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The userspace exception injection API and code path are entirely
unprepared for exceptions that might cause a VM-exit from L2 to L1, so
the best course of action may be to simply disallow this for now.
1. The API provides no mechanism for userspace to specify the new DR6
bits for a #DB exception or the new CR2 value for a #PF
exception. Presumably, userspace is expected to modify these registers
directly with KVM_SET_SREGS before the next KVM_RUN ioctl. However, in
the event that L1 intercepts the exception, these registers should not
be changed. Instead, the new values should be provided in the
exit_qualification field of vmcs12 (Intel SDM vol 3, section 27.1).
2. In the case of a userspace-injected #DB, inject_pending_event()
clears DR7.GD before calling vmx_queue_exception(). However, in the
event that L1 intercepts the exception, this is too early, because
DR7.GD should not be modified by a #DB that causes a VM-exit directly
(Intel SDM vol 3, section 27.1).
3. If the injected exception is a #PF, nested_vmx_check_exception()
doesn't properly check whether or not L1 is interested in the
associated error code (using the #PF error code mask and match fields
from vmcs12). It may either return 0 when it should call
nested_vmx_vmexit() or vice versa.
4. nested_vmx_check_exception() assumes that it is dealing with a
hardware-generated exception intercept from L2, with some of the
relevant details (the VM-exit interruption-information and the exit
qualification) live in vmcs02. For userspace-injected exceptions, this
is not the case.
5. prepare_vmcs12() assumes that when its exit_intr_info argument
specifies valid information with a valid error code that it can VMREAD
the VM-exit interruption error code from vmcs02. For
userspace-injected exceptions, this is not the case.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
If we already entered/are about to enter SMM, don't allow switching to
INIT/SIPI_RECEIVED, otherwise the next call to kvm_apic_accept_events()
will report a warning.
Same applies if we are already in MP state INIT_RECEIVED and SMM is
requested to be turned on. Refuse to set the VCPU events in this case.
Fixes: cd7764fe9f73 ("KVM: x86: latch INITs while in system management mode")
Cc: stable@vger.kernel.org # 4.2+
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Its value has never changed; we might as well make it part of the ABI instead
of using the return value of KVM_CHECK_EXTENSION(KVM_CAP_COALESCED_MMIO).
Because PPC does not always make MMIO available, the code has to be made
dependent on CONFIG_KVM_MMIO rather than KVM_COALESCED_MMIO_PAGE_OFFSET.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Remove code from architecture files that can be moved to virt/kvm, since there
is already common code for coalesced MMIO.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[Removed a pointless 'break' after 'return'.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
In order to simplify adding exit reasons in the future,
the array of exit reason names is now also sorted by
exit reason code.
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Now use bit 6 of EPTP to optionally enable A/D bits for EPTP. Another
thing to change is that, when EPT accessed and dirty bits are not in use,
VMX treats accesses to guest paging structures as data reads. When they
are in use (bit 6 of EPTP is set), they are treated as writes and the
corresponding EPT dirty bit is set. The MMU didn't know this detail,
so this patch adds it.
We also have to fix up the exit qualification. It may be wrong because
KVM sets bit 6 but the guest might not.
L1 emulates EPT A/D bits using write permissions, so in principle it may
be possible for EPT A/D bits to be used by L1 even though not available
in hardware. The problem is that guest page-table walks will be treated
as reads rather than writes, so they would not cause an EPT violation.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Fixed typo in walk_addr_generic() comment and changed bit clear +
conditional-set pattern in handle_ept_violation() to conditional-clear]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This prepares the MMU paging code for EPT accessed and dirty bits,
which can be enabled optionally at runtime. Code that updates the
accessed and dirty bits will need a pointer to the struct kvm_mmu.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
handle_ept_violation is checking for "guest-linear-address invalid" +
"not a paging-structure walk". However, _all_ EPT violations without
a valid guest linear address are paging structure walks, because those
EPT violations happen when loading the guest PDPTEs.
Therefore, the check can never be true, and even if it were, KVM doesn't
care about the guest linear address; it only uses the guest *physical*
address VMCS field. So, remove the check altogether.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Large pages at the PDPE level can be emulated by the MMU, so the bit
can be set unconditionally in the EPT capabilities MSR. The same is
true of 2MB EPT pages, though all Intel processors with EPT in practice
support those.
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Legacy device assignment has been deprecated since 4.2 (released
1.5 years ago). VFIO is better and everyone should have switched to it.
If they haven't, this should convince them. :)
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Virtual NMIs are only missing in Prescott and Yonah chips. Both are obsolete
for virtualization usage---Yonah is 32-bit only even---so drop vNMI emulation.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
MCG_CAP[63:9] bits are reserved on AMD. However, on an AMD guest, this
MSR returns 0x100010a. More specifically, bit 24 is set, which is simply
wrong. That bit is MCG_SER_P and is present only on Intel. Thus, clean
up the reserved bits in order not to confuse guests.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's combine it in a single function vmx_switch_vmcs().
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
According to the Intel SDM, volume 3, section 28.3.2: Creating and
Using Cached Translation Information, "No linear mappings are used
while EPT is in use." INVEPT will invalidate both the guest-physical
mappings and the combined mappings in the TLBs and paging-structure
caches, so an INVVPID is superfluous.
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Add basic support for the MIPS Virtualization Module (generally known as
MIPS VZ) in KVM. We primarily support the ImgTec P5600, P6600, I6400,
and Cavium Octeon III cores so far. Support is included for the
following VZ / guest hardware features:
- MIPS32 and MIPS64, r5 (VZ requires r5 or later) and r6
- TLBs with GuestID (IMG cores) or Root ASID Dealias (Octeon III)
- Shared physical root/guest TLB (IMG cores)
- FPU / MSA
- Cop0 timer (up to 1GHz for now due to soft timer limit)
- Segmentation control (EVA)
- Hardware page table walker (HTW) both for root and guest TLB
Also included is a proper implementation of the TLBR instruction for the
trap & emulate MIPS KVM implementation.
Preliminary MIPS architecture changes are applied directly with Ralf's
ack.
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Merge tag 'kvm_mips_4.12_1' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/kvm-mips
From: James Hogan <james.hogan@imgtec.com>
KVM: MIPS: VZ support, Octeon III, and TLBR
Add basic support for the MIPS Virtualization Module (generally known as
MIPS VZ) in KVM. We primarily support the ImgTec P5600, P6600, I6400,
and Cavium Octeon III cores so far. Support is included for the
following VZ / guest hardware features:
- MIPS32 and MIPS64, r5 (VZ requires r5 or later) and r6
- TLBs with GuestID (IMG cores) or Root ASID Dealias (Octeon III)
- Shared physical root/guest TLB (IMG cores)
- FPU / MSA
- Cop0 timer (up to 1GHz for now due to soft timer limit)
- Segmentation control (EVA)
- Hardware page table walker (HTW) both for root and guest TLB
Also included is a proper implementation of the TLBR instruction for the
trap & emulate MIPS KVM implementation.
Preliminary MIPS architecture changes are applied directly with Ralf's
ack.
Properly implement emulation of the TLBR instruction for Trap & Emulate.
This instruction reads the TLB entry pointed at by the CP0_Index
register into the other TLB registers, which may have the side effect of
changing the current ASID. Therefore abstract the CP0_EntryHi and ASID
changing code into a common function in the process.
A comment indicated that Linux doesn't use TLBR, which is true during
normal use, however dumping of the TLB does use it (for example with the
relatively recent 'x' magic sysrq key), as does a wired TLB entries test
case in my KVM tests.
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
Octeon III has VZ ASE support, so allow KVM to be enabled on Octeon
CPUs as it should now be functional.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <david.daney@cavium.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Octeon III implements a read-only guest CP0_PRid register, so add cases
to the KVM register access API for Octeon to ensure the correct value is
read and writes are ignored.
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: David Daney <david.daney@cavium.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Octeon III doesn't implement the optional GuestCtl0.CG bit to allow
guest mode to execute virtual address based CACHE instructions, so
implement emulation of a few important ones specifically for Octeon III
in response to a GPSI exception.
Currently the main reason to perform these operations is for icache
synchronisation, so they are implemented as a simple icache flush with
local_flush_icache_range().
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: David Daney <david.daney@cavium.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Set up hardware virtualisation on Octeon III cores, configuring guest
interrupt routing and carving out half of the root TLB for guest use,
restoring it back again afterwards.
We need to be careful to inhibit TLB shutdown machine check exceptions
while invalidating guest TLB entries, since TLB invalidation is not
available so guest entries must be invalidated by setting them to unique
unmapped addresses, which could conflict with mappings set by the guest
or root if recently repartitioned.
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: David Daney <david.daney@cavium.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Octeon CPUs don't report the correct dcache line size in CP0_Config1.DL,
so encode the correct value for the guest CP0_Config1.DL based on
cpu_dcache_line_size().
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: David Daney <david.daney@cavium.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
When TLB entries are invalidated in the presence of a virtually tagged
icache, such as that found on Octeon CPUs, flush the icache so that we
don't get a reserved instruction exception even though the TLB mapping
is removed.
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: David Daney <david.daney@cavium.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cache management is implemented separately for Cavium Octeon CPUs, so
r4k_blast_[id]cache aren't available. Instead for Octeon perform a local
icache flush using local_flush_icache_range(), and for other platforms
which don't use c-r4k.c use __flush_cache_all() / flush_icache_all().
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: David Daney <david.daney@cavium.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Add accessors for some VZ related Cavium Octeon III specific COP0
registers, along with field definitions. These will mostly be used by
KVM to set up interrupt routing and partition the TLB between root and
guest.
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: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Create a trace event for guest mode changes, and enable VZ's
GuestCtl0.MC bit after the trace event is enabled to trap all guest mode
changes.
The MC bit causes Guest Hardware Field Change (GHFC) exceptions whenever
a guest mode change occurs (such as an exception entry or return from
exception), so we need to handle this exception now. The MC bit is only
enabled when restoring register state, so enabling the trace event won't
take immediate effect.
Tracing guest mode changes can be particularly handy when trying to work
out what a guest OS gets up to before something goes wrong, especially
if the problem occurs as a result of some previous guest userland
exception which would otherwise be invisible in the trace.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Transfer timer state to the VZ guest context (CP0_GTOffset & guest
CP0_Count) when entering guest mode, enabling direct guest access to it,
and transfer back to soft timer when saving guest register state.
This usually allows guest code to directly read CP0_Count (via MFC0 and
RDHWR) and read/write CP0_Compare, without trapping to the hypervisor
for it to emulate the guest timer. Writing to CP0_Count or CP0_Cause.DC
is much less common and still triggers a hypervisor GPSI exception, in
which case the timer state is transferred back to an hrtimer before
emulating the write.
We are careful to prevent small amounts of drift from building up due to
undeterministic time intervals between reading of the ktime and reading
of CP0_Count. Some drift is expected however, since the system
clocksource may use a different timer to the local CP0_Count timer used
by VZ. This is permitted to prevent guest CP0_Count from appearing to go
backwards.
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
Add emulation of Memory Accessibility Attribute Registers (MAARs) when
necessary. We can't actually do anything with whatever the guest
provides, but it may not be possible to clear Guest.Config5.MRP so we
have to emulate at least a pair of MAARs.
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: Jonathan Corbet <corbet@lwn.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-doc@vger.kernel.org
When restoring guest state after another VCPU has run, be sure to clear
CP0_LLAddr.LLB in order to break any interrupted atomic critical
section. Without this SMP guest atomics don't work when LLB is present
as one guest can complete the atomic section started by another guest.
MIPS VZ guest read of CP0_LLAddr causes Guest Privileged Sensitive
Instruction (GPSI) exception due to the address being root physical.
Handle this by reporting only the LLB bit, which contains the bit for
whether a ll/sc atomic is in progress without any reason for failure.
Similarly on P5600 a guest write to CP0_LLAddr also causes a GPSI
exception. Handle this also by clearing the guest LLB bit from root
mode.
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
Add support for VZ guest CP0_PWBase, CP0_PWField, CP0_PWSize, and
CP0_PWCtl registers for controlling the guest hardware page table walker
(HTW) present on P5600 and P6600 cores. These guest registers need
initialising on R6, context switching, and exposing via the KVM ioctl
API when they are present.
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: Jonathan Corbet <corbet@lwn.net>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Add support for VZ guest CP0_SegCtl0, CP0_SegCtl1, and CP0_SegCtl2
registers, as found on P5600 and P6600 cores. These guest registers need
initialising, context switching, and exposing via the KVM ioctl API when
they are present.
They also require the GVA -> GPA translation code for handling a GVA
root exception to be updated to interpret the segmentation registers and
decode the faulting instruction enough to detect EVA memory access
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: Jonathan Corbet <corbet@lwn.net>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Add support for VZ guest CP0_ContextConfig and CP0_XContextConfig
(MIPS64 only) registers, as found on P5600 and P6600 cores. These guest
registers need initialising, context switching, and exposing via the KVM
ioctl API when they are present.
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: Jonathan Corbet <corbet@lwn.net>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Add support for VZ guest CP0_BadInstr and CP0_BadInstrP registers, as
found on most VZ capable cores. These guest registers need context
switching, and exposing via the KVM ioctl API when they are present.
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: Jonathan Corbet <corbet@lwn.net>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Add support for the MIPS Virtualization (VZ) ASE to the MIPS KVM build
system. For now KVM can only be configured for T&E or VZ and not both,
but the design of the user facing APIs support the possibility of having
both available, so this could change in future.
Note that support for various optional guest features (some of which
can't be turned off) are implemented in immediately following commits,
so although it should now be possible to build VZ support, it may not
work yet on your hardware.
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
Add the main support for the MIPS Virtualization ASE (A.K.A. VZ) to MIPS
KVM. The bulk of this work is in vz.c, with various new state and
definitions elsewhere.
Enough is implemented to be able to run on a minimal VZ core. Further
patches will fill out support for guest features which are optional or
can be disabled.
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: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-doc@vger.kernel.org
The general guest exit handler needs a few tweaks for VZ compared to
trap & emulate, which for now are made directly depending on
CONFIG_KVM_MIPS_VZ:
- There is no need to re-enable the hardware page table walker (HTW), as
it can be left enabled during guest mode operation with VZ.
- There is no need to perform a privilege check, as any guest privilege
violations should have already been detected by the hardware and
triggered the appropriate guest 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: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Ifdef out the trap & emulate CACHE instruction emulation functions for
VZ. We will provide separate CACHE instruction emulation in vz.c, and we
need to avoid linker errors due to the use of T&E specific MMU helpers.
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
Update emulation of guest writes to CP0_Compare for VZ. There are two
main differences compared to trap & emulate:
- Writing to CP0_Compare in the VZ hardware guest context acks any
pending timer, clearing CP0_Cause.TI. If we don't want an ack to take
place we must carefully restore the TI bit if it was previously set.
- Even with guest timer access disabled in CP0_GuestCtl0.GT, if the
guest CP0_Count reaches the guest CP0_Compare the timer interrupt
will assert. To prevent this we must set CP0_GTOffset to move the
guest CP0_Count out of the way of the new guest CP0_Compare, either
before or after depending on whether it is a forwards or backwards
change.
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
Add functions for MIPS VZ TLB management to tlb.c.
kvm_vz_host_tlb_inv() will be used for invalidating root TLB entries
after GPA page tables have been modified due to a KVM page fault. It
arranges for a root GPA mapping to be flushed from the TLB, using the
gpa_mm ASID or the current GuestID to do the probe.
kvm_vz_local_flush_roottlb_all_guests() and
kvm_vz_local_flush_guesttlb_all() flush all TLB entries in the
corresponding TLB for guest mappings (GPA->RPA for root TLB with
GuestID, and all entries for guest TLB). They will be used when starting
a new GuestID cycle, when VZ hardware is enabled/disabled, and also when
switching to a guest when the guest TLB contents may be stale or belong
to a different VM.
kvm_vz_guest_tlb_lookup() converts a guest virtual address to a guest
physical address using the guest TLB. This will be used to decode guest
virtual addresses which are sometimes provided by VZ hardware in
CP0_BadVAddr for certain exceptions when the guest physical address is
unavailable.
kvm_vz_save_guesttlb() and kvm_vz_load_guesttlb() will be used to
preserve wired guest VTLB entries while a guest isn't running.
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
Update MIPS KVM entry code to support VZ:
- We need to set GuestCtl0.GM while in guest mode.
- For cores supporting GuestID, we need to set the root GuestID to
match the main GuestID while in guest mode so that the root TLB
refill handler writes the correct GuestID into the TLB.
- For cores without GuestID where the root ASID dealiases RVA/GPA
mappings, we need to load that ASID from the gpa_mm rather than the
per-VCPU guest_kernel_mm or guest_user_mm, since the root TLB maps
guest physical addresses. We also need to restore the normal process
ASID on exit.
- The normal linux process pgd needs restoring on exit, as we can't
leave the GPA mappings active for kernel code.
- GuestCtl0 needs saving on exit for the GExcCode field, as it may be
clobbered if a preemption occurs.
We also need to move the TLB refill handler to the XTLB vector at offset
0x80 on 64-bit VZ kernels, as hardware will use Root.Status.KX to
determine whether a TLB refill or XTLB Refill exception is to be taken
on a root TLB miss from guest mode, and KX needs to be set for kernel
code to be able to access the 64-bit segments.
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
Abstract the MIPS KVM guest CP0 register access macros into inline
functions which are generated by macros. This allows them to be
generated differently for VZ, where they will usually need to access the
hardware guest CP0 context rather than the saved values in RAM.
Accessors for each individual register are generated using these macros:
- __BUILD_KVM_*_SW() for registers which are not present in the VZ
hardware guest context, so kvm_{read,write}_c0_guest_##name() will
access the saved value in RAM regardless of whether VZ is enabled.
- __BUILD_KVM_*_HW() for registers which are present in the VZ hardware
guest context, so kvm_{read,write}_c0_guest_##name() will access the
hardware register when VZ is enabled.
These build the underlying accessors using further macros:
- __BUILD_KVM_*_SAVED() builds e.g. kvm_{read,write}_sw_gc0_##name()
functions for accessing the saved versions of the registers in RAM.
This is used for implementing the common
kvm_{read,write}_c0_guest_##name() accessors with T&E where registers
are always stored in RAM, but are also available with VZ HW registers
to allow them to be accessed while saved.
- __BUILD_KVM_*_VZ() builds e.g. kvm_{read,write}_vz_gc0_##name()
functions for accessing the VZ hardware guest context registers
directly. This is used for implementing the common
kvm_{read,write}_c0_guest_##name() accessors with VZ.
- __BUILD_KVM_*_WRAP() builds wrappers with different names, which
allows the common kvm_{read,write}_c0_guest_##name() functions to be
implemented using the VZ accessors while still having the SAVED
accessors available too.
- __BUILD_KVM_SAVE_VZ() builds functions for saving and restoring VZ
hardware guest context register state to RAM, improving conciseness
of VZ context saving and restoring.
Similar macros exist for generating modifiers (set, clear, change),
either with a normal unlocked read/modify/write, or using atomic LL/SC
sequences.
These changes change the types of 32-bit registers to u32 instead of
unsigned long, which requires some changes to printk() functions in MIPS
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
Add a callback for MIPS KVM implementations to handle the VZ guest
exit exception. Currently the trap & emulate implementation contains a
stub which reports an internal error, but the callback will be used
properly by the VZ 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: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Add an implementation callback for the kvm_arch_hardware_enable() and
kvm_arch_hardware_disable() architecture functions, with simple stubs
for trap & emulate. This is in preparation for VZ which will make use of
them.
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
Add an implementation callback for checking presence of KVM extensions.
This allows implementation specific extensions to be provided without
ifdefs in 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
Currently the software emulated timer is initialised to a frequency of
100MHz by kvm_mips_init_count(), but this isn't suitable for VZ where
the frequency of the guest timer matches that of the host.
Add a count_hz argument so the caller can specify the default frequency,
and move the call from kvm_arch_vcpu_create() to the implementation
specific vcpu_setup() callback, so that VZ can specify a different
frequency.
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
Add new KVM_CAP_MIPS_VZ and KVM_CAP_MIPS_TE capabilities, and in order
to allow MIPS KVM to support VZ without confusing old users (which
expect the trap & emulate implementation), define and start checking
KVM_CREATE_VM type codes.
The codes available are:
- KVM_VM_MIPS_TE = 0
This is the current value expected from the user, and will create a
VM using trap & emulate in user mode, confined to the user mode
address space. This may in future become unavailable if the kernel is
only configured to support VZ, in which case the EINVAL error will be
returned and KVM_CAP_MIPS_TE won't be available even though
KVM_CAP_MIPS_VZ is.
- KVM_VM_MIPS_VZ = 1
This can be provided when the KVM_CAP_MIPS_VZ capability is available
to create a VM using VZ, with a fully virtualized guest virtual
address space. If VZ support is unavailable in the kernel, the EINVAL
error will be returned (although old kernels without the
KVM_CAP_MIPS_VZ capability may well succeed and create a trap &
emulate VM).
This is designed to allow the desired implementation (T&E vs VZ) to be
potentially chosen at runtime rather than being fixed in the kernel
configuration.
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: Jonathan Corbet <corbet@lwn.net>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Extend MIPS KVM stats counters and kvm_transition trace event codes to
cover hypervisor exceptions, which have their own GExcCode field in
CP0_GuestCtl0 with up to 32 hypervisor exception cause codes.
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
Update the implementation of kvm_lose_fpu() for VZ, where there is no
need to enable the FPU/MSA in the root context if the FPU/MSA state is
loaded but disabled in the guest context.
The trap & emulate implementation needs to disable FPU/MSA in the root
context when the guest disables them in order to catch the COP1 unusable
or MSA disabled exception when they're used and pass it on to the guest.
For VZ however as long as the context is loaded and enabled in the root
context, the guest can enable and disable it in the guest context
without the hypervisor having to do much, and will take guest exceptions
without hypervisor intervention if used without being enabled in the
guest context.
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
Implement additional MMIO emulation for MIPS64, including 64-bit
loads/stores, and 32-bit unsigned loads. These are only exposed on
64-bit VZ hosts.
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
Refactor MIPS KVM MMIO load/store emulation to reduce code duplication.
Each duplicate differed slightly anyway, and it will simplify adding
64-bit MMIO support for VZ.
kvm_mips_emulate_store() and kvm_mips_emulate_load() can now return
EMULATE_DO_MMIO (as possibly originally intended). We therefore stop
calling either of these from kvm_mips_emulate_inst(), which is now only
used by kvm_trap_emul_handle_cop_unusable() which is picky about return
values.
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
