diff options
| author | James Hogan <james.hogan@imgtec.com> | 2014-03-14 13:06:07 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-13 13:32:48 +0200 |
| commit | 2981534733f5deaa4ed86bc7f91f3bd18152abe0 (patch) | |
| tree | ea0ef98046339579ae8a5322bea80566adde101b /arch/mips | |
| parent | f8944acc97ceebf902e5b26b900aefef987ab4be (diff) | |
MIPS: KVM: Pass reserved instruction exceptions to guest
commit 15505679362270d02c449626385cb74af8905514 upstream.
Previously a reserved instruction exception while in guest code would
cause a KVM internal error if kvm_mips_handle_ri() didn't recognise the
instruction (including a RDHWR from an unrecognised hardware register).
However the guest OS should really have the opportunity to catch the
exception so that it can take the appropriate actions such as sending a
SIGILL to the guest user process or emulating the instruction itself.
Therefore in these cases emulate a guest RI exception and only return
EMULATE_FAIL if that fails, being careful to revert the PC first in case
the exception occurred in a branch delay slot in which case the PC will
already point to the branch target.
Also turn the printk messages relating to these cases into kvm_debug
messages so that they aren't usually visible.
This allows crashme to run in the guest without killing the entire VM.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/kvm/kvm_mips_emul.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/mips/kvm/kvm_mips_emul.c b/arch/mips/kvm/kvm_mips_emul.c index 4b6274b47f33..e75ef8219caf 100644 --- a/arch/mips/kvm/kvm_mips_emul.c +++ b/arch/mips/kvm/kvm_mips_emul.c @@ -1571,17 +1571,17 @@ kvm_mips_handle_ri(unsigned long cause, uint32_t *opc, arch->gprs[rt] = kvm_read_c0_guest_userlocal(cop0); #else /* UserLocal not implemented */ - er = kvm_mips_emulate_ri_exc(cause, opc, run, vcpu); + er = EMULATE_FAIL; #endif break; default: - printk("RDHWR not supported\n"); + kvm_debug("RDHWR %#x not supported @ %p\n", rd, opc); er = EMULATE_FAIL; break; } } else { - printk("Emulate RI not supported @ %p: %#x\n", opc, inst); + kvm_debug("Emulate RI not supported @ %p: %#x\n", opc, inst); er = EMULATE_FAIL; } @@ -1590,6 +1590,7 @@ kvm_mips_handle_ri(unsigned long cause, uint32_t *opc, */ if (er == EMULATE_FAIL) { vcpu->arch.pc = curr_pc; + er = kvm_mips_emulate_ri_exc(cause, opc, run, vcpu); } return er; } |