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* KVM: MIPS: Fix lazy user ASID regenerate for SMPJames Hogan2016-10-261-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kvm_mips_check_asids() runs before entering the guest and performs lazy regeneration of host ASID for guest usermode, using last_user_gasid to track the last guest ASID in the VCPU that was used by guest usermode on any host CPU. last_user_gasid is reset after performing the lazy ASID regeneration on the current CPU, and by kvm_arch_vcpu_load() if the host ASID for guest usermode is regenerated due to staleness (to cancel outstanding lazy ASID regenerations). Unfortunately neither case handles SMP hosts correctly: - When the lazy ASID regeneration is performed it should apply to all CPUs (as last_user_gasid does), so reset the ASID on other CPUs to zero to trigger regeneration when the VCPU is next loaded on those CPUs. - When the ASID is found to be stale on the current CPU, we should not cancel lazy ASID regenerations globally, so drop the reset of last_user_gasid altogether here. Both cases would require a guest ASID change and two host CPU migrations (and in the latter case one of the CPUs to start a new ASID cycle) before guest usermode could potentially access stale user pages from a previously running ASID in the same VCPU. Fixes: 25b08c7fb0e4 ("KVM: MIPS: Invalidate TLB by regenerating ASIDs") 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>
* Merge tag 'kvm_mips_4.9_1' of ↵Radim Krčmář2016-09-291-2/+14
|\ | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/kvm-mips into next MIPS KVM updates for v4.9 - A couple of fixes in preparation for supporting MIPS EVA host kernels. - MIPS SMP host & TLB invalidation fixes.
| * KVM: MIPS: Invalidate TLB by regenerating ASIDsJames Hogan2016-09-291-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Invalidate host TLB mappings when the guest ASID is changed by regenerating ASIDs, rather than flushing the entire host TLB except entries in the guest KSeg0 range. For the guest kernel mode ASID we regenerate on the spot when the guest ASID is changed, as that will always take place while the guest is in kernel mode. However when the guest invalidates TLB entries the ASID will often by changed temporarily as part of writing EntryHi without the guest returning to user mode in between. We therefore regenerate the user mode ASID lazily before entering the guest in user mode, if and only if the guest ASID has actually changed since the last guest user mode 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
| * KVM: MIPS: Split kernel/user ASID regenerationJames Hogan2016-09-291-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The host ASIDs for guest kernel and user mode are regenerated together if the ASID for guest kernel mode is out of date. That is fine as the ASID for guest kernel mode is always generated first, however it doesn't allow the ASIDs to be regenerated or invalidated individually instead of linearly flushing the entire host TLB. Therefore separate the regeneration code so that the ASIDs are checked and regenerated separately. 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
* | MIPS: KVM: Check for pfn noslot caseJames Hogan2016-08-191-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | When mapping a page into the guest we error check using is_error_pfn(), however this doesn't detect a value of KVM_PFN_NOSLOT, indicating an error HVA for the page. This can only happen on MIPS right now due to unusual memslot management (e.g. being moved / removed / resized), or with an Enhanced Virtual Memory (EVA) configuration where the default KVM_HVA_ERR_* and kvm_is_error_hva() definitions are unsuitable (fixed in a later patch). This case will be treated as a pfn of zero, mapping the first page of physical memory into the guest. It would appear the MIPS KVM port wasn't updated prior to being merged (in v3.10) to take commit 81c52c56e2b4 ("KVM: do not treat noslot pfn as a error pfn") into account (merged v3.8), which converted a bunch of is_error_pfn() calls to is_error_noslot_pfn(). Switch to using is_error_noslot_pfn() instead to catch this case properly. 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.y- Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* MIPS: KVM: Propagate kseg0/mapped tlb fault errorsJames Hogan2016-08-121-3/+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>
* MIPS: KVM: Fix gfn range check in kseg0 tlb faultsJames Hogan2016-08-121-1/+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>
* MIPS: KVM: Add missing gfn range checkJames Hogan2016-08-121-8/+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>
* MIPS: KVM: Fix mapped fault broken commpage handlingJames Hogan2016-08-121-21/+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>
* MIPS: KVM: Use kmap instead of CKSEG0ADDR()James Hogan2016-08-011-1/+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>
* MIPS: KVM: Use host CCA for TLB mappingsJames Hogan2016-06-151-8/+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>
* MIPS: KVM: Dump guest tlbs if kvm_get_inst() failsJames Hogan2016-06-141-0/+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>
* MIPS: KVM: Use va in kvm_get_inst()James Hogan2016-06-141-8/+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>
* MIPS: KVM: Use MIPS_ENTRYLO_* defs from mipsregs.hJames Hogan2016-06-141-10/+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>
* MIPS: KVM: Arrayify struct kvm_mips_tlb::tlb_lo*James Hogan2016-06-141-9/+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>
* MIPS: KVM: Drop unused hpa0/hpa1 args from functionJames Hogan2016-06-141-11/+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>
* MIPS: KVM: Simplify even/odd TLB handlingJames Hogan2016-06-141-9/+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>
* MIPS: KVM: Don't indirect KVM functionsJames Hogan2016-06-141-2/+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>
* MIPS: KVM: Move non-TLB handling code out of tlb.cJames Hogan2016-06-141-0/+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>
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