During a page table walk of TCG+SVM the code in target/i386/excp_helper.c
get_hphys() uses the cr4 register of the guest instead of the hypervisor
to check for the PSE bit. In the test case we have, the guest have not
enabled (yet) the PSE bit and so the page table walk results in a wrong
host physical address resolution and wrong content read by the guest.
Attached patch is against 4.2.1, but works also on 3.1.0. It fixes the
issue for our automated testcase, which is a 32bit hypervisor w/o PAE
support running a guest VM with tcg+svm.
The test worked beforehand up to qemu 2.12, started to fail with qemu 3.0
and later. The added TCG/SVM NPT commit seems to introduce the regression.
In case someone want to try to reproduce it, the iso is at [0], the good
case is [1] and the failing case is [2]. The used commandline is:
qemu-system-i386 -no-kvm -nographic -cpu phenom -m 512 -machine q35 -cdrom seoul-vmm-test.iso
[0] https://depot.genode.org/alex-ab/images/seoul-vmm-test.iso
[1] https://depot.genode.org/alex-ab/images/seoul-vmm-good.txt
[2] https://depot.genode.org/alex-ab/images/seoul-vmm-bad.txt
Signed-off-by: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cleanup in the boilerplate that each target must define.
Replace x86_env_get_cpu with env_archcpu. The combination
CPU(x86_env_get_cpu) should have used ENV_GET_CPU to begin;
use env_cpu now.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This flag will be used for KVM's nested VMX migration; the HF_GUEST_MASK name
is already used in KVM, adopt it in QEMU as well.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This implements NPT suport for SVM by hooking into
x86_cpu_handle_mmu_fault where it reads the stage-1 page table. Whether
we need to perform this 2nd stage translation, and how, is decided
during vmrun and stored in hflags2, along with nested_cr3 and
nested_pg_mode.
As get_hphys performs a direct cpu_vmexit in case of NPT faults, we need
retaddr in that function. To avoid changing the signature of
cpu_handle_mmu_fault, this passes the value from tlb_fill to get_hphys
via the CPU state.
This was tested successfully via the Jailhouse hypervisor.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Message-Id: <567473a0-6005-5843-4c73-951f476085ca@web.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It calls cpu_loop_exit in system emulation mode (and should never be
called in user emulation mode).
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Message-Id: <6f4d44ffde55d074cbceb48309c1678600abad2f.1522769774.git.jan.kiszka@web.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In icount mode, instructions that access io memory spaces in the middle
of the translation block invoke TB recompilation. After recompilation,
such instructions become last in the TB and are allowed to access io
memory spaces.
When the code includes instruction like i386 'xchg eax, 0xffffd080'
which accesses APIC, QEMU goes into an infinite loop of the recompilation.
This instruction includes two memory accesses - one read and one write.
After the first access, APIC calls cpu_report_tpr_access, which restores
the CPU state to get the current eip. But cpu_restore_state_from_tb
resets the cpu->can_do_io flag which makes the second memory access invalid.
Therefore the second memory access causes a recompilation of the block.
Then these operations repeat again and again.
This patch moves resetting cpu->can_do_io flag from
cpu_restore_state_from_tb to cpu_loop_exit* functions.
It also adds a parameter for cpu_restore_state which controls restoring
icount. There is no need to restore icount when we only query CPU state
without breaking the TB. Restoring it in such cases leads to the
incorrect flow of the virtual time.
In most cases new parameter is true (icount should be recalculated).
But there are two cases in i386 and openrisc when the CPU state is only
queried without the need to break the TB. This patch fixes both of
these cases.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <20180409091320.12504.35329.stgit@pasha-VirtualBox>
[rth: Make can_do_io setting unconditional; move from cpu_exec;
make cpu_loop_exit_{noexc,restore} call cpu_loop_exit.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
cpu_restore_state officially supports being passed an address it can't
resolve the state for. As a result the checks in the helpers are
superfluous and can be removed. This makes the code consistent with
other users of cpu_restore_state.
Of course this does nothing to address what to do if cpu_restore_state
can't resolve the state but so far it seems this is handled elsewhere.
The change was made with included coccinelle script.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
[rth: Fixed up comment indentation. Added second hunk to script to
combine cpu_restore_state and cpu_loop_exit.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
All but a handful of files include exec/cpu-all.h via cpu.h only.
As these files already include cpu.h, let's just drop the additional
include.
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170913132417.24384-2-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Paths through the softmmu code during code generation now need to be audited
to check for double locking of tb_lock. In particular, VMEXIT can take tb_lock
through cpu_vmexit -> cpu_x86_update_cr4 -> tlb_flush.
To avoid this, split VMEXIT delivery in two parts, similar to what is done with
exceptions. cpu_vmexit only records the VMEXIT exit code and information, and
cc->do_interrupt can then deliver it when it is safe to take the lock.
Reported-by: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Suggested-by: Richard Henderson <rth@twiddle.net>
Tested-by: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Commit 2afbdf8 ("target-i386: exception handling for memory helpers",
2015-09-15) changed tlb_fill's cpu_restore_state+raise_exception_err
to raise_exception_err_ra. After this change, the cpu_restore_state
and raise_exception_err's cpu_loop_exit are merged into
raise_exception_err_ra's cpu_loop_exit_restore.
This actually fixed some bugs, but when SVM is enabled there is a
second path from raise_exception_err_ra to cpu_loop_exit. This is
the VMEXIT path, and now cpu_vmexit is called without a
cpu_restore_state before.
The fix is to pass the retaddr to cpu_vmexit (via
cpu_svm_check_intercept_param). All helpers can now use GETPC() to pass
the correct retaddr, too.
Cc: qemu-stable@nongnu.org
Fixes: 2afbdf8480
Reported-by: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Tested-by: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We have never has the concept of global TLB entries which would avoid
the flush so we never actually use this flag. Drop it and make clear
that tlb_flush is the sledge-hammer it has always been.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
[DG: ppc portions]
Acked-by: David Gibson <david@gibson.dropbear.id.au>
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>
