Provides the ability for the guest to communicate with user-provided code inside
QEMU itself.
This backdoor communication channel is based on using instructions, as opposed
to methods based on MMIO/PIO or virtproxy/virtagent.
Then, these instructions are redirected to a set of user-provided routines,
which are expected to be in the static library "libbackdoor.a", identified by
the "--with-backdoor" configuration parameter.
The advantages of this method are:
* Minimal setup for the guest. Can be used with a simple library using
LD_PRELOAD, or simply adding calls to the macros in "backdoor/guest.h".
* Low-overhead. Using instructions does not go through any OS abstraction, not
even for the setup of the communication channel.
* Non-intrusive wrt OS. It can be used on any OS without prior modifications.
When possible, this will overload unused/meaningless instructions in order to
let the modified guest application to run natively without errors (e.g., using
the CPUID instruction in x86 systems).
v2:
Rebase onto latest QEMU version (d33ea50a958b2e050d2b28e5f17e3b55e91c6d74).
Signed-off-by: Lluís Vilanova <vilan...@ac.upc.edu>
---
Lluís Vilanova (6):
[arm m68k] move helpers.h to helper.h
backdoor: handle config-time activation
backdoor: declare host-side backdoor helpers
backdoor: declare guest-side interface macros
backdoor: [i386] provide and implement intruction-based backdoor interface
backdoor: add a simple example
.gitignore | 1
Makefile.target | 40 +++
backdoor/examples/print/README | 13 +
backdoor/examples/print/guest/Makefile | 7
backdoor/examples/print/guest/test.c | 33 ++
backdoor/examples/print/host/Makefile | 13 +
backdoor/examples/print/host/printcb.c | 36 +++
backdoor/guest.h | 54 ++++
backdoor/helper.h | 21 +
configure | 21 +
target-arm/helper.c | 2
target-arm/helper.h | 450 ++++++++++++++++++++++++++++++++
target-arm/helpers.h | 450 --------------------------------
target-arm/iwmmxt_helper.c | 2
target-arm/neon_helper.c | 2
target-arm/op_helper.c | 2
target-arm/translate.c | 6
target-i386/cpuid.c | 27 ++
target-i386/helper.h | 4
target-i386/translate.c | 4
target-m68k/helper.c | 2
target-m68k/helper.h | 54 ++++
target-m68k/helpers.h | 54 ----
target-m68k/op_helper.c | 2
target-m68k/translate.c | 6
25 files changed, 786 insertions(+), 520 deletions(-)
create mode 100644 backdoor/examples/print/README
create mode 100644 backdoor/examples/print/guest/Makefile
create mode 100644 backdoor/examples/print/guest/test.c
create mode 100644 backdoor/examples/print/host/Makefile
create mode 100644 backdoor/examples/print/host/printcb.c
create mode 100644 backdoor/guest.h
create mode 100644 backdoor/helper.h
create mode 100644 target-arm/helper.h
delete mode 100644 target-arm/helpers.h
create mode 100644 target-m68k/helper.h
delete mode 100644 target-m68k/helpers.h
