1. 06 11月, 2015 1 次提交
    • E
      mm: mlock: add mlock flags to enable VM_LOCKONFAULT usage · b0f205c2
      Eric B Munson 提交于
      The previous patch introduced a flag that specified pages in a VMA should
      be placed on the unevictable LRU, but they should not be made present when
      the area is created.  This patch adds the ability to set this state via
      the new mlock system calls.
      
      We add MLOCK_ONFAULT for mlock2 and MCL_ONFAULT for mlockall.
      MLOCK_ONFAULT will set the VM_LOCKONFAULT modifier for VM_LOCKED.
      MCL_ONFAULT should be used as a modifier to the two other mlockall flags.
      When used with MCL_CURRENT, all current mappings will be marked with
      VM_LOCKED | VM_LOCKONFAULT.  When used with MCL_FUTURE, the mm->def_flags
      will be marked with VM_LOCKED | VM_LOCKONFAULT.  When used with both
      MCL_CURRENT and MCL_FUTURE, all current mappings and mm->def_flags will be
      marked with VM_LOCKED | VM_LOCKONFAULT.
      
      Prior to this patch, mlockall() will unconditionally clear the
      mm->def_flags any time it is called without MCL_FUTURE.  This behavior is
      maintained after adding MCL_ONFAULT.  If a call to mlockall(MCL_FUTURE) is
      followed by mlockall(MCL_CURRENT), the mm->def_flags will be cleared and
      new VMAs will be unlocked.  This remains true with or without MCL_ONFAULT
      in either mlockall() invocation.
      
      munlock() will unconditionally clear both vma flags.  munlockall()
      unconditionally clears for VMA flags on all VMAs and in the mm->def_flags
      field.
      Signed-off-by: NEric B Munson <emunson@akamai.com>
      Acked-by: NMichal Hocko <mhocko@suse.com>
      Acked-by: NVlastimil Babka <vbabka@suse.cz>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guenter Roeck <linux@roeck-us.net>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Shuah Khan <shuahkh@osg.samsung.com>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b0f205c2
  2. 21 9月, 2015 1 次提交
  3. 09 9月, 2015 1 次提交
  4. 18 8月, 2015 1 次提交
  5. 29 7月, 2015 1 次提交
    • M
      powerpc/kernel: Switch to using MAX_ERRNO · c3525940
      Michael Ellerman 提交于
      Currently on powerpc we have our own #define for the highest (negative)
      errno value, called _LAST_ERRNO. This is defined to be 516, for reasons
      which are not clear.
      
      The generic code, and x86, use MAX_ERRNO, which is defined to be 4095.
      
      In particular seccomp uses MAX_ERRNO to restrict the value that a
      seccomp filter can return.
      
      Currently with the mismatch between _LAST_ERRNO and MAX_ERRNO, a seccomp
      tracer wanting to return 600, expecting it to be seen as an error, would
      instead find on powerpc that userspace sees a successful syscall with a
      return value of 600.
      
      To avoid this inconsistency, switch powerpc to use MAX_ERRNO.
      
      We are somewhat confident that generic syscalls that can return a
      non-error value above negative MAX_ERRNO have already been updated to
      use force_successful_syscall_return().
      
      I have also checked all the powerpc specific syscalls, and believe that
      none of them expect to return a non-error value between -MAX_ERRNO and
      -516. So this change should be safe ...
      Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      Reviewed-by: NKees Cook <keescook@chromium.org>
      c3525940
  6. 16 7月, 2015 1 次提交
  7. 19 6月, 2015 1 次提交
    • S
      powerpc/tm: Abort syscalls in active transactions · b4b56f9e
      Sam bobroff 提交于
      This patch changes the syscall handler to doom (tabort) active
      transactions when a syscall is made and return very early without
      performing the syscall and keeping side effects to a minimum (no CPU
      accounting or system call tracing is performed). Also included is a
      new HWCAP2 bit, PPC_FEATURE2_HTM_NOSC, to indicate this
      behaviour to userspace.
      
      Currently, the system call instruction automatically suspends an
      active transaction which causes side effects to persist when an active
      transaction fails.
      
      This does change the kernel's behaviour, but in a way that was
      documented as unsupported.  It doesn't reduce functionality as
      syscalls will still be performed after tsuspend; it just requires that
      the transaction be explicitly suspended.  It also provides a
      consistent interface and makes the behaviour of user code
      substantially the same across powerpc and platforms that do not
      support suspended transactions (e.g. x86 and s390).
      
      Performance measurements using
      http://ozlabs.org/~anton/junkcode/null_syscall.c indicate the cost of
      a normal (non-aborted) system call increases by about 0.25%.
      Signed-off-by: NSam Bobroff <sam.bobroff@au1.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      b4b56f9e
  8. 18 6月, 2015 1 次提交
  9. 05 6月, 2015 1 次提交
  10. 12 5月, 2015 2 次提交
  11. 30 4月, 2015 1 次提交
    • M
      Revert "powerpc/tm: Abort syscalls in active transactions" · 68fc378c
      Michael Ellerman 提交于
      This reverts commit feba4036.
      
      Although the principle of this change is good, the implementation has a
      few issues.
      
      Firstly we can sometimes fail to abort a syscall because r12 may have
      been clobbered by C code if we went down the virtual CPU accounting
      path, or if syscall tracing was enabled.
      
      Secondly we have decided that it is safer to abort the syscall even
      earlier in the syscall entry path, so that we avoid the syscall tracing
      path when we are transactional.
      
      So that we have time to thoroughly test those changes we have decided to
      revert this for this merge window and will merge the fixed version in
      the next window.
      
      NB. Rather than reverting the selftest we just drop tm-syscall from
      TEST_PROGS so that it's not run by default.
      
      Fixes: feba4036 ("powerpc/tm: Abort syscalls in active transactions")
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      68fc378c
  12. 17 4月, 2015 1 次提交
  13. 11 4月, 2015 1 次提交
    • S
      powerpc/tm: Abort syscalls in active transactions · feba4036
      Sam bobroff 提交于
      This patch changes the syscall handler to doom (tabort) active
      transactions when a syscall is made and return immediately without
      performing the syscall.
      
      Currently, the system call instruction automatically suspends an
      active transaction which causes side effects to persist when an active
      transaction fails.
      
      This does change the kernel's behaviour, but in a way that was
      documented as unsupported. It doesn't reduce functionality because
      syscalls will still be performed after tsuspend. It also provides a
      consistent interface and makes the behaviour of user code
      substantially the same across powerpc and platforms that do not
      support suspended transactions (e.g. x86 and s390).
      
      Performance measurements using
      http://ozlabs.org/~anton/junkcode/null_syscall.c
      indicate the cost of a system call increases by about 0.5%.
      Signed-off-by: NSam Bobroff <sam.bobroff@au1.ibm.com>
      Acked-By: NMichael Neuling <mikey@neuling.org>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      feba4036
  14. 28 3月, 2015 1 次提交
    • M
      powerpc: Add a proper syscall for switching endianness · 529d235a
      Michael Ellerman 提交于
      We currently have a "special" syscall for switching endianness. This is
      syscall number 0x1ebe, which is handled explicitly in the 64-bit syscall
      exception entry.
      
      That has a few problems, firstly the syscall number is outside of the
      usual range, which confuses various tools. For example strace doesn't
      recognise the syscall at all.
      
      Secondly it's handled explicitly as a special case in the syscall
      exception entry, which is complicated enough without it.
      
      As a first step toward removing the special syscall, we need to add a
      regular syscall that implements the same functionality.
      
      The logic is simple, it simply toggles the MSR_LE bit in the userspace
      MSR. This is the same as the special syscall, with the caveat that the
      special syscall clobbers fewer registers.
      
      This version clobbers r9-r12, XER, CTR, and CR0-1,5-7.
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      529d235a
  15. 16 3月, 2015 1 次提交
  16. 29 12月, 2014 1 次提交
    • P
      powerpc: Wire up sys_execveat() syscall · 1e5d0fdb
      Pranith Kumar 提交于
      Wire up sys_execveat(). This passes the selftests for the system call.
      
      Check success of execveat(3, '../execveat', 0)... [OK]
      Check success of execveat(5, 'execveat', 0)... [OK]
      Check success of execveat(6, 'execveat', 0)... [OK]
      Check success of execveat(-100, '/home/pranith/linux/...ftests/exec/execveat', 0)... [OK]
      Check success of execveat(99, '/home/pranith/linux/...ftests/exec/execveat', 0)... [OK]
      Check success of execveat(8, '', 4096)... [OK]
      Check success of execveat(17, '', 4096)... [OK]
      Check success of execveat(9, '', 4096)... [OK]
      Check success of execveat(14, '', 4096)... [OK]
      Check success of execveat(14, '', 4096)... [OK]
      Check success of execveat(15, '', 4096)... [OK]
      Check failure of execveat(8, '', 0) with ENOENT... [OK]
      Check failure of execveat(8, '(null)', 4096) with EFAULT... [OK]
      Check success of execveat(5, 'execveat.symlink', 0)... [OK]
      Check success of execveat(6, 'execveat.symlink', 0)... [OK]
      Check success of execveat(-100, '/home/pranith/linux/...xec/execveat.symlink', 0)... [OK]
      Check success of execveat(10, '', 4096)... [OK]
      Check success of execveat(10, '', 4352)... [OK]
      Check failure of execveat(5, 'execveat.symlink', 256) with ELOOP... [OK]
      Check failure of execveat(6, 'execveat.symlink', 256) with ELOOP... [OK]
      Check failure of execveat(-100, '/home/pranith/linux/tools/testing/selftests/exec/execveat.symlink', 256) with ELOOP... [OK]
      Check success of execveat(3, '../script', 0)... [OK]
      Check success of execveat(5, 'script', 0)... [OK]
      Check success of execveat(6, 'script', 0)... [OK]
      Check success of execveat(-100, '/home/pranith/linux/...elftests/exec/script', 0)... [OK]
      Check success of execveat(13, '', 4096)... [OK]
      Check success of execveat(13, '', 4352)... [OK]
      Check failure of execveat(18, '', 4096) with ENOENT... [OK]
      Check failure of execveat(7, 'script', 0) with ENOENT... [OK]
      Check success of execveat(16, '', 4096)... [OK]
      Check success of execveat(16, '', 4096)... [OK]
      Check success of execveat(4, '../script', 0)... [OK]
      Check success of execveat(4, 'script', 0)... [OK]
      Check success of execveat(4, '../script', 0)... [OK]
      Check failure of execveat(4, 'script', 0) with ENOENT... [OK]
      Check failure of execveat(5, 'execveat', 65535) with EINVAL... [OK]
      Check failure of execveat(5, 'no-such-file', 0) with ENOENT... [OK]
      Check failure of execveat(6, 'no-such-file', 0) with ENOENT... [OK]
      Check failure of execveat(-100, 'no-such-file', 0) with ENOENT... [OK]
      Check failure of execveat(5, '', 4096) with EACCES... [OK]
      Check failure of execveat(5, 'Makefile', 0) with EACCES... [OK]
      Check failure of execveat(11, '', 4096) with EACCES... [OK]
      Check failure of execveat(12, '', 4096) with EACCES... [OK]
      Check failure of execveat(99, '', 4096) with EBADF... [OK]
      Check failure of execveat(99, 'execveat', 0) with EBADF... [OK]
      Check failure of execveat(8, 'execveat', 0) with ENOTDIR... [OK]
      Invoke copy of 'execveat' via filename of length 4093:
      Check success of execveat(19, '', 4096)... [OK]
      Check success of execveat(5, 'xxxxxxxxxxxxxxxxxxxx...yyyyyyyyyyyyyyyyyyyy', 0)... [OK]
      Invoke copy of 'script' via filename of length 4093:
      Check success of execveat(20, '', 4096)... [OK]
      /bin/sh: 0: Can't open /dev/fd/5/xxxxxxx(... a long line of x's and y's, 0)... [OK]
      Check success of execveat(5, 'xxxxxxxxxxxxxxxxxxxx...yyyyyyyyyyyyyyyyyyyy', 0)... [OK]
      
      Tested on a 32-bit powerpc system.
      Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      1e5d0fdb
  17. 06 12月, 2014 1 次提交
    • A
      net: sock: allow eBPF programs to be attached to sockets · 89aa0758
      Alexei Starovoitov 提交于
      introduce new setsockopt() command:
      
      setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd, sizeof(prog_fd))
      
      where prog_fd was received from syscall bpf(BPF_PROG_LOAD, attr, ...)
      and attr->prog_type == BPF_PROG_TYPE_SOCKET_FILTER
      
      setsockopt() calls bpf_prog_get() which increments refcnt of the program,
      so it doesn't get unloaded while socket is using the program.
      
      The same eBPF program can be attached to multiple sockets.
      
      User task exit automatically closes socket which calls sk_filter_uncharge()
      which decrements refcnt of eBPF program
      Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      89aa0758
  18. 12 11月, 2014 1 次提交
    • E
      net: introduce SO_INCOMING_CPU · 2c8c56e1
      Eric Dumazet 提交于
      Alternative to RPS/RFS is to use hardware support for multiple
      queues.
      
      Then split a set of million of sockets into worker threads, each
      one using epoll() to manage events on its own socket pool.
      
      Ideally, we want one thread per RX/TX queue/cpu, but we have no way to
      know after accept() or connect() on which queue/cpu a socket is managed.
      
      We normally use one cpu per RX queue (IRQ smp_affinity being properly
      set), so remembering on socket structure which cpu delivered last packet
      is enough to solve the problem.
      
      After accept(), connect(), or even file descriptor passing around
      processes, applications can use :
      
       int cpu;
       socklen_t len = sizeof(cpu);
      
       getsockopt(fd, SOL_SOCKET, SO_INCOMING_CPU, &cpu, &len);
      
      And use this information to put the socket into the right silo
      for optimal performance, as all networking stack should run
      on the appropriate cpu, without need to send IPI (RPS/RFS).
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2c8c56e1
  19. 22 10月, 2014 1 次提交
    • P
      powerpc: Wire up sys_bpf() syscall · fcbb539f
      Pranith Kumar 提交于
      This patch wires up the new syscall sys_bpf() on powerpc.
      
      Passes the tests in samples/bpf:
      
          #0 add+sub+mul OK
          #1 unreachable OK
          #2 unreachable2 OK
          #3 out of range jump OK
          #4 out of range jump2 OK
          #5 test1 ld_imm64 OK
          #6 test2 ld_imm64 OK
          #7 test3 ld_imm64 OK
          #8 test4 ld_imm64 OK
          #9 test5 ld_imm64 OK
          #10 no bpf_exit OK
          #11 loop (back-edge) OK
          #12 loop2 (back-edge) OK
          #13 conditional loop OK
          #14 read uninitialized register OK
          #15 read invalid register OK
          #16 program doesn't init R0 before exit OK
          #17 stack out of bounds OK
          #18 invalid call insn1 OK
          #19 invalid call insn2 OK
          #20 invalid function call OK
          #21 uninitialized stack1 OK
          #22 uninitialized stack2 OK
          #23 check valid spill/fill OK
          #24 check corrupted spill/fill OK
          #25 invalid src register in STX OK
          #26 invalid dst register in STX OK
          #27 invalid dst register in ST OK
          #28 invalid src register in LDX OK
          #29 invalid dst register in LDX OK
          #30 junk insn OK
          #31 junk insn2 OK
          #32 junk insn3 OK
          #33 junk insn4 OK
          #34 junk insn5 OK
          #35 misaligned read from stack OK
          #36 invalid map_fd for function call OK
          #37 don't check return value before access OK
          #38 access memory with incorrect alignment OK
          #39 sometimes access memory with incorrect alignment OK
          #40 jump test 1 OK
          #41 jump test 2 OK
          #42 jump test 3 OK
          #43 jump test 4 OK
      Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
      [mpe: test using samples/bpf]
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      fcbb539f
  20. 22 9月, 2014 2 次提交
  21. 09 9月, 2014 1 次提交
  22. 28 7月, 2014 2 次提交
  23. 11 6月, 2014 1 次提交
  24. 02 6月, 2014 1 次提交
  25. 30 5月, 2014 2 次提交
  26. 20 5月, 2014 1 次提交
    • J
      powerpc: Remove non-uapi linkage.h export · dade934a
      James Hogan 提交于
      The arch/powerpc/include/asm/linkage.h is being unintentionally exported
      in the kernel headers since commit e1b5bb6d (consolidate
      cond_syscall and SYSCALL_ALIAS declarations) when
      arch/powerpc/include/uapi/asm/linkage.h was deleted but the header-y not
      removed from the Kbuild file. This happens because Makefile.headersinst
      still checks the old asm/ directory if the specified header doesn't
      exist in the uapi directory.
      
      The asm/linkage.h shouldn't ever have been exported anyway. No other
      arch does and it doesn't contain anything useful to userland, so remove
      the header-y line from the Kbuild file which triggers the export.
      Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: David Woodhouse <dwmw2@infradead.org>
      Cc: David Howells <dhowells@redhat.com>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      dade934a
  27. 28 4月, 2014 1 次提交
  28. 23 4月, 2014 2 次提交
  29. 29 1月, 2014 1 次提交
  30. 27 1月, 2014 3 次提交
    • M
      KVM: PPC: Book3S HV: Add software abort codes for transactional memory · b17dfec0
      Michael Neuling 提交于
      This adds the software abort code defines for transactional memory (TM).
      These values are from PAPR.
      Signed-off-by: NMichael Neuling <mikey@neuling.org>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      b17dfec0
    • P
      KVM: PPC: Book3S HV: Add support for DABRX register on POWER7 · 8563bf52
      Paul Mackerras 提交于
      The DABRX (DABR extension) register on POWER7 processors provides finer
      control over which accesses cause a data breakpoint interrupt.  It
      contains 3 bits which indicate whether to enable accesses in user,
      kernel and hypervisor modes respectively to cause data breakpoint
      interrupts, plus one bit that enables both real mode and virtual mode
      accesses to cause interrupts.  Currently, KVM sets DABRX to allow
      both kernel and user accesses to cause interrupts while in the guest.
      
      This adds support for the guest to specify other values for DABRX.
      PAPR defines a H_SET_XDABR hcall to allow the guest to set both DABR
      and DABRX with one call.  This adds a real-mode implementation of
      H_SET_XDABR, which shares most of its code with the existing H_SET_DABR
      implementation.  To support this, we add a per-vcpu field to store the
      DABRX value plus code to get and set it via the ONE_REG interface.
      
      For Linux guests to use this new hcall, userspace needs to add
      "hcall-xdabr" to the set of strings in the /chosen/hypertas-functions
      property in the device tree.  If userspace does this and then migrates
      the guest to a host where the kernel doesn't include this patch, then
      userspace will need to implement H_SET_XDABR by writing the specified
      DABR value to the DABR using the ONE_REG interface.  In that case, the
      old kernel will set DABRX to DABRX_USER | DABRX_KERNEL.  That should
      still work correctly, at least for Linux guests, since Linux guests
      cope with getting data breakpoint interrupts in modes that weren't
      requested by just ignoring the interrupt, and Linux guests never set
      DABRX_BTI.
      
      The other thing this does is to make H_SET_DABR and H_SET_XDABR work
      on POWER8, which has the DAWR and DAWRX instead of DABR/X.  Guests that
      know about POWER8 should use H_SET_MODE rather than H_SET_[X]DABR, but
      guests running in POWER7 compatibility mode will still use H_SET_[X]DABR.
      For them, this adds the logic to convert DABR/X values into DAWR/X values
      on POWER8.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      8563bf52
    • M
      KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs · b005255e
      Michael Neuling 提交于
      This adds fields to the struct kvm_vcpu_arch to store the new
      guest-accessible SPRs on POWER8, adds code to the get/set_one_reg
      functions to allow userspace to access this state, and adds code to
      the guest entry and exit to context-switch these SPRs between host
      and guest.
      
      Note that DPDES (Directed Privileged Doorbell Exception State) is
      shared between threads on a core; hence we store it in struct
      kvmppc_vcore and have the master thread save and restore it.
      Signed-off-by: NMichael Neuling <mikey@neuling.org>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      b005255e
  31. 19 1月, 2014 1 次提交
    • M
      net: introduce SO_BPF_EXTENSIONS · ea02f941
      Michal Sekletar 提交于
      For user space packet capturing libraries such as libpcap, there's
      currently only one way to check which BPF extensions are supported
      by the kernel, that is, commit aa1113d9 ("net: filter: return
      -EINVAL if BPF_S_ANC* operation is not supported"). For querying all
      extensions at once this might be rather inconvenient.
      
      Therefore, this patch introduces a new option which can be used as
      an argument for getsockopt(), and allows one to obtain information
      about which BPF extensions are supported by the current kernel.
      
      As David Miller suggests, we do not need to define any bits right
      now and status quo can just return 0 in order to state that this
      versions supports SKF_AD_PROTOCOL up to SKF_AD_PAY_OFFSET. Later
      additions to BPF extensions need to add their bits to the
      bpf_tell_extensions() function, as documented in the comment.
      Signed-off-by: NMichal Sekletar <msekleta@redhat.com>
      Cc: David Miller <davem@davemloft.net>
      Reviewed-by: NDaniel Borkmann <dborkman@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ea02f941
  32. 17 10月, 2013 2 次提交
    • B
      KVM: PPC: E500: Add userspace debug stub support · ce11e48b
      Bharat Bhushan 提交于
      This patch adds the debug stub support on booke/bookehv.
      Now QEMU debug stub can use hw breakpoint, watchpoint and
      software breakpoint to debug guest.
      
      This is how we save/restore debug register context when switching
      between guest, userspace and kernel user-process:
      
      When QEMU is running
       -> thread->debug_reg == QEMU debug register context.
       -> Kernel will handle switching the debug register on context switch.
       -> no vcpu_load() called
      
      QEMU makes ioctls (except RUN)
       -> This will call vcpu_load()
       -> should not change context.
       -> Some ioctls can change vcpu debug register, context saved in vcpu->debug_regs
      
      QEMU Makes RUN ioctl
       -> Save thread->debug_reg on STACK
       -> Store thread->debug_reg == vcpu->debug_reg
       -> load thread->debug_reg
       -> RUN VCPU ( So thread points to vcpu context )
      
      Context switch happens When VCPU running
       -> makes vcpu_load() should not load any context
       -> kernel loads the vcpu context as thread->debug_regs points to vcpu context.
      
      On heavyweight_exit
       -> Load the context saved on stack in thread->debug_reg
      
      Currently we do not support debug resource emulation to guest,
      On debug exception, always exit to user space irrespective of
      user space is expecting the debug exception or not. If this is
      unexpected exception (breakpoint/watchpoint event not set by
      userspace) then let us leave the action on user space. This
      is similar to what it was before, only thing is that now we
      have proper exit state available to user space.
      Signed-off-by: NBharat Bhushan <bharat.bhushan@freescale.com>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      ce11e48b
    • B
      KVM: PPC: E500: exit to user space on "ehpriv 1" instruction · b12c7841
      Bharat Bhushan 提交于
      "ehpriv 1" instruction is used for setting software breakpoints
      by user space. This patch adds support to exit to user space
      with "run->debug" have relevant information.
      
      As this is the first point we are using run->debug, also defined
      the run->debug structure.
      Signed-off-by: NBharat Bhushan <bharat.bhushan@freescale.com>
      Signed-off-by: NAlexander Graf <agraf@suse.de>
      b12c7841