- 15 Jun, 2016 14 commits
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James Hogan authored
The comm page which is mapped into the guest kernel address space at 0x0 has the unfortunate side effect of allowing guest kernel NULL pointer dereferences to succeed. The only constraint on this address is that it must be within 32KiB of 0x0, so that single lw/sw instructions (which have 16-bit signed offset fields) can be used to access it, using the zero register as a base. So lets move the comm page as high as possible within that constraint so that 0x0 can be left unmapped, at least for page sizes < 32KiB. Signed-off-by:
James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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James Hogan authored
Allow up to 6 KVM guest KScratch registers to be enabled and accessed via the KVM guest register API and from the guest itself (the fallback reading and writing of commpage registers is sufficient for KScratch registers to work as expected). User mode can expose the registers by setting the appropriate bits of the guest Config4.KScrExist field. KScratch registers that aren't usable won't be writeable via the KVM Ioctl API. Signed-off-by:
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James Hogan authored
Actually provide the VCPU number when emulating the RDHWR CPUNum register, so that it will match the CPUNum field of CP0_EBase register, rather than always returning 0. Signed-off-by:
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James Hogan authored
The ULRI bit in Config3 specifies whether the UserLocal register is implemented, but it is assumed to always be set. Now that the Config registers can be modified by userland, allow Config3.ULRI to be cleared and check ULRI before allowing the corresponding bit to be set in HWREna. In fact any HWREna bits corresponding to unimplemented RDHWR registers should read as zero and be ignored on write, so we actually prevent other unimplemented bits being set too. Signed-off-by:
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James Hogan authored
KVM modifies CP0_HWREna during guest execution so it can trap and emulate RDHWR instructions, however it always restores the hardcoded value 0x2000000F. This assumes the presence of the UserLocal register, and the absence of any implementation dependent or future HW registers. Fix by exporting the value that traps.c write into CP0_HWREna, and loading from there instead of hard coding. Signed-off-by:
Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by:
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James Hogan authored
No preprocessor definitions are used in the handling of the registers accessible with the RDHWR instruction, nor the corresponding bits in the CP0 HWREna register. Add definitions for both the register numbers (MIPS_HWR_*) and HWREna bits (MIPS_HWRENA_*) in asm/mipsregs.h and make use of them in the initialisation of HWREna and emulation of the RDHWR instruction. Signed-off-by:
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James Hogan authored
Make KVM_GET_REG_LIST list FPU & MSA registers. Specifically we list all 32 vector registers when MSA can be enabled, 32 single-precision FP registers when FPU can be enabled, and either 16 or 32 double-precision FP registers when FPU can be enabled depending on whether FR mode is supported (which provides 32 doubles instead of 16 even doubles). Note, these registers may still be inaccessible depending on the current FP mode of the guest. Signed-off-by:
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James Hogan authored
We need to use kvm_mips_guest_can_have_fpu() when deciding which registers to list with KVM_GET_REG_LIST, however it causes warnings with preemption since it uses cpu_has_fpu. KVM is only really supported on CPUs which have symmetric FPUs, so switch to raw_cpu_has_fpu to avoid the warning. Signed-off-by:
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James Hogan authored
Make the implementation of KVM_GET_REG_LIST more dynamic so that only the subset of registers actually available can be exposed to user mode. This is important for VZ where some of the guest register state may not be possible to prevent the guest from accessing, therefore the user process may need to be aware of the state even if it doesn't understand what the state is for. This also allows different MIPS KVM implementations to provide different registers to one another, by way of new num_regs(vcpu) and copy_reg_indices(vcpu, indices) callback functions, currently just stubbed for trap & emulate. Signed-off-by:
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James Hogan authored
Pass all unrecognised register IDs through to the set_one_reg() and get_one_reg() callbacks, not just select ones. This allows implementation specific registers to be more easily added without having to modify arch/mips/kvm/mips.c. Signed-off-by:
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James Hogan authored
Convert various MIPS KVM guest instruction emulation functions to decode instructions (and encode translations) using the union mips_instruction and related enumerations in asm/inst.h rather than #defines and hardcoded values. Signed-off-by:
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James Hogan authored
The code in kvm_mips_dyntrans.c to write a translated guest instruction to guest memory depending on the segment is duplicated between each of the functions. Additionally the cache op translation functions assume the instruction is in the KSEG0/1 segment rather than KSEG2/3, which is generally true but isn't guaranteed. Factor that code into a new kvm_mips_trans_replace() which handles both KSEG0/1 and KSEG2/3. Signed-off-by:
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James Hogan authored
The MIPS KVM dynamic translation is meant to translate "MFC0 rt, ErrCtl" instructions into "ADD rt, zero, zero" to zero the destination register, however the rt register number was copied into rt of the ADD instruction encoding, which is the 2nd source operand. This results in "ADD zero, zero, rt" which is a no-op, so only the first execution of each such MFC0 from ErrCtl will actually read 0. Fix the shift to put the rt from the MFC0 encoding into the rd field of the ADD. Fixes: 50c83085 ("KVM/MIPS32: Binary patching of select privileged instructions.") Signed-off-by:
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Paolo Bonzini authored
Merge tag 'kvm-s390-next-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: Features and fixes for 4.8 part1 Four bigger things: 1. The implementation of the STHYI opcode in the kernel. This is used in libraries like qclib [1] to provide enough information for a capacity and usage based software licence pricing. The STHYI content is defined by the related z/VM documentation [2]. Its data can be composed by accessing several other interfaces provided by LPAR or the machine. This information is partially sensitive or root-only so the kernel does the necessary filtering. 2. Preparation for nested virtualization (VSIE). KVM should query the proper sclp interfaces for the availability of some features before using it. In the past we have been sloppy and simply assumed that several features are available. With this we should be able to handle most cases of a missing feature. 3. CPU model interfaces extended by some additional features that are not covered by a facility bit in STFLE. For example all the crypto instructions of the coprocessor provide a query function. As reality tends to be more complex (e.g. export regulations might block some algorithms) we have to provide additional interfaces to query or set these non-stfle features. 4. Several fixes and changes detected and fixed when doing 1-3. All features change base s390 code. All relevant patches have an ACK from the s390 or component maintainers. The next pull request for 4.8 (part2) will contain the implementation of VSIE. [1] http://www.ibm.com/developerworks/linux/linux390/qclib.html [2] https://www.ibm.com/support/knowledgecenter/SSB27U_6.3.0/com.ibm.zvm.v630.hcpb4/hcpb4sth.htm
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- 14 Jun, 2016 26 commits
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Andrea Gelmini authored
Signed-off-by:
Andrea Gelmini <andrea.gelmini@gelma.net> Signed-off-by:
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Andrea Gelmini authored
Signed-off-by:
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Andrea Gelmini authored
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Andrea Gelmini authored
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James Hogan authored
When trying to emulate an unrecognised load or store instruction, print the encoding to aid debug. Signed-off-by:
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James Hogan authored
If kvm_get_inst() fails to find a guest TLB mapping for the guest PC then dump the guest TLB entries. The contents of the guest TLB is likely to be more interesting than the host TLB entries. Signed-off-by:
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James Hogan authored
Trace emulation of guest access to various registers via MFC0/MTC0/DMFC0/DMTC0 instructions (coprocessor 0) and the RDHWR instruction (hardware registers exposed to userland), replacing some existing kvm_debug calls. Trace events are much more practical for this kind of debug output. Signed-off-by:
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James Hogan authored
Add a few trace events for entering and coming out of guest mode, as well as re-entering it from a guest exit exception. Signed-off-by:
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James Hogan authored
Add a trace event for guest ASID changes, replacing the existing kvm_debug call. Signed-off-by:
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James Hogan authored
Clean up the MIPS kvm_exit trace event so that the exit reasons are specified in a trace friendly way (via __print_symbolic), and so that the exit reasons that derive straight from Cause.ExcCode values map directly, allowing a single trace_kvm_exit() call to replace a bunch of individual ones. Signed-off-by:
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James Hogan authored
Add a MIPS specific trace event for auxiliary context operations (notably FPU and MSA). Unfortunately the generic kvm_fpu trace event isn't flexible enough to handle the range of interesting things that can happen with FPU and MSA context. The type of state being operated on is traced: - FPU: Just the FPU registers. - MSA: Just the upper half of the MSA vector registers (low half already loaded with FPU state). - FPU & MSA: Full MSA vector state (includes FPU state). As is the type of operation: - Restore: State was enabled and restored. - Save: State was saved and disabled. - Enable: State was enabled (already loaded). - Disable: State was disabled (kept loaded). - Discard: State was discarded and disabled. Signed-off-by: -
James Hogan authored
Rename fpu_inuse and the related definitions to aux_inuse so it can be used for lazy context management of other auxiliary processor state too, such as VZ guest timer, watchpoints and performance counters. Signed-off-by:
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James Hogan authored
Like other functions, make use of a local unsigned long va, for the virtual address of the PC. This reduces the amount of verbose casting of the opc pointer to an unsigned long. Signed-off-by:
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James Hogan authored
The handle_tlb_ld/st_miss handlers are logically equivalent and textually almost identical, so combine their implementations into a single kvm_trap_emul_handle_tlb_miss(). Signed-off-by:
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James Hogan authored
Convert KVM to use the MIPS_ENTRYLO_* definitions from <asm/mipsregs.h> rather than custom definitions in kvm_host.h Signed-off-by:
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James Hogan authored
Simplify some of the TLB_ macros making use of the arrayification of tlb_lo. Basically we index the array by the bit of the virtual address which determines whether the even or odd entry is used, instead of having a conditional. Signed-off-by:
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James Hogan authored
The values of the EntryLo0 and EntryLo1 registers for a TLB entry are stored in separate members of struct kvm_mips_tlb called tlb_lo0 and tlb_lo1 respectively. To allow future code which needs to manipulate arbitrary EntryLo data in the TLB entry to be simpler and less conditional, replace these members with an array of two elements. Signed-off-by:
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James Hogan authored
KVM implements its own routine for dumping the host TLB entries, but we already have dump_tlb_all() which does something very similar (although it only prints out TLB entries which match the current ASID or are global). Make KVM use dump_tlb_all() along with dump_tlb_regs() to avoid the duplication and inevitable bitrot, allowing TLB dumping enhancements (e.g. for VZ and GuestIDs) to be made in a single place. Signed-off-by:
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James Hogan authored
KVM's host TLB handling routines were using tlbw hazard barrier macros around tlb_read(). Now that hazard barrier macros exist for tlbr, update this case to use them. Also fix various other unnecessary hazard barriers in this code. Signed-off-by:
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James Hogan authored
The host kernel's exception vector base address is currently saved in the VCPU structure at creation time, and restored on a guest exit. However it doesn't change and can already be easily accessed from the 'ebase' variable (arch/mips/kernel/traps.c), so drop the host_ebase member of kvm_vcpu_arch, export the 'ebase' variable to modules and load from there instead. This does result in a single extra instruction (lui) on the guest exit path, but simplifies the code a bit and removes the redundant storage of the host exception base address. Credit for the idea goes to Cavium's VZ KVM implementation. Signed-off-by:
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James Hogan authored
The function kvm_mips_handle_mapped_seg_tlb_fault() has two completely unused pointer arguments, hpa0 and hpa1, for which all users always pass NULL. Drop these two arguments and update the callers. Signed-off-by:
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James Hogan authored
When handling TLB faults in the guest KSeg0 region, a pair of physical addresses are read from the guest physical address map. However that process is rather convoluted with an if/then/else statement. Simplify it to just clear the lowest bit for the even entry and set the lowest bit for the odd entry. Signed-off-by:
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James Hogan authored
Several KVM module functions are indirected so that they can be accessed from tlb.c which is statically built into the kernel. This is no longer necessary as the relevant bits of code have moved into mmu.c which is part of the KVM module, so drop the indirections. Note: is_error_pfn() is defined inline in kvm_host.h, so didn't actually require the KVM module to be loaded for it to work anyway. Signed-off-by:
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James Hogan authored
Various functions in tlb.c perform higher level MMU handling, but don't strictly need to be statically built into the kernel as they don't directly manipulate TLB entries. Move these functions out into a separate mmu.c which will be built into the KVM kernel module. This allows them to directly reference KVM functions in the KVM kernel module in future. Module exports of these functions have been removed, since they aren't needed outside of KVM. Signed-off-by:
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James Hogan authored
The CP0 Cause register is passed around in KVM quite a bit, often as an unsigned long, even though it is always 32-bits long. Resize it to u32 throughout MIPS KVM. Signed-off-by:
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James Hogan authored
Convert the MIPS KVM C code to use standard kernel sized types (e.g. u32) instead of inttypes.h style ones (e.g. uint32_t) or other types as appropriate. Signed-off-by:
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