Paolo Bonzini [Mon, 13 Jun 2016 12:50:04 +0000 (14:50 +0200)]
KVM: remove kvm_vcpu_compatible
The new created_vcpus field makes it possible to avoid the race between
irqchip and VCPU creation in a much nicer way; just check under kvm->lock
whether a VCPU has already been created.
We can then remove KVM_APIC_ARCHITECTURE too, because at this point the
symbol is only governing the default definition of kvm_vcpu_compatible.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Paolo Bonzini [Mon, 13 Jun 2016 12:48:25 +0000 (14:48 +0200)]
KVM: introduce kvm->created_vcpus
The race between creating the irqchip and the first VCPU is
currently fixed by checking the presence of an irqchip before
updating kvm->online_vcpus, and undoing the whole VCPU creation
if someone created the irqchip in the meanwhile.
Instead, introduce a new field in struct kvm that will count VCPUs
under a mutex, without the atomic access and memory ordering that we
need elsewhere to protect the vcpus array. This also plugs the race
and is more easily applicable in all similar circumstances.
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
James Hogan [Wed, 15 Jun 2016 18:30:01 +0000 (19:30 +0100)]
MIPS: KVM: Use mipsregs.h defs for config registers
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>
James Hogan [Wed, 15 Jun 2016 18:30:00 +0000 (19:30 +0100)]
MIPS: KVM: Report more accurate CP0_Config fields to guest
Initialise the guest's CP0_Config register with a few more bits of
information from the host. The BE bit should be set on big endian
machines, the VI bit should be set on machines with a virtually tagged
instruction cache, and the reported architecture revision should match
that of the host (since we won't support emulating pre-r6 instruction
encodings on r6 or vice versa).
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>
James Hogan [Wed, 15 Jun 2016 18:29:59 +0000 (19:29 +0100)]
MIPS: Add define for Config.VI (virtual icache) bit
The Config.VI bit specifies that the instruction cache is virtually
tagged, which is checked in c-r4k.c's probe_pcache(). Add a proper
definition for it in mipsregs.h and make use of it.
Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
James Hogan [Wed, 15 Jun 2016 18:29:58 +0000 (19:29 +0100)]
MIPS: KVM: Use host CCA for TLB mappings
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>
James Hogan [Wed, 15 Jun 2016 18:29:57 +0000 (19:29 +0100)]
MIPS: KVM: Move commpage so 0x0 is unmapped
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>
James Hogan [Wed, 15 Jun 2016 18:29:56 +0000 (19:29 +0100)]
MIPS: KVM: Add KScratch registers
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>
James Hogan [Wed, 15 Jun 2016 18:29:55 +0000 (19:29 +0100)]
MIPS: KVM: Emulate RDHWR CPUNum register
Actually provide the VCPU number when emulating the RDHWR CPUNum
register, so that it will match the CPUNum field of CP0_EBase register,
rather than always returning 0.
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>
James Hogan [Wed, 15 Jun 2016 18:29:54 +0000 (19:29 +0100)]
MIPS: KVM: Allow ULRI to restrict UserLocal register
The ULRI bit in Config3 specifies whether the UserLocal register is
implemented, but it is assumed to always be set. Now that the Config
registers can be modified by userland, allow Config3.ULRI to be cleared
and check ULRI before allowing the corresponding bit to be set in
HWREna.
In fact any HWREna bits corresponding to unimplemented RDHWR registers
should read as zero and be ignored on write, so we actually prevent
other unimplemented bits being set too.
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>
James Hogan [Wed, 15 Jun 2016 18:29:53 +0000 (19:29 +0100)]
MIPS: KVM: Don't hardcode restored HWREna
KVM modifies CP0_HWREna during guest execution so it can trap and
emulate RDHWR instructions, however it always restores the hardcoded
value 0x2000000F. This assumes the presence of the UserLocal register,
and the absence of any implementation dependent or future HW registers.
Fix by exporting the value that traps.c write into CP0_HWREna, and
loading from there instead of hard coding.
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>
James Hogan [Wed, 15 Jun 2016 18:29:52 +0000 (19:29 +0100)]
MIPS: Clean up RDHWR handling
No preprocessor definitions are used in the handling of the registers
accessible with the RDHWR instruction, nor the corresponding bits in the
CP0 HWREna register.
Add definitions for both the register numbers (MIPS_HWR_*) and HWREna
bits (MIPS_HWRENA_*) in asm/mipsregs.h and make use of them in the
initialisation of HWREna and emulation of the RDHWR instruction.
Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> 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>
James Hogan [Wed, 15 Jun 2016 18:29:51 +0000 (19:29 +0100)]
MIPS: KVM: List FPU/MSA registers
Make KVM_GET_REG_LIST list FPU & MSA registers. Specifically we list all
32 vector registers when MSA can be enabled, 32 single-precision FP
registers when FPU can be enabled, and either 16 or 32 double-precision
FP registers when FPU can be enabled depending on whether FR mode is
supported (which provides 32 doubles instead of 16 even doubles).
Note, these registers may still be inaccessible depending on the current
FP mode of 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 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
James Hogan [Wed, 15 Jun 2016 18:29:50 +0000 (19:29 +0100)]
MIPS: KVM: Use raw_cpu_has_fpu in kvm_mips_guest_can_have_fpu()
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>
James Hogan [Wed, 15 Jun 2016 18:29:49 +0000 (19:29 +0100)]
MIPS: KVM: Make KVM_GET_REG_LIST dynamic
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>
James Hogan [Wed, 15 Jun 2016 18:29:48 +0000 (19:29 +0100)]
MIPS: KVM: Pass all unknown registers to callbacks
Pass all unrecognised register IDs through to the set_one_reg() and
get_one_reg() callbacks, not just select ones. This allows
implementation specific registers to be more easily added without having
to modify arch/mips/kvm/mips.c.
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>
James Hogan [Wed, 15 Jun 2016 18:29:47 +0000 (19:29 +0100)]
MIPS: KVM: Convert emulation to use asm/inst.h
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>
James Hogan [Wed, 15 Jun 2016 18:29:46 +0000 (19:29 +0100)]
MIPS: KVM: Factor writing of translated guest instructions
The code in kvm_mips_dyntrans.c to write a translated guest instruction
to guest memory depending on the segment is duplicated between each of
the functions. Additionally the cache op translation functions assume
the instruction is in the KSEG0/1 segment rather than KSEG2/3, which is
generally true but isn't guaranteed.
Factor that code into a new kvm_mips_trans_replace() which handles both
KSEG0/1 and KSEG2/3.
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>
James Hogan [Wed, 15 Jun 2016 18:29:45 +0000 (19:29 +0100)]
MIPS: KVM: Fix translation of MFC0 ErrCtl
The MIPS KVM dynamic translation is meant to translate "MFC0 rt, ErrCtl"
instructions into "ADD rt, zero, zero" to zero the destination register,
however the rt register number was copied into rt of the ADD instruction
encoding, which is the 2nd source operand. This results in "ADD zero,
zero, rt" which is a no-op, so only the first execution of each such
MFC0 from ErrCtl will actually read 0.
Fix the shift to put the rt from the MFC0 encoding into the rd field of
the ADD.
Fixes: 50c8308538dc ("KVM/MIPS32: Binary patching of select privileged instructions.") 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>
Paolo Bonzini [Wed, 15 Jun 2016 07:21:46 +0000 (09:21 +0200)]
Merge tag 'kvm-s390-next-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390: Features and fixes for 4.8 part1
Four bigger things:
1. The implementation of the STHYI opcode in the kernel. This is used
in libraries like qclib [1] to provide enough information for a
capacity and usage based software licence pricing. The STHYI content
is defined by the related z/VM documentation [2]. Its data can be
composed by accessing several other interfaces provided by LPAR or
the machine. This information is partially sensitive or root-only
so the kernel does the necessary filtering.
2. Preparation for nested virtualization (VSIE). KVM should query the
proper sclp interfaces for the availability of some features before
using it. In the past we have been sloppy and simply assumed that
several features are available. With this we should be able to handle
most cases of a missing feature.
3. CPU model interfaces extended by some additional features that are
not covered by a facility bit in STFLE. For example all the crypto
instructions of the coprocessor provide a query function. As reality
tends to be more complex (e.g. export regulations might block some
algorithms) we have to provide additional interfaces to query or
set these non-stfle features.
4. Several fixes and changes detected and fixed when doing 1-3.
All features change base s390 code. All relevant patches have an ACK
from the s390 or component maintainers.
The next pull request for 4.8 (part2) will contain the implementation
of VSIE.
James Hogan [Tue, 14 Jun 2016 08:40:16 +0000 (09:40 +0100)]
MIPS: KVM: Dump guest tlbs if kvm_get_inst() fails
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>
James Hogan [Tue, 14 Jun 2016 08:40:15 +0000 (09:40 +0100)]
MIPS: KVM: Trace guest register access emulation
Trace emulation of guest access to various registers via
MFC0/MTC0/DMFC0/DMTC0 instructions (coprocessor 0) and the RDHWR
instruction (hardware registers exposed to userland), replacing some
existing kvm_debug calls. Trace events are much more practical for this
kind of debug output.
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: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
James Hogan [Tue, 14 Jun 2016 08:40:12 +0000 (09:40 +0100)]
MIPS: KVM: Clean up kvm_exit trace event
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>
James Hogan [Tue, 14 Jun 2016 08:40:11 +0000 (09:40 +0100)]
MIPS: KVM: Add kvm_aux trace event
Add a MIPS specific trace event for auxiliary context operations
(notably FPU and MSA). Unfortunately the generic kvm_fpu trace event
isn't flexible enough to handle the range of interesting things that can
happen with FPU and MSA context.
The type of state being operated on is traced:
- FPU: Just the FPU registers.
- MSA: Just the upper half of the MSA vector registers (low half already
loaded with FPU state).
- FPU & MSA: Full MSA vector state (includes FPU state).
As is the type of operation:
- Restore: State was enabled and restored.
- Save: State was saved and disabled.
- Enable: State was enabled (already loaded).
- Disable: State was disabled (kept loaded).
- Discard: State was discarded and disabled.
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: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org
[Fix remaining occurrence of "fpu_msa", change to "aux". - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
James Hogan [Tue, 14 Jun 2016 08:40:10 +0000 (09:40 +0100)]
MIPS: KVM: Generalise fpu_inuse for other state
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>
James Hogan [Thu, 9 Jun 2016 13:19:21 +0000 (14:19 +0100)]
MIPS: KVM: Use va in kvm_get_inst()
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>
James Hogan [Thu, 9 Jun 2016 13:19:20 +0000 (14:19 +0100)]
MIPS: KVM: Combine handle_tlb_ld/st_miss
The handle_tlb_ld/st_miss handlers are logically equivalent and
textually almost identical, so combine their implementations into a
single kvm_trap_emul_handle_tlb_miss().
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>
James Hogan [Thu, 9 Jun 2016 13:19:18 +0000 (14:19 +0100)]
MIPS: KVM: Simplify TLB_* macros
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>
James Hogan [Thu, 9 Jun 2016 13:19:17 +0000 (14:19 +0100)]
MIPS: KVM: Arrayify struct kvm_mips_tlb::tlb_lo*
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>
James Hogan [Thu, 9 Jun 2016 13:19:16 +0000 (14:19 +0100)]
MIPS: KVM: Use dump_tlb_all() for kvm_mips_dump_host_tlbs()
KVM implements its own routine for dumping the host TLB entries, but we
already have dump_tlb_all() which does something very similar (although
it only prints out TLB entries which match the current ASID or are
global).
Make KVM use dump_tlb_all() along with dump_tlb_regs() to avoid the
duplication and inevitable bitrot, allowing TLB dumping enhancements
(e.g. for VZ and GuestIDs) to be made in a single place.
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>
James Hogan [Thu, 9 Jun 2016 13:19:15 +0000 (14:19 +0100)]
MIPS: KVM: Clean up TLB management hazards
KVM's host TLB handling routines were using tlbw hazard barrier macros
around tlb_read(). Now that hazard barrier macros exist for tlbr, update
this case to use them.
Also fix various other unnecessary hazard barriers in this code.
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>
James Hogan [Thu, 9 Jun 2016 13:19:14 +0000 (14:19 +0100)]
MIPS: KVM: Restore host EBase from ebase variable
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>
James Hogan [Thu, 9 Jun 2016 13:19:12 +0000 (14:19 +0100)]
MIPS: KVM: Simplify even/odd TLB handling
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>
James Hogan [Thu, 9 Jun 2016 13:19:11 +0000 (14:19 +0100)]
MIPS: KVM: Don't indirect KVM functions
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>
James Hogan [Thu, 9 Jun 2016 13:19:10 +0000 (14:19 +0100)]
MIPS: KVM: Move non-TLB handling code out of tlb.c
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>
James Hogan [Thu, 9 Jun 2016 13:19:08 +0000 (14:19 +0100)]
MIPS: KVM: Convert code to kernel sized types
Convert the MIPS KVM C code to use standard kernel sized types (e.g.
u32) instead of inttypes.h style ones (e.g. uint32_t) or other types as
appropriate.
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>
James Hogan [Thu, 9 Jun 2016 13:19:07 +0000 (14:19 +0100)]
MIPS: KVM: Convert headers to kernel sized types
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>
James Hogan [Thu, 9 Jun 2016 13:19:05 +0000 (14:19 +0100)]
MIPS: KVM: Drop unused host_cp0_entryhi
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>
When emulating TLB miss / invalid exceptions during CACHE instruction
emulation, be sure to set up the correct PC and host_cp0_badvaddr state
for the kvm_mips_emlulate_tlb*_ld() function to pick up for guest EPC
and BadVAddr.
PC needs to be rewound otherwise the guest EPC will end up pointing at
the next instruction after the faulting CACHE instruction.
host_cp0_badvaddr must be set because guest CACHE instructions trap with
a Coprocessor Unusable exception, which doesn't update the host BadVAddr
as a TLB exception would.
This doesn't tend to get hit when dynamic translation of emulated
instructions is enabled, since only the first execution of each CACHE
instruction actually goes through this code path, with subsequent
executions hitting the SYNCI instruction that it gets replaced with.
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>
James Hogan [Thu, 9 Jun 2016 09:50:45 +0000 (10:50 +0100)]
MIPS: KVM: Don't unwind PC when emulating CACHE
When a CACHE instruction is emulated by kvm_mips_emulate_cache(), the PC
is first updated to point to the next instruction, and afterwards it
falls through the "dont_update_pc" label, which rewinds the PC back to
its original address.
This works when dynamic translation of emulated instructions is enabled,
since the CACHE instruction is replaced with a SYNCI which works without
trapping, however when dynamic translation is disabled the guest hangs
on CACHE instructions as they always trap and are never stepped over.
Roughly swap the meanings of the "done" and "dont_update_pc" to match
kvm_mips_emulate_CP0(), so that "done" will roll back the PC on failure,
and "dont_update_pc" won't change PC at all (for the sake of exceptions
that have already modified the PC).
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>
James Hogan [Thu, 9 Jun 2016 09:50:44 +0000 (10:50 +0100)]
MIPS: KVM: Include bit 31 in segment matches
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>
James Hogan [Thu, 9 Jun 2016 09:50:43 +0000 (10:50 +0100)]
MIPS: KVM: Fix modular KVM under QEMU
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>
Without the storage-key facility, SIE won't interpret SSKE, ISKE and
RRBE for us. So let's add proper interception handlers that will be called
if lazy sske cannot be enabled.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's trace and count all skey handling operations, even if lazy skey
handling was already activated. Also, don't enable lazy skey handling if
anything went wrong while enabling skey handling for the SIE.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
In theory, end could always end up being < start, if overflowing to 0.
Although very unlikely for now, let's just fix it.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: pfmf: support conditional-sske facility
We already indicate that facility but don't implement it in our pfmf
interception handler. Let's add a new storage key handling function for
conditionally setting the guest storage key.
As we will reuse this function later on, let's directly implement returning
the old key via parameter and indicating if any change happened via rc.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: pfmf: take care of amode when setting reg2
Depending on the addressing mode, we must not overwrite bit 0-31 of the
register. In addition, 24 bit and 31 bit have to set certain bits to 0,
which is guaranteed by converting the end address to an effective
address.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: pfmf: MR and MC are ignored without CSSKE
These two bits are simply ignored when the conditional-SSKE facility is
not installed.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The current calculation is wrong if absolute != real address. Let's just
calculate the start address for 4k frames upfront. Otherwise, the
calculated end address will be wrong, resulting in wrong memory
location/storage keys getting touched.
To keep low-address protection working (using the effective address),
we have to move the check.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
No need to convert the storage key into an unsigned long, the target
function expects a char as argument.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
s390/mm: return key via pointer in get_guest_storage_key
Let's just split returning the key and reporting errors. This makes calling
code easier and avoids bugs as happened already.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We can safe a few LOC and make that function easier to understand
by rewriting existing code.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
s390/mm: set and get guest storage key mmap locking
Move the mmap semaphore locking out of set_guest_storage_key
and get_guest_storage_key. This makes the two functions more
like the other ptep_xxx operations and allows to avoid repeated
semaphore operations if multiple keys are read or written.
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
s390/mm: don't drop errors in get_guest_storage_key
Commit 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") changed
the return value of get_guest_storage_key to an unsigned char, resulting
in -EFAULT getting interpreted as a valid storage key.
Cc: stable@vger.kernel.org # 4.6+ Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
We currently have two issues with the I/O interrupt injection logging:
1. All QEMU versions up to 2.6 have a wrong encoding of device numbers
etc for the I/O interrupt type, so the inject VM_EVENT will have wrong
data. Let's fix this by using the interrupt parameters and not the
interrupt type number.
2. We only log in kvm_s390_inject_vm, but not when coming from
kvm_s390_reinject_io_int or from flic. Let's move the logging to the
common __inject_io function.
We also enhance the logging for delivery to match the data.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Constrained transactional execution is an addon of transactional execution.
Let's enable the assist also if only TX is enabled for the guest.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: enable host-protection-interruption only with ESOP
host-protection-interruption control was introduced with ESOP. So let's
enable it only if we have ESOP and add an explanatory comment why
we can live without it.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's enable interlock-and-broadcast suppression only if the facility is
actually available.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's enable interpretation of PFMFI only if the facility is
actually available. Emulation code still works in case the guest is
offered EDAT-1.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's only enable conditional-external-interruption if the facility is
actually available.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's enable intervention bypass only if the facility is acutally
available.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's detect if we have the intervention bypass facility installed.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
If guest-storage-limit-suppression is not available, we would for now
have a valid guest address space with size 0. So let's simply set the
origin to 0 and the limit to hamax.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: provide CMMA attributes only if available
Let's not provide the device attribute for cmma enabling and clearing
if the hardware doesn't support it.
This also helps getting rid of the undocumented return value "-EINVAL"
in case CMMA is not available when trying to enable it.
Also properly document the meaning of -EINVAL for CMMA clearing.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: guestdbg: signal missing hardware support
Without guest-PER enhancement, we can't provide any debugging support.
Therefore act like kernel support is missing.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's detect that facility, so we can correctly handle its abscence.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Without that facility, we may only use scaol. So fallback
to DMA allocation in that case, so we won't overwrite random memory
via the SIE.
Also disallow ESCA, so we don't have to handle that allocation case.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Let's correctly detect that facility, so we can correctly handle its
abscence later on.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: interface to query and configure cpu subfunctions
We have certain instructions that indicate available subfunctions via
a query subfunction (crypto functions and ptff), or via a test bit
function (plo).
By exposing these "subfunction blocks" to user space, we allow user space
to
1) query available subfunctions and make sure subfunctions won't get lost
during migration - e.g. properly indicate them via a CPU model
2) change the subfunctions to be reported to the guest (even adding
unavailable ones)
This mechanism works just like the way we indicate the stfl(e) list to
user space.
This way, user space could even emulate some subfunctions in QEMU in the
future. If this is ever applicable, we have to make sure later on, that
unsupported subfunctions result in an intercept to QEMU.
Please note that support to indicate them to the guest is still missing
and requires hardware support. Usually, the IBC takes already care of these
subfunctions for migration safety. QEMU should make sure to always set
these bits properly according to the machine generation to be emulated.
Available subfunctions are only valid in combination with STFLE bits
retrieved via KVM_S390_VM_CPU_MACHINE and enabled via
KVM_S390_VM_CPU_PROCESSOR. If the applicable bits are available, the
indicated subfunctions are guaranteed to be correct.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
KVM: s390: gaccess: function for preparing translation exceptions
Let's provide a function trans_exc() that can be used for handling
preparation of translation exceptions on a central basis. We will use
that function to replace existing code in gaccess.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
ESOP guarantees that during a protection exception, bit 61 of real location
168-175 will only be set to 1 if it was because of ALCP or DATP. If the
exception is due to LAP or KCP, the bit will always be set to 0.
The old SOP definition allowed bit 61 to be unpredictable in case of LAP
or KCP in some conditions. So ESOP replaces this unpredictability by
a guarantee.
Therefore, we can directly forward ESOP if it is available on our machine.
We don't have to do anything when ESOP is disabled - the guest will simply
expect unpredictable values. Our guest access functions are already
handling ESOP properly.
Please note that future functionality in KVM will require knowledge about
ESOP being enabled for a guest or not.
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
projects / mirror_ubuntu-hirsute-kernel.git / log