2020-08-31 09:11:20

by Pierre Morel

[permalink] [raw]
Subject: [PATCH v10 2/2] s390: virtio: PV needs VIRTIO I/O device protection

If protected virtualization is active on s390, VIRTIO has only retricted
access to the guest memory.
Define CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS and export
arch_has_restricted_virtio_memory_access to advertize VIRTIO if that's
the case, preventing a host error on access attempt.

Signed-off-by: Pierre Morel <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
---
arch/s390/Kconfig | 1 +
arch/s390/mm/init.c | 10 ++++++++++
2 files changed, 11 insertions(+)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9cfd8de907cb..c12422c26389 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -820,6 +820,7 @@ menu "Virtualization"
config PROTECTED_VIRTUALIZATION_GUEST
def_bool n
prompt "Protected virtualization guest support"
+ select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
help
Select this option, if you want to be able to run this
kernel as a protected virtualization KVM guest.
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 6dc7c3b60ef6..5f289ab1b0d2 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -161,6 +161,16 @@ bool force_dma_unencrypted(struct device *dev)
return is_prot_virt_guest();
}

+#ifdef CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
+
+int arch_has_restricted_virtio_memory_access(void)
+{
+ return is_prot_virt_guest();
+}
+EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access);
+
+#endif
+
/* protected virtualization */
static void pv_init(void)
{
--
2.25.1


2020-08-31 12:24:54

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH v10 2/2] s390: virtio: PV needs VIRTIO I/O device protection

Hi Pierre,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linux/master]
[cannot apply to s390/features linus/master v5.9-rc3 next-20200828]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url: https://github.com/0day-ci/linux/commits/Pierre-Morel/s390-virtio-let-arch-validate-VIRTIO-features/20200831-171552
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git bcf876870b95592b52519ed4aafcf9d95999bc9c
config: s390-randconfig-r004-20200831 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c10e63677f5d20f18010f8f68c631ddc97546f7d)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install s390 cross compiling tool for clang build
# apt-get install binutils-s390x-linux-gnu
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email protected]>

All warnings (new ones prefixed by >>):

#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:20:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
^
In file included from arch/s390/mm/init.c:20:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:22:
In file included from include/linux/writeback.h:14:
In file included from include/linux/blk-cgroup.h:23:
In file included from include/linux/blkdev.h:28:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
^
In file included from arch/s390/mm/init.c:20:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:22:
In file included from include/linux/writeback.h:14:
In file included from include/linux/blk-cgroup.h:23:
In file included from include/linux/blkdev.h:28:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0xff000000UL) >> 24)))
^
In file included from arch/s390/mm/init.c:20:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:22:
In file included from include/linux/writeback.h:14:
In file included from include/linux/blk-cgroup.h:23:
In file included from include/linux/blkdev.h:28:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:45: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu(__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32'
__fswab32(x))
^
In file included from arch/s390/mm/init.c:20:
In file included from include/linux/swap.h:9:
In file included from include/linux/memcontrol.h:22:
In file included from include/linux/writeback.h:14:
In file included from include/linux/blk-cgroup.h:23:
In file included from include/linux/blkdev.h:28:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:511:46: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew(cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:521:46: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel(cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
>> arch/s390/mm/init.c:166:5: warning: no previous prototype for function 'arch_has_restricted_virtio_memory_access' [-Wmissing-prototypes]
int arch_has_restricted_virtio_memory_access(void)
^
arch/s390/mm/init.c:166:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
int arch_has_restricted_virtio_memory_access(void)
^
static
In file included from arch/s390/mm/init.c:11:
In file included from include/linux/signal.h:5:
In file included from include/linux/bug.h:5:
In file included from arch/s390/include/asm/bug.h:5:
In file included from include/linux/kernel.h:12:
In file included from include/linux/bitops.h:29:
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
"oi %0,%b1\n"
^
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
21 warnings and 3 errors generated.

# https://github.com/0day-ci/linux/commit/76e649717b36f092b03739629b7a036fcc383ee1
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Pierre-Morel/s390-virtio-let-arch-validate-VIRTIO-features/20200831-171552
git checkout 76e649717b36f092b03739629b7a036fcc383ee1
vim +/arch_has_restricted_virtio_memory_access +166 arch/s390/mm/init.c

165
> 166 int arch_has_restricted_virtio_memory_access(void)
167 {
168 return is_prot_virt_guest();
169 }
170 EXPORT_SYMBOL(arch_has_restricted_virtio_memory_access);
171

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]


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