Commit Graph

3672 Commits

Author SHA1 Message Date
Radim Krčmář a3e1311549 KVM: i8254: remove pit and kvm from kvm_kpit_state
kvm isn't ever used and pit can be accessed with container_of.
If you *really* need kvm, pit_state_to_pit(ps)->kvm.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:12 +01:00
Radim Krčmář 08e5ccf3ae KVM: i8254: refactor kvm_free_pit
Could be easier to read, but git history will become deeper.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:07 +01:00
Radim Krčmář 10d2482126 KVM: i8254: refactor kvm_create_pit
Locks are gone, so we don't need to duplicate error paths.
Use goto everywhere.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:04 +01:00
Radim Krčmář 71474e2f0f KVM: i8254: remove notifiers from PIT discard policy
Discard policy doesn't rely on information from notifiers, so we don't
need to register notifiers unconditionally.  We kept correct counts in
case userspace switched between policies during runtime, but that can be
avoided by reseting the state.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:30:01 +01:00
Radim Krčmář b39c90b656 KVM: i8254: remove unnecessary uses of PIT state lock
- kvm_create_pit had to lock only because it exposed kvm->arch.vpit very
  early, but initialization doesn't use kvm->arch.vpit since the last
  patch, so we can drop locking.
- kvm_free_pit is only run after there are no users of KVM and therefore
  is the sole actor.
- Locking in kvm_vm_ioctl_reinject doesn't do anything, because reinject
  is only protected at that place.
- kvm_pit_reset isn't used anywhere and its locking can be dropped if we
  hide it.

Removing useless locking allows to see what actually is being protected
by PIT state lock (values accessible from the guest).

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:58 +01:00
Radim Krčmář 09edea72b7 KVM: i8254: pass struct kvm_pit instead of kvm in PIT
This patch passes struct kvm_pit into internal PIT functions.
Those functions used to get PIT through kvm->arch.vpit, even though most
of them never used *kvm for other purposes.  Another benefit is that we
don't need to set kvm->arch.vpit during initialization.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:55 +01:00
Radim Krčmář b69d920f68 KVM: i8254: tone down WARN_ON pit.state_lock
If the guest could hit this, it would hang the host kernel, bacause of
sheer number of those reports.  Internal callers have to be sensible
anyway, so we now only check for it in an API function.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:51 +01:00
Radim Krčmář ddf54503e2 KVM: i8254: use atomic_t instead of pit.inject_lock
The lock was an overkill, the same can be done with atomics.

A mb() was added in kvm_pit_ack_irq, to pair with implicit barrier
between pit_timer_fn and pit_do_work.  The mb() prevents a race that
could happen if pending == 0 and irq_ack == 0:

  kvm_pit_ack_irq:                | pit_timer_fn:
   p = atomic_read(&ps->pending); |
                                  |  atomic_inc(&ps->pending);
                                  |  queue_work(pit_do_work);
                                  | pit_do_work:
                                  |  atomic_xchg(&ps->irq_ack, 0);
                                  |  return;
   atomic_set(&ps->irq_ack, 1);   |
   if (p == 0) return;            |

where the interrupt would not be delivered in this tick of pit_timer_fn.
PIT would have eventually delivered the interrupt, but we sacrifice
perofmance to make sure that interrupts are not needlessly delayed.

sfence isn't enough: atomic_dec_if_positive does atomic_read first and
x86 can reorder loads before stores.  lfence isn't enough: store can
pass lfence, turning it into a nop.  A compiler barrier would be more
than enough as CPU needs to stall for unbelievably long to use fences.

This patch doesn't do anything in kvm_pit_reset_reinject, because any
order of resets can race, but the result differs by at most one
interrupt, which is ok, because it's the same result as if the reset
happened at a slightly different time.  (Original code didn't protect
the reset path with a proper lock, so users have to be robust.)

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:47 +01:00
Radim Krčmář fd700a00dc KVM: i8254: add kvm_pit_reset_reinject
pit_state.pending and pit_state.irq_ack are always reset at the same
time.  Create a function for them.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:43 +01:00
Radim Krčmář f6e0a0c113 KVM: i8254: simplify atomics in kvm_pit_ack_irq
We already have a helper that does the same thing.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:37 +01:00
Radim Krčmář 7dd0fdff14 KVM: i8254: change PIT discard tick policy
Discard policy uses ack_notifiers to prevent injection of PIT interrupts
before EOI from the last one.

This patch changes the policy to always try to deliver the interrupt,
which makes a difference when its vector is in ISR.
Old implementation would drop the interrupt, but proposed one injects to
IRR, like real hardware would.

The old policy breaks legacy NMI watchdogs, where PIT is used through
virtual wire (LVT0): PIT never sends an interrupt before receiving EOI,
thus a guest deadlock with disabled interrupts will stop NMIs.

Note that NMI doesn't do EOI, so PIT also had to send a normal interrupt
through IOAPIC.  (KVM's PIT is deeply rotten and luckily not used much
in modern systems.)

Even though there is a chance of regressions, I think we can fix the
LVT0 NMI bug without introducing a new tick policy.

Cc: <stable@vger.kernel.org>
Reported-by: Yuki Shibuya <shibuya.yk@ncos.nec.co.jp>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-04 09:29:31 +01:00
Xiao Guangrong 13d268ca2c KVM: MMU: apply page track notifier
Register the notifier to receive write track event so that we can update
our shadow page table

It makes kvm_mmu_pte_write() be the callback of the notifier, no function
is changed

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:24 +01:00
Xiao Guangrong 5c520e90af KVM: MMU: simplify mmu_need_write_protect
Now, all non-leaf shadow page are page tracked, if gfn is not tracked
there is no non-leaf shadow page of gfn is existed, we can directly
make the shadow page of gfn to unsync

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:23 +01:00
Xiao Guangrong 56ca57f9fe KVM: MMU: use page track for non-leaf shadow pages
non-leaf shadow pages are always write protected, it can be the user
of page track

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:23 +01:00
Xiao Guangrong 0eb05bf290 KVM: page track: add notifier support
Notifier list is introduced so that any node wants to receive the track
event can register to the list

Two APIs are introduced here:
- kvm_page_track_register_notifier(): register the notifier to receive
  track event

- kvm_page_track_unregister_notifier(): stop receiving track event by
  unregister the notifier

The callback, node->track_write() is called when a write access on the
write tracked page happens

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:22 +01:00
Xiao Guangrong e5691a81e8 KVM: MMU: clear write-flooding on the fast path of tracked page
If the page fault is caused by write access on write tracked page, the
real shadow page walking is skipped, we lost the chance to clear write
flooding for the page structure current vcpu is using

Fix it by locklessly waking shadow page table to clear write flooding
on the shadow page structure out of mmu-lock. So that we change the
count to atomic_t

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:22 +01:00
Xiao Guangrong 3d0c27ad6e KVM: MMU: let page fault handler be aware tracked page
The page fault caused by write access on the write tracked page can not
be fixed, it always need to be emulated. page_fault_handle_page_track()
is the fast path we introduce here to skip holding mmu-lock and shadow
page table walking

However, if the page table is not present, it is worth making the page
table entry present and readonly to make the read access happy

mmu_need_write_protect() need to be cooked to avoid page becoming writable
when making page table present or sync/prefetch shadow page table entries

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:21 +01:00
Xiao Guangrong f29d4d7810 KVM: page track: introduce kvm_slot_page_track_{add,remove}_page
These two functions are the user APIs:
- kvm_slot_page_track_add_page(): add the page to the tracking pool
  after that later specified access on that page will be tracked

- kvm_slot_page_track_remove_page(): remove the page from the tracking
  pool, the specified access on the page is not tracked after the last
  user is gone

Both of these are called under the protection both of mmu-lock and
kvm->srcu or kvm->slots_lock

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:21 +01:00
Xiao Guangrong 21ebbedadd KVM: page track: add the framework of guest page tracking
The array, gfn_track[mode][gfn], is introduced in memory slot for every
guest page, this is the tracking count for the gust page on different
modes. If the page is tracked then the count is increased, the page is
not tracked after the count reaches zero

We use 'unsigned short' as the tracking count which should be enough as
shadow page table only can use 2^14 (2^3 for level, 2^1 for cr4_pae, 2^2
for quadrant, 2^3 for access, 2^1 for nxe, 2^1 for cr0_wp, 2^1 for
smep_andnot_wp, 2^1 for smap_andnot_wp, and 2^1 for smm) at most, there
is enough room for other trackers

Two callbacks, kvm_page_track_create_memslot() and
kvm_page_track_free_memslot() are implemented in this patch, they are
internally used to initialize and reclaim the memory of the array

Currently, only write track mode is supported

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:20 +01:00
Xiao Guangrong aeecee2ea6 KVM: MMU: introduce kvm_mmu_slot_gfn_write_protect
Split rmap_write_protect() and introduce the function to abstract the write
protection based on the slot

This function will be used in the later patch

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:20 +01:00
Xiao Guangrong 547ffaed87 KVM: MMU: introduce kvm_mmu_gfn_{allow,disallow}_lpage
Abstract the common operations from account_shadowed() and
unaccount_shadowed(), then introduce kvm_mmu_gfn_disallow_lpage()
and kvm_mmu_gfn_allow_lpage()

These two functions will be used by page tracking in the later patch

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:19 +01:00
Xiao Guangrong 92f94f1e9e KVM: MMU: rename has_wrprotected_page to mmu_gfn_lpage_is_disallowed
kvm_lpage_info->write_count is used to detect if the large page mapping
for the gfn on the specified level is allowed, rename it to disallow_lpage
to reflect its purpose, also we rename has_wrprotected_page() to
mmu_gfn_lpage_is_disallowed() to make the code more clearer

Later we will extend this mechanism for page tracking: if the gfn is
tracked then large mapping for that gfn on any level is not allowed.
The new name is more straightforward

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:19 +01:00
Joerg Roedel 4d99ba898d kvm: x86: Check dest_map->vector to match eoi signals for rtc
Using the vector stored at interrupt delivery makes the eoi
matching safe agains irq migration in the ioapic.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:18 +01:00
Joerg Roedel 9daa50076f kvm: x86: Track irq vectors in ioapic->rtc_status.dest_map
This allows backtracking later in case the rtc irq has been
moved to another vcpu/vector.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:18 +01:00
Joerg Roedel 9e4aabe2bb kvm: x86: Convert ioapic->rtc_status.dest_map to a struct
Currently this is a bitmap which tracks which CPUs we expect
an EOI from. Move this bitmap to a struct so that we can
track additional information there.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:17 +01:00
Geliang Tang d74c0e6b54 KVM: x86: use list_last_entry
To make the intention clearer, use list_last_entry instead of
list_entry.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-23 15:40:54 +01:00
Geliang Tang 652fc08dae KVM: x86: use list_for_each_entry*
Use list_for_each_entry*() instead of list_for_each*() to simplify
the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-23 15:40:54 +01:00
Takuya Yoshikawa e9ee956e31 KVM: x86: MMU: Move handle_mmio_page_fault() call to kvm_mmu_page_fault()
Rather than placing a handle_mmio_page_fault() call in each
vcpu->arch.mmu.page_fault() handler, moving it up to
kvm_mmu_page_fault() makes the code better:

 - avoids code duplication
 - for kvm_arch_async_page_ready(), which is the other caller of
   vcpu->arch.mmu.page_fault(), removes an extra error_code check
 - avoids returning both RET_MMIO_PF_* values and raw integer values
   from vcpu->arch.mmu.page_fault()

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-23 14:20:27 +01:00
Takuya Yoshikawa ded5874946 KVM: x86: MMU: Consolidate quickly_check_mmio_pf() and is_mmio_page_fault()
These two have only slight differences:
 - whether 'addr' is of type u64 or of type gva_t
 - whether they have 'direct' parameter or not

Concerning the former, quickly_check_mmio_pf()'s u64 is better because
'addr' needs to be able to have both a guest physical address and a
guest virtual address.

The latter is just a stylistic issue as we can always calculate the mode
from the 'vcpu' as is_mmio_page_fault() does.  This patch keeps the
parameter to make the following patch cleaner.

In addition, the patch renames the function to mmio_info_in_cache() to
make it clear what it actually checks for.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-23 14:20:27 +01:00
Paolo Bonzini 3ae13faac4 KVM: x86: pass kvm_get_time_scale arguments in hertz
Prepare for improving the precision in the next patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:45 +01:00
Andrey Smetanin 83326e43f2 kvm/x86: Hyper-V VMBus hypercall userspace exit
The patch implements KVM_EXIT_HYPERV userspace exit
functionality for Hyper-V VMBus hypercalls:
HV_X64_HCALL_POST_MESSAGE, HV_X64_HCALL_SIGNAL_EVENT.

Changes v3:
* use vcpu->arch.complete_userspace_io to setup hypercall
result

Changes v2:
* use KVM_EXIT_HYPERV for hypercalls

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Joerg Roedel <joro@8bytes.org>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:44 +01:00
Andrey Smetanin b2fdc2570a kvm/x86: Reject Hyper-V hypercall continuation
Currently we do not support Hyper-V hypercall continuation
so reject it.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Joerg Roedel <joro@8bytes.org>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:42 +01:00
Andrey Smetanin 0d9c055eaa kvm/x86: Pass return code of kvm_emulate_hypercall
Pass the return code from kvm_emulate_hypercall on to the caller,
in order to allow it to indicate to the userspace that
the hypercall has to be handled there.

Also adjust all the existing code paths to return 1 to make sure the
hypercall isn't passed to the userspace without setting kvm_run
appropriately.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Joerg Roedel <joro@8bytes.org>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:41 +01:00
Andrey Smetanin 8ed6d76781 kvm/x86: Rename Hyper-V long spin wait hypercall
Rename HV_X64_HV_NOTIFY_LONG_SPIN_WAIT by HVCALL_NOTIFY_LONG_SPIN_WAIT,
so the name is more consistent with the other hypercalls.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Joerg Roedel <joro@8bytes.org>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
[Change name, Andrey used HV_X64_HCALL_NOTIFY_LONG_SPIN_WAIT. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:38 +01:00
Paolo Bonzini 4e422bdd2f KVM: x86: fix missed hardware breakpoints
Sometimes when setting a breakpoint a process doesn't stop on it.
This is because the debug registers are not loaded correctly on
VCPU load.

The following simple reproducer from Oleg Nesterov tries using debug
registers in both the host and the guest, for example by running "./bp
0 1" on the host and "./bp 14 15" under QEMU.

    #include <unistd.h>
    #include <signal.h>
    #include <stdlib.h>
    #include <stdio.h>
    #include <sys/wait.h>
    #include <sys/ptrace.h>
    #include <sys/user.h>
    #include <asm/debugreg.h>
    #include <assert.h>

    #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)

    unsigned long encode_dr7(int drnum, int enable, unsigned int type, unsigned int len)
    {
        unsigned long dr7;

        dr7 = ((len | type) & 0xf)
            << (DR_CONTROL_SHIFT + drnum * DR_CONTROL_SIZE);
        if (enable)
            dr7 |= (DR_GLOBAL_ENABLE << (drnum * DR_ENABLE_SIZE));

        return dr7;
    }

    int write_dr(int pid, int dr, unsigned long val)
    {
        return ptrace(PTRACE_POKEUSER, pid,
                offsetof (struct user, u_debugreg[dr]),
                val);
    }

    void set_bp(pid_t pid, void *addr)
    {
        unsigned long dr7;
        assert(write_dr(pid, 0, (long)addr) == 0);
        dr7 = encode_dr7(0, 1, DR_RW_EXECUTE, DR_LEN_1);
        assert(write_dr(pid, 7, dr7) == 0);
    }

    void *get_rip(int pid)
    {
        return (void*)ptrace(PTRACE_PEEKUSER, pid,
                offsetof(struct user, regs.rip), 0);
    }

    void test(int nr)
    {
        void *bp_addr = &&label + nr, *bp_hit;
        int pid;

        printf("test bp %d\n", nr);
        assert(nr < 16); // see 16 asm nops below

        pid = fork();
        if (!pid) {
            assert(ptrace(PTRACE_TRACEME, 0,0,0) == 0);
            kill(getpid(), SIGSTOP);
            for (;;) {
                label: asm (
                    "nop; nop; nop; nop;"
                    "nop; nop; nop; nop;"
                    "nop; nop; nop; nop;"
                    "nop; nop; nop; nop;"
                );
            }
        }

        assert(pid == wait(NULL));
        set_bp(pid, bp_addr);

        for (;;) {
            assert(ptrace(PTRACE_CONT, pid, 0, 0) == 0);
            assert(pid == wait(NULL));

            bp_hit = get_rip(pid);
            if (bp_hit != bp_addr)
                fprintf(stderr, "ERR!! hit wrong bp %ld != %d\n",
                    bp_hit - &&label, nr);
        }
    }

    int main(int argc, const char *argv[])
    {
        while (--argc) {
            int nr = atoi(*++argv);
            if (!fork())
                test(nr);
        }

        while (wait(NULL) > 0)
            ;
        return 0;
    }

Cc: stable@vger.kernel.org
Suggested-by: Nadadv Amit <namit@cs.technion.ac.il>
Reported-by: Andrey Wagin <avagin@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:37 +01:00
Radim Krčmář 4efd805fca KVM: x86: fix *NULL on invalid low-prio irq
Smatch noticed a NULL dereference in kvm_intr_is_single_vcpu_fast that
happens if VM already warned about invalid lowest-priority interrupt.

Create a function for common code while fixing it.

Fixes: 6228a0da80 ("KVM: x86: Add lowest-priority support for vt-d posted-interrupts")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:36 +01:00
Paolo Bonzini 78db6a5037 KVM: x86: rewrite handling of scaled TSC for kvmclock
This is the same as before:

    kvm_scale_tsc(tgt_tsc_khz)
        = tgt_tsc_khz * ratio
        = tgt_tsc_khz * user_tsc_khz / tsc_khz   (see set_tsc_khz)
        = user_tsc_khz                           (see kvm_guest_time_update)
        = vcpu->arch.virtual_tsc_khz             (see kvm_set_tsc_khz)

However, computing it through kvm_scale_tsc will make it possible
to include the NTP correction in tgt_tsc_khz.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:34 +01:00
Paolo Bonzini 4941b8cb37 KVM: x86: rename argument to kvm_set_tsc_khz
This refers to the desired (scaled) frequency, which is called
user_tsc_khz in the rest of the file.

Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:33 +01:00
Jan Kiszka 6f05485d3a KVM: VMX: Fix guest debugging while in L2
When we take a #DB or #BP vmexit while in guest mode, we first of all
need to check if there is ongoing guest debugging that might be
interested in the event. Currently, we unconditionally leave L2 and
inject the event into L1 if it is intercepting the exceptions. That
breaks things marvelously.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:32 +01:00
Jan Kiszka 5bb16016ce KVM: VMX: Factor out is_exception_n helper
There is quite some common code in all these is_<exception>() helpers.
Factor it out before adding even more of them.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:30 +01:00
Paolo Bonzini bce87cce88 KVM: x86: consolidate different ways to test for in-kernel LAPIC
Different pieces of code checked for vcpu->arch.apic being (non-)NULL,
or used kvm_vcpu_has_lapic (more optimized) or lapic_in_kernel.
Replace everything with lapic_in_kernel's name and kvm_vcpu_has_lapic's
implementation.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-09 16:57:45 +01:00
Paolo Bonzini 1e3161b414 KVM: x86: consolidate "has lapic" checks into irq.c
Do for kvm_cpu_has_pending_timer and kvm_inject_pending_timer_irqs
what the other irq.c routines have been doing.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-09 16:57:39 +01:00
Paolo Bonzini f8543d6a97 KVM: APIC: remove unnecessary double checks on APIC existence
Usually the in-kernel APIC's existence is checked in the caller.  Do not
bother checking it again in lapic.c.

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-09 16:57:14 +01:00
Feng Wu b6ce978067 KVM/VMX: Add host irq information in trace event when updating IRTE for posted interrupts
Add host irq information in trace event, so we can better understand
which irq is in posted mode.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-09 13:24:43 +01:00
Feng Wu 6228a0da80 KVM: x86: Add lowest-priority support for vt-d posted-interrupts
Use vector-hashing to deliver lowest-priority interrupts for
VT-d posted-interrupts. This patch extends kvm_intr_is_single_vcpu()
to support lowest-priority handling.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-09 13:24:42 +01:00
Feng Wu 520040146a KVM: x86: Use vector-hashing to deliver lowest-priority interrupts
Use vector-hashing to deliver lowest-priority interrupts, As an
example, modern Intel CPUs in server platform use this method to
handle lowest-priority interrupts.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-09 13:24:40 +01:00
Feng Wu 23a1c2579b KVM: Recover IRTE to remapped mode if the interrupt is not single-destination
When the interrupt is not single destination any more, we need
to change back IRTE to remapped mode explicitly.

Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-09 13:24:39 +01:00
Paolo Bonzini b51012deb3 KVM: x86: introduce do_shl32_div32
This is similar to the existing div_frac function, but it returns the
remainder too.  Unlike div_frac, it can be used to implement long
division, e.g. (a << 64) / b for 32-bit a and b.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-09 13:24:37 +01:00
Dan Williams ba049e93ae kvm: rename pfn_t to kvm_pfn_t
To date, we have implemented two I/O usage models for persistent memory,
PMEM (a persistent "ram disk") and DAX (mmap persistent memory into
userspace).  This series adds a third, DAX-GUP, that allows DAX mappings
to be the target of direct-i/o.  It allows userspace to coordinate
DMA/RDMA from/to persistent memory.

The implementation leverages the ZONE_DEVICE mm-zone that went into
4.3-rc1 (also discussed at kernel summit) to flag pages that are owned
and dynamically mapped by a device driver.  The pmem driver, after
mapping a persistent memory range into the system memmap via
devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus
page-backed pmem-pfns via flags in the new pfn_t type.

The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the
resulting pte(s) inserted into the process page tables with a new
_PAGE_DEVMAP flag.  Later, when get_user_pages() is walking ptes it keys
off _PAGE_DEVMAP to pin the device hosting the page range active.
Finally, get_page() and put_page() are modified to take references
against the device driver established page mapping.

Finally, this need for "struct page" for persistent memory requires
memory capacity to store the memmap array.  Given the memmap array for a
large pool of persistent may exhaust available DRAM introduce a
mechanism to allocate the memmap from persistent memory.  The new
"struct vmem_altmap *" parameter to devm_memremap_pages() enables
arch_add_memory() to use reserved pmem capacity rather than the page
allocator.

This patch (of 18):

The core has developed a need for a "pfn_t" type [1].  Move the existing
pfn_t in KVM to kvm_pfn_t [2].

[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html
[2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15 17:56:32 -08:00
Linus Torvalds 1baa5efbeb * s390: Support for runtime instrumentation within guests,
support of 248 VCPUs.
 
 * ARM: rewrite of the arm64 world switch in C, support for
 16-bit VM identifiers.  Performance counter virtualization
 missed the boat.
 
 * x86: Support for more Hyper-V features (synthetic interrupt
 controller), MMU cleanups
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "PPC changes will come next week.

   - s390: Support for runtime instrumentation within guests, support of
     248 VCPUs.

   - ARM: rewrite of the arm64 world switch in C, support for 16-bit VM
     identifiers.  Performance counter virtualization missed the boat.

   - x86: Support for more Hyper-V features (synthetic interrupt
     controller), MMU cleanups"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (115 commits)
  kvm: x86: Fix vmwrite to SECONDARY_VM_EXEC_CONTROL
  kvm/x86: Hyper-V SynIC timers tracepoints
  kvm/x86: Hyper-V SynIC tracepoints
  kvm/x86: Update SynIC timers on guest entry only
  kvm/x86: Skip SynIC vector check for QEMU side
  kvm/x86: Hyper-V fix SynIC timer disabling condition
  kvm/x86: Reorg stimer_expiration() to better control timer restart
  kvm/x86: Hyper-V unify stimer_start() and stimer_restart()
  kvm/x86: Drop stimer_stop() function
  kvm/x86: Hyper-V timers fix incorrect logical operation
  KVM: move architecture-dependent requests to arch/
  KVM: renumber vcpu->request bits
  KVM: document which architecture uses each request bit
  KVM: Remove unused KVM_REQ_KICK to save a bit in vcpu->requests
  kvm: x86: Check kvm_write_guest return value in kvm_write_wall_clock
  KVM: s390: implement the RI support of guest
  kvm/s390: drop unpaired smp_mb
  kvm: x86: fix comment about {mmu,nested_mmu}.gva_to_gpa
  KVM: x86: MMU: Use clear_page() instead of init_shadow_page_table()
  arm/arm64: KVM: Detect vGIC presence at runtime
  ...
2016-01-12 13:22:12 -08:00