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2016-08-12MIPS: KVM: Propagate kseg0/mapped tlb fault errorsJames Hogan1-3/+9
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 Hogan1-1/+1
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 Hogan1-8/+15
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 Hogan1-21/+28
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: Use kmap instead of CKSEG0ADDR()James Hogan1-1/+6
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>
2016-06-15MIPS: KVM: Use host CCA for TLB mappingsJames Hogan1-8/+10
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>
2016-06-14MIPS: KVM: Dump guest tlbs if kvm_get_inst() failsJames Hogan1-0/+1
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: Use va in kvm_get_inst()James Hogan1-8/+7
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: 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: Use MIPS_ENTRYLO_* defs from mipsregs.hJames Hogan1-10/+12
Convert KVM to use the MIPS_ENTRYLO_* definitions from <asm/mipsregs.h> rather than custom definitions in kvm_host.h Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: 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>
2016-06-14MIPS: KVM: Arrayify struct kvm_mips_tlb::tlb_lo*James Hogan1-9/+11
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: James Hogan <james.hogan@imgtec.com> Cc: 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>
2016-06-14MIPS: KVM: Drop unused hpa0/hpa1 args from functionJames Hogan1-11/+2
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: 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: Simplify even/odd TLB handlingJames Hogan1-9/+2
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: 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: Don't indirect KVM functionsJames Hogan1-2/+2
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: 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: Move non-TLB handling code out of tlb.cJames Hogan1-0/+380
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: 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>