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2023-06-26target/i386: implement SYSCALL/SYSRET in 32-bit emulatorsPaolo Bonzini
AMD supports both 32-bit and 64-bit SYSCALL/SYSRET, but the TCG only exposes it for 64-bit targets. For system emulation just reuse the helper; for user-mode emulation the ABI is the same as "int $80". The BSDs does not support any fast system call mechanism in 32-bit mode so add to bsd-user the same stub that FreeBSD has for 64-bit compatibility mode. Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-01-11i386: Emit correct error code for 64-bit IDT entryJoe Richey
When in 64-bit mode, IDT entiries are 16 bytes, so `intno * 16` is used for base/limit/offset calculations. However, even in 64-bit mode, the exception error code still uses bits [3,16) for the invlaid interrupt index. This means the error code should still be `intno * 8 + 2` even in 64-bit mode. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1382 Signed-off-by: Joe Richey <joerichey@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-10-11target/i386: Truncate values for lcall_real to i32Richard Henderson
Use i32 not int or tl for eip and cs arguments. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20221001140935.465607-15-richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-15target/i386: Throw a #SS when loading a non-canonical ISTGareth Webb
Loading a non-canonical address into rsp when handling an interrupt or performing a far call should raise a #SS not a #GP. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/870 Signed-off-by: Gareth Webb <gareth.webb@umbralsoftware.co.uk> Message-Id: <164529651121.25406.15337137068584246397-0@git.sr.ht> [Move get_pg_mode to seg_helper.c for user-mode emulators. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-14target/i386: Move x86_cpu_exec_interrupt() under sysemu/ folderPhilippe Mathieu-Daudé
Following the logic of commit 30493a030ff ("i386: split seg_helper into user-only and sysemu parts"), move x86_cpu_exec_interrupt() under sysemu/seg_helper.c. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-By: Warner Losh <imp@bsdimp.com> Message-Id: <20210911165434.531552-12-f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-09-14target/i386: Restrict cpu_exec_interrupt() handler to sysemuPhilippe Mathieu-Daudé
Restrict cpu_exec_interrupt() and its callees to sysemu. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Warner Losh <imp@bsdimp.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20210911165434.531552-11-f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-09-14target/i386: Simplify TARGET_X86_64 #ifdef'ryPhilippe Mathieu-Daudé
Merge two TARGET_X86_64 consecutive blocks. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Warner Losh <imp@bsdimp.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20210911165434.531552-4-f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-09-13target/i386: Moved int_ctl into CPUX86State structureLara Lazier
Moved int_ctl into the CPUX86State structure. It removes some unnecessary stores and loads, and prepares for tracking the vIRQ state even when it is masked due to vGIF. Signed-off-by: Lara Lazier <laramglazier@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-04target/i386: tcg: fix switching from 16-bit to 32-bit tasks or vice versaPaolo Bonzini
The format of the task state segment is governed by bit 3 in the descriptor type field. On a task switch, the format for saving is given by the current value of TR's type field, while the format for loading is given by the new descriptor. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-04target/i386: tcg: fix loading of registers from 16-bit TSSPaolo Bonzini
According to the manual, the high 16-bit of the registers are preserved when switching to a 16-bit task. Implement this in switch_tss_ra. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-04target/i386: tcg: fix segment register offsets for 16-bit TSSPaolo Bonzini
The TSS offsets in the manuals have only 2-byte slots for the segment registers. QEMU incorrectly uses 4-byte slots, so that SS overlaps the LDT selector. Resolves: #382 Reported-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-19target/i386: Move helper_check_io to sysemuRichard Henderson
The we never allow i/o from user-only, and the tss check that helper_check_io does will always fail. Use an ifdef within gen_check_io and return false, indicating that an exception is known to be raised. Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20210514151342.384376-50-richard.henderson@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-05-19target/i386: Create helper_check_ioRichard Henderson
Drop helper_check_io[bwl] and expose their common subroutine to tcg directly. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20210514151342.384376-49-richard.henderson@linaro.org>
2021-05-10i386: split seg_helper into user-only and sysemu partsClaudio Fontana
Signed-off-by: Claudio Fontana <cfontana@suse.de> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> [claudio]: Rebased on commit 68775856 ("target/i386: svm: do not discard high 32 bits") Signed-off-by: Claudio Fontana <cfontana@suse.de> Message-Id: <20210322132800.7470-18-cfontana@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-10i386: split smm helper (sysemu)Claudio Fontana
smm is only really useful for sysemu, split in two modules around the CONFIG_USER_ONLY, in order to remove the ifdef and use the build system instead. add cpu_abort() when detecting attempts to enter SMM mode via SMI interrupt in user-mode, and assert that the cpu is not in SMM mode while translating RSM instructions. Signed-off-by: Claudio Fontana <cfontana@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20210322132800.7470-12-cfontana@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-03-19target/i386: svm: do not discard high 32 bits of EXITINFO1Paolo Bonzini
env->error_code is only 32-bits wide, so the high 32 bits of EXITINFO1 are being lost. However, even though saving guest state and restoring host state must be delayed to do_vmexit, because they might take tb_lock, it is always possible to write to the VMCB. So do this for the exit code and EXITINFO1, just like it is already being done for EXITINFO2. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-12target/i386: Use X86Seg enum for segment registersPhilippe Mathieu-Daudé
Use the dedicated X86Seg enum type for segment registers. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20210109233427.749748-1-f4bug@amsat.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-01-02target/i386: Check privilege level for protected mode 'int N' task gatePeter Maydell
When the 'int N' instruction is executed in protected mode, the pseudocode in the architecture manual specifies that we need to check: * vector number within IDT limits * selected IDT descriptor is a valid type (interrupt, trap or task gate) * if this was a software interrupt then gate DPL < CPL The way we had structured the code meant that the privilege check for software interrupts ended up not in the code path taken for task gate handling, because all of the task gate handling code was in the 'case 5' of the switch which was checking "is this descriptor a valid type". Move the task gate handling code out of that switch (so that it is now purely doing the "valid type?" check) and below the software interrupt privilege check. The effect of this missing check was that in a guest userspace binary executing 'int 8' would cause a guest kernel panic rather than the userspace binary being handed a SEGV. This is essentially the same bug fixed in VirtualBox in 2012: https://www.halfdog.net/Security/2012/VirtualBoxSoftwareInterrupt0x8GuestCrash/ Note that for QEMU this is not a security issue because it is only present when using TCG. Fixes: https://bugs.launchpad.net/qemu/+bug/1813201 Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20201121224445.16236-1-peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2020-12-16i386: move TCG cpu class initialization to tcg/Claudio Fontana
to do this, we need to take code out of cpu.c and helper.c, and also move some prototypes from cpu.h, for code that is needed in tcg/xxx_helper.c, and which in turn is part of the callbacks registered by the class initialization. Therefore, do some shuffling of the parts of cpu.h that are only relevant for tcg/, and put them in tcg/helper-tcg.h For FT0 and similar macros, put them in tcg/fpu-helper.c since they are used only there. Signed-off-by: Claudio Fontana <cfontana@suse.de> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20201212155530.23098-8-cfontana@suse.de> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-12-16i386: move TCG accel files into tcg/Claudio Fontana
Signed-off-by: Claudio Fontana <cfontana@suse.de> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> [claudio: moved cc_helper_template.h to tcg/ too] Signed-off-by: Claudio Fontana <cfontana@suse.de> Message-Id: <20201212155530.23098-6-cfontana@suse.de> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>