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2019-11-19target/arm: Support EL0 v7m msr/mrs for CONFIG_USER_ONLYRichard Henderson
Simply moving the non-stub helper_v7m_mrs/msr outside of !CONFIG_USER_ONLY is not an option, because of all of the other system-mode helpers that are called. But we can split out a few subroutines to handle the few EL0 accessible registers without duplicating code. Reported-by: Christophe Lyon <christophe.lyon@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191118194916.3670-1-richard.henderson@linaro.org [PMM: deleted now-redundant comment; added a default case to switch in v7m_msr helper] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-19target/arm: Relax r13 restriction for ldrex/strex for v8.0Richard Henderson
Armv8-A removes UNPREDICTABLE for R13 for these cases. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191117090621.32425-3-richard.henderson@linaro.org [PMM: changed ENABLE_ARCH_8 checks to check a new bool 'v8a', since these cases are still UNPREDICTABLE for v8M] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-19target/arm: Do not reject rt == rt2 for strexdRichard Henderson
There was too much cut and paste between ldrexd and strexd, as ldrexd does prohibit two output registers the same. Fixes: af288228995 Reported-by: Michael Goffioul <michael.goffioul@gmail.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191117090621.32425-2-richard.henderson@linaro.org Reviewed-by: Robert Foley <robert.foley@linaro.org> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-19target/arm: Merge arm_cpu_vq_map_next_smaller into sole callerRichard Henderson
Coverity reports, in sve_zcr_get_valid_len, "Subtract operation overflows on operands arm_cpu_vq_map_next_smaller(cpu, start_vq + 1U) and 1U" First, the aarch32 stub version of arm_cpu_vq_map_next_smaller, returning 0, does exactly what Coverity reports. Remove it. Second, the aarch64 version of arm_cpu_vq_map_next_smaller has a set of asserts, but they don't cover the case in question. Further, there is a fair amount of extra arithmetic needed to convert from the 0-based zcr register, to the 1-base vq form, to the 0-based bitmap, and back again. This can be simplified by leaving the value in the 0-based form. Finally, use test_bit to simplify the common case, where the length in the zcr registers is in fact a supported length. Reported-by: Coverity (CID 1407217) Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Message-id: 20191118091414.19440-1-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm: Allow reading flags from FPSCR for M-profileChristophe Lyon
rt==15 is a special case when reading the flags: it means the destination is APSR. This patch avoids rejecting vmrs apsr_nzcv, fpscr as illegal instruction. Cc: qemu-stable@nongnu.org Signed-off-by: Christophe Lyon <christophe.lyon@linaro.org> Message-id: 20191025095711.10853-1-christophe.lyon@linaro.org [PMM: updated the comment] Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/kvm: host cpu: Add support for sve<N> propertiesAndrew Jones
Allow cpu 'host' to enable SVE when it's available, unless the user chooses to disable it with the added 'sve=off' cpu property. Also give the user the ability to select vector lengths with the sve<N> properties. We don't adopt 'max' cpu's other sve property, sve-max-vq, because that property is difficult to use with KVM. That property assumes all vector lengths in the range from 1 up to and including the specified maximum length are supported, but there may be optional lengths not supported by the host in that range. With KVM one must be more specific when enabling vector lengths. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Message-id: 20191031142734.8590-10-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/cpu64: max cpu: Support sve properties with KVMAndrew Jones
Extend the SVE vq map initialization and validation with KVM's supported vector lengths when KVM is enabled. In order to determine and select supported lengths we add two new KVM functions for getting and setting the KVM_REG_ARM64_SVE_VLS pseudo-register. This patch has been co-authored with Richard Henderson, who reworked the target/arm/cpu64.c changes in order to push all the validation and auto-enabling/disabling steps into the finalizer, resulting in a nice LOC reduction. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Message-id: 20191031142734.8590-9-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/kvm: scratch vcpu: Preserve input kvm_vcpu_init featuresAndrew Jones
kvm_arm_create_scratch_host_vcpu() takes a struct kvm_vcpu_init parameter. Rather than just using it as an output parameter to pass back the preferred target, use it also as an input parameter, allowing a caller to pass a selected target if they wish and to also pass cpu features. If the caller doesn't want to select a target they can pass -1 for the target which indicates they want to use the preferred target and have it passed back like before. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Reviewed-by: Beata Michalska <beata.michalska@linaro.org> Message-id: 20191031142734.8590-8-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/kvm64: max cpu: Enable SVE when availableAndrew Jones
Enable SVE in the KVM guest when the 'max' cpu type is configured and KVM supports it. KVM SVE requires use of the new finalize vcpu ioctl, so we add that now too. For starters SVE can only be turned on or off, getting all vector lengths the host CPU supports when on. We'll add the other SVE CPU properties in later patches. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Reviewed-by: Beata Michalska <beata.michalska@linaro.org> Message-id: 20191031142734.8590-7-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/kvm64: Add kvm_arch_get/put_sveAndrew Jones
These are the SVE equivalents to kvm_arch_get/put_fpsimd. Note, the swabbing is different than it is for fpsmid because the vector format is a little-endian stream of words. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Message-id: 20191031142734.8590-6-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/cpu64: max cpu: Introduce sve<N> propertiesAndrew Jones
Introduce cpu properties to give fine control over SVE vector lengths. We introduce a property for each valid length up to the current maximum supported, which is 2048-bits. The properties are named, e.g. sve128, sve256, sve384, sve512, ..., where the number is the number of bits. See the updates to docs/arm-cpu-features.rst for a description of the semantics and for example uses. Note, as sve-max-vq is still present and we'd like to be able to support qmp_query_cpu_model_expansion with guests launched with e.g. -cpu max,sve-max-vq=8 on their command lines, then we do allow sve-max-vq and sve<N> properties to be provided at the same time, but this is not recommended, and is why sve-max-vq is not mentioned in the document. If sve-max-vq is provided then it enables all lengths smaller than and including the max and disables all lengths larger. It also has the side-effect that no larger lengths may be enabled and that the max itself cannot be disabled. Smaller non-power-of-two lengths may, however, be disabled, e.g. -cpu max,sve-max-vq=4,sve384=off provides a guest the vector lengths 128, 256, and 512 bits. This patch has been co-authored with Richard Henderson, who reworked the target/arm/cpu64.c changes in order to push all the validation and auto-enabling/disabling steps into the finalizer, resulting in a nice LOC reduction. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Reviewed-by: Beata Michalska <beata.michalska@linaro.org> Message-id: 20191031142734.8590-5-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm: Allow SVE to be disabled via a CPU propertyAndrew Jones
Since 97a28b0eeac14 ("target/arm: Allow VFP and Neon to be disabled via a CPU property") we can disable the 'max' cpu model's VFP and neon features, but there's no way to disable SVE. Add the 'sve=on|off' property to give it that flexibility. We also rename cpu_max_get/set_sve_vq to cpu_max_get/set_sve_max_vq in order for them to follow the typical *_get/set_<property-name> pattern. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Reviewed-by: Beata Michalska <beata.michalska@linaro.org> Message-id: 20191031142734.8590-4-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-11-01target/arm/monitor: Introduce qmp_query_cpu_model_expansionAndrew Jones
Add support for the query-cpu-model-expansion QMP command to Arm. We do this selectively, only exposing CPU properties which represent optional CPU features which the user may want to enable/disable. Additionally we restrict the list of queryable cpu models to 'max', 'host', or the current type when KVM is in use. And, finally, we only implement expansion type 'full', as Arm does not yet have a "base" CPU type. More details and example queries are described in a new document (docs/arm-cpu-features.rst). Note, certainly more features may be added to the list of advertised features, e.g. 'vfp' and 'neon'. The only requirement is that we can detect invalid configurations and emit failures at QMP query time. For 'vfp' and 'neon' this will require some refactoring to share a validation function between the QMP query and the CPU realize functions. Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Beata Michalska <beata.michalska@linaro.org> Message-id: 20191031142734.8590-2-drjones@redhat.com Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-28target/arm: fetch code with translator_ldEmilio G. Cota
Now the arm_ld*_code functions are only used at translate time we can just pass down to translator_ld functions. Signed-off-by: Emilio G. Cota <cota@braap.org> [AJB: convert from plugin_insn_append to translator_ld] Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-10-24target/arm: Rely on hflags correct in cpu_get_tb_cpu_stateRichard Henderson
This is the payoff. From perf record -g data of ubuntu 18 boot and shutdown: BEFORE: - 23.02% 2.82% qemu-system-aar [.] helper_lookup_tb_ptr - 20.22% helper_lookup_tb_ptr + 10.05% tb_htable_lookup - 9.13% cpu_get_tb_cpu_state 3.20% aa64_va_parameters_both 0.55% fp_exception_el - 11.66% 4.74% qemu-system-aar [.] cpu_get_tb_cpu_state - 6.96% cpu_get_tb_cpu_state 3.63% aa64_va_parameters_both 0.60% fp_exception_el 0.53% sve_exception_el AFTER: - 16.40% 3.40% qemu-system-aar [.] helper_lookup_tb_ptr - 13.03% helper_lookup_tb_ptr + 11.19% tb_htable_lookup 0.55% cpu_get_tb_cpu_state 0.98% 0.71% qemu-system-aar [.] cpu_get_tb_cpu_state 0.87% 0.24% qemu-system-aar [.] rebuild_hflags_a64 Before, helper_lookup_tb_ptr is the second hottest function in the application, consuming almost a quarter of the runtime. Within the entire execution, cpu_get_tb_cpu_state consumes about 12%. After, helper_lookup_tb_ptr has dropped to the fourth hottest function, with consumption dropping to a sixth of the runtime. Within the entire execution, cpu_get_tb_cpu_state has dropped below 1%, and the supporting function to rebuild hflags also consumes about 1%. Assertions are retained for --enable-debug-tcg. Tested-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-25-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Rebuild hflags for M-profileRichard Henderson
Continue setting, but not relying upon, env->hflags. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-21-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Rebuild hflags at Xscale SCTLR writesRichard Henderson
Continue setting, but not relying upon, env->hflags. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-20-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Rebuild hflags at CPSR writesRichard Henderson
Continue setting, but not relying upon, env->hflags. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-19-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Rebuild hflags at MSR writesRichard Henderson
Continue setting, but not relying upon, env->hflags. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-18-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Rebuild hflags at EL changesRichard Henderson
Begin setting, but not relying upon, env->hflags. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-17-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Add HELPER(rebuild_hflags_{a32, a64, m32})Richard Henderson
This functions are given the mode and el state of the cpu and writes the computed value to env->hflags. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-16-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Hoist store to cs_base in cpu_get_tb_cpu_stateRichard Henderson
By performing this store early, we avoid having to save and restore the register holding the address around any function calls. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-15-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Split out arm_mmu_idx_elRichard Henderson
Avoid calling arm_current_el() twice. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-14-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Add arm_rebuild_hflagsRichard Henderson
This function assumes nothing about the current state of the cpu, and writes the computed value to env->hflags. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-13-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Hoist computation of TBFLAG_A32.VFPENRichard Henderson
There are 3 conditions that each enable this flag. M-profile always enables; A-profile with EL1 as AA64 always enables. Both of these conditions can easily be cached. The final condition relies on the FPEXC register which we are not prepared to cache. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-12-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Simplify set of PSTATE_SS in cpu_get_tb_cpu_stateRichard Henderson
Hoist the variable load for PSTATE into the existing test vs is_a64. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-11-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Hoist XSCALE_CPAR, VECLEN, VECSTRIDE in cpu_get_tb_cpu_stateRichard Henderson
We do not need to compute any of these values for M-profile. Further, XSCALE_CPAR overlaps VECSTRIDE so obviously the two sets must be mutually exclusive. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-10-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Split out rebuild_hflags_aprofileRichard Henderson
Create a function to compute the values of the TBFLAG_ANY bits that will be cached, and are used by A-profile. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-9-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Split out rebuild_hflags_a32Richard Henderson
Currently a trivial wrapper for rebuild_hflags_common_32. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-8-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Reduce tests vs M-profile in cpu_get_tb_cpu_stateRichard Henderson
Hoist the computation of some TBFLAG_A32 bits that only apply to M-profile under a single test for ARM_FEATURE_M. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-7-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Split out rebuild_hflags_m32Richard Henderson
Create a function to compute the values of the TBFLAG_A32 bits that will be cached, and are used by M-profile. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-6-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Split arm_cpu_data_is_big_endianRichard Henderson
Set TBFLAG_ANY.BE_DATA in rebuild_hflags_common_32 and rebuild_hflags_a64 instead of rebuild_hflags_common, where we do not need to re-test is_a64() nor re-compute the various inputs. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-5-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Split out rebuild_hflags_common_32Richard Henderson
Create a function to compute the values of the TBFLAG_A32 bits that will be cached, and are used by all profiles. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-4-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Split out rebuild_hflags_a64Richard Henderson
Create a function to compute the values of the TBFLAG_A64 bits that will be cached. For now, the env->hflags variable is not used, and the results are fed back to cpu_get_tb_cpu_state. Note that not all BTI related flags are cached, so we have to test the BTI feature twice -- once for those bits moved out to rebuild_hflags_a64 and once for those bits that remain in cpu_get_tb_cpu_state. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-3-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-24target/arm: Split out rebuild_hflags_commonRichard Henderson
Create a function to compute the values of the TBFLAG_ANY bits that will be cached. For now, the env->hflags variable is not used, and the results are fed back to cpu_get_tb_cpu_state. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20191023150057.25731-2-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-22target/arm: Fix sign-extension for SMLAL*Richard Henderson
The 32-bit product should be sign-extended, not zero-extended. Fixes: ea96b374641b Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Laurent Desnogues <laurent.desnogues@gmail.com> Message-id: 20190912183058.17947-1-richard.henderson@linaro.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-10-15target/arm/arm-semi: Implement SH_EXT_STDOUT_STDERR extensionPeter Maydell
SH_EXT_STDOUT_STDERR is a v2.0 semihosting extension: the guest can open ":tt" with a file mode requesting append access in order to open stderr, in addition to the existing "open for read for stdin or write for stdout". Implement this and report it via the :semihosting-features data. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 20190916141544.17540-16-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Implement SH_EXT_EXIT_EXTENDED extensionPeter Maydell
SH_EXT_EXIT_EXTENDED is a v2.0 semihosting extension: it indicates that the implementation supports the SYS_EXIT_EXTENDED function. This function allows both A64 and A32/T32 guests to exit with a specified exit status, unlike the older SYS_EXIT function which only allowed this for A64 guests. Implement this extension. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 20190916141544.17540-15-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Implement support for semihosting feature detectionPeter Maydell
Version 2.0 of the semihosting specification added support for allowing a guest to detect whether the implementation supported particular features. This works by the guest opening a magic file ":semihosting-features", which contains a fixed set of data with some magic numbers followed by a sequence of bytes with feature flags. The file is expected to behave sensibly for the various semihosting calls which operate on files (SYS_FLEN, SYS_SEEK, etc). Implement this as another kind of guest FD using our function table dispatch mechanism. Initially we report no extended features, so we have just one feature flag byte which is zero. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 20190916141544.17540-14-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Factor out implementation of SYS_FLENPeter Maydell
Factor out the implementation of SYS_FLEN via the new function tables. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190916141544.17540-13-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Factor out implementation of SYS_SEEKPeter Maydell
Factor out the implementation of SYS_SEEK via the new function tables. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190916141544.17540-12-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Factor out implementation of SYS_ISTTYPeter Maydell
Factor out the implementation of SYS_ISTTY via the new function tables. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190916141544.17540-11-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Factor out implementation of SYS_READPeter Maydell
Factor out the implementation of SYS_READ via the new function tables. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190916141544.17540-10-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Factor out implementation of SYS_WRITEPeter Maydell
Factor out the implementation of SYS_WRITE via the new function tables. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20190916141544.17540-9-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Factor out implementation of SYS_CLOSEPeter Maydell
Currently for the semihosting calls which take a file descriptor (SYS_CLOSE, SYS_WRITE, SYS_READ, SYS_ISTTY, SYS_SEEK, SYS_FLEN) we have effectively two implementations, one for real host files and one for when we indirect via the gdbstub. We want to add a third one to deal with the magic :semihosting-features file. Instead of having a three-way if statement in each of these cases, factor out the implementation of the calls to separate functions which we dispatch to via function pointers selected via the GuestFDType for the guest fd. In this commit, we set up the framework for the dispatch, and convert the SYS_CLOSE call to use it. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20190916141544.17540-8-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Use set_swi_errno() in gdbstub callback functionsPeter Maydell
When we are routing semihosting operations through the gdbstub, the work of sorting out the return value and setting errno if necessary is done by callback functions which are invoked by the gdbstub code. Clean up some ifdeffery in those functions by having them call set_swi_errno() to set the semihosting errno. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20190916141544.17540-7-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Restrict use of TaskState*Peter Maydell
The semihosting code needs accuss to the linux-user only TaskState pointer so it can set the semihosting errno per-thread for linux-user mode. At the moment we do this by having some ifdefs so that we define a 'ts' local in do_arm_semihosting() which is either a real TaskState * or just a CPUARMState *, depending on which mode we're compiling for. This is awkward if we want to refactor do_arm_semihosting() into other functions which might need to be passed the TaskState. Restrict usage of the TaskState local by: * making set_swi_errno() always take the CPUARMState pointer and (for the linux-user version) get TaskState from that * creating a new get_swi_errno() which reads the errno * having the two semihosting calls which need the TaskState for other purposes (SYS_GET_CMDLINE and SYS_HEAPINFO) define a variable with scope restricted to just that code Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20190916141544.17540-6-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Make semihosting code hand out its own file descriptorsPeter Maydell
Currently the Arm semihosting code returns the guest file descriptors (handles) which are simply the fd values from the host OS or the remote gdbstub. Part of the semihosting 2.0 specification requires that we implement special handling of opening a ":semihosting-features" filename. Guest fds which result from opening the special file won't correspond to host fds, so to ensure that we don't end up with duplicate fds we need to have QEMU code control the allocation of the fd values we give the guest. Add in an abstraction layer which lets us allocate new guest FD values, and translate from a guest FD value back to the host one. This also fixes an odd hole where a semihosting guest could use the semihosting API to read, write or close file descriptors that it had never allocated but which were being used by QEMU itself. (This isn't a security hole, because enabling semihosting permits the guest to do arbitrary file access to the whole host filesystem, and so should only be done if the guest is completely trusted.) Currently the only kind of guest fd is one which maps to a host fd, but in a following commit we will add one which maps to the :semihosting-features magic data. If the guest is migrated with an open semihosting file descriptor then subsequent attempts to use the fd will all fail; this is not a change from the previous situation (where the host fd being used on the source end would not be re-opened on the destination end). Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20190916141544.17540-5-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Correct comment about gdb syscall racesPeter Maydell
In arm_gdb_syscall() we have a comment suggesting a race because the syscall completion callback might not happen before the gdb_do_syscallv() call returns. The comment is correct that the callback may not happen but incorrect about the effects. Correct it and note the important caveat that callers must never do any work of any kind after return from arm_gdb_syscall() that depends on its return value. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20190916141544.17540-4-peter.maydell@linaro.org
2019-10-15target/arm/arm-semi: Always set some kind of errno for failed callsPeter Maydell
If we fail a semihosting call we should always set the semihosting errno to something; we were failing to do this for some of the "check inputs for sanity" cases. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20190916141544.17540-3-peter.maydell@linaro.org