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2015-03-18KVM: MIPS: Fix trace event to save PC directlyJames Hogan1-3/+3
commit b3cffac04eca9af46e1e23560a8ee22b1bd36d43 upstream. Currently the guest exit trace event saves the VCPU pointer to the structure, and the guest PC is retrieved by dereferencing it when the event is printed rather than directly from the trace record. This isn't safe as the printing may occur long afterwards, after the PC has changed and potentially after the VCPU has been freed. Usually this results in the same (wrong) PC being printed for multiple trace events. It also isn't portable as userland has no way to access the VCPU data structure when interpreting the trace record itself. Lets save the actual PC in the structure so that the correct value is accessible later. Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07KVM: MIPS: Don't leak FPU/DSP to guestJames Hogan2-4/+4
commit f798217dfd038af981a18bbe4bc57027a08bb182 upstream. The FPU and DSP are enabled via the CP0 Status CU1 and MX bits by kvm_mips_set_c0_status() on a guest exit, presumably in case there is active state that needs saving if pre-emption occurs. However neither of these bits are cleared again when returning to the guest. This effectively gives the guest access to the FPU/DSP hardware after the first guest exit even though it is not aware of its presence, allowing FP instructions in guest user code to intermittently actually execute instead of trapping into the guest OS for emulation. It will then read & manipulate the hardware FP registers which technically belong to the user process (e.g. QEMU), or are stale from another user process. It can also crash the guest OS by causing an FP exception, for which a guest exception handler won't have been registered. First lets save and disable the FPU (and MSA) state with lose_fpu(1) before entering the guest. This simplifies the problem, especially for when guest FPU/MSA support is added in the future, and prevents FR=1 FPU state being live when the FR bit gets cleared for the guest, which according to the architecture causes the contents of the FPU and vector registers to become UNPREDICTABLE. We can then safely remove the enabling of the FPU in kvm_mips_set_c0_status(), since there should never be any active FPU or MSA state to save at pre-emption, which should plug the FPU leak. DSP state is always live rather than being lazily restored, so for that it is simpler to just clear the MX bit again when re-entering the guest. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Sanjay Lal <sanjayl@kymasys.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # v3.10+: 044f0f03eca0: MIPS: KVM: Deliver guest interrupts Cc: <stable@vger.kernel.org> # v3.10+ Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-07MIPS: KVM: Deliver guest interrupts after local_irq_disable()James Hogan1-1/+1
commit 044f0f03eca0110e1835b2ea038a484b93950328 upstream. When about to run the guest, deliver guest interrupts after disabling host interrupts. This should prevent an hrtimer interrupt from being handled after delivering guest interrupts, and therefore not delivering the guest timer interrupt until after the next guest exit. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-07MIPS: KVM: Fix memory leak on VCPUDeng-Cheng Zhu1-0/+1
commit 8c9eb041cf76038eb3b62ee259607eec9b89f48d upstream. kvm_arch_vcpu_free() is called in 2 code paths: 1) kvm_vm_ioctl() kvm_vm_ioctl_create_vcpu() kvm_arch_vcpu_destroy() kvm_arch_vcpu_free() 2) kvm_put_kvm() kvm_destroy_vm() kvm_arch_destroy_vm() kvm_mips_free_vcpus() kvm_arch_vcpu_free() Neither of the paths handles VCPU free. We need to do it in kvm_arch_vcpu_free() corresponding to the memory allocation in kvm_arch_vcpu_create(). Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-07MIPS: KVM: Remove redundant NULL checks before kfree()James Hogan1-9/+3
commit c6c0a6637f9da54f9472144d44f71cf847f92e20 upstream. The kfree() function already NULL checks the parameter so remove the redundant NULL checks before kfree() calls in arch/mips/kvm/. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-26MIPS: KVM: Allocate at least 16KB for exception handlersJames Hogan1-1/+1
commit 7006e2dfda9adfa40251093604db76d7e44263b3 upstream. Each MIPS KVM guest has its own copy of the KVM exception vector. This contains the TLB refill exception handler at offset 0x000, the general exception handler at offset 0x180, and interrupt exception handlers at offset 0x200 in case Cause_IV=1. A common handler is copied to offset 0x2000 and offset 0x3000 is used for temporarily storing k1 during entry from guest. However the amount of memory allocated for this purpose is calculated as 0x200 rounded up to the next page boundary, which is insufficient if 4KB pages are in use. This can lead to the common handler at offset 0x2000 being overwritten and infinitely recursive exceptions on the next exit from the guest. Increase the minimum size from 0x200 to 0x4000 to cover the full use of the page. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Cc: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-13MIPS: KVM: Pass reserved instruction exceptions to guestJames Hogan1-3/+4
commit 15505679362270d02c449626385cb74af8905514 upstream. Previously a reserved instruction exception while in guest code would cause a KVM internal error if kvm_mips_handle_ri() didn't recognise the instruction (including a RDHWR from an unrecognised hardware register). However the guest OS should really have the opportunity to catch the exception so that it can take the appropriate actions such as sending a SIGILL to the guest user process or emulating the instruction itself. Therefore in these cases emulate a guest RI exception and only return EMULATE_FAIL if that fails, being careful to revert the PC first in case the exception occurred in a branch delay slot in which case the PC will already point to the branch target. Also turn the printk messages relating to these cases into kvm_debug messages so that they aren't usually visible. This allows crashme to run in the guest without killing the entire VM. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sanjay Lal <sanjayl@kymasys.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-11mips/kvm: Use KVM_REG_MIPS and proper size indicators for *_ONE_REGDavid Daney1-29/+54
The API requires that the GET_ONE_REG and SET_ONE_REG ioctls have this extra information encoded in the register identifiers. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-06-03mips/kvm: Use ENOIOCTLCMD to indicate unimplemented ioctls.David Daney1-9/+9
The Linux Way is to return -ENOIOCTLCMD to the vfs when an unimplemented ioctl is requested. Do this in kvm_mips instead of a random mixture of -ENOTSUPP and -EINVAL. Signed-off-by: David Daney <david.daney@cavium.com> Acked-by: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-06-03mips/kvm: Fix ABI by moving manipulation of CP0 registers to KVM_{G,S}ET_ONE_REGDavid Daney2-57/+245
Because not all 256 CP0 registers are ever implemented, we need a different method of manipulating them. Use the KVM_SET_ONE_REG/KVM_GET_ONE_REG mechanism. Now unused code and definitions are removed. Signed-off-by: David Daney <david.daney@cavium.com> Acked-by: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-06-03mips/kvm: Use ARRAY_SIZE() instead of hardcoded constants in ↵David Daney1-3/+3
kvm_arch_vcpu_ioctl_{s,g}et_regs Also we cannot set special zero register, so force it to zero. Signed-off-by: David Daney <david.daney@cavium.com> Acked-by: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-06-03mips/kvm: Fix name of gpr field in struct kvm_regs.David Daney1-2/+2
Signed-off-by: David Daney <david.daney@cavium.com> Acked-by: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-05-23Merge git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-9/+26
Pull kvm bugfixes from Gleb Natapov. * git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock() KVM/MIPS32: Move include/asm/kvm.h => include/uapi/asm/kvm.h since it is a user visible API. KVM: take over co-maintainership from Marcelo, fix MAINTAINERS entry
2013-05-22KVM/MIPS32: Wrap calls to gfn_to_pfn() with srcu_read_lock/unlock()Sanjay Lal1-9/+26
- As suggested by Gleb, wrap calls to gfn_to_pfn() with srcu_read_lock/unlock(). Memory slots should be acccessed from a SRCU read section. - kvm_mips_map_page() now returns an error code to it's callers, instead of calling panic() if it cannot find a mapping for a particular gfn. Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-16Revert "MIPS: Allow ASID size to be determined at boot time."David Daney2-24/+31
This reverts commit d532f3d26716a39dfd4b88d687bd344fbe77e390. The original commit has several problems: 1) Doesn't work with 64-bit kernels. 2) Calls TLBMISS_HANDLER_SETUP() before the code is generated. 3) Calls TLBMISS_HANDLER_SETUP() twice in per_cpu_trap_init() when only one call is needed. [ralf@linux-mips.org: Also revert the bits of the ASID patch which were hidden in the KVM merge.] Signed-off-by: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: "Steven J. Hill" <Steven.Hill@imgtec.com> Cc: David Daney <david.daney@cavium.com> Patchwork: https://patchwork.linux-mips.org/patch/5242/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-10Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds17-0/+5604
Pull MIPS updates from Ralf Baechle: - More work on DT support for various platforms - Various fixes that were to late to make it straight into 3.9 - Improved platform support, in particular the Netlogic XLR and BCM63xx, and the SEAD3 and Malta eval boards. - Support for several Ralink SOC families. - Complete support for the microMIPS ASE which basically reencodes the existing MIPS32/MIPS64 ISA to use non-constant size instructions. - Some fallout from LTO work which remove old cruft and will generally make the MIPS kernel easier to maintain and resistant to compiler optimization, even in absence of LTO. - KVM support. While MIPS has announced hardware virtualization extensions this KVM extension uses trap and emulate mode for virtualization of MIPS32. More KVM work to add support for VZ hardware virtualizaiton extensions and MIPS64 will probably already be merged for 3.11. Most of this has been sitting in -next for a long time. All defconfigs have been build or run time tested except three for which fixes are being sent by other maintainers. Semantic conflict with kvm updates done as per Ralf * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (118 commits) MIPS: Add new GIC clockevent driver. MIPS: Formatting clean-ups for clocksources. MIPS: Refactor GIC clocksource code. MIPS: Move 'gic_frequency' to common location. MIPS: Move 'gic_present' to common location. MIPS: MIPS16e: Add unaligned access support. MIPS: MIPS16e: Support handling of delay slots. MIPS: MIPS16e: Add instruction formats. MIPS: microMIPS: Optimise 'strnlen' core library function. MIPS: microMIPS: Optimise 'strlen' core library function. MIPS: microMIPS: Optimise 'strncpy' core library function. MIPS: microMIPS: Optimise 'memset' core library function. MIPS: microMIPS: Add configuration option for microMIPS kernel. MIPS: microMIPS: Disable LL/SC and fix linker bug. MIPS: microMIPS: Add vdso support. MIPS: microMIPS: Add unaligned access support. MIPS: microMIPS: Support handling of delay slots. MIPS: microMIPS: Add support for exception handling. MIPS: microMIPS: Floating point support. MIPS: microMIPS: Fix macro naming in micro-assembler. ...
2013-05-09Merge branch 'mti-next' of ↵Ralf Baechle2-31/+24
git://git.linux-mips.org/pub/scm/sjhill/linux-sjhill into mips-for-linux-next
2013-05-09KVM/MIPS32: Binary patching of select privileged instructions.Sanjay Lal3-0/+209
Currently, the following instructions are translated: - CACHE (indexed) - CACHE (va based): translated to a SYNCI, overkill on D-CACHE operations, but still much faster than a trap. - mfc0/mtc0: the virtual COP0 registers for the guest are implemented as 2-D array. [COP#][SEL] and this is mapped into the guest kernel address space @ VA 0x0. mfc0/mtc0 operations are transformed to load/stores. Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08KVM/MIPS32: Routines to handle specific traps/exceptions while executing the ↵Sanjay Lal2-0/+496
guest. Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08KVM/MIPS32: Guest interrupt delivery.Sanjay Lal2-0/+292
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08KVM/MIPS32: COP0 accesses profiling.Sanjay Lal1-0/+82
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08KVM/MIPS32: Release notes and KVM module MakefileSanjay Lal2-0/+44
Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08KVM/MIPS32: MMU/TLB operations for the Guest.Sanjay Lal1-0/+932
- Note that this file is statically linked with the rest of the host kernel (KSEG0). This is because kernel modules are loaded into mapped space on MIPS and we want to make sure that we don't get any host kernel TLB faults while manipulating TLBs. - Virtual Guest TLBs are implemented as 64 entry array regardless of the number of host TLB entries. - Shadow TLBs map Guest virtual addresses to Host physical addresses. - TLB miss handling details: Guest KSEG0 TLBMISS (0x40000000 – 0x60000000): Transparent to the Guest. Guest KSEG2/3 (0x60000000 – 0x80000000) & Guest UM TLBMISS (0x00000000 – 0x40000000) Lookup in Guest/Virtual TLB If an entry doesn’t match deliver appropriate TLBMISS LD/ST exception to the guest If entry does exist in the Guest TLB and is NOT Valid Deliver TLB invalid exception to the guest If entry does exist in the Guest TLB and is VALID Inject the TLB entry into the Shadow TLB Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08KVM/MIPS32: Privileged instruction/target branch emulation.Sanjay Lal2-0/+1853
- The Guest kernel is run in UM and privileged instructions cause a trap. - If the instruction causing the trap is in a branch delay slot, the branch needs to be emulated to figure out the PC @ which the guest will resume execution. Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08KVM/MIPS32: MIPS arch specific APIs for KVMSanjay Lal2-0/+1004
- Implements the arch specific APIs for KVM, some are stubs for MIPS - kvm_mips_handle_exit(): Main 'C' distpatch routine for handling exceptions while in "Guest" mode. - Also implements in-kernel timer interrupt support for the guest. Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08KVM/MIPS32: Entry point for trampolining to the guest and trap handlers.Sanjay Lal1-0/+650
- __kvm_mips_vcpu_run: main entry point to enter guest, we save kernel context, load up guest context from and ERET to guest context. - mips32_exception: L1 exception handler(s), save k0/k1 and jump to main handlers. - mips32_GuestException: Generic exception handlers for exceptions/interrupts while in guest context. Save guest context, restore some kernel context and jump to main 'C' handler: kvm_mips_handle_exit() Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-05-08KVM/MIPS32: Infrastructure/build files.Sanjay Lal1-0/+49
- Add the KVM option to MIPS build files. - Add default config files for KVM host/guest kernels. - Change the link address for the Malta KVM Guest kernel to UM (0x40100000). - Add KVM Kconfig file with KVM/MIPS specific options Signed-off-by: Sanjay Lal <sanjayl@kymasys.com> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>