The vmexit tracepoints format the exit_reason to make it human-readable.
Since the exit_reason depends on the instruction set (vmx or svm),
formatting is handled with ftrace_print_symbols_seq() by referring to
the appropriate exit reason table.

However, the ftrace_print_symbols_seq() function is not meant to be used
directly in tracepoints since it does not export the formatting table
which userspace tools like trace-cmd and perf use to format traces.

In practice perf dies when formatting vmexit-related events and
trace-cmd falls back to printing the numeric value (with extra
formatting code in the kvm plugin to paper over this limitation).  Other
userspace consumers of vmexit-related tracepoints would be in similar
trouble.

To avoid significant changes to the kvm_exit tracepoint, this patch
moves the vmx and svm exit reason tables into arch/x86/kvm/trace.h and
selects the right table with __print_symbolic() depending on the
instruction set.  Note that __print_symbolic() is designed for exporting
the formatting table to userspace and allows trace-cmd and perf to work.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The kvm_exit tracepoint recently added the isa argument to aid decoding
exit_reason.  The semantics of exit_reason depend on the instruction set
(vmx or svm) and the isa argument allows traces to be analyzed on other
machines.

Add the isa argument to kvm_nested_vmexit and kvm_nested_vmexit_inject
so these tracepoints can also be self-describing.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Commit 0945d4b228 tried to fix the get_msr path for the
HV_X64_MSR_APIC_ASSIST_PAGE msr, but was poorly tested.  We should be
returning 0 if the read succeeded, and passing the value back to the
caller via the pdata out argument, not returning the value directly.
Signed-off-by: NMike Waychison <mikew@google.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

"get" support for the HV_X64_MSR_APIC_ASSIST_PAGE msr was missing, even
though it is explicitly enumerated as something the vmm should save in
msrs_to_save and reported to userland via the KVM_GET_MSR_INDEX_LIST
ioctl.

Add "get" support for HV_X64_MSR_APIC_ASSIST_PAGE.  We simply return the
guest visible value of this register, which seems to be correct as a set
on the register is validated for us already.
Signed-off-by: NMike Waychison <mikew@google.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The patch raises the hard limit of VCPU count to 254.

This will allow developers to easily work on scalability
and will allow users to test high VCPU setups easily without
patching the kernel.

To prevent possible issues with current setups, KVM_CAP_NR_VCPUS
now returns the recommended VCPU limit (which is still 64) - this
should be a safe value for everybody, while a new KVM_CAP_MAX_VCPUS
returns the hard limit which is now 254.

Cc: Avi Kivity <avi@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Suggested-by: NPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: NSasha Levin <levinsasha928@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Using the read/write operation to remove the same code
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The operations of read emulation and write emulation are very similar, so we
can abstract the operation of them, in larter patch, it is used to cleanup the
same code
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If the range spans a page boundary, the mmio access can be broke, fix it as
write emulation.

And we already get the guest physical address, so use it to read guest data
directly to avoid walking guest page table again
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Src2CL decode (used for double width shifts) erronously decodes only bit 3
of %rcx, instead of bits 7:0.

Fix by decoding %cl in its entirety.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

__update_clear_spte_slow should return original spte while the
current code returns low half of original spte combined with high
half of new spte.
Signed-off-by: NZhao Jin <cronozhj@gmail.com>
Reviewed-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

CONFIG_TASKSTATS just had a change to use netlink, including
a change to "depends on NET".  Since "select" does not follow
dependencies, KVM also needs to depend on NET to prevent build
errors when CONFIG_NET is not enabled.

Sample of the reported "undefined reference" build errors:

taskstats.c:(.text+0x8f686): undefined reference to `nla_put'
taskstats.c:(.text+0x8f721): undefined reference to `nla_reserve'
taskstats.c:(.text+0x8f8fb): undefined reference to `init_net'
taskstats.c:(.text+0x8f905): undefined reference to `netlink_unicast'
taskstats.c:(.text+0x8f934): undefined reference to `kfree_skb'
taskstats.c:(.text+0x8f9e9): undefined reference to `skb_clone'
taskstats.c:(.text+0x90060): undefined reference to `__alloc_skb'
taskstats.c:(.text+0x901e9): undefined reference to `skb_put'
taskstats.c:(.init.text+0x4665): undefined reference to `genl_register_family'
taskstats.c:(.init.text+0x4699): undefined reference to `genl_register_ops'
taskstats.c:(.init.text+0x4710): undefined reference to `genl_unregister_ops'
taskstats.c:(.init.text+0x471c): undefined reference to `genl_unregister_family'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Fix kconfig dependency warning:

warning: (KVM) selects TASK_DELAY_ACCT which has unmet direct dependencies (TASKSTATS)
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: NArun Sharma <asharma@fb.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add tracepoints to trace mmio page fault
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The idea is from Avi:

| We could cache the result of a miss in an spte by using a reserved bit, and
| checking the page fault error code (or seeing if we get an ept violation or
| ept misconfiguration), so if we get repeated mmio on a page, we don't need to
| search the slot list/tree.
| (https://lkml.org/lkml/2011/2/22/221)

When the page fault is caused by mmio, we cache the info in the shadow page
table, and also set the reserved bits in the shadow page table, so if the mmio
is caused again, we can quickly identify it and emulate it directly

Searching mmio gfn in memslots is heavy since we need to walk all memeslots, it
can be reduced by this feature, and also avoid walking guest page table for
soft mmu.

[jan: fix operator precedence issue]
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Reorganize it for good using the cache
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Use rcu to protect shadow pages table to be freed, so we can safely walk it,
it should run fastly and is needed by mmio page fault
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Now, the spte is just from nonprsent to present or present to nonprsent, so
we can use some trick to set/clear spte non-atomicly as linux kernel does
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Introduce some interfaces to modify spte as linux kernel does:
- mmu_spte_clear_track_bits, it set the spte from present to nonpresent, and
  track the stat bits(accessed/dirty) of spte
- mmu_spte_clear_no_track, the same as mmu_spte_clear_track_bits except
  tracking the stat bits
- mmu_spte_set, set spte from nonpresent to present
- mmu_spte_update, only update the stat bits

Now, it does not allowed to set spte from present to present, later, we can
drop the atomicly opration for X86_32 host, and it is the preparing work to
get spte on X86_32 host out of the mmu lock
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Introduce handle_abnormal_pfn to handle fault pfn on page fault path,
introduce mmu_invalid_pfn to handle fault pfn on prefetch path

It is the preparing work for mmio page fault support
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If the page fault is caused by mmio, the gfn can not be found in memslots, and
'bad_pfn' is returned on gfn_to_hva path, so we can use 'bad_pfn' to identify
the mmio page fault.
And, to clarify the meaning of mmio pfn, we return fault page instead of bad
page when the gfn is not allowd to prefetch
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The idea is from Avi:
| Maybe it's time to kill off bypass_guest_pf=1.  It's not as effective as
| it used to be, since unsync pages always use shadow_trap_nonpresent_pte,
| and since we convert between the two nonpresent_ptes during sync and unsync.
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Split kvm_mmu_free_page to kvm_mmu_isolate_page and
kvm_mmu_free_page

One is used to remove the page from cache under mmu lock and the other is
used to free page table out of mmu lock
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Move counting used shadow pages from commiting path to preparing path to
reduce tlb flush on some paths
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If 'pt_write' is true, we need to emulate the fault. And in later patch, we
need to emulate the fault even though it is not a pt_write event, so rename
it to better fit the meaning
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

gw->pte_access is the final access permission, since it is unified with
gw->pt_access when we walked guest page table:

FNAME(walk_addr_generic):
	pte_access = pt_access & FNAME(gpte_access)(vcpu, pte, true);
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If dirty bit is not set, we can make the pte access read-only to avoid handing
dirty bit everywhere
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If the page fault is caused by mmio, we can cache the mmio info, later, we do
not need to walk guest page table and quickly know it is a mmio fault while we
emulate the mmio instruction
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Introduce vcpu_mmio_gva_to_gpa to translate the gva to gpa, we can use it
to cleanup the code between read emulation and write emulation
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Set slot bitmap only if the spte is present
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Properly check the last mapping, and do not walk to the next level if last spte
is met
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

virtio has been so far used only in the context of virtualization,
and the virtio Kconfig was sourced directly by the relevant arch
Kconfigs when VIRTUALIZATION was selected.

Now that we start using virtio for inter-processor communications,
we need to source the virtio Kconfig outside of the virtualization
scope too.

Moreover, some architectures might use virtio for both virtualization
and inter-processor communications, so directly sourcing virtio
might yield unexpected results due to conflicting selections.

The simple solution offered by this patch is to always source virtio's
Kconfig in drivers/Kconfig, and remove it from the appropriate arch
Kconfigs. Additionally, a virtio menu entry has been added so virtio
drivers don't show up in the general drivers menu.

This way anyone can use virtio, though it's arguably less accessible
(and neat!) for virtualization users now.

Note: some architectures (mips and sh) seem to have a VIRTUALIZATION
menu merely for sourcing virtio's Kconfig, so that menu is removed too.
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

To implement steal time, we need the hypervisor to pass the guest
information about how much time was spent running other processes
outside the VM, while the vcpu had meaningful work to do - halt
time does not count.

This information is acquired through the run_delay field of
delayacct/schedstats infrastructure, that counts time spent in a
runqueue but not running.

Steal time is a per-cpu information, so the traditional MSR-based
infrastructure is used. A new msr, KVM_MSR_STEAL_TIME, holds the
memory area address containing information about steal time

This patch contains the hypervisor part of the steal time infrasructure,
and can be backported independently of the guest portion.

[avi, yongjie: export delayacct_on, to avoid build failures in some configs]
Signed-off-by: NGlauber Costa <glommer@redhat.com>
Tested-by: NEric B Munson <emunson@mgebm.net>
CC: Rik van Riel <riel@redhat.com>
CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NYongjie Ren <yongjie.ren@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Suggested by Ingo and Avi.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The current name does not explain the meaning well.  So give it a better
name "retry_walk" to show that we are trying the walk again.

This was suggested by Ingo Molnar.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Avoid two step jump to the error handling part.  This eliminates the use
of the variables present and rsvd_fault.

We also use the const type qualifier to show that write/user/fetch_fault
do not change in the function.

Both of these were suggested by Ingo Molnar.

Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This reverts commit bee931d31e588b8eb86b7edee32fac2d16930cd7.

TLB flush should be done lazily during guest entry, in
kvm_mmu_load().
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

kvm_set_cr0() and kvm_set_cr4(), and possible other functions,
assume that kvm_mmu_reset_context() flushes the guest TLB.  However,
it does not.

Fix by flushing the tlb (and syncing the new root as well).
Signed-off-by: NAvi Kivity <avi@redhat.com>

When CR0.WP=0, we sometimes map user pages as kernel pages (to allow
the kernel to write to them).  Unfortunately this also allows the kernel
to fetch from these pages, even if CR4.SMEP is set.

Adjust for this by also setting NX on the spte in these circumstances.
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch exposes ERMS feature to KVM guests.

The REP MOVSB/STOSB instruction can enhance fast strings attempts to
move as much of the data with larger size load/stores as possible.
Signed-off-by: NYang, Wei <wei.y.yang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>