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KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits

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This allows both the guest and the host to use the referenced (R) and
changed (C) bits in the guest hashed page table.  The guest has a view
of R and C that is maintained in the guest_rpte field of the revmap
entry for the HPTE, and the host has a view that is maintained in the
rmap entry for the associated gfn.

Both view are updated from the guest HPT.  If a bit (R or C) is zero
in either view, it will be initially set to zero in the HPTE (or HPTEs),
until set to 1 by hardware.  When an HPTE is removed for any reason,
the R and C bits from the HPTE are ORed into both views.  We have to
be careful to read the R and C bits from the HPTE after invalidating
it, but before unlocking it, in case of any late updates by the hardware.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Paul Mackerras
2011-12-15 02:02:02 +00:00
committed by Avi Kivity
parent a92bce95f0
commit bad3b5075e
3 changed files with 59 additions and 39 deletions
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5
arch/powerpc/include/asm/kvm_host.h
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@@ -200,8 +200,9 @@ struct revmap_entry {
* index in the guest HPT of a HPTE that points to the page.
*/
#define KVMPPC_RMAP_LOCK_BIT 63
#define KVMPPC_RMAP_REF_BIT 33
#define KVMPPC_RMAP_REFERENCED (1ul << KVMPPC_RMAP_REF_BIT)
#define KVMPPC_RMAP_RC_SHIFT 32
#define KVMPPC_RMAP_REFERENCED (HPTE_R_R << KVMPPC_RMAP_RC_SHIFT)
#define KVMPPC_RMAP_CHANGED (HPTE_R_C << KVMPPC_RMAP_RC_SHIFT)
#define KVMPPC_RMAP_PRESENT 0x100000000ul
#define KVMPPC_RMAP_INDEX 0xfffffffful