# git rev-parse -q --verify 9e049ef80be988e91cb55f3ddfa7c80a7b376852^{commit}
9e049ef80be988e91cb55f3ddfa7c80a7b376852
already have revision, skipping fetch
# git checkout -q -f -B kisskb 9e049ef80be988e91cb55f3ddfa7c80a7b376852
# git clean -qxdf
# < git log -1
# commit 9e049ef80be988e91cb55f3ddfa7c80a7b376852
# Author: Alexey Kardashevskiy <aik@ozlabs.ru>
# Date:   Thu Jul 5 18:01:33 2018 +1000
# 
#     KVM: PPC: Check if IOMMU page is contained in the pinned physical page
#     
#     A VM which has:
#      - a DMA capable device passed through to it (eg. network card);
#      - running a malicious kernel that ignores H_PUT_TCE failure;
#      - capability of using IOMMU pages bigger that physical pages
#     can create an IOMMU mapping that exposes (for example) 16MB of
#     the host physical memory to the device when only 64K was allocated to
#     the VM.
#     
#     The remaining 16MB - 64K will be some other content of host memory,
#     possibly including pages of the VM, but also pages of host kernel memory,
#     host programs or other VMs.
#     
#     The attacking VM does not control the location of the page it can map,
#     and is only allowed to map as many pages as it has pages of RAM.
#     
#     We already have a check in drivers/vfio/vfio_iommu_spapr_tce.c that
#     an IOMMU page is contained in the physical page so the PCI hardware won't
#     get access to unassigned host memory; however this check is missing in
#     the KVM fastpath (H_PUT_TCE accelerated code). We were lucky so far and
#     did not hit this yet as the very first time when the mapping happens
#     we do not have tbl::it_userspace allocated yet and fall back to
#     the userspace which in turn calls VFIO IOMMU driver, this fails and
#     the guest does not retry,
#     
#     This stores the smallest preregistered page size in the preregistered
#     region descriptor and changes the mm_iommu_xxx API to check this against
#     the IOMMU page size. This calculates maximum page size as a minimum of
#     the natural region alignment and compound page size.
#     
#     Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/mips-linux/bin/mips-linux-gcc --version
# < git log --format=%s --max-count=1 9e049ef80be988e91cb55f3ddfa7c80a7b376852
# < make -s -j 48 ARCH=mips O=/kisskb/build/powerpc-fixes_mips-defconfig_mips CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/mips-linux/bin/mips-linux-  defconfig
# make -s -j 48 ARCH=mips O=/kisskb/build/powerpc-fixes_mips-defconfig_mips CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/mips-linux/bin/mips-linux-  
/kisskb/src/arch/mips/vdso/Makefile:32: MIPS VDSO requires binutils >= 2.25
/kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter.
/kisskb/src/arch/mips/vdso/Makefile:32: MIPS VDSO requires binutils >= 2.25
/kisskb/src/kernel/rcu/srcutree.c: In function 'init_srcu_struct_fields':
/kisskb/src/kernel/rcu/srcutree.c:146:32: warning: 'levelspread[<U5960>]' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c:94:6: note: 'levelspread[<U5960>]' was declared here
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:183:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter.
/kisskb/src/kernel/cgroup/cgroup-v1.c: In function 'cgroup1_mount':
/kisskb/src/kernel/cgroup/cgroup-v1.c:1256:20: warning: 'root' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write':
/kisskb/src/drivers/base/regmap/regmap.c:1819:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read':
/kisskb/src/drivers/base/regmap/regmap.c:2497:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq':
/kisskb/src/drivers/tty/serial/8250/8250_core.c:251:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/tty/serial/8250/8250_core.c:231:19: note: 'i' was declared here
/kisskb/src/fs/proc/inode.c: In function 'proc_reg_open':
/kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/proc/inode.c:339:21: note: 'pdeo' was declared here
/kisskb/src/arch/mips/vdso/Makefile:32: MIPS VDSO requires binutils >= 2.25
/kisskb/src/net/Makefile:24: CC cannot link executables. Skipping bpfilter.
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:183:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
FIT description: Linux 4.18.0-rc3-g9e049ef
Created:         Fri Jul  6 09:55:23 2018
 Image 0 (kernel@0)
  Description:  Linux 4.18.0-rc3-g9e049ef
  Created:      Fri Jul  6 09:55:23 2018
  Type:         Kernel Image
  Compression:  gzip compressed
  Data Size:    4335999 Bytes = 4234.37 kB = 4.14 MB
  Architecture: MIPS
  OS:           Linux
  Load Address: 0x80100000
  Entry Point:  0x8082fb50
  Hash algo:    sha1
  Hash value:   a047094b1aed245566697631fd1b5d0f6753726c
 Image 1 (fdt@boston)
  Description:  img,boston Device Tree
  Created:      Fri Jul  6 09:55:23 2018
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    3668 Bytes = 3.58 kB = 0.00 MB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   569c37cc891ce1e1f3a193cb41cc691a5d2debb5
 Image 2 (fdt@ni169445)
  Description:  NI 169445 device tree
  Created:      Fri Jul  6 09:55:23 2018
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    1871 Bytes = 1.83 kB = 0.00 MB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   51b89b31605ee62038c8468c429af091dfc75ec7
 Image 3 (fdt@xilfpga)
  Description:  MIPSfpga (xilfpga) Device Tree
  Created:      Fri Jul  6 09:55:23 2018
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    2708 Bytes = 2.64 kB = 0.00 MB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   509ce58e44c561d54539e64e9d4b47054e696fc6
 Default Configuration: 'conf@default'
 Configuration 0 (conf@default)
  Description:  Generic Linux kernel
  Kernel:       kernel@0
 Configuration 1 (conf@boston)
  Description:  Boston Linux kernel
  Kernel:       kernel@0
  FDT:          fdt@boston
 Configuration 2 (conf@ni169445)
  Description:  NI 169445 Linux Kernel
  Kernel:       kernel@0
  FDT:          fdt@ni169445
 Configuration 3 (conf@xilfpga)
  Description:  MIPSfpga Linux kernel
  Kernel:       kernel@0
  FDT:          fdt@xilfpga
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_mips-defconfig_mips
# Build took: 0:01:25.049010