Tlb search operation used for victim hint relies on the default tlb set by the
host. When hardware tablewalk support is enabled in the host, the default tlb is
TLB1 which leads KVM to evict the bolted entry. Set and restore the default tlb
when searching for victim hint.
Signed-off-by: NMihai Caraman <mihai.caraman@freescale.com>
Reviewed-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

KVM uses same WIM tlb attributes as the corresponding qemu pte.
For this we now search the linux pte for the requested page and
get these cache caching/coherency attributes from pte.
Signed-off-by: NBharat Bhushan <bharat.bhushan@freescale.com>
Reviewed-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

On booke, "struct tlbe_ref" contains host tlb mapping information
(pfn: for guest-pfn to pfn, flags: attribute associated with this mapping)
for a guest tlb entry. So when a guest creates a TLB entry then
"struct tlbe_ref" is set to point to valid "pfn" and set attributes in
"flags" field of the above said structure. When a guest TLB entry is
invalidated then flags field of corresponding "struct tlbe_ref" is
updated to point that this is no more valid, also we selectively clear
some other attribute bits, example: if E500_TLB_BITMAP was set then we clear
E500_TLB_BITMAP, if E500_TLB_TLB0 is set then we clear this.

Ideally we should clear complete "flags" as this entry is invalid and does not
have anything to re-used. The other part of the problem is that when we use
the same entry again then also we do not clear (started doing or-ing etc).

So far it was working because the selectively clearing mentioned above
actually clears "flags" what was set during TLB mapping. But the problem
starts coming when we add more attributes to this then we need to selectively
clear them and which is not needed.
Signed-off-by: NBharat Bhushan <bharat.bhushan@freescale.com>
Reviewed-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Mark the guest page as accessed so that there is likely
less chances of this page getting swap-out.
Signed-off-by: NBharat Bhushan <bharat.bhushan@freescale.com>
Acked-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

When the MM code is invalidating a range of pages, it calls the KVM
kvm_mmu_notifier_invalidate_range_start() notifier function, which calls
kvm_unmap_hva_range(), which arranges to flush all the TLBs for guest pages.
However, the Linux PTEs for the range being flushed are still valid at
that point.  We are not supposed to establish any new references to pages
in the range until the ...range_end() notifier gets called.
The PPC-specific KVM code doesn't get any explicit notification of that;
instead, we are supposed to use mmu_notifier_retry() to test whether we
are or have been inside a range flush notifier pair while we have been
referencing a page.

This patch calls the mmu_notifier_retry() while mapping the guest
page to ensure we are not referencing a page when in range invalidation.

This call is inside a region locked with kvm->mmu_lock, which is the
same lock that is called by the KVM MMU notifier functions, thus
ensuring that no new notification can proceed while we are in the
locked region.
Signed-off-by: NBharat Bhushan <bharat.bhushan@freescale.com>
Acked-by: NAlexander Graf <agraf@suse.de>
[Backported to 3.12 - Paolo]
Reviewed-by: NBharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commit 523f0e54 ("KVM: PPC: E500:
Explicitly mark shadow maps invalid") began using E500_TLB_VALID
for guest TLB1 entries, and skipping invalidations if it's not set.

However, when E500_TLB_VALID was set for such entries, it was on a
fake local ref, and so the invalidations never happen.  gtlb_privs
is documented as being only for guest TLB0, though we already violate
that with E500_TLB_BITMAP.

Now that we have MMU notifiers, and thus don't need to actually
retain a reference to the mapped pages, get rid of tlb_refs, and
use gtlb_privs for E500_TLB_VALID in TLB1.

Since we can have more than one host TLB entry for a given tlbe_ref,
be careful not to clear existing flags that are relevant to other
host TLB entries when preparing a new host TLB entry.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

It's possible that we're using the same host TLB1 slot to map (a
presumably different portion of) the same guest TLB1 entry.  Clear
the bit in the map before setting it, so that if the esels are the same
the bit will remain set.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Add one to esel values in h2g_tlb1_rmap, so that "no mapping" can be
distinguished from "esel 0".  Note that we're not saved by the fact
that host esel 0 is reserved for non-KVM use, because KVM host esel
numbering is not the raw host numbering (see to_htlb1_esel).
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Commit 523f0e54 ("KVM: PPC: E500:
Explicitly mark shadow maps invalid") began using E500_TLB_VALID
for guest TLB1 entries, and skipping invalidations if it's not set.

However, when E500_TLB_VALID was set for such entries, it was on a
fake local ref, and so the invalidations never happen.  gtlb_privs
is documented as being only for guest TLB0, though we already violate
that with E500_TLB_BITMAP.

Now that we have MMU notifiers, and thus don't need to actually
retain a reference to the mapped pages, get rid of tlb_refs, and
use gtlb_privs for E500_TLB_VALID in TLB1.

Since we can have more than one host TLB entry for a given tlbe_ref,
be careful not to clear existing flags that are relevant to other
host TLB entries when preparing a new host TLB entry.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

It's possible that we're using the same host TLB1 slot to map (a
presumably different portion of) the same guest TLB1 entry.  Clear
the bit in the map before setting it, so that if the esels are the same
the bit will remain set.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

Add one to esel values in h2g_tlb1_rmap, so that "no mapping" can be
distinguished from "esel 0".  Note that we're not saved by the fact
that host esel 0 is reserved for non-KVM use, because KVM host esel
numbering is not the raw host numbering (see to_htlb1_esel).
Signed-off-by: NScott Wood <scottwood@freescale.com>
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>