The guest TLB handling code should not have any insight into how the host
TLB shadow code works.

kvmppc_e500_tlbil_all() is a function that is used for distinction between
e500v2 and e500mc (E.HV) on how to flush shadow entries. This function really
is private between the e500.c/e500mc.c file and e500_mmu_host.c.

Instead of this one, use the public kvmppc_core_flush_tlb() function to flush
all shadow TLB entries. As a nice side effect, with this we also end up
flushing TLB1 entries which we forgot to do before.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Host shadow TLB flushing is logic that the guest TLB code should have
no insight about. Declare the internal clear_tlb_refs and clear_tlb1_bitmap
functions static to the host TLB handling file.

Instead of these, we can use the already exported kvmppc_core_flush_tlb().
This gives us a common API across the board to say "please flush any
pending host shadow translation".
Signed-off-by: NAlexander Graf <agraf@suse.de>

When a host mapping fault happens in a guest TLB1 entry today, we
map the translated guest entry into the host's TLB1.

This isn't particularly clever when the guest is mapped by normal 4k
pages, since these would be a lot better to put into TLB0 instead.

This patch adds the required logic to map 4k TLB1 shadow maps into
the host's TLB0.
Signed-off-by: NAlexander Graf <agraf@suse.de>

This patch splits the file e500_tlb.c into e500_mmu.c (guest TLB handling)
and e500_mmu_host.c (host TLB handling).

The main benefit of this split is readability and maintainability. It's
just a lot harder to write dirty code :).
Signed-off-by: NAlexander Graf <agraf@suse.de>

When emulating tlbwe, we want to automatically map the entry that just got
written in our shadow TLB map, because chances are quite high that it's
going to be used very soon.

Today this happens explicitly, duplicating all the logic that is in
kvmppc_mmu_map() already. Just call that one instead.
Signed-off-by: NAlexander Graf <agraf@suse.de>

When shadow mapping a page, mapping this page can fail. In that case we
don't have a shadow map.

Take this case into account, otherwise we might end up writing bogus TLB
entries into the host TLB.

While at it, also move the write_stlbe() calls into the respective TLBn
handlers.
Signed-off-by: NAlexander Graf <agraf@suse.de>

When we invalidate shadow TLB maps on the host, we don't mark them
as not valid. But we should.

Fix this by removing the E500_TLB_VALID from their flags when
invalidating.
Signed-off-by: NAlexander Graf <agraf@suse.de>

Later patches want to call the function and it doesn't have
dependencies on anything below write_host_tlbe.

Move it higher up in the file.
Signed-off-by: NAlexander Graf <agraf@suse.de>

If emulate_invalid_guest_state=false vmx->emulation_required is never
actually used, but it ends up to be always set to true since
handle_invalid_guest_state(), the only place it is reset back to
false, is never called. This, besides been not very clean, makes vmexit
and vmentry path to check emulate_invalid_guest_state needlessly.

The patch fixes that by keeping emulation_required coherent with
emulate_invalid_guest_state setting.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

If VMX reports segment as unusable, zero descriptor passed by the emulator
before returning. Such descriptor will be considered not present by the
emulator.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The function deals with code segment too.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Usability is returned in unusable field, so not need to clobber entire
AR. Callers have to know how to deal with unusable segments already
since if emulate_invalid_guest_state=true AR is not zeroed.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

vmx->rmode.vm86_active is never true is unrestricted guest is enabled.
Make it more explicit that neither enter_pmode() nor enter_rmode() is
called in this case.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

There is no reason for it. If state is suitable for vmentry it
will be detected during guest entry and no emulation will happen.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Since vmx_get_cpl() always returns 0 when VCPU is in real mode it is no
longer needed. Also reset CPL cache to zero during transaction to
protected mode since transaction may happen while CS.selectors & 3 != 0,
but in reality CPL is 0.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi.kivity@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Make fastop opcodes usable in other emulations.
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi.kivity@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi.kivity@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi.kivity@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi.kivity@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This is a bit of a special case since we don't have the usual
byte/word/long/quad switch; instead we switch on the condition code embedded
in the instruction.
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi.kivity@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

SHL, SHR, ROL, ROR, RCL, RCR, SAR, SAL
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi.kivity@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi.kivity@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The current reexecute_instruction can not well detect the failed instruction
emulation. It allows guest to retry all the instructions except it accesses
on error pfn

For example, some cases are nested-write-protect - if the page we want to
write is used as PDE but it chains to itself. Under this case, we should
stop the emulation and report the case to userspace
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Currently, reexecute_instruction refused to retry all instructions if
tdp is enabled. If nested npt is used, the emulation may be caused by
shadow page, it can be fixed by dropping the shadow page. And the only
condition that tdp can not retry the instruction is the access fault
on error pfn
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Little cleanup for reexecute_instruction, also use gpa_to_gfn in
retry_instruction
Reviewed-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

One such variable, slot, is enough for holding a pointer temporarily.
We also remove another local variable named slot, which is limited in
a block, since it is confusing to have the same name in this function.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Don't need the check for deleting an existing slot or just modifiying
the flags.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

This makes the separation between the sanity checks and the rest of the
code a bit clearer.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

the variable inti should be freed in the branch CPUSTAT_STOPPED.
Signed-off-by: NCong Ding <dinggnu@gmail.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

If the userspace starts dirty logging for a large slot, say 64GB of
memory, kvm_mmu_slot_remove_write_access() needs to hold mmu_lock for
a long time such as tens of milliseconds.  This patch controls the lock
hold time by asking the scheduler if we need to reschedule for others.

One penalty for this is that we need to flush TLBs before releasing
mmu_lock.  But since holding mmu_lock for a long time does affect not
only the guest, vCPU threads in other words, but also the host as a
whole, we should pay for that.

In practice, the cost will not be so high because we can protect a fair
amount of memory before being rescheduled: on my test environment,
cond_resched_lock() was called only once for protecting 12GB of memory
even without THP.  We can also revisit Avi's "unlocked TLB flush" work
later for completely suppressing extra TLB flushes if needed.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Better to place mmu_lock handling and TLB flushing code together since
this is a self-contained function.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

No reason to make callers take mmu_lock since we do not need to protect
kvm_mmu_change_mmu_pages() and kvm_mmu_slot_remove_write_access()
together by mmu_lock in kvm_arch_commit_memory_region(): the former
calls kvm_mmu_commit_zap_page() and flushes TLBs by itself.

Note: we do not need to protect kvm->arch.n_requested_mmu_pages by
mmu_lock as can be seen from the fact that it is read locklessly.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Not needed any more.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

This makes it possible to release mmu_lock and reschedule conditionally
in a later patch.  Although this may increase the time needed to protect
the whole slot when we start dirty logging, the kernel should not allow
the userspace to trigger something that will hold a spinlock for such a
long time as tens of milliseconds: actually there is no limit since it
is roughly proportional to the number of guest pages.

Another point to note is that this patch removes the only user of
slot_bitmap which will cause some problems when we increase the number
of slots further.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

No longer need to care about the mapping level in this function.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

Calling kvm_mmu_slot_remove_write_access() for a deleted slot does
nothing but search for non-existent mmu pages which have mappings to
that deleted memory; this is safe but a waste of time.

Since we want to make the function rmap based in a later patch, in a
manner which makes it unsafe to be called for a deleted slot, we makes
the caller see if the slot is non-zero and being dirty logged.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NTakuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: NGleb Natapov <gleb@redhat.com>