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2016-10-26KVM: MIPS: Precalculate MMIO load resume PCJames Hogan
The advancing of the PC when completing an MMIO load is done before re-entering the guest, i.e. before restoring the guest ASID. However if the load is in a branch delay slot it may need to access guest code to read the prior branch instruction. This isn't safe in TLB mapped code at the moment, nor in the future when we'll access unmapped guest segments using direct user accessors too, as it could read the branch from host user memory instead. Therefore calculate the resume PC in advance while we're still in the right context and save it in the new vcpu->arch.io_pc (replacing the no longer needed vcpu->arch.pending_load_cause), and restore it on MMIO completion. 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: Paolo Bonzini <pbonzini@redhat.com>
2016-09-29Merge tag 'kvm_mips_4.9_1' of ↵Radim Krčmář
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.
2016-09-29KVM: MIPS: Invalidate TLB by regenerating ASIDsJames Hogan
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
2016-09-08KVM: MIPS: Override HVA error values for EVAJames Hogan
MIPS Enhanced Virtual Addressing (EVA) allows the user mode and kernel mode address spaces to overlap, breaking the assumption that PAGE_OFFSET is an appropriate KVM HVA error value, since PAGE_OFFSET may be as low as zero. Fix this in the same way that s390 does in commit bf640876e21f ("KVM: s390: Make KVM_HVA_ERR_BAD usable on s390"), by overriding KVM_HVA_ERR_[RO_]BAD and kvm_is_error_hva() in asm/kvm_host.h. 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
2016-09-08KVM: Add provisioning for ulong vm stats and u64 vcpu statsSuraj Jitindar Singh
vms and vcpus have statistics associated with them which can be viewed within the debugfs. Currently it is assumed within the vcpu_stat_get() and vm_stat_get() functions that all of these statistics are represented as u32s, however the next patch adds some u64 vcpu statistics. Change all vcpu statistics to u64 and modify vcpu_stat_get() accordingly. Since vcpu statistics are per vcpu, they will only be updated by a single vcpu at a time so this shouldn't present a problem on 32-bit machines which can't atomically increment 64-bit numbers. However vm statistics could potentially be updated by multiple vcpus from that vm at a time. To avoid the overhead of atomics make all vm statistics ulong such that they are 64-bit on 64-bit systems where they can be atomically incremented and are 32-bit on 32-bit systems which may not be able to atomically increment 64-bit numbers. Modify vm_stat_get() to expect ulongs. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: David Matlack <dmatlack@google.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-07-05MIPS: KVM: Fix pre-r6 ll/sc instructions on r6James Hogan
The atomic KVM register access macros in kvm_host.h (for the guest Cause register with KVM in trap & emulate mode) use ll/sc instructions, however they still .set mips3, which causes pre-MIPSr6 instruction encodings to be emitted, even for a MIPSr6 build. Fix it to use MIPS_ISA_ARCH_LEVEL as other parts of arch/mips already do. 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: 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>
2016-06-15MIPS: 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: 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: Use raw_cpu_has_fpu in kvm_mips_guest_can_have_fpu()James Hogan
We need to use kvm_mips_guest_can_have_fpu() when deciding which registers to list with KVM_GET_REG_LIST, however it causes warnings with preemption since it uses cpu_has_fpu. KVM is only really supported on CPUs which have symmetric FPUs, so switch to raw_cpu_has_fpu to avoid the warning. 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>
2016-06-15MIPS: 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: 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>
2016-06-14MIPS: KVM: Clean up kvm_exit trace eventJames Hogan
Clean up the MIPS kvm_exit trace event so that the exit reasons are specified in a trace friendly way (via __print_symbolic), and so that the exit reasons that derive straight from Cause.ExcCode values map directly, allowing a single trace_kvm_exit() call to replace a bunch of individual ones. 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: Generalise fpu_inuse for other stateJames Hogan
Rename fpu_inuse and the related definitions to aux_inuse so it can be used for lazy context management of other auxiliary processor state too, such as VZ guest timer, watchpoints and performance counters. 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: Use MIPS_ENTRYLO_* defs from mipsregs.hJames Hogan
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: Simplify TLB_* macrosJames Hogan
Simplify some of the TLB_ macros making use of the arrayification of tlb_lo. Basically we index the array by the bit of the virtual address which determines whether the even or odd entry is used, instead of having a conditional. 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 Hogan
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: Restore host EBase from ebase variableJames Hogan
The host kernel's exception vector base address is currently saved in the VCPU structure at creation time, and restored on a guest exit. However it doesn't change and can already be easily accessed from the 'ebase' variable (arch/mips/kernel/traps.c), so drop the host_ebase member of kvm_vcpu_arch, export the 'ebase' variable to modules and load from there instead. This does result in a single extra instruction (lui) on the guest exit path, but simplifies the code a bit and removes the redundant storage of the host exception base address. Credit for the idea goes to Cavium's VZ KVM implementation. 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: Drop unused hpa0/hpa1 args from functionJames Hogan
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: Don't indirect KVM functionsJames Hogan
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 Hogan
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>
2016-06-14MIPS: KVM: Make various Cause variables 32-bitJames Hogan
The CP0 Cause register is passed around in KVM quite a bit, often as an unsigned long, even though it is always 32-bits long. Resize it to u32 throughout MIPS KVM. 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: Convert headers to kernel sized typesJames Hogan
Convert the MIPS kvm_host.h structs, function declaration prototypes and associated definition prototypes to use standard kernel sized types (e.g. u32) instead of inttypes.h style ones (e.g. uint32_t). 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 host_cp0_entryhiJames Hogan
The host EntryHi in the KVM VCPU context is virtually unused. It gets stored on exceptions, but only ever used in a kvm_debug() when a TLB miss occurs. Drop it entirely, removing that information from the kvm_debug output. 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 guest_inst from kvm_vcpu_archJames Hogan
The MIPS kvm_vcpu_arch::guest_inst isn't used, so drop it from the struct and drop its asm-offsets definition. 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: Include bit 31 in segment matchesJames Hogan
When faulting guest addresses are matched against guest segments with the KVM_GUEST_KSEGX() macro, change the mask to 0xe0000000 so as to include bit 31. This is mainly for safety's sake, as it prevents a rogue BadVAddr in the host kseg2/kseg3 segments (e.g. 0xC*******) after a TLB exception from matching the guest kseg0 segment (e.g. 0x4*******), triggering an internal KVM error instead of allowing the corresponding guest kseg0 page to be mapped into the host vmalloc space. Such a rogue BadVAddr was observed to happen with the host MIPS kernel running under QEMU with KVM built as a module, due to a not entirely transparent optimisation in the QEMU TLB handling. This has already been worked around properly in a previous commit. 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: Fix modular KVM under QEMUJames Hogan
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 <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 Cc: <stable@vger.kernel.org> # 3.10.x- Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-19Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "Small release overall. x86: - miscellaneous fixes - AVIC support (local APIC virtualization, AMD version) s390: - polling for interrupts after a VCPU goes to halted state is now enabled for s390 - use hardware provided information about facility bits that do not need any hypervisor activity, and other fixes for cpu models and facilities - improve perf output - floating interrupt controller improvements. MIPS: - miscellaneous fixes PPC: - bugfixes only ARM: - 16K page size support - generic firmware probing layer for timer and GIC Christoffer Dall (KVM-ARM maintainer) says: "There are a few changes in this pull request touching things outside KVM, but they should all carry the necessary acks and it made the merge process much easier to do it this way." though actually the irqchip maintainers' acks didn't make it into the patches. Marc Zyngier, who is both irqchip and KVM-ARM maintainer, later acked at http://mid.gmane.org/573351D1.4060303@arm.com ('more formally and for documentation purposes')" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (82 commits) KVM: MTRR: remove MSR 0x2f8 KVM: x86: make hwapic_isr_update and hwapic_irr_update look the same svm: Manage vcpu load/unload when enable AVIC svm: Do not intercept CR8 when enable AVIC svm: Do not expose x2APIC when enable AVIC KVM: x86: Introducing kvm_x86_ops.apicv_post_state_restore svm: Add VMEXIT handlers for AVIC svm: Add interrupt injection via AVIC KVM: x86: Detect and Initialize AVIC support svm: Introduce new AVIC VMCB registers KVM: split kvm_vcpu_wake_up from kvm_vcpu_kick KVM: x86: Introducing kvm_x86_ops VCPU blocking/unblocking hooks KVM: x86: Introducing kvm_x86_ops VM init/destroy hooks KVM: x86: Rename kvm_apic_get_reg to kvm_lapic_get_reg KVM: x86: Misc LAPIC changes to expose helper functions KVM: shrink halt polling even more for invalid wakeups KVM: s390: set halt polling to 80 microseconds KVM: halt_polling: provide a way to qualify wakeups during poll KVM: PPC: Book3S HV: Re-enable XICS fast path for irqfd-generated interrupts kvm: Conditionally register IRQ bypass consumer ...
2016-05-13KVM: halt_polling: provide a way to qualify wakeups during pollChristian Borntraeger
Some wakeups should not be considered a sucessful poll. For example on s390 I/O interrupts are usually floating, which means that _ALL_ CPUs would be considered runnable - letting all vCPUs poll all the time for transactional like workload, even if one vCPU would be enough. This can result in huge CPU usage for large guests. This patch lets architectures provide a way to qualify wakeups if they should be considered a good/bad wakeups in regard to polls. For s390 the implementation will fence of halt polling for anything but known good, single vCPU events. The s390 implementation for floating interrupts does a wakeup for one vCPU, but the interrupt will be delivered by whatever CPU checks first for a pending interrupt. We prefer the woken up CPU by marking the poll of this CPU as "good" poll. This code will also mark several other wakeup reasons like IPI or expired timers as "good". This will of course also mark some events as not sucessful. As KVM on z runs always as a 2nd level hypervisor, we prefer to not poll, unless we are really sure, though. This patch successfully limits the CPU usage for cases like uperf 1byte transactional ping pong workload or wakeup heavy workload like OLTP while still providing a proper speedup. This also introduced a new vcpu stat "halt_poll_no_tuning" that marks wakeups that are considered not good for polling. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version) Cc: David Matlack <dmatlack@google.com> Cc: Wanpeng Li <kernellwp@gmail.com> [Rename config symbol. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-13MIPS: KVM: Abstract guest ASID maskPaul Burton
In preparation for supporting varied widths of ASID mask in the kernel in general, switch KVM's guest ASIDs to a new KVM_ENTRYHI_ASID definition based on the 8-bit MIPS_ENTRYHI_ASID instead of ASID_MASK. It could potentially be used to support extended guest ASIDs in the future. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13207/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-10MIPS: KVM: Fix timer IRQ race when writing CP0_CompareJames Hogan
Writing CP0_Compare clears the timer interrupt pending bit (CP0_Cause.TI), but this wasn't being done atomically. If a timer interrupt raced with the write of the guest CP0_Compare, the timer interrupt could end up being pending even though the new CP0_Compare is nowhere near CP0_Count. We were already updating the hrtimer expiry with kvm_mips_update_hrtimer(), which used both kvm_mips_freeze_hrtimer() and kvm_mips_resume_hrtimer(). Close the race window by expanding out kvm_mips_update_hrtimer(), and clearing CP0_Cause.TI and setting CP0_Compare between the freeze and resume. Since the pending timer interrupt should not be cleared when CP0_Compare is written via the KVM user API, an ack argument is added to distinguish the source of the write. Fixes: e30492bbe95a ("MIPS: KVM: Rewrite count/compare timer 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> # 3.16.x- Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-24Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS for 4.5 plus some 4.4 fixes. The executive summary: - ATH79 platform improvments, use DT bindings for the ATH79 USB PHY. - Avoid useless rebuilds for zboot. - jz4780: Add NEMC, BCH and NAND device tree nodes - Initial support for the MicroChip's DT platform. As all the device drivers are missing this is still of limited use. - Some Loongson3 cleanups. - The unavoidable whitespace polishing. - Reduce clock skew when synchronizing the CPU cycle counters on CPU startup. - Add MIPS R6 fixes. - Lots of cleanups across arch/mips as fallout from KVM. - Lots of minor fixes and changes for IEEE 754-2008 support to the FPU emulator / fp-assist software. - Minor Ralink, BCM47xx and bcm963xx platform support improvments. - Support SMP on BCM63168" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (84 commits) MIPS: zboot: Add support for serial debug using the PROM MIPS: zboot: Avoid useless rebuilds MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function MIPS: bcm963xx: Update bcm_tag field image_sequence MIPS: bcm963xx: Move extended flash address to bcm_tag header file MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure MIPS: bcm63xx: nvram: Use nvram structure definition from header file MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure MAINTAINERS: Add KVM for MIPS entry MIPS: KVM: Add missing newline to kvm_err() MIPS: Move KVM specific opcodes into asm/inst.h MIPS: KVM: Use cacheops.h definitions MIPS: Break down cacheops.h definitions MIPS: Use EXCCODE_ constants with set_except_vector() MIPS: Update trap codes MIPS: Move Cause.ExcCode trap codes to mipsregs.h MIPS: KVM: Make kvm_mips_{init,exit}() static MIPS: KVM: Refactor added offsetof()s MIPS: KVM: Convert EXPORT_SYMBOL to _GPL ...
2016-01-24MIPS: Move Cause.ExcCode trap codes to mipsregs.hJames Hogan
Move the Cause.ExcCode trap code definitions from kvm_host.h to mipsregs.h, since they describe architectural bits rather than KVM specific constants, and change the prefix from T_ to EXCCODE_. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11891/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-24MIPS: KVM: Drop unused kvm_mips_host_tlb_inv_index()James Hogan
The function kvm_mips_host_tlb_inv_index() is unused, so drop it completely. 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: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11886/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-24MIPS: Move definition of DC bit to mipsregs.hJames Hogan
The CAUSEB_DC and CAUSEF_DC definitions used by KVM are defined in asm/kvm_host.h, but all the other Cause register field definitions are found in asm/mipsregs.h. Lets reunite the DC bit definitions with its friends in mipsregs.h. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/11885/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-24MIPS: KVM: Drop some unused definitions from kvm_host.hJames Hogan
Some definitions in the MIPS asm/kvm_host.h are completely unused, so lets drop them. MS_TO_NS is no longer used since commit e30492bbe95a ("MIPS: KVM: Rewrite count/compare timer emulation"). The others don't appear ever to have been used. 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: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11884/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-24MIPS: KVM: Trivial whitespace and style fixesJames Hogan
A bunch of misc whitespace and style fixes within arch/mips/kvm/. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11883/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-15kvm: rename pfn_t to kvm_pfn_tDan Williams
To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-22KVM: Add kvm_arch_vcpu_{un}blocking callbacksChristoffer Dall
Some times it is useful for architecture implementations of KVM to know when the VCPU thread is about to block or when it comes back from blocking (arm/arm64 needs to know this to properly implement timers, for example). Therefore provide a generic architecture callback function in line with what we do elsewhere for KVM generic-arch interactions. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-09-25KVM: disable halt_poll_ns as default for s390xDavid Hildenbrand
We observed some performance degradation on s390x with dynamic halt polling. Until we can provide a proper fix, let's enable halt_poll_ns as default only for supported architectures. Architectures are now free to set their own halt_poll_ns default value. Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-16KVM: add halt_attempted_poll to VCPU statsPaolo Bonzini
This new statistic can help diagnosing VCPUs that, for any reason, trigger bad behavior of halt_poll_ns autotuning. For example, say halt_poll_ns = 480000, and wakeups are spaced exactly like 479us, 481us, 479us, 481us. Then KVM always fails polling and wastes 10+20+40+80+160+320+480 = 1110 microseconds out of every 479+481+479+481+479+481+479 = 3359 microseconds. The VCPU then is consuming about 30% more CPU than it would use without polling. This would show as an abnormally high number of attempted polling compared to the successful polls. Acked-by: Christian Borntraeger <borntraeger@de.ibm.com< Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-05-26KVM: add memslots argument to kvm_arch_memslots_updatedPaolo Bonzini
Prepare for the case of multiple address spaces. Reviewed-by: Radim Krcmar <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-03-27MIPS: KVM: Add MSA exception handlingJames Hogan
Add guest exception handling for MIPS SIMD Architecture (MSA) floating point exceptions and MSA disabled exceptions. MSA floating point exceptions from the guest need passing to the guest kernel, so for these a guest MSAFPE is emulated. MSA disabled exceptions are normally handled by passing a reserved instruction exception to the guest (because no guest MSA was supported), but the hypervisor can now handle them if the guest has MSA by passing an MSA disabled exception to the guest, or if the guest has MSA enabled by transparently restoring the guest MSA context and enabling MSA and the FPU. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Add base guest MSA supportJames Hogan
Add base code for supporting the MIPS SIMD Architecture (MSA) in MIPS KVM guests. MSA cannot yet be enabled in the guest, we're just laying the groundwork. As with the FPU, whether the guest's MSA context is loaded is stored in another bit in the fpu_inuse vcpu member. This allows MSA to be disabled when the guest disables it, but keeping the MSA context loaded so it doesn't have to be reloaded if the guest re-enables it. New assembly code is added for saving and restoring the MSA context, restoring only the upper half of the MSA context (for if the FPU context is already loaded) and for saving/clearing and restoring MSACSR (which can itself cause an MSA FP exception depending on the value). The MSACSR is restored before returning to the guest if MSA is already enabled, and the existing FP exception die notifier is extended to catch the possible MSA FP exception and step over the ctcmsa instruction. The helper function kvm_own_msa() is added to enable MSA and restore the MSA context if it isn't already loaded, which will be used in a later patch when the guest attempts to use MSA for the first time and triggers an MSA disabled exception. The existing FPU helpers are extended to handle MSA. kvm_lose_fpu() saves the full MSA context if it is loaded (which includes the FPU context) and both kvm_lose_fpu() and kvm_drop_fpu() disable MSA. kvm_own_fpu() also needs to lose any MSA context if FR=0, since there would be a risk of getting reserved instruction exceptions if CU1 is enabled and we later try and save the MSA context. We shouldn't usually hit this case since it will be handled when emulating CU1 changes, however there's nothing to stop the guest modifying the Status register directly via the comm page, which will cause this case to get hit. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Add FP exception handlingJames Hogan
Add guest exception handling for floating point exceptions and coprocessor 1 unusable exceptions. Floating point exceptions from the guest need passing to the guest kernel, so for these a guest FPE is emulated. Also, coprocessor 1 unusable exceptions are normally passed straight through to the guest (because no guest FPU was supported), but the hypervisor can now handle them if the guest has its FPU enabled by restoring the guest FPU context and enabling the FPU. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Add base guest FPU supportJames Hogan
Add base code for supporting FPU in MIPS KVM guests. The FPU cannot yet be enabled in the guest, we're just laying the groundwork. Whether the guest's FPU context is loaded is stored in a bit in the fpu_inuse vcpu member. This allows the FPU to be disabled when the guest disables it, but keeping the FPU context loaded so it doesn't have to be reloaded if the guest re-enables it. An fpu_enabled vcpu member stores whether userland has enabled the FPU capability (which will be wired up in a later patch). New assembly code is added for saving and restoring the FPU context, and for saving/clearing and restoring FCSR (which can itself cause an FP exception depending on the value). The FCSR is restored before returning to the guest if the FPU is already enabled, and a die notifier is registered to catch the possible FP exception and step over the ctc1 instruction. The helper function kvm_lose_fpu() is added to save FPU context and disable the FPU, which is used when saving hardware state before a context switch or KVM exit (the vcpu_get_regs() callback). The helper function kvm_own_fpu() is added to enable the FPU and restore the FPU context if it isn't already loaded, which will be used in a later patch when the guest attempts to use the FPU for the first time and triggers a co-processor unusable exception. The helper function kvm_drop_fpu() is added to discard the FPU context and disable the FPU, which will be used in a later patch when the FPU state will become architecturally UNPREDICTABLE (change of FR mode) to force a reload of [stale] context in the new FR mode. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
2015-03-27MIPS: KVM: Add vcpu_get_regs/vcpu_set_regs callbackJames Hogan
Add a vcpu_get_regs() and vcpu_set_regs() callbacks for loading and restoring context which may be in hardware registers. This may include floating point and MIPS SIMD Architecture (MSA) state which may be accessed directly by the guest (but restored lazily by the hypervisor), and also dedicated guest registers as provided by the VZ ASE. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Gleb Natapov <gleb@kernel.org> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org