MMIO exits are more expensive in KVM or Xen than in QEMU because they
involve, at least, privilege transitions. However, MMIO write
operations can be effectively batched if those writes do not have side
effects.
Good examples of this include VGA pixel operations when in a planar
mode. As it turns out, we can get a nice boost in other areas too.
Laurent mentioned a 9.7% performance boost in iperf with the coalesced
MMIO changes for the e1000 when he originally posted this work for KVM.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5961 c046a42c-6fe2-441c-8c8c-71466251a162
Introduce h2g_valid to check if a given host address can be converted
into a valid guest address.
Based on a patch from Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5956 c046a42c-6fe2-441c-8c8c-71466251a162
h2g can only work on 64-bit hosts if the provided address is mappable to
the guest range. Neglecting this was already the source for several
bugs. Instrument the macro so that it will trigger earlier in the
future (at least as long as we have this kind of mapping mechanism).
Based on a patch from Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5955 c046a42c-6fe2-441c-8c8c-71466251a162
Hypervisors like KVM perform badly while doing mmio on
a loop, because it'll generate an exit on each access.
This is the case with VGA, which results in very bad
performance.
In this patch, we map the linear frame buffer as RAM,
make sure it has dirty region tracking enabled, and then
just let the region to be written.
Cleanups suggestions by:
Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Glauber Costa <glommer@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5793 c046a42c-6fe2-441c-8c8c-71466251a162
Add another breakpoint/watchpoint type to BP_GDB: BP_CPU. This type is
intended for hardware-assisted break/watchpoint emulations like the x86
architecture requires.
To keep the highest priority for BP_GDB breakpoints, this type is
always inserted at the head of break/watchpoint lists, thus is found
first when looking up the origin of a debug interruption.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5746 c046a42c-6fe2-441c-8c8c-71466251a162
When one watchpoint is hit, others might have triggered as well. To
support users of the watchpoint API which need to detect such cases,
the BP_WATCHPOINT_HIT flag is introduced and maintained.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5744 c046a42c-6fe2-441c-8c8c-71466251a162
In order to provide accurate information about the triggering
instruction, this patch adds the required bits to restore the pc if the
access happened inside a TB. With the BP_STOP_BEFORE_ACCESS flag, the
watchpoint user can control if the debug trap should be issued on or
after the accessing instruction.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5741 c046a42c-6fe2-441c-8c8c-71466251a162
This patch prepares the QEMU cpu_watchpoint/breakpoint API to allow the
succeeding enhancements this series comes with.
First of all, it overcomes MAX_BREAKPOINTS/MAX_WATCHPOINTS by switching
to dynamically allocated data structures that are kept in linked lists.
This also allows to return a stable reference to the related objects,
required for later introduced x86 debug register support.
Breakpoints and watchpoints are stored with their full information set
and an additional flag field that makes them easily extensible for use
beyond pure guest debugging.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5738 c046a42c-6fe2-441c-8c8c-71466251a162
This patch adds a dirty tracking bit for live migration. We use 0x08 because
kqemu uses 0x04.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5433 c046a42c-6fe2-441c-8c8c-71466251a162
The IO index is now stored in its own field, instead of being wedged
into the vaddr field. This eliminates the ROMD and watchpoint host
pointer weirdness. The IO index space is expanded by 1 bit, and
several additional bits are made available in the TLB vaddr field.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4704 c046a42c-6fe2-441c-8c8c-71466251a162
Implement the 'k' gdbserial packet which kills the qemu instance via
the debugger stub.
Implement the 'D' detach packet for the gdb stub such that you can
disconnect gdb with the "detach" command. This required implementing
a cpu_breakpoint_remove_all() and a cpu_watchpoint_remove_all()
function to cleanup all the breakpoints and watchpoints prior to
leaving the gdb stub else simulation can stop with no debugger
attached.
On a '?' packet remove all the breakpoints and watchpoints. This is
considered more of a safety net in case you force killed gdb or it
crashed and you are reconnecting. The identical behavior exists for
kgdb in the linux kernel.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4478 c046a42c-6fe2-441c-8c8c-71466251a162
This patch allows the qemu backend debugger to single step an
instruction without running the hardware interrupts.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4391 c046a42c-6fe2-441c-8c8c-71466251a162
The patch below uses the float32 and float64 types instead of the float
and double types in the PPC code. This doesn't change anything when
using softfloat-native as the types are the same, but that helps
compiling the PPC target with softfloat.
It also defines a new union CPU_FloatU in addition to CPU_DoubleU, and
use them instead of identical unions that are defined in numerous
places.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4047 c046a42c-6fe2-441c-8c8c-71466251a162
