Hi all,
could you give a check to this detail, marked as a comment here?
While doing the refactoring and looking at the history,
I _think_ I noticed something that could be wrong related to whpx and hax,
and I marked this as a comment. Maybe Paolo?
On 8/3/20 11:05 AM, Claudio Fontana wrote:
[...]
> -static void qemu_wait_io_event(CPUState *cpu)
> +void qemu_wait_io_event(CPUState *cpu)
> {
> bool slept = false;
>
> @@ -437,7 +538,8 @@ static void qemu_wait_io_event(CPUState *cpu)
> }
>
> #ifdef _WIN32
> - /* Eat dummy APC queued by qemu_cpu_kick_thread. */
> + /* Eat dummy APC queued by qemu_cpu_kick_thread. */
> + /* NB!!! Should not this be if (hax_enabled)? Is this wrong for whpx? */
> if (!tcg_enabled()) {
> SleepEx(0, TRUE);
> }
Looking at the history here, I think this should be if (hax_enabled());
this check was added at a time when whpx did not exist, so I _think_ there
might have been an assumption here
that !tcg_enabled() on windows means actually hax_enabled() for eating this
dummy APC.
Probably it does not cause problems, because whpx does not end up calling
qemu_wait_io_event,
instead it calls qemu_wait_io_event_common. But it would be more expressive to
use if (hax_enabled()) I think.
Could be separately patched.. relevant commits in history follow.
Thanks,
Claudio
commit db08b687cdd5319286665aabd34f82665630416f
Author: Paolo Bonzini <[email protected]>
Date: Thu Jan 11 13:53:12 2018 +0100
cpus: unify qemu_*_wait_io_event
Except for round-robin TCG, every other accelerator is using more or
less the same code around qemu_wait_io_event_common. The exception
is HAX, which also has to eat the dummy APC that is queued by
qemu_cpu_kick_thread.
We can add the SleepEx call to qemu_wait_io_event under "if
(!tcg_enabled())", since that is the condition that is used in
qemu_cpu_kick_thread, and unify the function for KVM, HAX, HVF and
multi-threaded TCG. Single-threaded TCG code can also be simplified
since it is only used in the round-robin, sleep-if-all-CPUs-idle case.
Signed-off-by: Paolo Bonzini <[email protected]>
commit 19306806ae30b7fb5fe61a9130c6995402acad00
Author: Justin Terry (VM) <[email protected]>
Date: Mon Jan 22 13:07:49 2018 -0800
Add the WHPX acceleration enlightenments
Implements the WHPX accelerator cpu enlightenments to actually use the
whpx-all
accelerator on Windows platforms.
Signed-off-by: Justin Terry (VM) <[email protected]>
Message-Id: <[email protected]>
[Register/unregister VCPU thread with RCU. - Paolo]
Signed-off-by: Paolo Bonzini <[email protected]>
commit b0cb0a66d6d535112aa513568ef21dcb1ad283ed
Author: Vincent Palatin <[email protected]>
Date: Tue Jan 10 11:59:57 2017 +0100
Plumb the HAXM-based hardware acceleration support
Use the Intel HAX is kernel-based hardware acceleration module for
Windows (similar to KVM on Linux).
Based on the "target/i386: Add Intel HAX to android emulator" patch
from David Chou <[email protected]>
Signed-off-by: Vincent Palatin <[email protected]>
Message-Id:
<7b9cae28a0c379ab459c7a8545c9a39762bd394f.1484045952.git.vpala...@chromium.org>
[Drop hax_populate_ram stub. - Paolo]
Signed-off-by: Paolo Bonzini <[email protected]>
