In cpu_exec() we have a longstanding workaround for compilers which
do not correctly implement the part of the sigsetjmp()/siglongjmp()
spec which requires that local variables which are not changed
between the setjmp and the longjmp retain their value.
I recently ran across the upstream clang bug report for this; add a
link to it to the comment describing the workaround, and generally
expand the comment, so that we have a reasonable chance in future of
understanding why it's there and determining when we can remove it,
assuming clang eventually fixes the bug.
Remove the /* buggy compiler */ comments on the #else and #endif:
they don't add anything to understanding and are somewhat misleading
since they're sandwiching the code path for *non*-buggy compilers.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20210129130330.30820-1-peter.maydell@linaro.org
Sometimes interrupt event comes at the same time with
the virtual timers. In this case replay tries to proceed
the timers, because deadline for them is zero.
This patch allows processing interrupts and exceptions
by entering the vCPU execution loop, when deadline is zero,
but checkpoint associated with virtual timers is not ready
to be replayed.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Message-Id: <161216312794.2030770.1709657858900983160.stgit@pasha-ThinkPad-X280>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The kvm_vm_ioctl() wrapper already returns -errno if the ioctl itself
returned -1, so the callers of kvm_vm_ioctl() should not check for -1
but for a value < 0 instead.
This problem has been fixed once already in commit b533f658a9
but that commit missed that the ENOENT error code is not fatal for
this ioctl, so the commit has been reverted in commit 50212d6346
since the problem occurred close to a pending release at that point
in time. The plan was to fix it properly after the release, but it
seems like this has been forgotten. So let's do it now finally instead.
Resolves: https://bugs.launchpad.net/qemu/+bug/1294227
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210129084354.42928-1-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
While we've abstracted some (potential) differences between mechanisms for
securing guest memory, the initialization is still specific to SEV. Given
that, move it into x86's kvm_arch_init() code, rather than the generic
kvm_init() code.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
This allows failures to be reported richly and idiomatically.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Currently the "memory-encryption" property is only looked at once we
get to kvm_init(). Although protection of guest memory from the
hypervisor isn't something that could really ever work with TCG, it's
not conceptually tied to the KVM accelerator.
In addition, the way the string property is resolved to an object is
almost identical to how a QOM link property is handled.
So, create a new "confidential-guest-support" link property which sets
this QOM interface link directly in the machine. For compatibility we
keep the "memory-encryption" property, but now implemented in terms of
the new property.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
When AMD's SEV memory encryption is in use, flash memory banks (which are
initialed by pc_system_flash_map()) need to be encrypted with the guest's
key, so that the guest can read them.
That's abstracted via the kvm_memcrypt_encrypt_data() callback in the KVM
state.. except, that it doesn't really abstract much at all.
For starters, the only call site is in code specific to the 'pc'
family of machine types, so it's obviously specific to those and to
x86 to begin with. But it makes a bunch of further assumptions that
need not be true about an arbitrary confidential guest system based on
memory encryption, let alone one based on other mechanisms:
* it assumes that the flash memory is defined to be encrypted with the
guest key, rather than being shared with hypervisor
* it assumes that that hypervisor has some mechanism to encrypt data into
the guest, even though it can't decrypt it out, since that's the whole
point
* the interface assumes that this encrypt can be done in place, which
implies that the hypervisor can write into a confidential guests's
memory, even if what it writes isn't meaningful
So really, this "abstraction" is actually pretty specific to the way SEV
works. So, this patch removes it and instead has the PC flash
initialization code call into a SEV specific callback.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
add a new optional interface to CPUClass, which allows accelerators
to extend the CPUClass with additional accelerator-specific
initializations.
This will allow to separate the target cpu code that is specific
to each accelerator, and register it automatically with object
hierarchy lookup depending on accelerator code availability,
as part of the accel_init_interfaces() initialization step.
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210204163931.7358-19-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This will allow us to centralize the registration of
the cpus.c module accelerator operations (in accel/accel-softmmu.c),
and trigger it automatically using object hierarchy lookup from the
new accel_init_interfaces() initialization step, depending just on
which accelerators are available in the code.
Rename all tcg-cpus.c, kvm-cpus.c, etc to tcg-accel-ops.c,
kvm-accel-ops.c, etc, matching the object type names.
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210204163931.7358-18-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
we cannot in principle make the TCG Operations field definitions
conditional on CONFIG_TCG in code that is included by both common_ss
and specific_ss modules.
Therefore, what we can do safely to restrict the TCG fields to TCG-only
builds, is to move all tcg cpu operations into a separate header file,
which is only included by TCG, target-specific code.
This leaves just a NULL pointer in the cpu.h for the non-TCG builds.
This also tidies up the code in all targets a bit, having all TCG cpu
operations neatly contained by a dedicated data struct.
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210204163931.7358-16-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
commit 568496c0c0 ("cpu: Add callback to check architectural") and
commit 3826121d92 ("target-arm: Implement checking of fired")
introduced an ARM-specific hack for cpu_check_watchpoint.
Make debug_check_watchpoint optional, and move it to tcg_ops.
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210204163931.7358-15-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
move away TCG-only code, make it compile only on TCG.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[claudio: moved the prototypes from hw/core/cpu.h to exec/cpu-all.h]
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210204163931.7358-4-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In macOS 11, QEMU only gets access to Hypervisor.framework if it has the
respective entitlement. Add an entitlement template and automatically self
sign and apply the entitlement in the build.
Signed-off-by: Alexander Graf <agraf@csgraf.de>
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Tested-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Some large translation blocks can generate so many unique
constants that we run out of temps to hold them. In this
case, longjmp back to the start of code generation and
restart with a smaller translation block.
Buglink: https://bugs.launchpad.net/bugs/1912065
Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Pages can't be both write and executable at the same time on Apple
Silicon. macOS provides public API to switch write protection [1] for
JIT applications, like TCG.
1. https://developer.apple.com/documentation/apple_silicon/porting_just-in-time_compilers_to_apple_silicon
Tested-by: Alexander Graf <agraf@csgraf.de>
Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>
Message-Id: <20210113032806.18220-1-r.bolshakov@yadro.com>
[rth: Inline the qemu_thread_jit_* functions;
drop the MAP_JIT change for a follow-on patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
As cpu_io_recompile() is only called within TCG accelerator
in cputlb.c, declare it locally.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210117164813.4101761-6-f4bug@amsat.org>
[rth: Adjust vs changed tb_flush_jmp_cache patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
cpu_loop_exit*() functions are declared in accel/tcg/cpu-exec-common.c,
and are not available when TCG accelerator is not built. Add stubs so
linking without TCG succeed.
Problematic files:
- hw/semihosting/console.c in qemu_semihosting_console_inc()
- hw/ppc/spapr_hcall.c in h_confer()
- hw/s390x/ipl.c in s390_ipl_reset_request()
- hw/misc/mips_itu.c
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210117164813.4101761-5-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
tb_gen_code() is only called within TCG accelerator, declare it locally.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210117164813.4101761-4-f4bug@amsat.org>
[rth: Adjust vs changed tb_flush_jmp_cache patch.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move and make the function static, as the only users
are here in cputlb.c.
Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
cpu_gen_init() is TCG specific, only used in tcg/translate-all.c.
No need to export it to other accelerators, declare it statically.
Reviewed-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210117164813.4101761-2-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The cpu_exec_step_atomic() function is called with the cpu->running
clear and proceeds to run target code without setting this flag. If
this target code generates an exception then handle_cpu_signal() will
unnecessarily abort. For example if atomic code generates a memory
protection fault.
This patch at least sets and clears this running flag, and adds some
assertions to help detect other cases.
Signed-off-by: Douglas Crosher <dtc-ubuntu@scieneer.com>
Message-Id: <a272c656-f7c5-019d-1cc0-499b8f80f2fc@scieneer.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
As per POSIX specification of limits.h [1], OS libc may define
PAGE_SIZE in limits.h.
PAGE_SIZE is used in included kernel uapi headers.
To prevent collosion of definition, we discard PAGE_SIZE from
defined by libc and take QEMU's variable.
[1]: https://pubs.opengroup.org/onlinepubs/7908799/xsh/limits.h.html
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Message-Id: <20210118063808.12471-8-jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Now that all native tcg hosts support splitwx, remove the define.
Replace the one use with a test for CONFIG_TCG_INTERPRETER.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Re-use the 256MiB region handling from alloc_code_gen_buffer_anon,
and replace that with the shared file mapping.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This produces a small pc-relative displacement within the
generated code to the TB structure that preceeds it.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Cribbed from code posted by Joelle van Dyne <j@getutm.app>,
and rearranged to a cleaner structure.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We cannot use a real temp file, because we would need to find
a filesystem that does not have noexec enabled. However, a
memfd is not associated with any filesystem.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Plumb the value through to alloc_code_gen_buffer. This is not
supported by any os or tcg backend, so for now enabling it will
result in an error.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Report better error messages than just "could not allocate".
Let alloc_code_gen_buffer set ctx->code_gen_buffer_size
and ctx->code_gen_buffer, and simply return bool.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
There is nothing within the translators that ought to be
changing the TranslationBlock data, so make it const.
This does not actually use the read-only copy of the
data structure that exists within the rx region.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Pass both rx and rw addresses to tb_target_set_jmp_target.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Add two helper functions, using a global variable to hold
the displacement. The displacement is currently always 0,
so no change in behaviour.
Begin using the functions in tcg common code only.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Create a function to determine if a pointer is within the buffer.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This value is constant across all thread-local copies of TCGContext,
so we might as well move it out of thread-local storage.
Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In f47db80cc0, we handled odd-sized tail clearing for
the case of hosts that have vector operations, but did
not handle the case of hosts that do not have vector ops.
This was ok until e2e7168a21, which changed the encoding
of simd_desc such that the odd sizes are impossible.
Add memset as a tcg helper, and use that for all out-of-line
byte stores to vectors. This includes, but is not limited to,
the tail clearing operation in question.
Cc: qemu-stable@nongnu.org
Buglink: https://bugs.launchpad.net/bugs/1907817
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Build the array of command line arguments coming from config_host
once for all targets. Add all accelerators to accel/Kconfig so
that the command line arguments for accelerators can be computed
easily in the existing "foreach sym: accelerators" loop.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Enable removing tcg/$tcg_arch from the include path when TCG is disabled.
Move translate-all.h to include/exec, since stubs exist for the functions
defined therein.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
LLVM/Clang, supports runtime checks for forward-edge Control-Flow
Integrity (CFI).
CFI on indirect function calls (cfi-icall) ensures that, in indirect
function calls, the function called is of the right signature for the
pointer type defined at compile time.
For this check to work, the code must always respect the function
signature when using function pointer, the function must be defined
at compile time, and be compiled with link-time optimization.
This rules out, for example, shared libraries that are dynamically loaded
(given that functions are not known at compile time), and code that is
dynamically generated at run-time.
This patch:
1) Introduces the CONFIG_CFI flag to support cfi in QEMU
2) Introduces a decorator to allow the definition of "sensitive"
functions, where a non-instrumented function may be called at runtime
through a pointer. The decorator will take care of disabling cfi-icall
checks on such functions, when cfi is enabled.
3) Marks functions currently in QEMU that exhibit such behavior,
in particular:
- The function in TCG that calls pre-compiled TBs
- The function in TCI that interprets instructions
- Functions in the plugin infrastructures that jump to callbacks
- Functions in util that directly call a signal handler
Signed-off-by: Daniele Buono <dbuono@linux.vnet.ibm.com>
Acked-by: Alex Bennée <alex.bennee@linaro.org
Message-Id: <20201204230615.2392-3-dbuono@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
../accel/tcg/user-exec.c: In function ‘handle_cpu_signal’:
../accel/tcg/user-exec.c:169:13: warning: this statement may fall through [-Wimplicit-fallthrough=]
169 | cpu_exit_tb_from_sighandler(cpu, old_set);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../accel/tcg/user-exec.c:172:9: note: here
172 | default:
Mark the cpu_exit_tb_from_sighandler() function with QEMU_NORETURN to fix it.
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20201211152426.350966-8-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
This will let us simplify the code that initializes CPU class
methods, when we move cpu_exec_*() to a separate struct.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20201212155530.23098-11-cfontana@suse.de>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Move invocation of CPUClass.cpu_exec_*() to separate helpers,
to make it easier to refactor that code later.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20201212155530.23098-10-cfontana@suse.de>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
