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2016-08-12MIPS: KVM: Propagate kseg0/mapped tlb fault errorsJames Hogan
Propagate errors from kvm_mips_handle_kseg0_tlb_fault() and kvm_mips_handle_mapped_seg_tlb_fault(), usually triggering an internal error since they normally indicate the guest accessed bad physical memory or the commpage in an unexpected way. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.") 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 Cc: <stable@vger.kernel.org> # 3.10.x- Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-12MIPS: KVM: Fix gfn range check in kseg0 tlb faultsJames Hogan
Two consecutive gfns are loaded into host TLB, so ensure the range check isn't off by one if guest_pmap_npages is odd. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") 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 Cc: <stable@vger.kernel.org> # 3.10.x- Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-12MIPS: KVM: Add missing gfn range checkJames Hogan
kvm_mips_handle_mapped_seg_tlb_fault() calculates the guest frame number based on the guest TLB EntryLo values, however it is not range checked to ensure it lies within the guest_pmap. If the physical memory the guest refers to is out of range then dump the guest TLB and emit an internal error. Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") 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 Cc: <stable@vger.kernel.org> # 3.10.x- Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-12MIPS: KVM: Fix mapped fault broken commpage handlingJames Hogan
kvm_mips_handle_mapped_seg_tlb_fault() appears to map the guest page at virtual address 0 to PFN 0 if the guest has created its own mapping there. The intention is unclear, but it may have been an attempt to protect the zero page from being mapped to anything but the comm page in code paths you wouldn't expect from genuine commpage accesses (guest kernel mode cache instructions on that address, hitting trapping instructions when executing from that address with a coincidental TLB eviction during the KVM handling, and guest user mode accesses to that address). Fix this to check for mappings exactly at KVM_GUEST_COMMPAGE_ADDR (it may not be at address 0 since commit 42aa12e74e91 ("MIPS: KVM: Move commpage so 0x0 is unmapped")), and set the corresponding EntryLo to be interpreted as 0 (invalid). Fixes: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.") 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 Cc: <stable@vger.kernel.org> # 3.10.x- Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-08-01MIPS: KVM: Reset CP0_PageMask during host TLB flushJames Hogan
KVM sometimes flushes host TLB entries, reading each one to check if it corresponds to a guest KSeg0 address. In the absence of EntryHi.EHInv bits to invalidate the whole entry, the entries will be set to unique virtual addresses in KSeg0 (which is not TLB mapped), spaced 2*PAGE_SIZE apart. The TLB read however will clobber the CP0_PageMask register with whatever page size that TLB entry had, and that same page size will be written back into the TLB entry along with the unique address. This would cause breakage when transparent huge pages are enabled on 64-bit host kernels, since huge page entries will overlap other nearby entries when separated by only 2*PAGE_SIZE, causing a machine check exception. Fix this by restoring the old CP0_PageMask value (which should be set to the normal page size) after reading the TLB entry if we're going to go ahead and invalidate it. 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>
2016-08-01MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX()James Hogan
kvm_mips_trans_replace() passes a pointer to KVM_GUEST_KSEGX(). This breaks on 64-bit builds due to the cast of that 64-bit pointer to a different sized 32-bit int. Cast the pointer argument to an unsigned long to work around the warning. 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>
2016-08-01MIPS: KVM: Sign extend MFC0/RDHWR resultsJames Hogan
When emulating MFC0 instructions to load 32-bit values from guest COP0 registers and the RDHWR instruction to read the CC (Count) register, sign extend the result to comply with the MIPS64 architecture. The result must be in canonical 32-bit form or the guest may malfunction. 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>
2016-08-01MIPS: KVM: Fix 64-bit big endian dynamic translationJames Hogan
The MFC0 and MTC0 instructions in the guest which cause traps can be replaced with 32-bit loads and stores to the commpage, however on big endian 64-bit builds the offset needs to have 4 added so as to load/store the least significant half of the long instead of the most significant half. 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>
2016-08-01MIPS: KVM: Fail if ebase doesn't fit in CP0_EBaseJames Hogan
Fail if the address of the allocated exception base doesn't fit into the CP0_EBase register. This can happen on MIPS64 if CP0_EBase.WG isn't implemented but RAM is available outside of the range of KSeg0. 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>
2016-08-01MIPS: KVM: Use 64-bit CP0_EBase when appropriateJames Hogan
Update the KVM entry point to write CP0_EBase as a 64-bit register when it is 64-bits wide, and to set the WG (write gate) bit if it exists in order to write bits 63:30 (or 31:30 on MIPS32). Prior to MIPS64r6 it was UNDEFINED to perform a 64-bit read or write of a 32-bit COP0 register. Since this is dynamically generated code, generate the right type of access depending on whether the kernel is 64-bit and cpu_has_ebase_wg. 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>
2016-08-01MIPS: KVM: Set CP0_Status.KX on MIPS64James Hogan
Update the KVM entry code to set the CP0_Entry.KX bit on 64-bit kernels. This is important to allow the entry code, running in kernel mode, to access the full 64-bit address space right up to the point of entering the guest, and immediately after exiting the guest, so it can safely restore & save the guest context from 64-bit segments. 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>
2016-08-01MIPS: KVM: Make entry code MIPS64 friendlyJames Hogan
The MIPS KVM entry code (originally kvm_locore.S, later locore.S, and now entry.c) has never quite been right when built for 64-bit, using 32-bit instructions when 64-bit instructions were needed for handling 64-bit registers and pointers. Fix several cases of this now. The changes roughly fall into the following categories. - COP0 scratch registers contain guest register values and the VCPU pointer, and are themselves full width. Similarly CP0_EPC and CP0_BadVAddr registers are full width (even though technically we don't support 64-bit guest address spaces with trap & emulate KVM). Use MFC0/MTC0 for accessing them. - Handling of stack pointers and the VCPU pointer must match the pointer size of the kernel ABI (always o32 or n64), so use ADDIU. - The CPU number in thread_info, and the guest_{user,kernel}_asid arrays in kvm_vcpu_arch are all 32 bit integers, so use lw (instead of LW) to load them. 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>
2016-08-01MIPS: KVM: Use kmap instead of CKSEG0ADDR()James Hogan
There are several unportable uses of CKSEG0ADDR() in MIPS KVM, which implicitly assume that a host physical address will be in the low 512MB of the physical address space (accessible in KSeg0). These assumptions don't hold for highmem or on 64-bit kernels. When interpreting the guest physical address when reading or overwriting a trapping instruction, use kmap_atomic() to get a usable virtual address to access guest memory, which is portable to 64-bit and highmem kernels. 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>
2016-08-01MIPS: KVM: Use virt_to_phys() to get commpage PFNJames Hogan
Calculate the PFN of the commpage using virt_to_phys() instead of CPHYSADDR(). This is more portable as kzalloc() may allocate from XKPhys instead of KSeg0 on 64-bit kernels, which CPHYSADDR() doesn't handle. This is sufficient for highmem kernels too since kzalloc() will allocate from lowmem in KSeg0. 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>
2016-07-05MIPS: KVM: Emulate generic QEMU machine on r6 T&EJames Hogan
Default the guest PRId register to represent a generic QEMU machine instead of a 24kc on MIPSr6. 24kc isn't supported by r6 Linux kernels. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Decode RDHWR more strictlyJames Hogan
When KVM emulates the RDHWR instruction, decode the instruction more strictly. The rs field (bits 25:21) should be zero, as should bits 10:9. Bits 8:6 is the register select field in MIPSr6, so we aren't strict about those bits (no other operations should use that encoding space). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Recognise r6 CACHE encodingJames Hogan
Recognise the new MIPSr6 CACHE instruction encoding rather than the pre-r6 one when an r6 kernel is being built. A SPECIAL3 opcode is used and the immediate field is reduced to 9 bits wide since MIPSr6. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Support r6 compact branch emulationJames Hogan
Add support in KVM for emulation of instructions in the forbidden slot of MIPSr6 compact branches. If we hit an exception on the forbidden slot, then the branch must not have been taken, which makes calculation of the resume PC trivial. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Don't save/restore lo/hi for r6James Hogan
MIPSr6 doesn't have lo/hi registers, so don't bother saving or restoring them, and don't expose them to userland with the KVM ioctl interface either. In fact the lo/hi registers aren't callee saved in the MIPS ABIs anyway, so there is no need to preserve the host lo/hi values at all when transitioning to and from the guest (which happens via a function call). Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Fix fpu.S misassembly with r6James Hogan
__kvm_save_fpu and __kvm_restore_fpu use .set mips64r2 so that they can access the odd FPU registers as well as the even, however this causes misassembly of the return instruction on MIPSr6. Fix by replacing .set mips64r2 with .set fp=64, which doesn't change the architecture revision. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Save k0 straight into VCPU structureJames Hogan
Currently on a guest exception the guest's k0 register is saved to the scratch temp register and the guest k1 saved to the exception base address + 0x3000 using k0 to extract the Exception Base field of the EBase register and as the base operand to the store. Both are then copied into the VCPU structure after the other general purpose registers have been saved there. This bouncing to exception base + 0x3000 is not actually necessary as the VCPU pointer can be determined and written through just as easily with only a single spare register. The VCPU pointer is already needed in k1 for saving the other GP registers, so lets save the guest k0 register straight into the VCPU structure through k1, first saving k1 into the scratch temp register instead of k0. This could potentially pave the way for having a single exception base area for use by all guests. The ehb after saving the k register to the scratch temp register is also delayed until just before it needs to be read back. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Relative branch to common exit handlerJames Hogan
Use a relative branch to get from the individual exception vectors to the common guest exit handler, rather than loading the address of the exit handler and jumping to it. This is made easier due to the fact we are now generating the entry code dynamically. This will also allow the exception code to be further reduced in future patches. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Dynamically choose scratch registersJames Hogan
Scratch cop0 registers are needed by KVM to be able to save/restore all the GPRs, including k0/k1, and for storing the VCPU pointer. However no registers are universally suitable for these purposes, so the decision should be made at runtime. Until now, we've used DDATA_LO to store the VCPU pointer, and ErrorEPC as a temporary. It could be argued that this is abuse of those registers, and DDATA_LO is known not to be usable on certain implementations (Cavium Octeon). If KScratch registers are present, use them instead. We save & restore the temporary register in addition to the VCPU pointer register when using a KScratch register for it, as it may be used for normal host TLB handling too. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Drop redundant restore of DDATA_LOJames Hogan
On return from the exit handler to the host (without re-entering the guest) we restore the saved value of the DDATA_LO register which we use as a scratch register. However we've already restored it ready for calling the exit handler so there is no need to do it again, so drop that code. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Check MSA presence at uasm timeJames Hogan
Check for presence of MSA at uasm assembly time rather than at runtime in the generated KVM host entry code. This optimises the guest exit path by eliminating the MSA code entirely if not present, and eliminating the read of Config3.MSAP and conditional branch if MSA is present. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Omit FPU handling entry code if possibleJames Hogan
The FPU handling code on entry from guest is unnecessary if no FPU is present, so allow it to be dropped at uasm assembly time. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS: KVM: Add dumping of generated entry codeJames Hogan
Dump the generated entry code with pr_debug(), similar to how it is done in tlbex.c, so it can be more easily debugged. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-05MIPS; KVM: Convert exception entry to uasmJames Hogan
Convert the whole of locore.S (assembly to enter guest and handle exception entry) to be generated dynamically with uasm. This is done with minimal changes to the resulting code. The main changes are: - Some constants are generated by uasm using LUI+ADDIU instead of LUI+ORI. - Loading of lo and hi are swapped around in vcpu_run but not when resuming the guest after an exit. Both bits of logic are now generated by the same code. - Register MOVEs in uasm use different ADDU operand ordering to GNU as, putting zero register into rs instead of rt. - The JALR.HB to call the C exit handler is switched to JALR, since the hazard barrier would appear to be unnecessary. This will allow further optimisation in the future to dynamically handle the capabilities of the CPU. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim KrÄmář <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>
2016-07-01KVM: remove kvm_guest_enter/exit wrappersPaolo Bonzini
Use the functions from context_tracking.h directly. Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-23MIPS: KVM: Combine entry trace events into classJames Hogan
Combine the kvm_enter, kvm_reenter and kvm_out trace events into a single kvm_transition event class to reduce duplication and bloat. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Fixes: 93258604ab6d ("MIPS: KVM: Add guest mode switch trace events") 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: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-15MIPS: KVM: Use mipsregs.h defs for config registersJames Hogan
Convert MIPS KVM guest register state initialisation to use the standard <asm/mipsregs.h> register field definitions for Config registers, and drop the custom definitions in kvm_host.h which it was using before. 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>
2016-06-15MIPS: KVM: Report more accurate CP0_Config fields to guestJames Hogan
Initialise the guest's CP0_Config register with a few more bits of information from the host. The BE bit should be set on big endian machines, the VI bit should be set on machines with a virtually tagged instruction cache, and the reported architecture revision should match that of the host (since we won't support emulating pre-r6 instruction encodings on r6 or vice versa). 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>
2016-06-15MIPS: KVM: Use host CCA for TLB mappingsJames Hogan
KVM TLB mappings for the guest were being created with a cache coherency attribute (CCA) of 3, which is cached incoherent. Create them instead with the default host CCA, which should be the correct one for coherency on SMP systems. 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>
2016-06-15MIPS: KVM: Move commpage so 0x0 is unmappedJames Hogan
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>
2016-06-15MIPS: KVM: Add KScratch registersJames Hogan
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: 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>
2016-06-15MIPS: KVM: Emulate RDHWR CPUNum registerJames Hogan
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: 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>
2016-06-15MIPS: KVM: Allow ULRI to restrict UserLocal registerJames Hogan
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: 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>
2016-06-15MIPS: KVM: Don't hardcode restored HWREnaJames Hogan
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: James Hogan <james.hogan@imgtec.com> Acked-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: Paolo Bonzini <pbonzini@redhat.com>
2016-06-15MIPS: Clean up RDHWR handlingJames Hogan
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: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> 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: Paolo Bonzini <pbonzini@redhat.com>
2016-06-15MIPS: KVM: List FPU/MSA registersJames Hogan
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: 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>
2016-06-15MIPS: KVM: Make KVM_GET_REG_LIST dynamicJames Hogan
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: 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>
2016-06-15MIPS: KVM: Pass all unknown registers to callbacksJames Hogan
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: 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>
2016-06-15MIPS: KVM: Convert emulation to use asm/inst.hJames Hogan
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: James Hogan <james.hogan@imgtec.com> Acked-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: Paolo Bonzini <pbonzini@redhat.com>
2016-06-15MIPS: KVM: Factor writing of translated guest instructionsJames Hogan
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: 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>
2016-06-15MIPS: KVM: Fix translation of MFC0 ErrCtlJames Hogan
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: 50c8308538dc ("KVM/MIPS32: Binary patching of select privileged instructions.") 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>
2016-06-14MIPS: KVM: Print unknown load/store encodingsJames Hogan
When trying to emulate an unrecognised load or store instruction, print the encoding to aid debug. 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>
2016-06-14MIPS: KVM: Dump guest tlbs if kvm_get_inst() failsJames Hogan
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: 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: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Trace guest register access emulationJames Hogan
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: 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: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Add guest mode switch trace eventsJames Hogan
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: 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: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-14MIPS: KVM: Add kvm_asid_change trace eventJames Hogan
Add a trace event for guest ASID changes, replacing the existing kvm_debug call. 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: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>