to clean and invalidate dcache on register R (may be an
  * inline asm operand) */
diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
index fb57295..474a778 100644
--- a/xen/include/asm-arm/cpufeature.h
+++ b/xen/include/asm-arm/cpufeature.h
@@ -35,7 +35,9 @@
 #endif
 #define cpu_has_security  (boot_cpu_feature32(security) > 0)
 
-#define ARM_NCAPS           0
+#define ARM64_WORKAROUND_CLEAN_CACHE    0
+
+#define ARM_NCAPS           1
 
 #ifndef __ASSEMBLY__
 
diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
index dba9b9a..5089bfd 100644
--- a/xen/include/asm-arm/processor.h
+++ b/xen/include/asm-arm/processor.h
@@ -44,6 +44,12 @@
         _model == (model) && _rv >= (rv_min) && _rv <= (rv_max);        \
 })
 
+#define ARM_CPU_IMP_ARM             0x41
+
+#define ARM_CPU_PART_CORTEX_A53     0xD03
+
+#define MIDR_CORTEX_A53 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)
+
 /* MPIDR Multiprocessor Affinity Register */
 #define _MPIDR_UP           (30)
 #define MPIDR_UP            (_AC(1,U) << _MPIDR_UP)
-- 
1.9.1


_______________________________________________
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http://lists.xen.org/xen-devel

^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 14/16] xen/arm: arm64: Add cortex-A57 erratum 832075 workaround
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (12 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 13/16] xen/arm: arm64: Add Cortex-A53 cache errata workaround Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-22 10:10   ` Stefano Stabellini
  2016-06-07 16:06 ` [PATCH v3 15/16] xen/arm: traps: Don't inject a fault if the translation VA -> IPA fails Julien Grall
  2016-06-07 16:06 ` [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220 Julien Grall
  15 siblings, 1 reply; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

The ARM erratum 832075 applies to certain revisions of Cortex-A57, one
of the workarounds is to change device loads into using load-acquire
semantics.

Use the alternative framework to enable the workaround only on affected
cores.

Whilst a guest could trigger the deadlock, it can be broken when the
processor is receiving an interrupt. As the Xen scheduler will always setup
a timer (firing to every 1ms to 300ms depending on the running time
slice) on each processor, the deadlock would last only few milliseconds
and only affects the guest time slice.

Therefore a malicious guest could only hurt itself. Note that all the
guests should implement/enable the workaround for the affected cores.

Signed-off-by: Julien Grall <julien.grall@arm.com>

---
    Changes in v2:
        - Update the commit message to explain why it is not necessary
        to take care of possible deadlock from the guest.
---
 docs/misc/arm/silicon-errata.txt |  1 +
 xen/arch/arm/Kconfig             | 20 ++++++++++++++++++++
 xen/arch/arm/cpuerrata.c         |  9 +++++++++
 xen/include/asm-arm/arm64/io.h   | 21 +++++++++++++++++----
 xen/include/asm-arm/cpufeature.h |  3 ++-
 xen/include/asm-arm/processor.h  |  2 ++
 6 files changed, 51 insertions(+), 5 deletions(-)

diff --git a/docs/misc/arm/silicon-errata.txt b/docs/misc/arm/silicon-errata.txt
index fe9f52e..4b2c7c6 100644
--- a/docs/misc/arm/silicon-errata.txt
+++ b/docs/misc/arm/silicon-errata.txt
@@ -46,3 +46,4 @@ stable hypervisors.
 | ARM            | Cortex-A53      | #824069         | ARM64_ERRATUM_824069    |
 | ARM            | Cortex-A53      | #819472         | ARM64_ERRATUM_819472    |
 | ARM            | Cortex-A57      | #852523         | N/A                     |
+| ARM            | Cortex-A57      | #832075         | ARM64_ERRATUM_832075    |
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index a473d9c..e26c4c8 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -122,6 +122,26 @@ config ARM64_ERRATUM_819472
 	  the kernel if an affected CPU is detected.
 
 	  If unsure, say Y.
+
+config ARM64_ERRATUM_832075
+	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
+	default y
+	depends on ARM_64
+	help
+	  This option adds an alternative code sequence to work around ARM
+	  erratum 832075 on Cortex-A57 parts up to r1p2.
+
+	  Affected Cortex-A57 parts might deadlock when exclusive load/store
+	  instructions to Write-Back memory are mixed with Device loads.
+
+	  The workaround is to promote device loads to use Load-Acquire
+	  semantics.
+	  Please note that this does not necessarily enable the workaround,
+	  as it depends on the alternative framework, which will only patch
+	  the kernel if an affected CPU is detected.
+
+	  If unsure, say Y.
+
 endmenu
 
 source "common/Kconfig"
diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
index 211b520..48fc87a 100644
--- a/xen/arch/arm/cpuerrata.c
+++ b/xen/arch/arm/cpuerrata.c
@@ -34,6 +34,15 @@ static const struct arm_cpu_capabilities arm_errata[] = {
         MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x01),
     },
 #endif
+#ifdef CONFIG_ARM64_ERRATUM_832075
+    {
+        /* Cortex-A57 r0p0 - r1p2 */
+        .desc = "ARM erratum 832075",
+        .capability = ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE,
+        MIDR_RANGE(MIDR_CORTEX_A57, 0x00,
+                   (1 << MIDR_VARIANT_SHIFT) | 2),
+    },
+#endif
     {},
 };
 
diff --git a/xen/include/asm-arm/arm64/io.h b/xen/include/asm-arm/arm64/io.h
index f80156f..30bfc78 100644
--- a/xen/include/asm-arm/arm64/io.h
+++ b/xen/include/asm-arm/arm64/io.h
@@ -22,6 +22,7 @@
 
 #include <asm/system.h>
 #include <asm/byteorder.h>
+#include <asm/alternative.h>
 
 /*
  * Generic IO read/write.  These perform native-endian accesses.
@@ -49,28 +50,40 @@ static inline void __raw_writeq(u64 val, volatile void __iomem *addr)
 static inline u8 __raw_readb(const volatile void __iomem *addr)
 {
         u8 val;
-        asm volatile("ldrb %w0, [%1]" : "=r" (val) : "r" (addr));
+        asm volatile(ALTERNATIVE("ldrb %w0, [%1]",
+                                 "ldarb %w0, [%1]",
+                                 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
+                     : "=r" (val) : "r" (addr));
         return val;
 }
 
 static inline u16 __raw_readw(const volatile void __iomem *addr)
 {
         u16 val;
-        asm volatile("ldrh %w0, [%1]" : "=r" (val) : "r" (addr));
+        asm volatile(ALTERNATIVE("ldrh %w0, [%1]",
+                                 "ldarh %w0, [%1]",
+                                 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
+                     : "=r" (val) : "r" (addr));
         return val;
 }
 
 static inline u32 __raw_readl(const volatile void __iomem *addr)
 {
         u32 val;
-        asm volatile("ldr %w0, [%1]" : "=r" (val) : "r" (addr));
+        asm volatile(ALTERNATIVE("ldr %w0, [%1]",
+                                 "ldar %w0, [%1]",
+                                 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
+                     : "=r" (val) : "r" (addr));
         return val;
 }
 
 static inline u64 __raw_readq(const volatile void __iomem *addr)
 {
         u64 val;
-        asm volatile("ldr %0, [%1]" : "=r" (val) : "r" (addr));
+        asm volatile(ALTERNATIVE("ldr %0, [%1]",
+                                 "ldar %0, [%1]",
+                                 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
+                     : "=r" (val) : "r" (addr));
         return val;
 }
 
diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
index 474a778..78e2263 100644
--- a/xen/include/asm-arm/cpufeature.h
+++ b/xen/include/asm-arm/cpufeature.h
@@ -36,8 +36,9 @@
 #define cpu_has_security  (boot_cpu_feature32(security) > 0)
 
 #define ARM64_WORKAROUND_CLEAN_CACHE    0
+#define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE    1
 
-#define ARM_NCAPS           1
+#define ARM_NCAPS           2
 
 #ifndef __ASSEMBLY__
 
diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
index 5089bfd..1708253 100644
--- a/xen/include/asm-arm/processor.h
+++ b/xen/include/asm-arm/processor.h
@@ -47,8 +47,10 @@
 #define ARM_CPU_IMP_ARM             0x41
 
 #define ARM_CPU_PART_CORTEX_A53     0xD03
+#define ARM_CPU_PART_CORTEX_A57     0xD07
 
 #define MIDR_CORTEX_A53 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)
+#define MIDR_CORTEX_A57 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A57)
 
 /* MPIDR Multiprocessor Affinity Register */
 #define _MPIDR_UP           (30)
-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 15/16] xen/arm: traps: Don't inject a fault if the translation VA -> IPA fails
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (13 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 14/16] xen/arm: arm64: Add cortex-A57 erratum 832075 workaround Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-07 16:06 ` [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220 Julien Grall
  15 siblings, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

Based on ARM ARM (D4.5.3 in ARM DDI 0486A and B3.12.7 in ARM DDI 0406C.c),
a Stage 1 translation error has priority over a Stage 2 translation error.

Therefore gva_to_ipa can only fail if another vCPU is playing with the
page table.

Rather than injecting a custom fault, replay the instruction and let the
processor injecting the correct fault.

This is fine as Xen is handling all the pending softirqs
(see leave_hypervisor_tail) before returning to the guest. One of them
is the scheduler which could reschuled the vCPU.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>

---
    Changes in v3:
        - Add Stefano's acked-by

    Changes in v2:
        - Update commit message to explain why a guest cannot DoS the
        hypervisor with it.
---
 xen/arch/arm/traps.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index a4eedca..175033b 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -2408,7 +2408,7 @@ static void do_trap_instr_abort_guest(struct cpu_user_regs *regs,
 
             rc = gva_to_ipa(gva, &gpa, GV2M_READ);
             if ( rc == -EFAULT )
-                goto bad_insn_abort;
+                return; /* Try again */
         }
 
         rc = p2m_mem_access_check(gpa, gva, npfec);
@@ -2420,7 +2420,6 @@ static void do_trap_instr_abort_guest(struct cpu_user_regs *regs,
     break;
     }
 
-bad_insn_abort:
     inject_iabt_exception(regs, gva, hsr.len);
 }
 
@@ -2450,7 +2449,7 @@ static void do_trap_data_abort_guest(struct cpu_user_regs *regs,
     {
         rc = gva_to_ipa(info.gva, &info.gpa, GV2M_READ);
         if ( rc == -EFAULT )
-            goto bad_data_abort;
+            return; /* Try again */
     }
 
     switch ( dabt.dfsc & 0x3f )
-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220
  2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
                   ` (14 preceding siblings ...)
  2016-06-07 16:06 ` [PATCH v3 15/16] xen/arm: traps: Don't inject a fault if the translation VA -> IPA fails Julien Grall
@ 2016-06-07 16:06 ` Julien Grall
  2016-06-14 12:15   ` Julien Grall
  2016-06-22 10:08   ` Stefano Stabellini
  15 siblings, 2 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-07 16:06 UTC (permalink / raw)
  To: xen-devel
  Cc: andre.przywara, Julien Grall, sstabellini, wei.chen, steve.capper

The ARM erratum applies to certain revisions of Cortex-A57. The
processor may report a Stage 2 translation fault as the result of
Stage 1 fault for load crossing a page boundary when there is a
permission fault or device memory fault at stage 1 and a translation
fault at Stage 2.

So Xen needs to check that Stage 1 translation does not generate a fault
before handling the Stage 2 fault. If it is a Stage 1 translation fault,
return to the guest to let the processor injecting the correct fault.

Only document it as this is already the behavior of the fault handlers.
Note that some optimization could be done to avoid unnecessary translation
fault. This is because HPFAR_EL2 is valid for more use case. For the moment,
the code is left unmodified.

Signed-off-by: Julien Grall <julien.grall@arm.com>

---
    Changes in v3:
        - s/unecessary/unnecessary
        - Rationalize the comment in the code. The full description can
        be found either in the errata document or in the commit message.
---
 docs/misc/arm/silicon-errata.txt | 1 +
 xen/arch/arm/traps.c             | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/docs/misc/arm/silicon-errata.txt b/docs/misc/arm/silicon-errata.txt
index 4b2c7c6..d620c2e 100644
--- a/docs/misc/arm/silicon-errata.txt
+++ b/docs/misc/arm/silicon-errata.txt
@@ -47,3 +47,4 @@ stable hypervisors.
 | ARM            | Cortex-A53      | #819472         | ARM64_ERRATUM_819472    |
 | ARM            | Cortex-A57      | #852523         | N/A                     |
 | ARM            | Cortex-A57      | #832075         | ARM64_ERRATUM_832075    |
+| ARM            | Cortex-A57      | #834220         | N/A                     |
diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 175033b..757be27 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -2394,6 +2394,10 @@ static void do_trap_instr_abort_guest(struct cpu_user_regs *regs,
             .kind = hsr.iabt.s1ptw ? npfec_kind_in_gpt : npfec_kind_with_gla
         };
 
+        /*
+         * Erratum #834220: Check Stage 1 translation does not generate
+         * a fault first!
+         */
         if ( hsr.iabt.s1ptw )
             gpa = get_faulting_ipa();
         else
@@ -2443,6 +2447,10 @@ static void do_trap_data_abort_guest(struct cpu_user_regs *regs,
     info.gva = READ_SYSREG64(FAR_EL2);
 #endif
 
+     /*
+      * Erratum #834220: Check Stage 1 translation does not generate
+      * a fault first!
+      */
     if ( dabt.s1ptw )
         info.gpa = get_faulting_ipa();
     else
-- 
1.9.1


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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching
  2016-06-07 16:06 ` [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching Julien Grall
@ 2016-06-07 17:24   ` Konrad Rzeszutek Wilk
  2016-06-08  9:39     ` Julien Grall
  2016-06-09 13:33   ` Julien Grall
  1 sibling, 1 reply; 34+ messages in thread
From: Konrad Rzeszutek Wilk @ 2016-06-07 17:24 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

> +
> +/*
> + * We might be patching the stop_machine state machine, so implement a
> + * really simple polling protocol here.
> + */
> +static int __apply_alternatives_multi_stop(void *unused)
> +{
> +    static int patched = 0;
> +    struct alt_region region = {
> +        .begin = __alt_instructions,
> +        .end = __alt_instructions_end,
> +    };
> +
> +    /* We always have a CPU 0 at this point (__init) */
> +    if ( smp_processor_id() )
> +    {
> +        while ( !read_atomic(&patched) )
> +            cpu_relax();
> +        isb();
> +    }
> +    else
> +    {
> +        int ret;
> +
> +        BUG_ON(patched);
> +        ret = __apply_alternatives(&region);
> +        /* The patching is not expected to fail during boot. */
> +        BUG_ON(ret != 0);
> +
> +        /* Barriers provided by the cache flushing */

Could you add the stop at the end here (and above in the 'We always have..)'?

> +        write_atomic(&patched, 1);
> +    }
> +
> +    return 0;
> +}
> +
> +/*
> + * This function should only be called during boot and before CPU0 jump

Would it make sense to then have an ASSERT or BUG on:

SYS_STATE_early_boot ?

> + * into the idle_loop.
> + */
> +void __init apply_alternatives_all(void)

s/apply_alternatives_all/apply_alternatives_init/ ?

> +{
> +    int ret;
> +
> +	/* better not try code patching on a live SMP system */

Something is off with this comment (wrong column). And while
at it you could also add the '.' at the end.

> +    ret = stop_machine_run(__apply_alternatives_multi_stop, NULL, NR_CPUS);
> +
> +    /* stop_machine_run should never fail at this stage of the boot */

Missing stpo.
> +    BUG_ON(ret);
> +}
> +
..snip..
> diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
> index 1f010bd..495f9d8 100644
> --- a/xen/arch/arm/xen.lds.S
> +++ b/xen/arch/arm/xen.lds.S
> @@ -129,6 +129,9 @@ SECTIONS
>         _sinittext = .;
>         *(.init.text)
>         _einittext = .;
> +#ifdef CONFIG_ALTERNATIVE
> +       *(.altinstr_replacement)
> +#endif

This is outside the _einittext? x86 looks to have .altinstr_replacement
inside the _einittext.

>    } :text
>    . = ALIGN(PAGE_SIZE);
>    .init.data : {
> @@ -167,6 +170,13 @@ SECTIONS
>         *(.xsm_initcall.init)
>         __xsm_initcall_end = .;
>    } :text
> +#ifdef CONFIG_ALTERNATIVE
> +  .init.alternatives : {
> +      __alt_instructions = .;
> +      *(.altinstructions)
> +      __alt_instructions_end = .;
> +  }
> +#endif
>    __init_end_efi = .;
>    . = ALIGN(STACK_SIZE);
>    __init_end = .;

Otherwise it looks OK to me.

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching
  2016-06-07 17:24   ` Konrad Rzeszutek Wilk
@ 2016-06-08  9:39     ` Julien Grall
  2016-06-08 18:17       ` Konrad Rzeszutek Wilk
  0 siblings, 1 reply; 34+ messages in thread
From: Julien Grall @ 2016-06-08  9:39 UTC (permalink / raw)
  To: Konrad Rzeszutek Wilk
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

Hi Konrad,

On 07/06/2016 18:24, Konrad Rzeszutek Wilk wrote:
>> +
>> +/*
>> + * We might be patching the stop_machine state machine, so implement a
>> + * really simple polling protocol here.
>> + */
>> +static int __apply_alternatives_multi_stop(void *unused)
>> +{
>> +    static int patched = 0;
>> +    struct alt_region region = {
>> +        .begin = __alt_instructions,
>> +        .end = __alt_instructions_end,
>> +    };
>> +
>> +    /* We always have a CPU 0 at this point (__init) */
>> +    if ( smp_processor_id() )
>> +    {
>> +        while ( !read_atomic(&patched) )
>> +            cpu_relax();
>> +        isb();
>> +    }
>> +    else
>> +    {
>> +        int ret;
>> +
>> +        BUG_ON(patched);
>> +        ret = __apply_alternatives(&region);
>> +        /* The patching is not expected to fail during boot. */
>> +        BUG_ON(ret != 0);
>> +
>> +        /* Barriers provided by the cache flushing */
>
> Could you add the stop at the end here (and above in the 'We always have..)'?

Will do.

>
>> +        write_atomic(&patched, 1);
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +/*
>> + * This function should only be called during boot and before CPU0 jump
>
> Would it make sense to then have an ASSERT or BUG on:
>
> SYS_STATE_early_boot ?

No need, this function is part of __init. Anyone calling this function 
after boot will crash the hypervisor :).

>
>> + * into the idle_loop.
>> + */
>> +void __init apply_alternatives_all(void)
>
> s/apply_alternatives_all/apply_alternatives_init/ ?

I think _all makes more sense because we apply all the alternatives to 
the hypervisor.

>
>> +{
>> +    int ret;
>> +
>> +	/* better not try code patching on a live SMP system */
>
> Something is off with this comment (wrong column). And while
> at it you could also add the '.' at the end.

It contains an hard tab. I will fix it in the next version.

>
>> +    ret = stop_machine_run(__apply_alternatives_multi_stop, NULL, NR_CPUS);
>> +
>> +    /* stop_machine_run should never fail at this stage of the boot */
>
> Missing stpo.

ok.

>> +    BUG_ON(ret);
>> +}
>> +
> ..snip..
>> diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
>> index 1f010bd..495f9d8 100644
>> --- a/xen/arch/arm/xen.lds.S
>> +++ b/xen/arch/arm/xen.lds.S
>> @@ -129,6 +129,9 @@ SECTIONS
>>         _sinittext = .;
>>         *(.init.text)
>>         _einittext = .;
>> +#ifdef CONFIG_ALTERNATIVE
>> +       *(.altinstr_replacement)
>> +#endif
>
> This is outside the _einittext? x86 looks to have .altinstr_replacement
> inside the _einittext.

Yes, I looked at the x86 code when I did the implement and I did not 
find any good reason to keep .altinstr_replace inside the inittext.

altinstr_replacement contains replacement instructions. Anything inside 
the inittext region will be mark executable, which is not what we want here.

Regards,

-- 
Julien Grall

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching
  2016-06-08  9:39     ` Julien Grall
@ 2016-06-08 18:17       ` Konrad Rzeszutek Wilk
  2016-06-08 18:22         ` Julien Grall
  0 siblings, 1 reply; 34+ messages in thread
From: Konrad Rzeszutek Wilk @ 2016-06-08 18:17 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

> >>diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
> >>index 1f010bd..495f9d8 100644
> >>--- a/xen/arch/arm/xen.lds.S
> >>+++ b/xen/arch/arm/xen.lds.S
> >>@@ -129,6 +129,9 @@ SECTIONS
> >>        _sinittext = .;
> >>        *(.init.text)
> >>        _einittext = .;
> >>+#ifdef CONFIG_ALTERNATIVE
> >>+       *(.altinstr_replacement)
> >>+#endif
> >
> >This is outside the _einittext? x86 looks to have .altinstr_replacement
> >inside the _einittext.
> 
> Yes, I looked at the x86 code when I did the implement and I did not find
> any good reason to keep .altinstr_replace inside the inittext.
> 
> altinstr_replacement contains replacement instructions. Anything inside the
> inittext region will be mark executable, which is not what we want here.

Right, but we don't this code after the bootup (as in we patch the
.text and we can eject the .altinstr_replacement).

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching
  2016-06-08 18:17       ` Konrad Rzeszutek Wilk
@ 2016-06-08 18:22         ` Julien Grall
  2016-06-08 18:35           ` Konrad Rzeszutek Wilk
  0 siblings, 1 reply; 34+ messages in thread
From: Julien Grall @ 2016-06-08 18:22 UTC (permalink / raw)
  To: Konrad Rzeszutek Wilk
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

Hi Konrad,

On 08/06/16 19:17, Konrad Rzeszutek Wilk wrote:
>>>> diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
>>>> index 1f010bd..495f9d8 100644
>>>> --- a/xen/arch/arm/xen.lds.S
>>>> +++ b/xen/arch/arm/xen.lds.S
>>>> @@ -129,6 +129,9 @@ SECTIONS
>>>>         _sinittext = .;
>>>>         *(.init.text)
>>>>         _einittext = .;
>>>> +#ifdef CONFIG_ALTERNATIVE
>>>> +       *(.altinstr_replacement)
>>>> +#endif
>>>
>>> This is outside the _einittext? x86 looks to have .altinstr_replacement
>>> inside the _einittext.
>>
>> Yes, I looked at the x86 code when I did the implement and I did not find
>> any good reason to keep .altinstr_replace inside the inittext.
>>
>> altinstr_replacement contains replacement instructions. Anything inside the
>> inittext region will be mark executable, which is not what we want here.
>
> Right, but we don't this code after the bootup (as in we patch the
> .text and we can eject the .altinstr_replacement).

I don't see any problem, .altinstr_replacement is within __init_begin 
and __init_end. So it will be free when free_init_memory will be called.

_sinittex and _einittext are used to know which page will be executable.

Regards,

-- 
Julien Grall

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching
  2016-06-08 18:22         ` Julien Grall
@ 2016-06-08 18:35           ` Konrad Rzeszutek Wilk
  0 siblings, 0 replies; 34+ messages in thread
From: Konrad Rzeszutek Wilk @ 2016-06-08 18:35 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

On Wed, Jun 08, 2016 at 07:22:45PM +0100, Julien Grall wrote:
> Hi Konrad,
> 
> On 08/06/16 19:17, Konrad Rzeszutek Wilk wrote:
> >>>>diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
> >>>>index 1f010bd..495f9d8 100644
> >>>>--- a/xen/arch/arm/xen.lds.S
> >>>>+++ b/xen/arch/arm/xen.lds.S
> >>>>@@ -129,6 +129,9 @@ SECTIONS
> >>>>        _sinittext = .;
> >>>>        *(.init.text)
> >>>>        _einittext = .;
> >>>>+#ifdef CONFIG_ALTERNATIVE
> >>>>+       *(.altinstr_replacement)
> >>>>+#endif
> >>>
> >>>This is outside the _einittext? x86 looks to have .altinstr_replacement
> >>>inside the _einittext.
> >>
> >>Yes, I looked at the x86 code when I did the implement and I did not find
> >>any good reason to keep .altinstr_replace inside the inittext.
> >>
> >>altinstr_replacement contains replacement instructions. Anything inside the
> >>inittext region will be mark executable, which is not what we want here.
> >
> >Right, but we don't this code after the bootup (as in we patch the
> >.text and we can eject the .altinstr_replacement).
> 
> I don't see any problem, .altinstr_replacement is within __init_begin and
> __init_end. So it will be free when free_init_memory will be called.
> 
> _sinittex and _einittext are used to know which page will be executable.

Aaah, right! In that case, pls disregard my question.
> 
> Regards,
> 
> -- 
> Julien Grall

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching
  2016-06-07 16:06 ` [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching Julien Grall
  2016-06-07 17:24   ` Konrad Rzeszutek Wilk
@ 2016-06-09 13:33   ` Julien Grall
  1 sibling, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-09 13:33 UTC (permalink / raw)
  To: xen-devel; +Cc: andre.przywara, sstabellini, wei.chen, steve.capper

Hi,

On 07/06/16 17:06, Julien Grall wrote:
> +#else /* !CONFIG_ALTERNATIVE */
> +
> +static inline void apply_alternatives_all(void)
> +{
> +}
> +
> +int apply_alternatives(void *start, size_t lenght)

I have just notice a compilation issue on ARM32 with this patch which I 
did not spot during build testing.

This function should be static inline and s/lenght/lenght/. I will fix 
both in the next version of this series.

Cheers,

-- 
Julien Grall

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220
  2016-06-07 16:06 ` [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220 Julien Grall
@ 2016-06-14 12:15   ` Julien Grall
  2016-06-22 10:08   ` Stefano Stabellini
  1 sibling, 0 replies; 34+ messages in thread
From: Julien Grall @ 2016-06-14 12:15 UTC (permalink / raw)
  To: xen-devel, sstabellini; +Cc: andre.przywara, wei.chen, steve.capper

Hello,

On 07/06/16 17:06, Julien Grall wrote:
> The ARM erratum applies to certain revisions of Cortex-A57. The
> processor may report a Stage 2 translation fault as the result of
> Stage 1 fault for load crossing a page boundary when there is a
> permission fault or device memory fault at stage 1 and a translation
> fault at Stage 2.
>
> So Xen needs to check that Stage 1 translation does not generate a fault
> before handling the Stage 2 fault. If it is a Stage 1 translation fault,
> return to the guest to let the processor injecting the correct fault.
>
> Only document it as this is already the behavior of the fault handlers.
> Note that some optimization could be done to avoid unnecessary translation
> fault. This is because HPFAR_EL2 is valid for more use case. For the moment,
> the code is left unmodified.
>
> Signed-off-by: Julien Grall <julien.grall@arm.com>

Actually I am working on a patch series to optimize the data handles 
(i.e to avoid unnecessary translation). I don't think the documentation 
is strictly necessary for now. So I will drop this patch and implement 
the workaround on top of the other series.

Regards,

-- 
Julien Grall

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 10/16] xen/arm: cpufeature: Provide an helper to check if a capability is supported
  2016-06-07 16:06 ` [PATCH v3 10/16] xen/arm: cpufeature: Provide an helper to check if a capability is supported Julien Grall
@ 2016-06-22  9:59   ` Stefano Stabellini
  2016-06-22 10:09     ` Julien Grall
  0 siblings, 1 reply; 34+ messages in thread
From: Stefano Stabellini @ 2016-06-22  9:59 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

On Tue, 7 Jun 2016, Julien Grall wrote:
> The CPU capabilities will be set depending on the value found in the CPU
> registers. This patch provides a generic to go through a set of capabilities
> and find which one should be enabled.
> 
> The parameter "info" is used to display the kind of capability updated (e.g
> workaround, feature...).
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>
> 
> ---
>     Changes in v3:
>          - Patch added. The code was previously part of "Detect
>          silicon...".
> ---
>  xen/arch/arm/cpufeature.c        | 16 ++++++++++++++++
>  xen/include/asm-arm/cpufeature.h |  9 +++++++++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/xen/arch/arm/cpufeature.c b/xen/arch/arm/cpufeature.c
> index 7a1b56b..088625b 100644
> --- a/xen/arch/arm/cpufeature.c
> +++ b/xen/arch/arm/cpufeature.c
> @@ -24,6 +24,22 @@
>  
>  DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS);
>  
> +void update_cpu_capabilities(const struct arm_cpu_capabilities *caps,
> +                             const char *info)
> +{
> +    int i;
> +
> +    for ( i = 0; caps[i].matches; i++ )
> +    {
> +        if ( !caps[i].matches(&caps[i]) )
> +            continue;
> +
> +        if ( !cpus_have_cap(caps[i].capability) && caps[i].desc )
> +            printk(XENLOG_INFO "%s: %s\n", info, caps[i].desc);

The patch is OK. I still have the same comment as before: if an info
parameter is passed to this function with a string, then I think the
string should contain some useful information. Not a generic message.
I would just do:

    printk(XENLOG_INFO "enable workaround for: %s\n", caps[i].desc);

If one day we need to change the message depending on the caller, then
that day we'll add a parameter to update_cpu_capabilities.


> +        cpus_set_cap(caps[i].capability);
> +    }
> +}
> +
>  /*
>   * Local variables:
>   * mode: C
> diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
> index 2bebad1..be2414c 100644
> --- a/xen/include/asm-arm/cpufeature.h
> +++ b/xen/include/asm-arm/cpufeature.h
> @@ -62,6 +62,15 @@ static inline void cpus_set_cap(unsigned int num)
>          __set_bit(num, cpu_hwcaps);
>  }
>  
> +struct arm_cpu_capabilities {
> +    const char *desc;
> +    u16 capability;
> +    bool_t (*matches)(const struct arm_cpu_capabilities *);
> +};
> +
> +void update_cpu_capabilities(const struct arm_cpu_capabilities *caps,
> +                             const char *info);
> +
>  #endif /* __ASSEMBLY__ */
>  
>  #endif
> -- 
> 1.9.1
> 

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 11/16] xen/arm: Detect silicon revision and set cap bits accordingly
  2016-06-07 16:06 ` [PATCH v3 11/16] xen/arm: Detect silicon revision and set cap bits accordingly Julien Grall
@ 2016-06-22 10:00   ` Stefano Stabellini
  0 siblings, 0 replies; 34+ messages in thread
From: Stefano Stabellini @ 2016-06-22 10:00 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

On Tue, 7 Jun 2016, Julien Grall wrote:
> After each CPU has been started, we iterate through a list of CPU
> errata to detect CPUs which need from hypervisor code patches.
> 
> For each bug there is a function which check if that a particular CPU is
> affected. This needs to be done on every CPUs to cover heterogenous
> system properly.
> 
> If a certain erratum has been detected, the capability bit will be set.
> In the case the erratum requires code patching, this will be triggered
> by the call to apply_alternatives.
> 
> The code is based on the file arch/arm64/kernel/cpu_errata.c in Linux
> v4.6-rc3.
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>

Regardless of the disagreement on the number of parameters to
update_cpu_capabilities:

Acked-by: Stefano Stabellini <sstabellini@kernel.org>


>     Changes in v3:
>         - Move update_cpu_capabilities in a separate patch
>         - Update the commit message to mention that workaround may
>         not require code patching.
> 
>     Changes in v2:
>         - Use XENLOG_INFO for the loglevel of the message
> ---
>  xen/arch/arm/Makefile            |  1 +
>  xen/arch/arm/cpuerrata.c         | 26 ++++++++++++++++++++++++++
>  xen/arch/arm/setup.c             |  3 +++
>  xen/arch/arm/smpboot.c           |  3 +++
>  xen/include/asm-arm/cpuerrata.h  |  6 ++++++
>  xen/include/asm-arm/cpufeature.h |  6 ++++++
>  6 files changed, 45 insertions(+)
>  create mode 100644 xen/arch/arm/cpuerrata.c
>  create mode 100644 xen/include/asm-arm/cpuerrata.h
> 
> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> index 67ccc43..a90ecf3 100644
> --- a/xen/arch/arm/Makefile
> +++ b/xen/arch/arm/Makefile
> @@ -7,6 +7,7 @@ subdir-$(CONFIG_ACPI) += acpi
>  obj-$(CONFIG_ALTERNATIVE) += alternative.o
>  obj-y += bootfdt.o
>  obj-y += cpu.o
> +obj-y += cpuerrata.o
>  obj-y += cpufeature.o
>  obj-y += decode.o
>  obj-y += device.o
> diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
> new file mode 100644
> index 0000000..52d39f8
> --- /dev/null
> +++ b/xen/arch/arm/cpuerrata.c
> @@ -0,0 +1,26 @@
> +#include <xen/config.h>
> +#include <asm/cpufeature.h>
> +#include <asm/cpuerrata.h>
> +
> +#define MIDR_RANGE(model, min, max)     \
> +    .matches = is_affected_midr_range,  \
> +    .midr_model = model,                \
> +    .midr_range_min = min,              \
> +    .midr_range_max = max
> +
> +static bool_t __maybe_unused
> +is_affected_midr_range(const struct arm_cpu_capabilities *entry)
> +{
> +    return MIDR_IS_CPU_MODEL_RANGE(boot_cpu_data.midr.bits, entry->midr_model,
> +                                   entry->midr_range_min,
> +                                   entry->midr_range_max);
> +}
> +
> +static const struct arm_cpu_capabilities arm_errata[] = {
> +    {},
> +};
> +
> +void check_local_cpu_errata(void)
> +{
> +    update_cpu_capabilities(arm_errata, "enabled workaround for");
> +}
> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
> index 01e2900..6e34bea 100644
> --- a/xen/arch/arm/setup.c
> +++ b/xen/arch/arm/setup.c
> @@ -43,6 +43,7 @@
>  #include <asm/current.h>
>  #include <asm/setup.h>
>  #include <asm/gic.h>
> +#include <asm/cpuerrata.h>
>  #include <asm/cpufeature.h>
>  #include <asm/platform.h>
>  #include <asm/procinfo.h>
> @@ -171,6 +172,8 @@ static void __init processor_id(void)
>      }
>  
>      processor_setup();
> +
> +    check_local_cpu_errata();
>  }
>  
>  void dt_unreserved_regions(paddr_t s, paddr_t e,
> diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
> index ba83406..fdd11b5 100644
> --- a/xen/arch/arm/smpboot.c
> +++ b/xen/arch/arm/smpboot.c
> @@ -29,6 +29,7 @@
>  #include <xen/timer.h>
>  #include <xen/irq.h>
>  #include <xen/console.h>
> +#include <asm/cpuerrata.h>
>  #include <asm/gic.h>
>  #include <asm/psci.h>
>  #include <asm/acpi.h>
> @@ -317,6 +318,8 @@ void start_secondary(unsigned long boot_phys_offset,
>      local_irq_enable();
>      local_abort_enable();
>  
> +    check_local_cpu_errata();
> +
>      printk(XENLOG_DEBUG "CPU %u booted.\n", smp_processor_id());
>  
>      startup_cpu_idle_loop();
> diff --git a/xen/include/asm-arm/cpuerrata.h b/xen/include/asm-arm/cpuerrata.h
> new file mode 100644
> index 0000000..8ffd7ba
> --- /dev/null
> +++ b/xen/include/asm-arm/cpuerrata.h
> @@ -0,0 +1,6 @@
> +#ifndef __ARM_CPUERRATA_H
> +#define __ARM_CPUERRATA_H
> +
> +void check_local_cpu_errata(void);
> +
> +#endif /* __ARM_CPUERRATA_H */
> diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
> index be2414c..fb57295 100644
> --- a/xen/include/asm-arm/cpufeature.h
> +++ b/xen/include/asm-arm/cpufeature.h
> @@ -66,6 +66,12 @@ struct arm_cpu_capabilities {
>      const char *desc;
>      u16 capability;
>      bool_t (*matches)(const struct arm_cpu_capabilities *);
> +    union {
> +        struct {    /* To be used for eratum handling only */
> +            u32 midr_model;
> +            u32 midr_range_min, midr_range_max;
> +        };
> +    };
>  };
>  
>  void update_cpu_capabilities(const struct arm_cpu_capabilities *caps,
> -- 
> 1.9.1
> 

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 12/16] xen/arm: Document the errata implemented in Xen
  2016-06-07 16:06 ` [PATCH v3 12/16] xen/arm: Document the errata implemented in Xen Julien Grall
@ 2016-06-22 10:03   ` Stefano Stabellini
  0 siblings, 0 replies; 34+ messages in thread
From: Stefano Stabellini @ 2016-06-22 10:03 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

On Tue, 7 Jun 2016, Julien Grall wrote:
> The new document will help to keep track of each erratum Xen is able to
> handle.
> 
> The text is based on the Linux doc in Documents/arm64/silicon-errata.txt.
> 
> Also list the current errata that Xen is aware of.
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>
> 
> ---
>     Changes in v3:
>         - Fix grammar in the commit message
>         - s/Linux/Xen/
>         - Mention that runtime patching is only supported by ARM64
> ---
>  docs/misc/arm/silicon-errata.txt | 45 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
>  create mode 100644 docs/misc/arm/silicon-errata.txt
> 
> diff --git a/docs/misc/arm/silicon-errata.txt b/docs/misc/arm/silicon-errata.txt
> new file mode 100644
> index 0000000..374a63a
> --- /dev/null
> +++ b/docs/misc/arm/silicon-errata.txt
> @@ -0,0 +1,45 @@
> +                Silicon Errata and Software Workarounds
> +                =======================================
> +
> +It is an unfortunate fact of life that hardware is often produced with
> +so-called "errata", which can cause it to deviate from the architecture
> +under specific circumstances.  For hardware produced by ARM, these
> +errata are broadly classified into the following categories:
> +
> +  Category A: A critical error without a viable workaround.
> +  Category B: A significant or critical error with an acceptable
> +              workaround.
> +  Category C: A minor error that is not expected to occur under normal
> +              operation.
> +
> +For more information, consult one of the "Software Developers Errata
> +Notice" documents available on infocenter.arm.com (registration
> +required).
> +
> +As far as Xen is concerned, Category B errata may require some special
> +treatment in the hypervisor. For example, avoiding a particular sequence
> +of code, or configuring the processor in a particular way. A less common
> +situation may require similar actions in order to declassify a Category A
> +erratum into a Category C erratum. These are collectively known as
> +"software workarounds" and are only required in the minority of cases
> +(e.g. those cases that both require a non-secure workaround *and* can
> +be triggered by Xen).
> +
> +For software workarounds that may adversely impact systems unaffected by
> +the erratum in question, a Kconfig entry is added under "ARM errata
> +workarounds via the alternatives framework". These are enabled by default
> +and patched in at runtime when an affected CPU is detected. Note that
> +runtime patching is only supported by ARM64. For less-intrusive workarounds,

I think it is more correct to say "supported on ARM64", because it is
not ARM64 which has support for it but Xen when runs on it.
Alternatively "supported by Xen on ARM64".

With this small issue fixed:

Acked-by: Stefano Stabellini <sstabellini@kernel.org>


> +a Kconfig option is not available and the code is structured (preferably
> +with a comment) in such a way that the erratum will not be hit.
> +
> +This approach can make it slightly onerous to determine exactly which
> +errata are worked around in an arbitrary hypervisor source tree, so this
> +file acts as a registry of software workarounds in the Xen hypervisor and
> +will be updated when new workarounds are committed and backported to
> +stable hypervisors.
> +
> +| Implementor    | Component       | Erratum ID      | Kconfig                 |
> ++----------------+-----------------+-----------------+-------------------------+
> +| ARM            | Cortex-A15      | #766422         | N/A                     |
> +| ARM            | Cortex-A57      | #852523         | N/A                     |
> -- 
> 1.9.1
> 

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 13/16] xen/arm: arm64: Add Cortex-A53 cache errata workaround
  2016-06-07 16:06 ` [PATCH v3 13/16] xen/arm: arm64: Add Cortex-A53 cache errata workaround Julien Grall
@ 2016-06-22 10:04   ` Stefano Stabellini
  0 siblings, 0 replies; 34+ messages in thread
From: Stefano Stabellini @ 2016-06-22 10:04 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

On Tue, 7 Jun 2016, Julien Grall wrote:
> The ARM errata 819472, 827319 and 824069 define the same workaround for
> these hardware issues in certain Cortex-A53 parts.
> 
> The cache instructions "dc cvac" and "dc cvau" need to be upgraded to
> "dc civac".
> 
> Use the alternative framework to replace those instructions only on
> affected cores.
> 
> Whilst the errata affect cache instructions issued at any exception
> level, it is not necessary to trap EL1/EL0 data cache instructions
> access in order to upgrade them. Indeed the data cache corruption would
> always be at the address used by the data cache instructions. Note that
> this address could point to a shared memory between guests and the
> hypervisors, however all the information present in it are be validated
> before any use.
> 
> Therefore a malicious guest could only hurt itself. Note that all the
> guests should implement/enable the workaround for the affected cores.
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>

Acked-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
>     Changes in v3:
>         - Remove conflict introduced whilst rebasing this series
> ---
>  docs/misc/arm/silicon-errata.txt |  3 ++
>  xen/arch/arm/Kconfig             | 71 ++++++++++++++++++++++++++++++++++++++++
>  xen/arch/arm/arm64/cache.S       |  2 ++
>  xen/arch/arm/cpuerrata.c         | 17 ++++++++++
>  xen/include/asm-arm/arm64/page.h |  7 +++-
>  xen/include/asm-arm/cpufeature.h |  4 ++-
>  xen/include/asm-arm/processor.h  |  6 ++++
>  7 files changed, 108 insertions(+), 2 deletions(-)
> 
> diff --git a/docs/misc/arm/silicon-errata.txt b/docs/misc/arm/silicon-errata.txt
> index 374a63a..fe9f52e 100644
> --- a/docs/misc/arm/silicon-errata.txt
> +++ b/docs/misc/arm/silicon-errata.txt
> @@ -42,4 +42,7 @@ stable hypervisors.
>  | Implementor    | Component       | Erratum ID      | Kconfig                 |
>  +----------------+-----------------+-----------------+-------------------------+
>  | ARM            | Cortex-A15      | #766422         | N/A                     |
> +| ARM            | Cortex-A53      | #827319         | ARM64_ERRATUM_827319    |
> +| ARM            | Cortex-A53      | #824069         | ARM64_ERRATUM_824069    |
> +| ARM            | Cortex-A53      | #819472         | ARM64_ERRATUM_819472    |
>  | ARM            | Cortex-A57      | #852523         | N/A                     |
> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> index 0141bd9..a473d9c 100644
> --- a/xen/arch/arm/Kconfig
> +++ b/xen/arch/arm/Kconfig
> @@ -53,6 +53,77 @@ config ALTERNATIVE
>  
>  endmenu
>  
> +menu "ARM errata workaround via the alternative framework"
> +	depends on ALTERNATIVE
> +
> +config ARM64_ERRATUM_827319
> +	bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect"
> +	default y
> +	depends on ARM_64
> +	help
> +	  This option adds an alternative code sequence to work around ARM
> +	  erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI
> +	  master interface and an L2 cache.
> +
> +	  Under certain conditions this erratum can cause a clean line eviction
> +	  to occur at the same time as another transaction to the same address
> +	  on the AMBA 5 CHI interface, which can cause data corruption if the
> +	  interconnect reorders the two transactions.
> +
> +	  The workaround promotes data cache clean instructions to
> +	  data cache clean-and-invalidate.
> +	  Please note that this does not necessarily enable the workaround,
> +	  as it depends on the alternative framework, which will only patch
> +	  the kernel if an affected CPU is detected.
> +
> +	  If unsure, say Y.
> +
> +config ARM64_ERRATUM_824069
> +	bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop"
> +	default y
> +	depends on ARM_64
> +	help
> +	  This option adds an alternative code sequence to work around ARM
> +	  erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected
> +	  to a coherent interconnect.
> +
> +	  If a Cortex-A53 processor is executing a store or prefetch for
> +	  write instruction at the same time as a processor in another
> +	  cluster is executing a cache maintenance operation to the same
> +	  address, then this erratum might cause a clean cache line to be
> +	  incorrectly marked as dirty.
> +
> +	  The workaround promotes data cache clean instructions to
> +	  data cache clean-and-invalidate.
> +	  Please note that this option does not necessarily enable the
> +	  workaround, as it depends on the alternative framework, which will
> +	  only patch the kernel if an affected CPU is detected.
> +
> +	  If unsure, say Y.
> +
> +config ARM64_ERRATUM_819472
> +	bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption"
> +	default y
> +	depends on ARM_64
> +	help
> +	  This option adds an alternative code sequence to work around ARM
> +	  erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache
> +	  present when it is connected to a coherent interconnect.
> +
> +	  If the processor is executing a load and store exclusive sequence at
> +	  the same time as a processor in another cluster is executing a cache
> +	  maintenance operation to the same address, then this erratum might
> +	  cause data corruption.
> +
> +	  The workaround promotes data cache clean instructions to
> +	  data cache clean-and-invalidate.
> +	  Please note that this does not necessarily enable the workaround,
> +	  as it depends on the alternative framework, which will only patch
> +	  the kernel if an affected CPU is detected.
> +
> +	  If unsure, say Y.
> +endmenu
> +
>  source "common/Kconfig"
>  
>  source "drivers/Kconfig"
> diff --git a/xen/arch/arm/arm64/cache.S b/xen/arch/arm/arm64/cache.S
> index eff4e16..9a88a2b 100644
> --- a/xen/arch/arm/arm64/cache.S
> +++ b/xen/arch/arm/arm64/cache.S
> @@ -19,6 +19,8 @@
>   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
>   */
>  
> +#include <asm/alternative.h>
> +
>  /*
>   * dcache_line_size - get the minimum D-cache line size from the CTR register.
>   */
> diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
> index 52d39f8..211b520 100644
> --- a/xen/arch/arm/cpuerrata.c
> +++ b/xen/arch/arm/cpuerrata.c
> @@ -17,6 +17,23 @@ is_affected_midr_range(const struct arm_cpu_capabilities *entry)
>  }
>  
>  static const struct arm_cpu_capabilities arm_errata[] = {
> +#if defined(CONFIG_ARM64_ERRATUM_827319) || \
> +    defined(CONFIG_ARM64_ERRATUM_824069)
> +    {
> +        /* Cortex-A53 r0p[012] */
> +        .desc = "ARM errata 827319, 824069",
> +        .capability = ARM64_WORKAROUND_CLEAN_CACHE,
> +        MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x02),
> +    },
> +#endif
> +#ifdef CONFIG_ARM64_ERRATUM_819472
> +    {
> +        /* Cortex-A53 r0[01] */
> +        .desc = "ARM erratum 819472",
> +        .capability = ARM64_WORKAROUND_CLEAN_CACHE,
> +        MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x01),
> +    },
> +#endif
>      {},
>  };
>  
> diff --git a/xen/include/asm-arm/arm64/page.h b/xen/include/asm-arm/arm64/page.h
> index fbdc8fb..79ef7bd 100644
> --- a/xen/include/asm-arm/arm64/page.h
> +++ b/xen/include/asm-arm/arm64/page.h
> @@ -3,6 +3,8 @@
>  
>  #ifndef __ASSEMBLY__
>  
> +#include <asm/alternative.h>
> +
>  /* Write a pagetable entry */
>  static inline void write_pte(lpae_t *p, lpae_t pte)
>  {
> @@ -18,7 +20,10 @@ static inline void write_pte(lpae_t *p, lpae_t pte)
>  #define __invalidate_dcache_one(R) "dc ivac, %" #R ";"
>  
>  /* Inline ASM to flush dcache on register R (may be an inline asm operand) */
> -#define __clean_dcache_one(R) "dc cvac, %" #R ";"
> +#define __clean_dcache_one(R)                   \
> +    ALTERNATIVE("dc cvac, %" #R ";",            \
> +                "dc civac, %" #R ";",           \
> +                ARM64_WORKAROUND_CLEAN_CACHE)   \
>  
>  /* Inline ASM to clean and invalidate dcache on register R (may be an
>   * inline asm operand) */
> diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
> index fb57295..474a778 100644
> --- a/xen/include/asm-arm/cpufeature.h
> +++ b/xen/include/asm-arm/cpufeature.h
> @@ -35,7 +35,9 @@
>  #endif
>  #define cpu_has_security  (boot_cpu_feature32(security) > 0)
>  
> -#define ARM_NCAPS           0
> +#define ARM64_WORKAROUND_CLEAN_CACHE    0
> +
> +#define ARM_NCAPS           1
>  
>  #ifndef __ASSEMBLY__
>  
> diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
> index dba9b9a..5089bfd 100644
> --- a/xen/include/asm-arm/processor.h
> +++ b/xen/include/asm-arm/processor.h
> @@ -44,6 +44,12 @@
>          _model == (model) && _rv >= (rv_min) && _rv <= (rv_max);        \
>  })
>  
> +#define ARM_CPU_IMP_ARM             0x41
> +
> +#define ARM_CPU_PART_CORTEX_A53     0xD03
> +
> +#define MIDR_CORTEX_A53 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)
> +
>  /* MPIDR Multiprocessor Affinity Register */
>  #define _MPIDR_UP           (30)
>  #define MPIDR_UP            (_AC(1,U) << _MPIDR_UP)
> -- 
> 1.9.1
> 

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220
  2016-06-07 16:06 ` [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220 Julien Grall
  2016-06-14 12:15   ` Julien Grall
@ 2016-06-22 10:08   ` Stefano Stabellini
  2016-06-22 10:18     ` Julien Grall
  1 sibling, 1 reply; 34+ messages in thread
From: Stefano Stabellini @ 2016-06-22 10:08 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

On Tue, 7 Jun 2016, Julien Grall wrote:
> The ARM erratum applies to certain revisions of Cortex-A57. The
> processor may report a Stage 2 translation fault as the result of
> Stage 1 fault for load crossing a page boundary when there is a
> permission fault or device memory fault at stage 1 and a translation
> fault at Stage 2.
> 
> So Xen needs to check that Stage 1 translation does not generate a fault
> before handling the Stage 2 fault. If it is a Stage 1 translation fault,
> return to the guest to let the processor injecting the correct fault.
                          ^let the process inject (let somebody do something)


> Only document it as this is already the behavior of the fault handlers.
> Note that some optimization could be done to avoid unnecessary translation
> fault. This is because HPFAR_EL2 is valid for more use case. For the moment,
> the code is left unmodified.
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>

Acked-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
>     Changes in v3:
>         - s/unecessary/unnecessary
>         - Rationalize the comment in the code. The full description can
>         be found either in the errata document or in the commit message.
> ---
>  docs/misc/arm/silicon-errata.txt | 1 +
>  xen/arch/arm/traps.c             | 8 ++++++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/docs/misc/arm/silicon-errata.txt b/docs/misc/arm/silicon-errata.txt
> index 4b2c7c6..d620c2e 100644
> --- a/docs/misc/arm/silicon-errata.txt
> +++ b/docs/misc/arm/silicon-errata.txt
> @@ -47,3 +47,4 @@ stable hypervisors.
>  | ARM            | Cortex-A53      | #819472         | ARM64_ERRATUM_819472    |
>  | ARM            | Cortex-A57      | #852523         | N/A                     |
>  | ARM            | Cortex-A57      | #832075         | ARM64_ERRATUM_832075    |
> +| ARM            | Cortex-A57      | #834220         | N/A                     |
> diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
> index 175033b..757be27 100644
> --- a/xen/arch/arm/traps.c
> +++ b/xen/arch/arm/traps.c
> @@ -2394,6 +2394,10 @@ static void do_trap_instr_abort_guest(struct cpu_user_regs *regs,
>              .kind = hsr.iabt.s1ptw ? npfec_kind_in_gpt : npfec_kind_with_gla
>          };
>  
> +        /*
> +         * Erratum #834220: Check Stage 1 translation does not generate
> +         * a fault first!
> +         */
>          if ( hsr.iabt.s1ptw )
>              gpa = get_faulting_ipa();
>          else
> @@ -2443,6 +2447,10 @@ static void do_trap_data_abort_guest(struct cpu_user_regs *regs,
>      info.gva = READ_SYSREG64(FAR_EL2);
>  #endif
>  
> +     /*
> +      * Erratum #834220: Check Stage 1 translation does not generate
> +      * a fault first!
> +      */
>      if ( dabt.s1ptw )
>          info.gpa = get_faulting_ipa();
>      else
> -- 
> 1.9.1
> 

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 10/16] xen/arm: cpufeature: Provide an helper to check if a capability is supported
  2016-06-22  9:59   ` Stefano Stabellini
@ 2016-06-22 10:09     ` Julien Grall
  2016-06-22 10:14       ` Stefano Stabellini
  0 siblings, 1 reply; 34+ messages in thread
From: Julien Grall @ 2016-06-22 10:09 UTC (permalink / raw)
  To: Stefano Stabellini; +Cc: andre.przywara, steve.capper, wei.chen, xen-devel

Hi Stefano,

On 22/06/16 10:59, Stefano Stabellini wrote:
> On Tue, 7 Jun 2016, Julien Grall wrote:
>> The CPU capabilities will be set depending on the value found in the CPU
>> registers. This patch provides a generic to go through a set of capabilities
>> and find which one should be enabled.
>>
>> The parameter "info" is used to display the kind of capability updated (e.g
>> workaround, feature...).
>>
>> Signed-off-by: Julien Grall <julien.grall@arm.com>
>>
>> ---
>>      Changes in v3:
>>           - Patch added. The code was previously part of "Detect
>>           silicon...".
>> ---
>>   xen/arch/arm/cpufeature.c        | 16 ++++++++++++++++
>>   xen/include/asm-arm/cpufeature.h |  9 +++++++++
>>   2 files changed, 25 insertions(+)
>>
>> diff --git a/xen/arch/arm/cpufeature.c b/xen/arch/arm/cpufeature.c
>> index 7a1b56b..088625b 100644
>> --- a/xen/arch/arm/cpufeature.c
>> +++ b/xen/arch/arm/cpufeature.c
>> @@ -24,6 +24,22 @@
>>
>>   DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS);
>>
>> +void update_cpu_capabilities(const struct arm_cpu_capabilities *caps,
>> +                             const char *info)
>> +{
>> +    int i;
>> +
>> +    for ( i = 0; caps[i].matches; i++ )
>> +    {
>> +        if ( !caps[i].matches(&caps[i]) )
>> +            continue;
>> +
>> +        if ( !cpus_have_cap(caps[i].capability) && caps[i].desc )
>> +            printk(XENLOG_INFO "%s: %s\n", info, caps[i].desc);
>
> The patch is OK. I still have the same comment as before: if an info
> parameter is passed to this function with a string, then I think the
> string should contain some useful information. Not a generic message.

It is useful. As mentioned in the commit message the parameter "info" is 
used to display the kind of capability updated (e.g workaround, feature, 
...).

> I would just do:
>
>      printk(XENLOG_INFO "enable workaround for: %s\n", caps[i].desc);
>
> If one day we need to change the message depending on the caller, then
> that day we'll add a parameter to update_cpu_capabilities.

We both know that this function will be used for other purpose very 
soon. So I would rather avoid to modify again in the future. That is why 
I described the purpose in the commit message.

Cheers,

-- 
Julien Grall

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 14/16] xen/arm: arm64: Add cortex-A57 erratum 832075 workaround
  2016-06-07 16:06 ` [PATCH v3 14/16] xen/arm: arm64: Add cortex-A57 erratum 832075 workaround Julien Grall
@ 2016-06-22 10:10   ` Stefano Stabellini
  0 siblings, 0 replies; 34+ messages in thread
From: Stefano Stabellini @ 2016-06-22 10:10 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, sstabellini, steve.capper, wei.chen, xen-devel

On Tue, 7 Jun 2016, Julien Grall wrote:
> The ARM erratum 832075 applies to certain revisions of Cortex-A57, one
> of the workarounds is to change device loads into using load-acquire
> semantics.
> 
> Use the alternative framework to enable the workaround only on affected
> cores.
> 
> Whilst a guest could trigger the deadlock, it can be broken when the
> processor is receiving an interrupt. As the Xen scheduler will always setup
> a timer (firing to every 1ms to 300ms depending on the running time
> slice) on each processor, the deadlock would last only few milliseconds
> and only affects the guest time slice.
> 
> Therefore a malicious guest could only hurt itself. Note that all the
> guests should implement/enable the workaround for the affected cores.
> 
> Signed-off-by: Julien Grall <julien.grall@arm.com>

Acked-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
>     Changes in v2:
>         - Update the commit message to explain why it is not necessary
>         to take care of possible deadlock from the guest.
> ---
>  docs/misc/arm/silicon-errata.txt |  1 +
>  xen/arch/arm/Kconfig             | 20 ++++++++++++++++++++
>  xen/arch/arm/cpuerrata.c         |  9 +++++++++
>  xen/include/asm-arm/arm64/io.h   | 21 +++++++++++++++++----
>  xen/include/asm-arm/cpufeature.h |  3 ++-
>  xen/include/asm-arm/processor.h  |  2 ++
>  6 files changed, 51 insertions(+), 5 deletions(-)
> 
> diff --git a/docs/misc/arm/silicon-errata.txt b/docs/misc/arm/silicon-errata.txt
> index fe9f52e..4b2c7c6 100644
> --- a/docs/misc/arm/silicon-errata.txt
> +++ b/docs/misc/arm/silicon-errata.txt
> @@ -46,3 +46,4 @@ stable hypervisors.
>  | ARM            | Cortex-A53      | #824069         | ARM64_ERRATUM_824069    |
>  | ARM            | Cortex-A53      | #819472         | ARM64_ERRATUM_819472    |
>  | ARM            | Cortex-A57      | #852523         | N/A                     |
> +| ARM            | Cortex-A57      | #832075         | ARM64_ERRATUM_832075    |
> diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> index a473d9c..e26c4c8 100644
> --- a/xen/arch/arm/Kconfig
> +++ b/xen/arch/arm/Kconfig
> @@ -122,6 +122,26 @@ config ARM64_ERRATUM_819472
>  	  the kernel if an affected CPU is detected.
>  
>  	  If unsure, say Y.
> +
> +config ARM64_ERRATUM_832075
> +	bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads"
> +	default y
> +	depends on ARM_64
> +	help
> +	  This option adds an alternative code sequence to work around ARM
> +	  erratum 832075 on Cortex-A57 parts up to r1p2.
> +
> +	  Affected Cortex-A57 parts might deadlock when exclusive load/store
> +	  instructions to Write-Back memory are mixed with Device loads.
> +
> +	  The workaround is to promote device loads to use Load-Acquire
> +	  semantics.
> +	  Please note that this does not necessarily enable the workaround,
> +	  as it depends on the alternative framework, which will only patch
> +	  the kernel if an affected CPU is detected.
> +
> +	  If unsure, say Y.
> +
>  endmenu
>  
>  source "common/Kconfig"
> diff --git a/xen/arch/arm/cpuerrata.c b/xen/arch/arm/cpuerrata.c
> index 211b520..48fc87a 100644
> --- a/xen/arch/arm/cpuerrata.c
> +++ b/xen/arch/arm/cpuerrata.c
> @@ -34,6 +34,15 @@ static const struct arm_cpu_capabilities arm_errata[] = {
>          MIDR_RANGE(MIDR_CORTEX_A53, 0x00, 0x01),
>      },
>  #endif
> +#ifdef CONFIG_ARM64_ERRATUM_832075
> +    {
> +        /* Cortex-A57 r0p0 - r1p2 */
> +        .desc = "ARM erratum 832075",
> +        .capability = ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE,
> +        MIDR_RANGE(MIDR_CORTEX_A57, 0x00,
> +                   (1 << MIDR_VARIANT_SHIFT) | 2),
> +    },
> +#endif
>      {},
>  };
>  
> diff --git a/xen/include/asm-arm/arm64/io.h b/xen/include/asm-arm/arm64/io.h
> index f80156f..30bfc78 100644
> --- a/xen/include/asm-arm/arm64/io.h
> +++ b/xen/include/asm-arm/arm64/io.h
> @@ -22,6 +22,7 @@
>  
>  #include <asm/system.h>
>  #include <asm/byteorder.h>
> +#include <asm/alternative.h>
>  
>  /*
>   * Generic IO read/write.  These perform native-endian accesses.
> @@ -49,28 +50,40 @@ static inline void __raw_writeq(u64 val, volatile void __iomem *addr)
>  static inline u8 __raw_readb(const volatile void __iomem *addr)
>  {
>          u8 val;
> -        asm volatile("ldrb %w0, [%1]" : "=r" (val) : "r" (addr));
> +        asm volatile(ALTERNATIVE("ldrb %w0, [%1]",
> +                                 "ldarb %w0, [%1]",
> +                                 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
> +                     : "=r" (val) : "r" (addr));
>          return val;
>  }
>  
>  static inline u16 __raw_readw(const volatile void __iomem *addr)
>  {
>          u16 val;
> -        asm volatile("ldrh %w0, [%1]" : "=r" (val) : "r" (addr));
> +        asm volatile(ALTERNATIVE("ldrh %w0, [%1]",
> +                                 "ldarh %w0, [%1]",
> +                                 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
> +                     : "=r" (val) : "r" (addr));
>          return val;
>  }
>  
>  static inline u32 __raw_readl(const volatile void __iomem *addr)
>  {
>          u32 val;
> -        asm volatile("ldr %w0, [%1]" : "=r" (val) : "r" (addr));
> +        asm volatile(ALTERNATIVE("ldr %w0, [%1]",
> +                                 "ldar %w0, [%1]",
> +                                 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
> +                     : "=r" (val) : "r" (addr));
>          return val;
>  }
>  
>  static inline u64 __raw_readq(const volatile void __iomem *addr)
>  {
>          u64 val;
> -        asm volatile("ldr %0, [%1]" : "=r" (val) : "r" (addr));
> +        asm volatile(ALTERNATIVE("ldr %0, [%1]",
> +                                 "ldar %0, [%1]",
> +                                 ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE)
> +                     : "=r" (val) : "r" (addr));
>          return val;
>  }
>  
> diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
> index 474a778..78e2263 100644
> --- a/xen/include/asm-arm/cpufeature.h
> +++ b/xen/include/asm-arm/cpufeature.h
> @@ -36,8 +36,9 @@
>  #define cpu_has_security  (boot_cpu_feature32(security) > 0)
>  
>  #define ARM64_WORKAROUND_CLEAN_CACHE    0
> +#define ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE    1
>  
> -#define ARM_NCAPS           1
> +#define ARM_NCAPS           2
>  
>  #ifndef __ASSEMBLY__
>  
> diff --git a/xen/include/asm-arm/processor.h b/xen/include/asm-arm/processor.h
> index 5089bfd..1708253 100644
> --- a/xen/include/asm-arm/processor.h
> +++ b/xen/include/asm-arm/processor.h
> @@ -47,8 +47,10 @@
>  #define ARM_CPU_IMP_ARM             0x41
>  
>  #define ARM_CPU_PART_CORTEX_A53     0xD03
> +#define ARM_CPU_PART_CORTEX_A57     0xD07
>  
>  #define MIDR_CORTEX_A53 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)
> +#define MIDR_CORTEX_A57 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A57)
>  
>  /* MPIDR Multiprocessor Affinity Register */
>  #define _MPIDR_UP           (30)
> -- 
> 1.9.1
> 

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 10/16] xen/arm: cpufeature: Provide an helper to check if a capability is supported
  2016-06-22 10:09     ` Julien Grall
@ 2016-06-22 10:14       ` Stefano Stabellini
  0 siblings, 0 replies; 34+ messages in thread
From: Stefano Stabellini @ 2016-06-22 10:14 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, Stefano Stabellini, steve.capper, wei.chen, xen-devel

On Wed, 22 Jun 2016, Julien Grall wrote:
> Hi Stefano,
> 
> On 22/06/16 10:59, Stefano Stabellini wrote:
> > On Tue, 7 Jun 2016, Julien Grall wrote:
> > > The CPU capabilities will be set depending on the value found in the CPU
> > > registers. This patch provides a generic to go through a set of
> > > capabilities
> > > and find which one should be enabled.
> > > 
> > > The parameter "info" is used to display the kind of capability updated
> > > (e.g
> > > workaround, feature...).
> > > 
> > > Signed-off-by: Julien Grall <julien.grall@arm.com>
> > > 
> > > ---
> > >      Changes in v3:
> > >           - Patch added. The code was previously part of "Detect
> > >           silicon...".
> > > ---
> > >   xen/arch/arm/cpufeature.c        | 16 ++++++++++++++++
> > >   xen/include/asm-arm/cpufeature.h |  9 +++++++++
> > >   2 files changed, 25 insertions(+)
> > > 
> > > diff --git a/xen/arch/arm/cpufeature.c b/xen/arch/arm/cpufeature.c
> > > index 7a1b56b..088625b 100644
> > > --- a/xen/arch/arm/cpufeature.c
> > > +++ b/xen/arch/arm/cpufeature.c
> > > @@ -24,6 +24,22 @@
> > > 
> > >   DECLARE_BITMAP(cpu_hwcaps, ARM_NCAPS);
> > > 
> > > +void update_cpu_capabilities(const struct arm_cpu_capabilities *caps,
> > > +                             const char *info)
> > > +{
> > > +    int i;
> > > +
> > > +    for ( i = 0; caps[i].matches; i++ )
> > > +    {
> > > +        if ( !caps[i].matches(&caps[i]) )
> > > +            continue;
> > > +
> > > +        if ( !cpus_have_cap(caps[i].capability) && caps[i].desc )
> > > +            printk(XENLOG_INFO "%s: %s\n", info, caps[i].desc);
> > 
> > The patch is OK. I still have the same comment as before: if an info
> > parameter is passed to this function with a string, then I think the
> > string should contain some useful information. Not a generic message.
> 
> It is useful. As mentioned in the commit message the parameter "info" is used
> to display the kind of capability updated (e.g workaround, feature, ...).
> 
> > I would just do:
> > 
> >      printk(XENLOG_INFO "enable workaround for: %s\n", caps[i].desc);
> > 
> > If one day we need to change the message depending on the caller, then
> > that day we'll add a parameter to update_cpu_capabilities.
> 
> We both know that this function will be used for other purpose very soon. So I
> would rather avoid to modify again in the future. That is why I described the
> purpose in the commit message.

I am unconvinced, but I'll leave it be.

Acked-by: Stefano Stabellini <sstabellini@kernel.org>

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220
  2016-06-22 10:08   ` Stefano Stabellini
@ 2016-06-22 10:18     ` Julien Grall
  2016-06-22 10:37       ` Stefano Stabellini
  0 siblings, 1 reply; 34+ messages in thread
From: Julien Grall @ 2016-06-22 10:18 UTC (permalink / raw)
  To: Stefano Stabellini; +Cc: andre.przywara, steve.capper, wei.chen, xen-devel

Hi Stefano,

On 22/06/16 11:08, Stefano Stabellini wrote:
> On Tue, 7 Jun 2016, Julien Grall wrote:
>> The ARM erratum applies to certain revisions of Cortex-A57. The
>> processor may report a Stage 2 translation fault as the result of
>> Stage 1 fault for load crossing a page boundary when there is a
>> permission fault or device memory fault at stage 1 and a translation
>> fault at Stage 2.
>>
>> So Xen needs to check that Stage 1 translation does not generate a fault
>> before handling the Stage 2 fault. If it is a Stage 1 translation fault,
>> return to the guest to let the processor injecting the correct fault.
>                            ^let the process inject (let somebody do something)
>
>
>> Only document it as this is already the behavior of the fault handlers.
>> Note that some optimization could be done to avoid unnecessary translation
>> fault. This is because HPFAR_EL2 is valid for more use case. For the moment,
>> the code is left unmodified.
>>
>> Signed-off-by: Julien Grall <julien.grall@arm.com>
>
> Acked-by: Stefano Stabellini <sstabellini@kernel.org>

I have another series coming up which require to implement a workaround 
for the erratum.

Given this is only documentation, I am planning to drop this patch from 
the series.

Regards,

-- 
Julien Grall

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^ permalink raw reply	[flat|nested] 34+ messages in thread

* Re: [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220
  2016-06-22 10:18     ` Julien Grall
@ 2016-06-22 10:37       ` Stefano Stabellini
  0 siblings, 0 replies; 34+ messages in thread
From: Stefano Stabellini @ 2016-06-22 10:37 UTC (permalink / raw)
  To: Julien Grall
  Cc: andre.przywara, Stefano Stabellini, steve.capper, wei.chen, xen-devel

On Wed, 22 Jun 2016, Julien Grall wrote:
> Hi Stefano,
> 
> On 22/06/16 11:08, Stefano Stabellini wrote:
> > On Tue, 7 Jun 2016, Julien Grall wrote:
> > > The ARM erratum applies to certain revisions of Cortex-A57. The
> > > processor may report a Stage 2 translation fault as the result of
> > > Stage 1 fault for load crossing a page boundary when there is a
> > > permission fault or device memory fault at stage 1 and a translation
> > > fault at Stage 2.
> > > 
> > > So Xen needs to check that Stage 1 translation does not generate a fault
> > > before handling the Stage 2 fault. If it is a Stage 1 translation fault,
> > > return to the guest to let the processor injecting the correct fault.
> >                            ^let the process inject (let somebody do
> > something)
> > 
> > 
> > > Only document it as this is already the behavior of the fault handlers.
> > > Note that some optimization could be done to avoid unnecessary translation
> > > fault. This is because HPFAR_EL2 is valid for more use case. For the
> > > moment,
> > > the code is left unmodified.
> > > 
> > > Signed-off-by: Julien Grall <julien.grall@arm.com>
> > 
> > Acked-by: Stefano Stabellini <sstabellini@kernel.org>
> 
> I have another series coming up which require to implement a workaround for
> the erratum.
> 
> Given this is only documentation, I am planning to drop this patch from the
> series.

All right

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^ permalink raw reply	[flat|nested] 34+ messages in thread

end of thread, other threads:[~2016-06-22 10:37 UTC | newest]

Thread overview: 34+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-06-07 16:06 [PATCH v3 00/16] xen/arm: Introduce alternative runtime patching for ARM64 Julien Grall
2016-06-07 16:06 ` [PATCH v3 01/16] xen/arm: Makefile: Sort the entries alphabetically Julien Grall
2016-06-07 16:06 ` [PATCH v3 02/16] xen/arm: Include the header asm-arm/system.h in asm-arm/page.h Julien Grall
2016-06-07 16:06 ` [PATCH v3 03/16] xen/arm: Add macros to handle the MIDR Julien Grall
2016-06-07 16:06 ` [PATCH v3 04/16] xen/arm: Add cpu_hwcap bitmap Julien Grall
2016-06-07 16:06 ` [PATCH v3 05/16] xen/arm64: Add an helper to invalidate all instruction caches Julien Grall
2016-06-07 16:06 ` [PATCH v3 06/16] xen/arm: arm64: Move the define BRK_BUG_FRAME into a separate header Julien Grall
2016-06-07 16:06 ` [PATCH v3 07/16] xen/arm: arm64: Reserve a brk immediate to fault on purpose Julien Grall
2016-06-07 16:06 ` [PATCH v3 08/16] xen/arm: arm64: Add helpers to decode and encode branch instructions Julien Grall
2016-06-07 16:06 ` [PATCH v3 09/16] xen/arm: Introduce alternative runtime patching Julien Grall
2016-06-07 17:24   ` Konrad Rzeszutek Wilk
2016-06-08  9:39     ` Julien Grall
2016-06-08 18:17       ` Konrad Rzeszutek Wilk
2016-06-08 18:22         ` Julien Grall
2016-06-08 18:35           ` Konrad Rzeszutek Wilk
2016-06-09 13:33   ` Julien Grall
2016-06-07 16:06 ` [PATCH v3 10/16] xen/arm: cpufeature: Provide an helper to check if a capability is supported Julien Grall
2016-06-22  9:59   ` Stefano Stabellini
2016-06-22 10:09     ` Julien Grall
2016-06-22 10:14       ` Stefano Stabellini
2016-06-07 16:06 ` [PATCH v3 11/16] xen/arm: Detect silicon revision and set cap bits accordingly Julien Grall
2016-06-22 10:00   ` Stefano Stabellini
2016-06-07 16:06 ` [PATCH v3 12/16] xen/arm: Document the errata implemented in Xen Julien Grall
2016-06-22 10:03   ` Stefano Stabellini
2016-06-07 16:06 ` [PATCH v3 13/16] xen/arm: arm64: Add Cortex-A53 cache errata workaround Julien Grall
2016-06-22 10:04   ` Stefano Stabellini
2016-06-07 16:06 ` [PATCH v3 14/16] xen/arm: arm64: Add cortex-A57 erratum 832075 workaround Julien Grall
2016-06-22 10:10   ` Stefano Stabellini
2016-06-07 16:06 ` [PATCH v3 15/16] xen/arm: traps: Don't inject a fault if the translation VA -> IPA fails Julien Grall
2016-06-07 16:06 ` [PATCH v3 16/16] xen/arm: arm64: Document Cortex-A57 erratum 834220 Julien Grall
2016-06-14 12:15   ` Julien Grall
2016-06-22 10:08   ` Stefano Stabellini
2016-06-22 10:18     ` Julien Grall
2016-06-22 10:37       ` Stefano Stabellini

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