97867 Commits

Author SHA1 Message Date
Alexander Graf
616dff8602 KVM: PPC: Book3S PR: Handle Facility interrupt and FSCR
POWER8 introduced a new interrupt type called "Facility unavailable interrupt"
which contains its status message in a new register called FSCR.

Handle these exits and try to emulate instructions for unhandled facilities.
Follow-on patches enable KVM to expose specific facilities into the guest.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:22 +02:00
Alexander Graf
a5948fa092 KVM: PPC: Book3S PR: Emulate TIR register
In parallel to the Processor ID Register (PIR) threaded POWER8 also adds a
Thread ID Register (TIR). Since PR KVM doesn't emulate more than one thread
per core, we can just always expose 0 here.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:22 +02:00
Alexander Graf
f8f6eb0d18 KVM: PPC: Book3S PR: Ignore PMU SPRs
When we expose a POWER8 CPU into the guest, it will start accessing PMU SPRs
that we don't emulate. Just ignore accesses to them.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:22 +02:00
Alexander Graf
f24bc1ed45 KVM: PPC: Book3S: Move little endian conflict to HV KVM
With the previous patches applied, we can now successfully use PR KVM on
little endian hosts which means we can now allow users to select it.

However, HV KVM still needs some work, so let's keep the kconfig conflict
on that one.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:21 +02:00
Alexander Graf
cd087eefe6 KVM: PPC: Book3S PR: Do dcbz32 patching with big endian instructions
When the host CPU we're running on doesn't support dcbz32 itself, but the
guest wants to have dcbz only clear 32 bytes of data, we loop through every
executable mapped page to search for dcbz instructions and patch them with
a special privileged instruction that we emulate as dcbz32.

The only guests that want to see dcbz act as 32byte are book3s_32 guests, so
we don't have to worry about little endian instruction ordering. So let's
just always search for big endian dcbz instructions, also when we're on a
little endian host.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:21 +02:00
Alexander Graf
5deb8e7ad8 KVM: PPC: Make shared struct aka magic page guest endian
The shared (magic) page is a data structure that contains often used
supervisor privileged SPRs accessible via memory to the user to reduce
the number of exits we have to take to read/write them.

When we actually share this structure with the guest we have to maintain
it in guest endianness, because some of the patch tricks only work with
native endian load/store operations.

Since we only share the structure with either host or guest in little
endian on book3s_64 pr mode, we don't have to worry about booke or book3s hv.

For booke, the shared struct stays big endian. For book3s_64 hv we maintain
the struct in host native endian, since it never gets shared with the guest.

For book3s_64 pr we introduce a variable that tells us which endianness the
shared struct is in and route every access to it through helper inline
functions that evaluate this variable.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:21 +02:00
Alexander Graf
2743103f91 KVM: PPC: PR: Fill pvinfo hcall instructions in big endian
We expose a blob of hypercall instructions to user space that it gives to
the guest via device tree again. That blob should contain a stream of
instructions necessary to do a hypercall in big endian, as it just gets
passed into the guest and old guests use them straight away.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:20 +02:00
Alexander Graf
b59d9d26be KVM: PPC: Book3S PR: PAPR: Access RTAS in big endian
When the guest does an RTAS hypercall it keeps all RTAS variables inside a
big endian data structure.

To make sure we don't have to bother about endianness inside the actual RTAS
handlers, let's just convert the whole structure to host endian before we
call our RTAS handlers and back to big endian when we return to the guest.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:20 +02:00
Alexander Graf
1692aa3faa KVM: PPC: Book3S PR: PAPR: Access HTAB in big endian
The HTAB on PPC is always in big endian. When we access it via hypercalls
on behalf of the guest and we're running on a little endian host, we need
to make sure we swap the bits accordingly.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:20 +02:00
Alexander Graf
94810ba4ed KVM: PPC: Book3S PR: Default to big endian guest
The default MSR when user space does not define anything should be identical
on little and big endian hosts, so remove MSR_LE from it.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:20 +02:00
Alexander Graf
14a7d41dad KVM: PPC: Book3S_64 PR: Access shadow slb in big endian
The "shadow SLB" in the PACA is shared with the hypervisor, so it has to
be big endian. We access the shadow SLB during world switch, so let's make
sure we access it in big endian even when we're on a little endian host.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:19 +02:00
Alexander Graf
4e509af9f8 KVM: PPC: Book3S_64 PR: Access HTAB in big endian
The HTAB is always big endian. We access the guest's HTAB using
copy_from/to_user, but don't yet take care of the fact that we might
be running on an LE host.

Wrap all accesses to the guest HTAB with big endian accessors.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:19 +02:00
Alexander Graf
860540bc50 KVM: PPC: Book3S_32: PR: Access HTAB in big endian
The HTAB is always big endian. We access the guest's HTAB using
copy_from/to_user, but don't yet take care of the fact that we might
be running on an LE host.

Wrap all accesses to the guest HTAB with big endian accessors.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:19 +02:00
Alexander Graf
740f834eb2 KVM: PPC: Book3S: PR: Fix C/R bit setting
Commit 9308ab8e2d made C/R HTAB updates go byte-wise into the target HTAB.
However, it didn't update the guest's copy of the HTAB, but instead the
host local copy of it.

Write to the guest's HTAB instead.

Signed-off-by: Alexander Graf <agraf@suse.de>
CC: Paul Mackerras <paulus@samba.org>
Acked-by: Paul Mackerras <paulus@samba.org>
2014-05-30 14:26:18 +02:00
Aneesh Kumar K.V
7562c4fded KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on
With debug option "sleep inside atomic section checking" enabled we get
the below WARN_ON during a PR KVM boot. This is because upstream now
have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the
warning by adding preempt_disable/enable around floating point and altivec
enable.

WARNING: at arch/powerpc/kernel/process.c:156
Modules linked in: kvm_pr kvm
CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G        W     3.15.0-rc1+ #4
task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000
NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00
REGS: c0000000ec59f140 TRAP: 0700   Tainted: G        W      (3.15.0-rc1+)
MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI>  CR: 42000024  XER: 20000000
CFAR: c000000000015c24 SOFTE: 1
GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000
GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000
GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00
GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1
GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38
GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013
GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000
NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90
LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr]
Call Trace:
[c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable)
[c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr]
[c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm]
[c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr]
[c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm]
[c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr]
[c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr]
[c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr]
[c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm]
[c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm]
[c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm]
[c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790
[c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0
[c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:18 +02:00
Aneesh Kumar K.V
e5ee5422f8 KVM: PPC: BOOK3S: PR: Enable Little Endian PR guest
This patch make sure we inherit the LE bit correctly in different case
so that we can run Little Endian distro in PR mode

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:18 +02:00
Alexander Graf
8f20a3ab27 KVM: PPC: E500: Add dcbtls emulation
The dcbtls instruction is able to lock data inside the L1 cache.

We don't want to give the guest actual access to hardware cache locks,
as that could influence other VMs on the same system. But we can tell
the guest that its locking attempt failed.

By implementing the instruction we at least don't give the guest a
program exception which it definitely does not expect.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:17 +02:00
Alexander Graf
07fec1c2e7 KVM: PPC: E500: Ignore L1CSR1_ICFI,ICLFR
The L1 instruction cache control register contains bits that indicate
that we're still handling a request. Mask those out when we set the SPR
so that a read doesn't assume we're still doing something.

Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-30 14:26:17 +02:00
James Hogan
ee1a725f44 MIPS: KVM: Remove redundant semicolon
Remove extra semicolon in kvm_arch_vcpu_dump_regs().

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:59 +02:00
James Hogan
c6c0a6637f MIPS: KVM: Remove redundant NULL checks before kfree()
The kfree() function already NULL checks the parameter so remove the
redundant NULL checks before kfree() calls in arch/mips/kvm/.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:46 +02:00
James Hogan
6e95bfd267 MIPS: KVM: Quieten kvm_info() logging
The logging from MIPS KVM is fairly noisy with kvm_info() in places
where it shouldn't be, such as on VM creation and migration to a
different CPU. Replace these kvm_info() calls with kvm_debug().

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:37 +02:00
James Hogan
d5c704d525 MIPS: KVM: Remove ifdef DEBUG around kvm_debug
kvm_debug() uses pr_debug() which is already compiled out in the absence
of a DEBUG define, so remove the unnecessary ifdef DEBUG lines around
kvm_debug() calls which are littered around arch/mips/kvm/.

As well as generally cleaning up, this prevents future bit-rot due to
DEBUG not being commonly used.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:28 +02:00
James Hogan
3d65483371 MIPS: KVM: Fix kvm_debug bit-rottage
Fix build errors when DEBUG is defined in arch/mips/kvm/.
 - The DEBUG code in kvm_mips_handle_tlbmod() was missing some variables.
 - The DEBUG code in kvm_mips_host_tlb_write() was conditional on an
   undefined "debug" variable.
 - The DEBUG code in kvm_mips_host_tlb_inv() accessed asid_map directly
   rather than using kvm_mips_get_user_asid(). Also fixed brace
   placement.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:20 +02:00
James Hogan
2dca3725cb MIPS: KVM: Whitespace fixes in kvm_mips_callbacks
Fix whitespace in struct kvm_mips_callbacks function pointers.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:05:07 +02:00
James Hogan
0fae34f464 MIPS: KVM: Make kvm_mips_comparecount_{func,wakeup} static
The kvm_mips_comparecount_func() and kvm_mips_comparecount_wakeup()
functions are only used within arch/mips/kvm/kvm_mips.c, so make them
static.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:04:59 +02:00
James Hogan
f74a8e224e MIPS: KVM: Add count frequency KVM register
Expose the KVM guest CP0_Count frequency to userland via a new
KVM_REG_MIPS_COUNT_HZ register accessible with the KVM_{GET,SET}_ONE_REG
ioctls.

When the frequency is altered the bias is adjusted such that the guest
CP0_Count doesn't jump discontinuously or lose any timer interrupts.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:02:54 +02:00
James Hogan
f82393426a MIPS: KVM: Add master disable count interface
Expose two new virtual registers to userland via the
KVM_{GET,SET}_ONE_REG ioctls.

KVM_REG_MIPS_COUNT_CTL is for timer configuration fields and just
contains a master disable count bit. This can be used by userland to
freeze the timer in order to read a consistent state from the timer
count value and timer interrupt pending bit. This cannot be done with
the CP0_Cause.DC bit because the timer interrupt pending bit (TI) is
also in CP0_Cause so it would be impossible to stop the timer without
also risking a race with an hrtimer interrupt and having to explicitly
check whether an interrupt should have occurred.

When the timer is re-enabled it resumes without losing time, i.e. the
CP0_Count value jumps to what it would have been had the timer not been
disabled, which would also be impossible to do from userland with
CP0_Cause.DC. The timer interrupt also cannot be lost, i.e. if a timer
interrupt would have occurred had the timer not been disabled it is
queued when the timer is re-enabled.

This works by storing the nanosecond monotonic time when the master
disable is set, and using it for various operations instead of the
current monotonic time (e.g. when recalculating the bias when the
CP0_Count is set), until the master disable is cleared again, i.e. the
timer state is read/written as it would have been at that time. This
state is exposed to userland via the read-only KVM_REG_MIPS_COUNT_RESUME
virtual register so that userland can determine the exact time the
master disable took effect.

This should allow userland to atomically save the state of the timer,
and later restore it.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:02:45 +02:00
James Hogan
eda3d33c68 MIPS: KVM: Override guest kernel timer frequency directly
The KVM_HOST_FREQ Kconfig symbol was used by KVM guest kernels to
override the timer frequency calculation to a value based on the host
frequency. Now that the KVM timer emulation is implemented independent
of the host timer frequency and defaults to 100MHz, adjust the working
of CONFIG_KVM_HOST_FREQ to match.

The Kconfig symbol now specifies the guest timer frequency directly, and
has been renamed accordingly to KVM_GUEST_TIMER_FREQ. It now defaults to
100MHz too and the help text is updated to make it clear that a zero
value will allow the normal timer frequency calculation to take place
(based on the emulated RTC).

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:02:23 +02:00
James Hogan
e30492bbe9 MIPS: KVM: Rewrite count/compare timer emulation
Previously the emulation of the CPU timer was just enough to get a Linux
guest running but some shortcuts were taken:
 - The guest timer interrupt was hard coded to always happen every 10 ms
   rather than being timed to when CP0_Count would match CP0_Compare.
 - The guest's CP0_Count register was based on the host's CP0_Count
   register. This isn't very portable and fails on cores without a
   CP_Count register implemented such as Ingenic XBurst. It also meant
   that the guest's CP0_Cause.DC bit to disable the CP0_Count register
   took no effect.
 - The guest's CP0_Count register was emulated by just dividing the
   host's CP0_Count register by 4. This resulted in continuity problems
   when used as a clock source, since when the host CP0_Count overflows
   from 0x7fffffff to 0x80000000, the guest CP0_Count transitions
   discontinuously from 0x1fffffff to 0xe0000000.

Therefore rewrite & fix emulation of the guest timer based on the
monotonic kernel time (i.e. ktime_get()). Internally a 32-bit count_bias
value is added to the frequency scaled nanosecond monotonic time to get
the guest's CP0_Count. The frequency of the timer is initialised to
100MHz and cannot yet be changed, but a later patch will allow the
frequency to be configured via the KVM_{GET,SET}_ONE_REG ioctl
interface.

The timer can now be stopped via the CP0_Cause.DC bit (by the guest or
via the KVM_SET_ONE_REG ioctl interface), at which point the current
CP0_Count is stored and can be read directly. When it is restarted the
bias is recalculated such that the CP0_Count value is continuous.

Due to the nature of hrtimer interrupts any read of the guest's
CP0_Count register while it is running triggers a check for whether the
hrtimer has expired, so that the guest/userland cannot observe the
CP0_Count passing CP0_Compare without queuing a timer interrupt. This is
also taken advantage of when stopping the timer to ensure that a pending
timer interrupt is queued.

This replaces the implementation of:
 - Guest read of CP0_Count
 - Guest write of CP0_Count
 - Guest write of CP0_Compare
 - Guest write of CP0_Cause
 - Guest read of HWR 2 (CC) with RDHWR
 - Host read of CP0_Count via KVM_GET_ONE_REG ioctl interface
 - Host write of CP0_Count via KVM_SET_ONE_REG ioctl interface
 - Host write of CP0_Compare via KVM_SET_ONE_REG ioctl interface
 - Host write of CP0_Cause via KVM_SET_ONE_REG ioctl interface

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:01:48 +02:00
James Hogan
3a0ba77408 MIPS: KVM: Migrate hrtimer to follow VCPU
When a VCPU is scheduled in on a different CPU, refresh the hrtimer used
for emulating count/compare so that it gets migrated to the same CPU.

This should prevent a timer interrupt occurring on a different CPU to
where the guest it relates to is running, which would cause the guest
timer interrupt not to be delivered until after the next guest exit.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:01:33 +02:00
James Hogan
c73c99b0df MIPS: KVM: Fix timer race modifying guest CP0_Cause
The hrtimer callback for guest timer timeouts sets the guest's
CP0_Cause.TI bit to indicate to the guest that a timer interrupt is
pending, however there is no mutual exclusion implemented to prevent
this occurring while the guest's CP0_Cause register is being
read-modify-written elsewhere.

When this occurs the setting of the CP0_Cause.TI bit is undone and the
guest misses the timer interrupt and doesn't reprogram the CP0_Compare
register for the next timeout. Currently another timer interrupt will be
triggered again in another 10ms anyway due to the way timers are
emulated, but after the MIPS timer emulation is fixed this would result
in Linux guest time standing still and the guest scheduler not being
invoked until the guest CP0_Count has looped around again, which at
100MHz takes just under 43 seconds.

Currently this is the only asynchronous modification of guest registers,
therefore it is fixed by adjusting the implementations of the
kvm_set_c0_guest_cause(), kvm_clear_c0_guest_cause(), and
kvm_change_c0_guest_cause() macros which are used for modifying the
guest CP0_Cause register to use ll/sc to ensure atomic modification.
This should work in both UP and SMP cases without requiring interrupts
to be disabled.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:01:25 +02:00
James Hogan
044f0f03ec MIPS: KVM: Deliver guest interrupts after local_irq_disable()
When about to run the guest, deliver guest interrupts after disabling
host interrupts. This should prevent an hrtimer interrupt from being
handled after delivering guest interrupts, and therefore not delivering
the guest timer interrupt until after the next guest exit.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:01:10 +02:00
James Hogan
16fd5c1de4 MIPS: KVM: Add CP0_HWREna KVM register access
Implement KVM_{GET,SET}_ONE_REG ioctl based access to the guest CP0
HWREna register. This is so that userland can save and restore its
value so that RDHWR instructions don't have to be emulated by the guest.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:01:03 +02:00
James Hogan
7767b7d2f7 MIPS: KVM: Add CP0_UserLocal KVM register access
Implement KVM_{GET,SET}_ONE_REG ioctl based access to the guest CP0
UserLocal register. This is so that userland can save and restore its
value.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:57 +02:00
James Hogan
f8be02daca MIPS: KVM: Add CP0_Count/Compare KVM register access
Implement KVM_{GET,SET}_ONE_REG ioctl based access to the guest CP0
Count and Compare registers. These registers are special in that writing
to them has side effects (adjusting the time until the next timer
interrupt) and reading of Count depends on the time. Therefore add a
couple of callbacks so that different implementations (trap & emulate or
VZ) can implement them differently depending on what the hardware
provides.

The trap & emulate versions mostly duplicate what happens when a T&E
guest reads or writes these registers, so it inherits the same
limitations which can be fixed in later patches.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:44 +02:00
James Hogan
48a3c4e4cd MIPS: KVM: Move KVM_{GET,SET}_ONE_REG definitions into kvm_host.h
Move the KVM_{GET,SET}_ONE_REG MIPS register id definitions out of
kvm_mips.c to kvm_host.h so that they can be shared between multiple
source files. This allows register access to be indirected depending on
the underlying implementation (trap & emulate or VZ).

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:35 +02:00
James Hogan
fb6df0cdf0 MIPS: KVM: Add CP0_EPC KVM register access
Contrary to the comment, the guest CP0_EPC register cannot be set via
kvm_regs, since it is distinct from the guest PC. Add the EPC register
to the KVM_{GET,SET}_ONE_REG ioctl interface.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:26 +02:00
James Hogan
b5dfc6c106 MIPS: KVM: Use tlb_write_random
When MIPS KVM needs to write a TLB entry for the guest it reads the
CP0_Random register, uses it to generate the CP_Index, and writes the
TLB entry using the TLBWI instruction (tlb_write_indexed()).

However there's an instruction for that, TLBWR (tlb_write_random()) so
use that instead.

This happens to also fix an issue with Ingenic XBurst cores where the
same TLB entry is replaced each time preventing forward progress on
stores due to alternating between TLB load misses for the instruction
fetch and TLB store misses.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 13:00:02 +02:00
James Hogan
facaaec1a7 MIPS: KVM: Use local_flush_icache_range to fix RI on XBurst
MIPS KVM uses mips32_SyncICache to synchronise the icache with the
dcache after dynamically modifying guest instructions or writing guest
exception vector. However this uses rdhwr to get the SYNCI step, which
causes a reserved instruction exception on Ingenic XBurst cores.

It would seem to make more sense to use local_flush_icache_range()
instead which does the same thing but is more portable.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 12:59:54 +02:00
James Hogan
90f91356c7 MIPS: Export local_flush_icache_range for KVM
Export the local_flush_icache_range function pointer for GPL modules so
that it can be used by KVM for syncing the icache after binary
translation of trapping instructions.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 12:59:28 +02:00
James Hogan
7006e2dfda MIPS: KVM: Allocate at least 16KB for exception handlers
Each MIPS KVM guest has its own copy of the KVM exception vector. This
contains the TLB refill exception handler at offset 0x000, the general
exception handler at offset 0x180, and interrupt exception handlers at
offset 0x200 in case Cause_IV=1. A common handler is copied to offset
0x2000 and offset 0x3000 is used for temporarily storing k1 during entry
from guest.

However the amount of memory allocated for this purpose is calculated as
0x200 rounded up to the next page boundary, which is insufficient if 4KB
pages are in use. This can lead to the common handler at offset 0x2000
being overwritten and infinitely recursive exceptions on the next exit
from the guest.

Increase the minimum size from 0x200 to 0x4000 to cover the full use of
the page.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-05-30 12:59:13 +02:00
Paolo Bonzini
146b2cfe0c 1. Several minor fixes and cleanups for KVM:
2. Fix flag check for gdb support
 3. Remove unnecessary vcpu start
 4. Remove code duplication for sigp interrupts
 5. Better DAT handling for the TPROT instruction
 6. Correct addressing exception for standby memory
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Merge tag 'kvm-s390-20140530' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-next

1. Several minor fixes and cleanups for KVM:
2. Fix flag check for gdb support
3. Remove unnecessary vcpu start
4. Remove code duplication for sigp interrupts
5. Better DAT handling for the TPROT instruction
6. Correct addressing exception for standby memory
2014-05-30 12:57:10 +02:00
Markos Chandras
beef8e020d MIPS: uasm: Add u3u2u1 instruction builders
It will be used later on by the sllv and srlv instructions.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/6723/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-30 12:36:03 +02:00
Deng-Cheng Zhu
c410352699 MIPS: math-emu: Add IEEE754 exception statistics to debugfs
Sometimes it's useful to let the user, while doing performance research,
know what in the IEEE754 exceptions has caused many times of FP emulation
when running a specific application. This patch adds 5 more files to
/sys/kernel/debug/mips/fpuemustats/, whose filenames begin with "ieee754".
These stats are in addition to the existing cp1ops, cp1xops, errors, loads
and stores, which may not be useful in understanding the reasons of ieee754
exceptions.

[ralf@linux-mips.org: Fixed reject due to other changes to the kernel
FP assist software.]

Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven.Hill@imgtec.com
Cc: james.hogan@imgtec.com
Patchwork: http://patchwork.linux-mips.org/patch/7044/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-30 11:55:23 +02:00
Rafał Miłecki
96a8123e5f MIPS: BCM47XX: Slightly clean memory detection
Patch was tested on devices with 64 MiB and 256 MiB of RAM.
It documents every part nicely and drops this hacky part of code:
max = off | ((128 << 20) - 1);

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: https://patchwork.linux-mips.org/patch/6808/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-30 11:00:21 +02:00
Matthew Rosato
5a5e65361f KVM: s390: Intercept the tprot instruction
Based on original patch from Jeng-fang (Nick) Wang

When standby memory is specified for a guest Linux, but no virtual memory has
been allocated on the Qemu host backing that guest, the guest memory detection
process encounters a memory access exception which is not thrown from the KVM
handle_tprot() instruction-handler function. The access exception comes from
sie64a returning EFAULT, which then passes an addressing exception to the guest.
Unfortunately this does not the proper PSW fixup (nullifying vs.
suppressing) so the guest will get a fault for the wrong address.

Let's just intercept the tprot instruction all the time to do the right thing
and not go the page fault handler path for standby memory. tprot is only used
by Linux during startup so some exits should be ok.
Without this patch, standby memory cannot be used with KVM.

Signed-off-by: Nick Wang <jfwang@us.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-05-30 09:39:40 +02:00
David Hildenbrand
3192c63950 KVM: s390: a VCPU is already started when delivering interrupts
This patch removes the start of a VCPU when delivering a RESTART interrupt.
Interrupt delivery is called from kvm_arch_vcpu_ioctl_run. So the VCPU is
already considered started - no need to call kvm_s390_vcpu_start. This function
will early exit anyway.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-05-30 09:39:39 +02:00
David Hildenbrand
2de3bfc25a KVM: s390: check the given debug flags, not the set ones
This patch fixes a minor bug when updating the guest debug settings.
We should check the given debug flags, not the already set ones.
Doesn't do any harm but too many (for now unused) flags could be set internally
without error.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
2014-05-30 09:39:38 +02:00
Jens Freimann
22ff4a3366 KVM: s390: clean up interrupt injection in sigp code
We have all the logic to inject interrupts available in
kvm_s390_inject_vcpu(), so let's use it instead of
injecting irqs manually to the list in sigp code.

SIGP stop is special because we have to check the
action_flags before injecting the interrupt. As
the action_flags are not available in kvm_s390_inject_vcpu()
we leave the code for the stop order code untouched for now.

Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-05-30 09:39:37 +02:00
Thomas Huth
a0465f9ae4 KVM: s390: Enable DAT support for TPROT handler
The TPROT instruction can be used to check the accessability of storage
for any kind of logical addresses. So far, our handler only supported
real addresses. This patch now also enables support for addresses that
have to be translated via DAT first. And while we're at it, change the
code to use the common KVM function gfn_to_hva_prot() to check for the
validity and writability of the memory page.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-05-30 09:39:36 +02:00