Before trying to do nested_get_page() in nested_vmx_merge_msr_bitmap(),
we have already checked that the MSR bitmap address is valid (4k aligned
and within physical limits). SDM doesn't specify what happens if the
there is no memory mapped at the valid address, but Intel CPUs treat the
situation as if the bitmap was configured to trap all MSRs.
KVM already does that by returning false and a correct handling doesn't
need the guest-trigerrable warning that was reported by syzkaller:
(The warning was originally there to catch some possible bugs in nVMX.)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 7832 at arch/x86/kvm/vmx.c:9709
nested_vmx_merge_msr_bitmap arch/x86/kvm/vmx.c:9709 [inline]
WARNING: CPU: 0 PID: 7832 at arch/x86/kvm/vmx.c:9709
nested_get_vmcs12_pages+0xfb6/0x15c0 arch/x86/kvm/vmx.c:9640
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 7832 Comm: syz-executor1 Not tainted 4.10.0+ #229
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:15 [inline]
dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
panic+0x1fb/0x412 kernel/panic.c:179
__warn+0x1c4/0x1e0 kernel/panic.c:540
warn_slowpath_null+0x2c/0x40 kernel/panic.c:583
nested_vmx_merge_msr_bitmap arch/x86/kvm/vmx.c:9709 [inline]
nested_get_vmcs12_pages+0xfb6/0x15c0 arch/x86/kvm/vmx.c:9640
enter_vmx_non_root_mode arch/x86/kvm/vmx.c:10471 [inline]
nested_vmx_run+0x6186/0xaab0 arch/x86/kvm/vmx.c:10561
handle_vmlaunch+0x1a/0x20 arch/x86/kvm/vmx.c:7312
vmx_handle_exit+0xfc0/0x3f00 arch/x86/kvm/vmx.c:8526
vcpu_enter_guest arch/x86/kvm/x86.c:6982 [inline]
vcpu_run arch/x86/kvm/x86.c:7044 [inline]
kvm_arch_vcpu_ioctl_run+0x1418/0x4840 arch/x86/kvm/x86.c:7205
kvm_vcpu_ioctl+0x673/0x1120 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2570
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
[Jim Mattson explained the bare metal behavior: "I believe this behavior
would be documented in the chipset data sheet rather than the SDM,
since the chipset returns all 1s for an unclaimed read."]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
VMCLEAR should silently ignore a failure to clear the launch state of
the VMCS referenced by the operand.
Signed-off-by: Jim Mattson <jmattson@google.com>
[Changed "kvm_write_guest(vcpu->kvm" to "kvm_vcpu_write_guest(vcpu".]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
PPC:
* correct assumption about ASDR on POWER9
* fix MMIO emulation on POWER9
x86:
* add a simple test for ioperm
* cleanup TSS
(going through KVM tree as the whole undertaking was caused by VMX's
use of TSS)
* fix nVMX interrupt delivery
* fix some performance counters in the guest
And two cleanup patches.
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Merge tag 'kvm-4.11-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull more KVM updates from Radim Krčmář:
"Second batch of KVM changes for the 4.11 merge window:
PPC:
- correct assumption about ASDR on POWER9
- fix MMIO emulation on POWER9
x86:
- add a simple test for ioperm
- cleanup TSS (going through KVM tree as the whole undertaking was
caused by VMX's use of TSS)
- fix nVMX interrupt delivery
- fix some performance counters in the guest
... and two cleanup patches"
* tag 'kvm-4.11-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: nVMX: Fix pending events injection
x86/kvm/vmx: remove unused variable in segment_base()
selftests/x86: Add a basic selftest for ioperm
x86/asm: Tidy up TSS limit code
kvm: convert kvm.users_count from atomic_t to refcount_t
KVM: x86: never specify a sample period for virtualized in_tx_cp counters
KVM: PPC: Book3S HV: Don't use ASDR for real-mode HPT faults on POWER9
KVM: PPC: Book3S HV: Fix software walk of guest process page tables
But first update usage sites with the new header dependency.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Introduce a trivial, mostly empty <linux/sched/cputime.h> header
to prepare for the moving of cputime functionality out of sched.h.
Update all code that relies on these facilities.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We don't actually need the full rculist.h header in sched.h anymore,
we will be able to include the smaller rcupdate.h header instead.
But first update code that relied on the implicit header inclusion.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
L2 fails to boot on a non-APICv box dues to 'commit 0ad3bed6c5
("kvm: nVMX: move nested events check to kvm_vcpu_running")'
KVM internal error. Suberror: 3
extra data[0]: 800000ef
extra data[1]: 1
RAX=0000000000000000 RBX=ffffffff81f36140 RCX=0000000000000000 RDX=0000000000000000
RSI=0000000000000000 RDI=0000000000000000 RBP=ffff88007c92fe90 RSP=ffff88007c92fe90
R8 =ffff88007fccdca0 R9 =0000000000000000 R10=00000000fffedb3d R11=0000000000000000
R12=0000000000000003 R13=0000000000000000 R14=0000000000000000 R15=ffff88007c92c000
RIP=ffffffff810645e6 RFL=00000246 [---Z-P-] CPL=0 II=0 A20=1 SMM=0 HLT=0
ES =0000 0000000000000000 ffffffff 00c00000
CS =0010 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA]
SS =0000 0000000000000000 ffffffff 00c00000
DS =0000 0000000000000000 ffffffff 00c00000
FS =0000 0000000000000000 ffffffff 00c00000
GS =0000 ffff88007fcc0000 ffffffff 00c00000
LDT=0000 0000000000000000 ffffffff 00c00000
TR =0040 ffff88007fcd4200 00002087 00008b00 DPL=0 TSS64-busy
GDT= ffff88007fcc9000 0000007f
IDT= ffffffffff578000 00000fff
CR0=80050033 CR2=00000000ffffffff CR3=0000000001e0a000 CR4=003406e0
DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000
DR6=00000000fffe0ff0 DR7=0000000000000400
EFER=0000000000000d01
We should try to reinject previous events if any before trying to inject
new event if pending. If vmexit is triggered by L2 guest and L0 interested
in, we should reinject IDT-vectoring info to L2 through vmcs02 if any,
otherwise, we can consider new IRQs/NMIs which can be injected and call
nested events callback to switch from L2 to L1 if needed and inject the
proper vmexit events. However, 'commit 0ad3bed6c5 ("kvm: nVMX: move
nested events check to kvm_vcpu_running")' results in the handle events
order reversely on non-APICv box. This patch fixes it by bailing out for
pending events and not consider new events in this scenario.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Fixes: 0ad3bed6c5 ("kvm: nVMX: move nested events check to kvm_vcpu_running")
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The pointer 'struct desc_struct *d' is unused since commit 8c2e41f7ae
("x86/kvm/vmx: Simplify segment_base()") so let's remove it.
Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
pmc_reprogram_counter() always sets a sample period based on the value of
pmc->counter. However, hsw_hw_config() rejects sample periods less than
2^31 - 1. So for example, if a KVM guest does
struct perf_event_attr attr;
memset(&attr, 0, sizeof(attr));
attr.type = PERF_TYPE_RAW;
attr.size = sizeof(attr);
attr.config = 0x2005101c4; // conditional branches retired IN_TXCP
attr.sample_period = 0;
int fd = syscall(__NR_perf_event_open, &attr, 0, -1, -1, 0);
ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
the guest kernel counts some conditional branch events, then updates the
virtual PMU register with a nonzero count. The host reaches
pmc_reprogram_counter() with nonzero pmc->counter, triggers EOPNOTSUPP
in hsw_hw_config(), prints "kvm_pmu: event creation failed" in
pmc_reprogram_counter(), and silently (from the guest's point of view) stops
counting events.
We fix event counting by forcing attr.sample_period to always be zero for
in_tx_cp counters. Sampling doesn't work, but it already didn't work and
can't be fixed without major changes to the approach in hsw_hw_config().
Signed-off-by: Robert O'Callahan <robert@ocallahan.org>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Fix typos and add the following to the scripts/spelling.txt:
an user||a user
an userspace||a userspace
I also added "userspace" to the list since it is a common word in Linux.
I found some instances for "an userfaultfd", but I did not add it to the
list. I felt it is endless to find words that start with "user" such as
"userland" etc., so must draw a line somewhere.
Link: http://lkml.kernel.org/r/1481573103-11329-4-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
200 commits and noteworthy changes for most architectures.
* ARM:
- GICv3 save/restore
- cache flushing fixes
- working MSI injection for GICv3 ITS
- physical timer emulation
* MIPS:
- various improvements under the hood
- support for SMP guests
- a large rewrite of MMU emulation. KVM MIPS can now use MMU notifiers
to support copy-on-write, KSM, idle page tracking, swapping, ballooning
and everything else. KVM_CAP_READONLY_MEM is also supported, so that
writes to some memory regions can be treated as MMIO. The new MMU also
paves the way for hardware virtualization support.
* PPC:
- support for POWER9 using the radix-tree MMU for host and guest
- resizable hashed page table
- bugfixes.
* s390: expose more features to the guest
- more SIMD extensions
- instruction execution protection
- ESOP2
* x86:
- improved hashing in the MMU
- faster PageLRU tracking for Intel CPUs without EPT A/D bits
- some refactoring of nested VMX entry/exit code, preparing for live
migration support of nested hypervisors
- expose yet another AVX512 CPUID bit
- host-to-guest PTP support
- refactoring of interrupt injection, with some optimizations thrown in
and some duct tape removed.
- remove lazy FPU handling
- optimizations of user-mode exits
- optimizations of vcpu_is_preempted() for KVM guests
* generic:
- alternative signaling mechanism that doesn't pound on tsk->sighand->siglock
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"4.11 is going to be a relatively large release for KVM, with a little
over 200 commits and noteworthy changes for most architectures.
ARM:
- GICv3 save/restore
- cache flushing fixes
- working MSI injection for GICv3 ITS
- physical timer emulation
MIPS:
- various improvements under the hood
- support for SMP guests
- a large rewrite of MMU emulation. KVM MIPS can now use MMU
notifiers to support copy-on-write, KSM, idle page tracking,
swapping, ballooning and everything else. KVM_CAP_READONLY_MEM is
also supported, so that writes to some memory regions can be
treated as MMIO. The new MMU also paves the way for hardware
virtualization support.
PPC:
- support for POWER9 using the radix-tree MMU for host and guest
- resizable hashed page table
- bugfixes.
s390:
- expose more features to the guest
- more SIMD extensions
- instruction execution protection
- ESOP2
x86:
- improved hashing in the MMU
- faster PageLRU tracking for Intel CPUs without EPT A/D bits
- some refactoring of nested VMX entry/exit code, preparing for live
migration support of nested hypervisors
- expose yet another AVX512 CPUID bit
- host-to-guest PTP support
- refactoring of interrupt injection, with some optimizations thrown
in and some duct tape removed.
- remove lazy FPU handling
- optimizations of user-mode exits
- optimizations of vcpu_is_preempted() for KVM guests
generic:
- alternative signaling mechanism that doesn't pound on
tsk->sighand->siglock"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (195 commits)
x86/kvm: Provide optimized version of vcpu_is_preempted() for x86-64
x86/paravirt: Change vcp_is_preempted() arg type to long
KVM: VMX: use correct vmcs_read/write for guest segment selector/base
x86/kvm/vmx: Defer TR reload after VM exit
x86/asm/64: Drop __cacheline_aligned from struct x86_hw_tss
x86/kvm/vmx: Simplify segment_base()
x86/kvm/vmx: Get rid of segment_base() on 64-bit kernels
x86/kvm/vmx: Don't fetch the TSS base from the GDT
x86/asm: Define the kernel TSS limit in a macro
kvm: fix page struct leak in handle_vmon
KVM: PPC: Book3S HV: Disable HPT resizing on POWER9 for now
KVM: Return an error code only as a constant in kvm_get_dirty_log()
KVM: Return an error code only as a constant in kvm_get_dirty_log_protect()
KVM: Return directly after a failed copy_from_user() in kvm_vm_compat_ioctl()
KVM: x86: remove code for lazy FPU handling
KVM: race-free exit from KVM_RUN without POSIX signals
KVM: PPC: Book3S HV: Turn "KVM guest htab" message into a debug message
KVM: PPC: Book3S PR: Ratelimit copy data failure error messages
KVM: Support vCPU-based gfn->hva cache
KVM: use separate generations for each address space
...
Guest segment selector is 16 bit field and guest segment base is natural
width field. Fix two incorrect invocations accordingly.
Without this patch, build fails when aggressive inlining is used with ICC.
Cc: stable@vger.kernel.org
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Intel's VMX is daft and resets the hidden TSS limit register to 0x67
on VMX reload, and the 0x67 is not configurable. KVM currently
reloads TR using the LTR instruction on every exit, but this is quite
slow because LTR is serializing.
The 0x67 limit is entirely harmless unless ioperm() is in use, so
defer the reload until a task using ioperm() is actually running.
Here's some poorly done benchmarking using kvm-unit-tests:
Before:
cpuid 1313
vmcall 1195
mov_from_cr8 11
mov_to_cr8 17
inl_from_pmtimer 6770
inl_from_qemu 6856
inl_from_kernel 2435
outl_to_kernel 1402
After:
cpuid 1291
vmcall 1181
mov_from_cr8 11
mov_to_cr8 16
inl_from_pmtimer 6457
inl_from_qemu 6209
inl_from_kernel 2339
outl_to_kernel 1391
Signed-off-by: Andy Lutomirski <luto@kernel.org>
[Force-reload TR in invalidate_tss_limit. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use actual pointer types for pointers (instead of unsigned long) and
replace hardcoded constants with the appropriate self-documenting
macros.
The function is still a bit messy, but this seems a lot better than
before to me.
This is mostly borrowed from a patch by Thomas Garnier.
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It was a bit buggy (it didn't list all segment types that needed
64-bit fixups), but the bug was irrelevant because it wasn't called
in any interesting context on 64-bit kernels and was only used for
data segents on 32-bit kernels.
To avoid confusion, make it explicitly 32-bit only.
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The current CPU's TSS base is a foregone conclusion, so there's no need
to parse it out of the segment tables. This should save a couple cycles
(as STR is surely microcoded and poorly optimized) but, more importantly,
it's a cleanup and it means that segment_base() will never be called on
64-bit kernels.
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Jim Mattson <jmattson@google.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull scheduler updates from Ingo Molnar:
"The main changes in this (fairly busy) cycle were:
- There was a class of scheduler bugs related to forgetting to update
the rq-clock timestamp which can cause weird and hard to debug
problems, so there's a new debug facility for this: which uncovered
a whole lot of bugs which convinced us that we want to keep the
debug facility.
(Peter Zijlstra, Matt Fleming)
- Various cputime related updates: eliminate cputime and use u64
nanoseconds directly, simplify and improve the arch interfaces,
implement delayed accounting more widely, etc. - (Frederic
Weisbecker)
- Move code around for better structure plus cleanups (Ingo Molnar)
- Move IO schedule accounting deeper into the scheduler plus related
changes to improve the situation (Tejun Heo)
- ... plus a round of sched/rt and sched/deadline fixes, plus other
fixes, updats and cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (85 commits)
sched/core: Remove unlikely() annotation from sched_move_task()
sched/autogroup: Rename auto_group.[ch] to autogroup.[ch]
sched/topology: Split out scheduler topology code from core.c into topology.c
sched/core: Remove unnecessary #include headers
sched/rq_clock: Consolidate the ordering of the rq_clock methods
delayacct: Include <uapi/linux/taskstats.h>
sched/core: Clean up comments
sched/rt: Show the 'sched_rr_timeslice' SCHED_RR timeslice tuning knob in milliseconds
sched/clock: Add dummy clear_sched_clock_stable() stub function
sched/cputime: Remove generic asm headers
sched/cputime: Remove unused nsec_to_cputime()
s390, sched/cputime: Remove unused cputime definitions
powerpc, sched/cputime: Remove unused cputime definitions
s390, sched/cputime: Make arch_cpu_idle_time() to return nsecs
ia64, sched/cputime: Remove unused cputime definitions
ia64: Convert vtime to use nsec units directly
ia64, sched/cputime: Move the nsecs based cputime headers to the last arch using it
sched/cputime: Remove jiffies based cputime
sched/cputime, vtime: Return nsecs instead of cputime_t to account
sched/cputime: Complete nsec conversion of tick based accounting
...
handle_vmon gets a reference on VMXON region page,
but does not release it. Release the reference.
Found by syzkaller; based on a patch by Dmitry.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The FPU is always active now when running KVM.
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The purpose of the KVM_SET_SIGNAL_MASK API is to let userspace "kick"
a VCPU out of KVM_RUN through a POSIX signal. A signal is attached
to a dummy signal handler; by blocking the signal outside KVM_RUN and
unblocking it inside, this possible race is closed:
VCPU thread service thread
--------------------------------------------------------------
check flag
set flag
raise signal
(signal handler does nothing)
KVM_RUN
However, one issue with KVM_SET_SIGNAL_MASK is that it has to take
tsk->sighand->siglock on every KVM_RUN. This lock is often on a
remote NUMA node, because it is on the node of a thread's creator.
Taking this lock can be very expensive if there are many userspace
exits (as is the case for SMP Windows VMs without Hyper-V reference
time counter).
As an alternative, we can put the flag directly in kvm_run so that
KVM can see it:
VCPU thread service thread
--------------------------------------------------------------
raise signal
signal handler
set run->immediate_exit
KVM_RUN
check run->immediate_exit
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Provide versions of struct gfn_to_hva_cache functions that
take vcpu as a parameter instead of struct kvm. The existing functions
are not needed anymore, so delete them. This allows dirty pages to
be logged in the vcpu dirty ring, instead of the global dirty ring,
for ring-based dirty memory tracking.
Signed-off-by: Lei Cao <lei.cao@stratus.com>
Message-Id: <CY1PR08MB19929BD2AC47A291FD680E83F04F0@CY1PR08MB1992.namprd08.prod.outlook.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The hashtable and guarding spinlock are global data structures,
we can inititalize them statically.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170124212116.4568-1-david@redhat.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Nested_vmx_run is split into two parts: the part that handles the
VMLAUNCH/VMRESUME instruction, and the part that modifies the vcpu state
to transition from VMX root mode to VMX non-root mode. The latter will
be used when restoring the checkpointed state of a vCPU that was in VMX
operation when a snapshot was taken.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The checks performed on the contents of the vmcs12 are extracted from
nested_vmx_run so that they can be used to validate a vmcs12 that has
been restored from a checkpoint.
Signed-off-by: Jim Mattson <jmattson@google.com>
[Change prepare_vmcs02 and nested_vmx_load_cr3's last argument to u32,
to match check_vmentry_postreqs. Update comments for singlestep
handling. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Perform the checks on vmcs12 state early, but defer the gpa->hpa lookups
until after prepare_vmcs02. Later, when we restore the checkpointed
state of a vCPU in guest mode, we will not be able to do the gpa->hpa
lookups when the restore is done.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Handle_vmptrld is split into two parts: the part that handles the
VMPTRLD instruction, and the part that establishes the current VMCS
pointer. The latter will be used when restoring the checkpointed state
of a vCPU that had a valid VMCS pointer when a snapshot was taken.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Handle_vmon is split into two parts: the part that handles the VMXON
instruction, and the part that modifies the vcpu state to transition
from legacy mode to VMX operation. The latter will be used when
restoring the checkpointed state of a vCPU that was in VMX operation
when a snapshot was taken.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Split prepare_vmcs12 into two parts: the part that stores the current L2
guest state and the part that sets up the exit information fields. The
former will be used when checkpointing the vCPU's VMX state.
Modify prepare_vmcs02 so that it can construct a vmcs02 midway through
L2 execution, using the checkpointed L2 guest state saved into the
cached vmcs12 above.
Signed-off-by: Jim Mattson <jmattson@google.com>
[Rebasing: add from_vmentry argument to prepare_vmcs02 instead of using
vmx->nested.nested_run_pending, because it is no longer 1 at the
point prepare_vmcs02 is called. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since bf9f6ac8d7 ("KVM: Update Posted-Interrupts Descriptor when vCPU
is blocked", 2015-09-18) the posted interrupt descriptor is checked
unconditionally for PIR.ON. Therefore we don't need KVM_REQ_EVENT to
trigger the scan and, if NMIs or SMIs are not involved, we can avoid
the complicated event injection path.
Calling kvm_vcpu_kick if PIR.ON=1 is also useless, though it has been
there since APICv was introduced.
However, without the KVM_REQ_EVENT safety net KVM needs to be much
more careful about races between vmx_deliver_posted_interrupt and
vcpu_enter_guest. First, the IPI for posted interrupts may be issued
between setting vcpu->mode = IN_GUEST_MODE and disabling interrupts.
If that happens, kvm_trigger_posted_interrupt returns true, but
smp_kvm_posted_intr_ipi doesn't do anything about it. The guest is
entered with PIR.ON, but the posted interrupt IPI has not been sent
and the interrupt is only delivered to the guest on the next vmentry
(if any). To fix this, disable interrupts before setting vcpu->mode.
This ensures that the IPI is delayed until the guest enters non-root mode;
it is then trapped by the processor causing the interrupt to be injected.
Second, the IPI may be issued between kvm_x86_ops->sync_pir_to_irr(vcpu)
and vcpu->mode = IN_GUEST_MODE. In this case, kvm_vcpu_kick is called
but it (correctly) doesn't do anything because it sees vcpu->mode ==
OUTSIDE_GUEST_MODE. Again, the guest is entered with PIR.ON but no
posted interrupt IPI is pending; this time, the fix for this is to move
the RVI update after IN_GUEST_MODE.
Both issues were mostly masked by the liberal usage of KVM_REQ_EVENT,
though the second could actually happen with VT-d posted interrupts.
In both race scenarios KVM_REQ_EVENT would cancel guest entry, resulting
in another vmentry which would inject the interrupt.
This saves about 300 cycles on the self_ipi_* tests of vmexit.flat.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Calls to apic_find_highest_irr are scanning IRR twice, once
in vmx_sync_pir_from_irr and once in apic_search_irr. Change
sync_pir_from_irr to get the new maximum IRR from kvm_apic_update_irr;
now that it does the computation, it can also do the RVI write.
In order to avoid complications in svm.c, make the callback optional.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
vcpu_run calls kvm_vcpu_running, not kvm_arch_vcpu_runnable,
and the former does not call check_nested_events.
Once KVM_REQ_EVENT is removed from the APICv interrupt injection
path, however, this would leave no place to trigger a vmexit
from L2 to L1, causing a missed interrupt delivery while in guest
mode. This is caught by the "ack interrupt on exit" test in
vmx.flat.
[This does not change the calls to check_nested_events in
inject_pending_event. That is material for a separate cleanup.]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pending interrupts might be in the PI descriptor when the
LAPIC is restored from an external state; we do not want
them to be injected.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
As in the SVM patch, the guest physical address is passed by
VMX to x86_emulate_instruction already, so mark the GPA as available
in vcpu->arch.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The newly added hypercall doesn't work on x86-32:
arch/x86/kvm/x86.c: In function 'kvm_pv_clock_pairing':
arch/x86/kvm/x86.c:6163:6: error: implicit declaration of function 'kvm_get_walltime_and_clockread';did you mean 'kvm_get_time_scale'? [-Werror=implicit-function-declaration]
This adds an #ifdef around it, matching the one around the related
functions that are also only implemented on 64-bit systems.
Fixes: 55dd00a73a ("KVM: x86: add KVM_HC_CLOCK_PAIRING hypercall")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Fix rebase breakage from commit 55dd00a73a ("KVM: x86: add
KVM_HC_CLOCK_PAIRING hypercall", 2017-01-24), courtesy of the
"I could have sworn I had pushed the right branch" department.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add a hypercall to retrieve the host realtime clock and the TSC value
used to calculate that clock read.
Used to implement clock synchronization between host and guest.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
vmx_complete_nested_posted_interrupt() can't fail, let's turn it into
a void function.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
kmap() can't fail, therefore it will always return a valid pointer. Let's
just get rid of the unnecessary checks.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Saving unsupported state prevents migration when the new host does not
support a XSAVE feature of the original host, even if the feature is not
exposed to the guest.
We've masked host features with guest-visible features before, with
4344ee981e ("KVM: x86: only copy XSAVE state for the supported
features") and dropped it when implementing XSAVES. Do it again.
Fixes: df1daba7d1 ("KVM: x86: support XSAVES usage in the host")
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Now that most cputime readers use the transition API which return the
task cputime in old style cputime_t, we can safely store the cputime in
nsecs. This will eventually make cputime statistics less opaque and more
granular. Back and forth convertions between cputime_t and nsecs in order
to deal with cputime_t random granularity won't be needed anymore.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1485832191-26889-8-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Before fast page fault restores an access track PTE back to a regular PTE,
it now also verifies that the restored PTE would grant the necessary
permissions for the faulting access to succeed. If not, it falls back
to the slow page fault path.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Redo the page table walk in fast_page_fault when retrying so that we are
working on the latest PTE even if the hierarchy changes.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reword the comment to hopefully make it more clear.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Instead of the caller including the SPTE_SPECIAL_MASK in the masks being
supplied to kvm_mmu_set_mmio_spte_mask() and kvm_mmu_set_mask_ptes(),
those functions now themselves include the SPTE_SPECIAL_MASK.
Note that bit 63 is now reset in the default MMIO mask.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
