kernel/git/stable/linux.git/arch/mips/kvm, branch linux-3.14.y

MIPS: KVM: Propagate kseg0/mapped tlb fault errors

2016-08-20T09:53:21+00:00

commit 9b731bcfdec4c159ad2e4312e25d69221709b96a upstream. 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 Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář [james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y] Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

MIPS: KVM: Fix gfn range check in kseg0 tlb faults

2016-08-20T09:53:21+00:00

commit 0741f52d1b980dbeb290afe67d88fc2928edd8ab upstream. 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 Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář [james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y] Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

MIPS: KVM: Add missing gfn range check

2016-08-20T09:53:20+00:00

commit 8985d50382359e5bf118fdbefc859d0dbf6cebc7 upstream. 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 Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář [james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y] Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

MIPS: KVM: Fix mapped fault broken commpage handling

2016-08-20T09:53:20+00:00

commit c604cffa93478f8888bec62b23d6073dad03d43a upstream. 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 Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář [james.hogan@imgtec.com: Backport to v3.10.y - v3.15.y] Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

MIPS: KVM: Fix modular KVM under QEMU

2016-07-27T16:55:49+00:00

commit 797179bc4fe06c89e47a9f36f886f68640b423f8 upstream. Copy __kvm_mips_vcpu_run() into unmapped memory, so that we can never get a TLB refill exception in it when KVM is built as a module. This was observed to happen with the host MIPS kernel running under QEMU, due to a not entirely transparent optimisation in the QEMU TLB handling where TLB entries replaced with TLBWR are copied to a separate part of the TLB array. Code in those pages continue to be executable, but those mappings persist only until the next ASID switch, even if they are marked global. An ASID switch happens in __kvm_mips_vcpu_run() at exception level after switching to the guest exception base. Subsequent TLB mapped kernel instructions just prior to switching to the guest trigger a TLB refill exception, which enters the guest exception handlers without updating EPC. This appears as a guest triggered TLB refill on a host kernel mapped (host KSeg2) address, which is not handled correctly as user (guest) mode accesses to kernel (host) segments always generate address error exceptions. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Ralf Baechle Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: # 3.10.x- Signed-off-by: Paolo Bonzini [james.hogan@imgtec.com: backported for stable 3.14] Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

MIPS: KVM: Uninit VCPU in vcpu_create error path

2016-03-03T23:06:46+00:00

commit 585bb8f9a5e592f2ce7abbe5ed3112d5438d2754 upstream. If either of the memory allocations in kvm_arch_vcpu_create() fail, the vcpu which has been allocated and kvm_vcpu_init'd doesn't get uninit'd in the error handling path. Add a call to kvm_vcpu_uninit() to fix this. Fixes: 669e846e6c4e ("KVM/MIPS32: MIPS arch specific APIs for KVM") Signed-off-by: James Hogan Cc: Ralf Baechle Cc: Paolo Bonzini Cc: Gleb Natapov Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

MIPS: KVM: Fix CACHE immediate offset sign extension

2016-03-03T23:06:46+00:00

commit c5c2a3b998f1ff5a586f9d37e154070b8d550d17 upstream. The immediate field of the CACHE instruction is signed, so ensure that it gets sign extended by casting it to an int16_t rather than just masking the low 16 bits. Fixes: e685c689f3a8 ("KVM/MIPS32: Privileged instruction/target branch emulation.") Signed-off-by: James Hogan Cc: Ralf Baechle Cc: Paolo Bonzini Cc: Gleb Natapov Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

MIPS: KVM: Fix ASID restoration logic

2016-03-03T23:06:46+00:00

commit 002374f371bd02df864cce1fe85d90dc5b292837 upstream. ASID restoration on guest resume should determine the guest execution mode based on the guest Status register rather than bit 30 of the guest PC. Fix the two places in locore.S that do this, loading the guest status from the cop0 area. Note, this assembly is specific to the trap & emulate implementation of KVM, so it doesn't need to check the supervisor bit as that mode is not implemented in the guest. Fixes: b680f70fc111 ("KVM/MIPS32: Entry point for trampolining to...") Signed-off-by: James Hogan Cc: Ralf Baechle Cc: Paolo Bonzini Cc: Gleb Natapov Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

MIPS: KVM: Do not sign extend on unsigned MMIO load

2015-08-03T16:29:59+00:00

commit ed9244e6c534612d2b5ae47feab2f55a0d4b4ced upstream. Fix possible unintended sign extension in unsigned MMIO loads by casting to uint16_t in the case of mmio_needed != 2. Signed-off-by: Nicholas Mc Guire Reviewed-by: James Hogan Tested-by: James Hogan Cc: Gleb Natapov Cc: Paolo Bonzini Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9985/ Signed-off-by: Ralf Baechle Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman

KVM: MIPS: Fix trace event to save PC directly

2015-03-18T12:31:28+00:00

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 Cc: Paolo Bonzini Cc: Ralf Baechle Cc: Marcelo Tosatti Cc: Gleb Natapov Cc: Steven Rostedt Cc: Ingo Molnar Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Acked-by: Steven Rostedt Signed-off-by: Marcelo Tosatti Signed-off-by: Greg Kroah-Hartman