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KVM: PPC: Book3S HV: Create kvmppc_unmap_hpte_helper() 

The kvm_unmap_rmapp() function, called from certain MMU notifiers, is used
to force all guest mappings of a particular host page to be set ABSENT, and
removed from the reverse mappings.

For HPT resizing, we will have some cases where we want to set just a
single guest HPTE ABSENT and remove its reverse mappings.  To prepare with
this, we split out the logic from kvm_unmap_rmapp() to evict a single HPTE,
moving it to a new helper function.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This commit is contained in:
David Gibson 2016-12-20 16:49:04 +11:00 committed by Paul Mackerras
parent f98a8bf9ee
commit 639e459768
1 changed files with 44 additions and 33 deletions
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77
arch/powerpc/kvm/book3s_64_mmu_hv.c
View File

@ -742,13 +742,53 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
return kvm_handle_hva_range(kvm, hva, hva + 1, handler); return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
} }
/* Must be called with both HPTE and rmap locked */
static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i,
unsigned long *rmapp, unsigned long gfn)
{
__be64 *hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4));
struct revmap_entry *rev = kvm->arch.hpt.rev;
unsigned long j, h;
unsigned long ptel, psize, rcbits;
j = rev[i].forw;
if (j == i) {
/* chain is now empty */
*rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
} else {
/* remove i from chain */
h = rev[i].back;
rev[h].forw = j;
rev[j].back = h;
rev[i].forw = rev[i].back = i;
*rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
}
/* Now check and modify the HPTE */
ptel = rev[i].guest_rpte;
psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel);
if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
hpte_rpn(ptel, psize) == gfn) {
hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
kvmppc_invalidate_hpte(kvm, hptep, i);
hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
/* Harvest R and C */
rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
*rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
if (rcbits & HPTE_R_C)
kvmppc_update_rmap_change(rmapp, psize);
if (rcbits & ~rev[i].guest_rpte) {
rev[i].guest_rpte = ptel | rcbits;
note_hpte_modification(kvm, &rev[i]);
}
}
}
static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot, static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long gfn) unsigned long gfn)
{ {
struct revmap_entry *rev = kvm->arch.hpt.rev; unsigned long i;
unsigned long h, i, j;
__be64 *hptep; __be64 *hptep;
unsigned long ptel, psize, rcbits;
unsigned long *rmapp; unsigned long *rmapp;
rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
@ -773,37 +813,8 @@ static int kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot,
cpu_relax(); cpu_relax();
continue; continue;
} }
j = rev[i].forw;
if (j == i) {
/* chain is now empty */
*rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
} else {
/* remove i from chain */
h = rev[i].back;
rev[h].forw = j;
rev[j].back = h;
rev[i].forw = rev[i].back = i;
*rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
}
/* Now check and modify the HPTE */ kvmppc_unmap_hpte(kvm, i, rmapp, gfn);
ptel = rev[i].guest_rpte;
psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel);
if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
hpte_rpn(ptel, psize) == gfn) {
hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
kvmppc_invalidate_hpte(kvm, hptep, i);
hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
/* Harvest R and C */
rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
*rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
if (rcbits & HPTE_R_C)
kvmppc_update_rmap_change(rmapp, psize);
if (rcbits & ~rev[i].guest_rpte) {
rev[i].guest_rpte = ptel | rcbits;
note_hpte_modification(kvm, &rev[i]);
}
}
unlock_rmap(rmapp); unlock_rmap(rmapp);
__unlock_hpte(hptep, be64_to_cpu(hptep[0])); __unlock_hpte(hptep, be64_to_cpu(hptep[0]));
} }