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: NPaolo 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: 55dd00a7 ("KVM: x86: add KVM_HC_CLOCK_PAIRING hypercall")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Fix rebase breakage from commit 55dd00a7 ("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: NPaolo 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: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NPaolo 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: NJunaid Shahid <junaids@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

emulator_fix_hypercall() replaces hypercall with vmcall instruction,
but it does not handle GP exception properly when writes the new instruction.
It can return X86EMUL_PROPAGATE_FAULT without setting exception information.
This leads to incorrect emulation and triggers
WARN_ON(ctxt->exception.vector > 0x1f) in x86_emulate_insn()
as discovered by syzkaller fuzzer:

WARNING: CPU: 2 PID: 18646 at arch/x86/kvm/emulate.c:5558
Call Trace:
 warn_slowpath_null+0x2c/0x40 kernel/panic.c:582
 x86_emulate_insn+0x16a5/0x4090 arch/x86/kvm/emulate.c:5572
 x86_emulate_instruction+0x403/0x1cc0 arch/x86/kvm/x86.c:5618
 emulate_instruction arch/x86/include/asm/kvm_host.h:1127 [inline]
 handle_exception+0x594/0xfd0 arch/x86/kvm/vmx.c:5762
 vmx_handle_exit+0x2b7/0x38b0 arch/x86/kvm/vmx.c:8625
 vcpu_enter_guest arch/x86/kvm/x86.c:6888 [inline]
 vcpu_run arch/x86/kvm/x86.c:6947 [inline]

Set exception information when write in emulator_fix_hypercall() fails.
Signed-off-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: kvm@vger.kernel.org
Cc: syzkaller@googlegroups.com
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Reported by syzkaller:

    BUG: unable to handle kernel NULL pointer dereference at 00000000000001b0
    IP: _raw_spin_lock+0xc/0x30
    PGD 3e28eb067
    PUD 3f0ac6067
    PMD 0
    Oops: 0002 [#1] SMP
    CPU: 0 PID: 2431 Comm: test Tainted: G           OE   4.10.0-rc1+ #3
    Call Trace:
     ? kvm_ioapic_scan_entry+0x3e/0x110 [kvm]
     kvm_arch_vcpu_ioctl_run+0x10a8/0x15f0 [kvm]
     ? pick_next_task_fair+0xe1/0x4e0
     ? kvm_arch_vcpu_load+0xea/0x260 [kvm]
     kvm_vcpu_ioctl+0x33a/0x600 [kvm]
     ? hrtimer_try_to_cancel+0x29/0x130
     ? do_nanosleep+0x97/0xf0
     do_vfs_ioctl+0xa1/0x5d0
     ? __hrtimer_init+0x90/0x90
     ? do_nanosleep+0x5b/0xf0
     SyS_ioctl+0x79/0x90
     do_syscall_64+0x6e/0x180
     entry_SYSCALL64_slow_path+0x25/0x25
    RIP: _raw_spin_lock+0xc/0x30 RSP: ffffa43688973cc0

The syzkaller folks reported a NULL pointer dereference due to
ENABLE_CAP succeeding even without an irqchip.  The Hyper-V
synthetic interrupt controller is activated, resulting in a
wrong request to rescan the ioapic and a NULL pointer dereference.

    #include <sys/ioctl.h>
    #include <sys/mman.h>
    #include <sys/types.h>
    #include <linux/kvm.h>
    #include <pthread.h>
    #include <stddef.h>
    #include <stdint.h>
    #include <stdlib.h>
    #include <string.h>
    #include <unistd.h>

    #ifndef KVM_CAP_HYPERV_SYNIC
    #define KVM_CAP_HYPERV_SYNIC 123
    #endif

    void* thr(void* arg)
    {
	struct kvm_enable_cap cap;
	cap.flags = 0;
	cap.cap = KVM_CAP_HYPERV_SYNIC;
	ioctl((long)arg, KVM_ENABLE_CAP, &cap);
	return 0;
    }

    int main()
    {
	void *host_mem = mmap(0, 0x1000, PROT_READ|PROT_WRITE,
			MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
	int kvmfd = open("/dev/kvm", 0);
	int vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0);
	struct kvm_userspace_memory_region memreg;
	memreg.slot = 0;
	memreg.flags = 0;
	memreg.guest_phys_addr = 0;
	memreg.memory_size = 0x1000;
	memreg.userspace_addr = (unsigned long)host_mem;
	host_mem[0] = 0xf4;
	ioctl(vmfd, KVM_SET_USER_MEMORY_REGION, &memreg);
	int cpufd = ioctl(vmfd, KVM_CREATE_VCPU, 0);
	struct kvm_sregs sregs;
	ioctl(cpufd, KVM_GET_SREGS, &sregs);
	sregs.cr0 = 0;
	sregs.cr4 = 0;
	sregs.efer = 0;
	sregs.cs.selector = 0;
	sregs.cs.base = 0;
	ioctl(cpufd, KVM_SET_SREGS, &sregs);
	struct kvm_regs regs = { .rflags = 2 };
	ioctl(cpufd, KVM_SET_REGS, &regs);
	ioctl(vmfd, KVM_CREATE_IRQCHIP, 0);
	pthread_t th;
	pthread_create(&th, 0, thr, (void*)(long)cpufd);
	usleep(rand() % 10000);
	ioctl(cpufd, KVM_RUN, 0);
	pthread_join(th, 0);
	return 0;
    }

This patch fixes it by failing ENABLE_CAP if without an irqchip.
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Fixes: 5c919412 (kvm/x86: Hyper-V synthetic interrupt controller)
Cc: stable@vger.kernel.org # 4.5+
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

KVM's lapic emulation uses static_key_deferred (apic_{hw,sw}_disabled).
These are implemented with delayed_work structs which can still be
pending when the KVM module is unloaded. We've seen this cause kernel
panics when the kvm_intel module is quickly reloaded.

Use the new static_key_deferred_flush() API to flush pending updates on
module unload.
Signed-off-by: NDavid Matlack <dmatlack@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This statistic can be useful to estimate the cost of an IRQ injection
scenario, by comparing it with irq_injections.  For example the stat
shows that sti;hlt triggers more KVM_REQ_EVENT than sti;nop.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When a guest causes a NPF which requires emulation, KVM sometimes walks
the guest page tables to translate the GVA to a GPA. This is unnecessary
most of the time on AMD hardware since the hardware provides the GPA in
EXITINFO2.

The only exception cases involve string operations involving rep or
operations that use two memory locations. With rep, the GPA will only be
the value of the initial NPF and with dual memory locations we won't know
which memory address was translated into EXITINFO2.
Signed-off-by: NTom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This change implements lockless access tracking for Intel CPUs without EPT
A bits. This is achieved by marking the PTEs as not-present (but not
completely clearing them) when clear_flush_young() is called after marking
the pages as accessed. When an EPT Violation is generated as a result of
the VM accessing those pages, the PTEs are restored to their original values.
Signed-off-by: NJunaid Shahid <junaids@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Report the maximum number of mmu_page_hash collisions as a per-VM stat.
This will make it easy to identify problems with the mmu_page_hash in
the future.
Signed-off-by: NDavid Matlack <dmatlack@google.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

We don't treat kvm->arch.vpic specially anymore, so the setup can look
like ioapic.  This gets a bit more information out of return values.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

irqchip_in_kernel() tried to save a bit by reusing pic_irqchip(), but it
just complicated the code.
Add a separate state for the irqchip mode.
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
[Used Paolo's version of condition in irqchip_in_kernel().]
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Split irqchip cannot be created after creating the kernel irqchip, but
we forgot to restrict the other way.  This is an API change.
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>

When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.

Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Otherwise, mismatch between the smm bit in hflags and the MMU role
can cause a NULL pointer dereference.

Cc: stable@vger.kernel.org
Signed-off-by: NXiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

kvm_memslots() will be called by kvm_write_guest_offset_cached() so
take the srcu lock.
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

kvm_steal_time_set_preempted() isn't disabling the pagefaults before
calling __copy_to_user and the kernel debug notices.
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Introduce a new mutex to avoid an AB-BA deadlock between kvm->lock and
vcpu->mutex.  Protect accesses in kvm_hv_setup_tsc_page too, as suggested
by Roman.
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Reviewed-by: NRoman Kagan <rkagan@virtuozzo.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Loading CR3 as part of emulating vmentry is different from regular CR3 loads,
as implemented in kvm_set_cr3, in several ways.

* different rules are followed to check CR3 and it is desirable for the caller
to distinguish between the possible failures
* PDPTRs are not loaded if PAE paging and nested EPT are both enabled
* many MMU operations are not necessary

This patch introduces nested_vmx_load_cr3 suitable for CR3 loads as part of
nested vmentry and vmexit, and makes use of it on the nested vmentry path.
Signed-off-by: NLadi Prosek <lprosek@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

The trap flag stays set until software clears it.
Signed-off-by: NKyle Huey <khuey@kylehuey.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

kvm_skip_emulated_instruction calls both
kvm_x86_ops->skip_emulated_instruction and kvm_vcpu_check_singlestep,
skipping the emulated instruction and generating a trap if necessary.

Replacing skip_emulated_instruction calls with
kvm_skip_emulated_instruction is straightforward, except for:

- ICEBP, which is already inside a trap, so avoid triggering another trap.
- Instructions that can trigger exits to userspace, such as the IO insns,
  MOVs to CR8, and HALT. If kvm_skip_emulated_instruction does trigger a
  KVM_GUESTDBG_SINGLESTEP exit, and the handling code for
  IN/OUT/MOV CR8/HALT also triggers an exit to userspace, the latter will
  take precedence. The singlestep will be triggered again on the next
  instruction, which is the current behavior.
- Task switch instructions which would require additional handling (e.g.
  the task switch bit) and are instead left alone.
- Cases where VMLAUNCH/VMRESUME do not proceed to the next instruction,
  which do not trigger singlestep traps as mentioned previously.
Signed-off-by: NKyle Huey <khuey@kylehuey.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Update the I/O interception support to add the kvm_fast_pio_in function
to speed up the in instruction similar to the out instruction.
Signed-off-by: NTom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NBrijesh Singh <brijesh.singh@amd.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Change unimplemented msrs messages to use pr_debug.
If CONFIG_DYNAMIC_DEBUG is set, then these messages can be
enabled at run time or else -DDEBUG can be used at compile
time to enable them. These messages will still be printed if
ignore_msrs=1.
Signed-off-by: NBandan Das <bsd@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Support the vcpu_is_preempted() functionality under KVM. This will
enhance lock performance on overcommitted hosts (more runnable vCPUs
than physical CPUs in the system) as doing busy waits for preempted
vCPUs will hurt system performance far worse than early yielding.

Use struct kvm_steal_time::preempted to indicate that if a vCPU
is running or not.
Signed-off-by: NPan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: boqun.feng@gmail.com
Cc: borntraeger@de.ibm.com
Cc: bsingharora@gmail.com
Cc: dave@stgolabs.net
Cc: jgross@suse.com
Cc: kernellwp@gmail.com
Cc: konrad.wilk@oracle.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: mpe@ellerman.id.au
Cc: paulmck@linux.vnet.ibm.com
Cc: paulus@samba.org
Cc: rkrcmar@redhat.com
Cc: virtualization@lists.linux-foundation.org
Cc: will.deacon@arm.com
Cc: xen-devel-request@lists.xenproject.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1478077718-37424-9-git-send-email-xinhui.pan@linux.vnet.ibm.com
[ Typo fixes. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Reported by syzkaller:

    [ INFO: suspicious RCU usage. ]
    4.9.0-rc4+ #47 Not tainted
    -------------------------------
    ./include/linux/kvm_host.h:536 suspicious rcu_dereference_check() usage!

    stack backtrace:
    CPU: 1 PID: 6679 Comm: syz-executor Not tainted 4.9.0-rc4+ #47
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
     ffff880039e2f6d0 ffffffff81c2e46b ffff88003e3a5b40 0000000000000000
     0000000000000001 ffffffff83215600 ffff880039e2f700 ffffffff81334ea9
     ffffc9000730b000 0000000000000004 ffff88003c4f8420 ffff88003d3f8000
    Call Trace:
     [<     inline     >] __dump_stack lib/dump_stack.c:15
     [<ffffffff81c2e46b>] dump_stack+0xb3/0x118 lib/dump_stack.c:51
     [<ffffffff81334ea9>] lockdep_rcu_suspicious+0x139/0x180 kernel/locking/lockdep.c:4445
     [<     inline     >] __kvm_memslots include/linux/kvm_host.h:534
     [<     inline     >] kvm_memslots include/linux/kvm_host.h:541
     [<ffffffff8105d6ae>] kvm_gfn_to_hva_cache_init+0xa1e/0xce0 virt/kvm/kvm_main.c:1941
     [<ffffffff8112685d>] kvm_lapic_set_vapic_addr+0xed/0x140 arch/x86/kvm/lapic.c:2217
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Fixes: fda4e2e8
Cc: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Userspace can read the exact value of kvmclock by reading the TSC
and fetching the timekeeping parameters out of guest memory.  This
however is brittle and not necessary anymore with KVM 4.11.  Provide
a mechanism that lets userspace know if the new KVM_GET_CLOCK
semantics are in effect, and---since we are at it---if the clock
is stable across all VCPUs.

Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Function user_notifier_unregister should be called only once for each
registered user notifier.

Function kvm_arch_hardware_disable can be executed from an IPI context
which could cause a race condition with a VCPU returning to user mode
and attempting to unregister the notifier.
Signed-off-by: NIgnacio Alvarado <ikalvarado@google.com>
Cc: stable@vger.kernel.org
Fixes: 18863bdd ("KVM: x86 shared msr infrastructure")
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Going through the first VCPU is wrong if you follow a KVM_SET_CLOCK with
a KVM_GET_CLOCK immediately after, without letting the VCPU run and
call kvm_guest_time_update.

To fix this, compute the kvmclock value ourselves, using the master
clock (tsc, nsec) pair as the base and the host CPU frequency as
the scale.
Reported-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

The local variable *gpa_offset* is set but not used afterwards,
which make the compiler issue a warning with option
-Wunused-but-set-variable. Remove it to avoid the warning.
Signed-off-by: NJiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

kvm_emulate_wbinvd_noskip is only used in x86.c, and should be
static to avoid compiling warning when with -Wmissing-prototypes
option.
Signed-off-by: NJiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

When a memory slot is being moved or removed users of page track
can be notified. So users can drop write-protection for the pages
in that memory slot.

This notifier type is needed by KVMGT to sync up its shadow page
table when memory slot is being moved or removed.

Register the notifier type track_flush_slot to receive memslot move
and remove event.
Reviewed-by: NXiao Guangrong <guangrong.xiao@intel.com>
Signed-off-by: NChen Xiaoguang <xiaoguang.chen@intel.com>
[Squashed commits to avoid bisection breakage and reworded the subject.]
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Introdce kvm_get_lapic_target_expiration_tsc() to get APIC Timer target
deadline tsc.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

When a memory slot is being moved or removed users of page track
can be notified. So users can drop write-protection for the pages
in that memory slot.

This notifier type is needed by KVMGT to sync up its shadow page
table when memory slot is being moved or removed.

Register the notifier type track_flush_slot to receive memslot move
and remove event.
Reviewed-by: NXiao Guangrong <guangrong.xiao@intel.com>
Signed-off-by: NChen Xiaoguang <xiaoguang.chen@intel.com>
[Squashed commits to avoid bisection breakage and reworded the subject.]
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>

Since commit a545ab6a ("kvm: x86: add tsc_offset field to struct
kvm_vcpu_arch", 2016-09-07) the offset between host and L1 TSC is
cached and need not be fished out of the VMCS or VMCB.  This means
that we can implement adjust_tsc_offset_guest and read_l1_tsc
entirely in generic code.  The simplification is particularly
significant for VMX code, where vmx->nested.vmcs01_tsc_offset
was duplicating what is now in vcpu->arch.tsc_offset.  Therefore
the vmcs01_tsc_offset can be dropped completely.

More importantly, this fixes KVM_GET_CLOCK/KVM_SET_CLOCK
which, after commit 108b249c ("KVM: x86: introduce get_kvmclock_ns",
2016-09-01) called read_l1_tsc while the VMCS was not loaded.
It thus returned bogus values on Intel CPUs.

Fixes: 108b249cReported-by: NRoman Kagan <rkagan@virtuozzo.com>
Reviewed-by: NRadim Krčmář <rkrcmar@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Now that x86 always uses eager FPU switching on the host, there's no
need for KVM to manipulate the host's CR0.TS.

This should be both simpler and faster.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm list <kvm@vger.kernel.org>
Link: http://lkml.kernel.org/r/b212064922537c05d0c81d931fc4dbe769127ce7.1477951965.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

vcpu->arch.wbinvd_dirty_mask may still be used after freeing it,
corrupting memory. For example, the following call trace may set a bit
in an already freed cpu mask:
    kvm_arch_vcpu_load
    vcpu_load
    vmx_free_vcpu_nested
    vmx_free_vcpu
    kvm_arch_vcpu_free

Fix this by deferring freeing of wbinvd_dirty_mask.

Cc: stable@vger.kernel.org
Signed-off-by: NIdo Yariv <ido@wizery.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NRadim Krčmář <rkrcmar@redhat.com>