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>
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>
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>
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>
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: 50c8308538 ("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>
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.
[1] http://www.ibm.com/developerworks/linux/linux390/qclib.html
[2] https://www.ibm.com/support/knowledgecenter/SSB27U_6.3.0/com.ibm.zvm.v630.hcpb4/hcpb4sth.htm
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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.
[1] http://www.ibm.com/developerworks/linux/linux390/qclib.html
[2] https://www.ibm.com/support/knowledgecenter/SSB27U_6.3.0/com.ibm.zvm.v630.hcpb4/hcpb4sth.htm
When trying to emulate an unrecognised load or store instruction, print
the encoding to aid debug.
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>
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>
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>
Add a few trace events for entering and coming out of guest mode, as well
as re-entering it from a guest exit exception.
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
The function kvm_mips_sync_icache() is unused, so lets remove it.
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>
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>
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>
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>
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>
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>
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>
Let's correctly detect that facility.
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>
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>
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>
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>
