The code for powering on a CPU in arm-powerctl.c has two separate
use cases:
* emulation of a real hardware power controller
* emulation of firmware interfaces (primarily PSCI) with
CPU on/off APIs
For the first case, we only need to reset the CPU and set its
starting PC and X0. For the second case, because we're emulating the
firmware we need to ensure that it's in the state that the firmware
provides. In particular, when we reset to a lower EL than the
highest one we are emulating, we need to put the CPU into a state
that permits correct running at that lower EL. We already do a
little of this in arm-powerctl.c (for instance we set SCR_HCE to
enable the HVC insn) but we don't do enough of it. This means that
in the case where we are emulating EL3 but also providing emulated
PSCI the guest will crash when a secondary core tries to use a
feature that needs an SCR_EL3 bit to be set, such as MTE or PAuth.
The hw/arm/boot.c code also has to support this "start guest code in
an EL that's lower than the highest emulated EL" case in order to do
direct guest kernel booting; it has all the necessary initialization
code to set the SCR_EL3 bits. Pull the relevant boot.c code out into
a separate function so we can share it between there and
arm-powerctl.c.
This refactoring has a few code changes that look like they
might be behaviour changes but aren't:
* if info->secure_boot is false and info->secure_board_setup is
true, then the old code would start the first CPU in Hyp
mode but without changing SCR.NS and NSACR.{CP11,CP10}.
This was wrong behaviour because there's no such thing
as Secure Hyp mode. The new code will leave the CPU in SVC.
(There is no board which sets secure_boot to false and
secure_board_setup to true, so this isn't a behaviour
change for any of our boards.)
* we don't explicitly clear SCR.NS when arm-powerctl.c
does a CPU-on to EL3. This was a no-op because CPU reset
will reset to NS == 0.
And some real behaviour changes:
* we no longer set HCR_EL2.RW when booting into EL2: the guest
can and should do that themselves before dropping into their
EL1 code. (arm-powerctl and boot did this differently; I
opted to use the logic from arm-powerctl, which only sets
HCR_EL2.RW when it's directly starting the guest in EL1,
because it's more correct, and I don't expect guests to be
accidentally depending on our having set the RW bit for them.)
* if we are booting a CPU into AArch32 Secure SVC then we won't
set SCR.HCE any more. This affects only the vexpress-a15 and
raspi2b machine types. Guests booting in this case will either:
- be able to set SCR.HCE themselves as part of moving from
Secure SVC into NS Hyp mode
- will move from Secure SVC to NS SVC, and won't care about
behaviour of the HVC insn
- will stay in Secure SVC, and won't care about HVC
* on an arm-powerctl CPU-on we will now set the SCR bits for
pauth/mte/sve/sme/hcx/fgt features
The first two of these are very minor and I don't expect guest
code to trip over them, so I didn't judge it worth convoluting
the code in an attempt to keep exactly the same boot.c behaviour.
The third change fixes issue 1899.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1899
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230926155619.4028618-1-peter.maydell@linaro.org
This is in preparation to moving the hflags code into its own file
under the tcg/ directory.
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
After setting CP15 bits in arm_set_cpu_on() the cached hflags must
be rebuild to reflect the changed processor state. Without rebuilding,
the cached hflags would be inconsistent until the next call to
arm_rebuild_hflags(). When QEMU is compiled with debugging enabled
(--enable-debug), this problem is captured shortly after the first
call to arm_set_cpu_on() for CPUs running in ARM 32-bit non-secure mode:
qemu-system-arm: target/arm/helper.c:11359: cpu_get_tb_cpu_state:
Assertion `flags == rebuild_hflags_internal(env)' failed.
Aborted (core dumped)
Fixes: 0c7f8c43da
Cc: qemu-stable@nongnu.org
Signed-off-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This change ensures that the FPU can be accessed in Non-Secure mode
when the CPU core is reset using the arm_set_cpu_on() function call.
The NSACR.{CP11,CP10} bits define the exception level required to
access the FPU in Non-Secure mode. Without these bits set, the CPU
will give an undefined exception trap on the first FPU access for the
secondary cores under Linux.
This is necessary because in this power-control codepath QEMU
is effectively emulating a bit of EL3 firmware, and has to set
the CPU up as the EL3 firmware would.
Fixes: fc1120a7f5
Cc: qemu-stable@nongnu.org
Signed-off-by: Niek Linnenbank <nieklinnenbank@gmail.com>
[PMM: added clarifying para to commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Currently the Arm arm-powerctl.h APIs allow:
* arm_set_cpu_on(), which powers on a CPU and sets its
initial PC and other startup state
* arm_reset_cpu(), which resets a CPU which is already on
(and fails if the CPU is powered off)
but there is no way to say "power on a CPU as if it had
just come out of reset and don't do anything else to it".
Add a new function arm_set_cpu_on_and_reset(), which does this.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190219125808.25174-5-peter.maydell@linaro.org
Until now, the set_pc logic was unclear, which raised questions about
whether it should be used directly, applying a value to PC or adding
additional checks, for example, set the Thumb bit in Arm cpu. Let's set
the set_pc logic for “Configure the PC, as was done in the ELF file”
and implement synchronize_with_tb hook for preserving PC to cpu_tb_exec.
Signed-off-by: Julia Suvorova <jusual@mail.ru>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190129121817.7109-1-jusual@mail.ru
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When QEMU provides the equivalent of the EL3 firmware, we
need to enable HVCs in scr_el3 when turning on CPUs that
target EL2.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 20181011021931.4249-10-edgar.iglesias@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
When switching a new vCPU on we want to complete a bunch of the setup
work before we start scheduling the vCPU thread. To do this cleanly we
defer vCPU setup to async work which will run the vCPUs execution
context as the thread is woken up. The scheduling of the work will kick
the vCPU awake.
This avoids potential races in MTTCG system emulation.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.
Acked-by: Laurent Vivier <laurent@vivier.eu> [m68k part]
Acked-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de> [tricore part]
Acked-by: Michael Walle <michael@walle.cc> [lm32 part]
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> [s390x part]
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> [s390x part]
Acked-by: Eduardo Habkost <ehabkost@redhat.com> [i386 part]
Acked-by: Artyom Tarasenko <atar4qemu@gmail.com> [sparc part]
Acked-by: Richard Henderson <rth@twiddle.net> [alpha part]
Acked-by: Max Filippov <jcmvbkbc@gmail.com> [xtensa part]
Reviewed-by: David Gibson <david@gibson.dropbear.id.au> [ppc part]
Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> [crisµblaze part]
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> [unicore32 part]
Signed-off-by: Thomas Huth <thuth@redhat.com>
