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KVM: PPC: Book3S HV: Clear the key field of HPTE when the page is paged out

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Currently we mark a HPTE for emulated MMIO with HPTE_V_ABSENT bit
set as well as key 0x1f. However, those HPTEs may be conflicted with
the HPTE for real guest RAM page HPTE with key 0x1f when the page
get paged out.

This patch clears the key field of HPTE when the page is paged out,
then recover it when HPTE is re-established.

Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This commit is contained in:
Yongji Xie 2016-11-04 13:55:11 +08:00 committed by Paul Mackerras
parent 28d057c897
commit f05859827d
2 changed files with 7 additions and 2 deletions
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4
arch/powerpc/kvm/book3s_64_mmu_hv.c
View File

@ -575,7 +575,8 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
*/
if (psize < PAGE_SIZE)
psize = PAGE_SIZE;
r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1));
r = (r & HPTE_R_KEY_HI) | (r & ~(HPTE_R_PP0 - psize)) |
((pfn << PAGE_SHIFT) & ~(psize - 1));
if (hpte_is_writable(r) && !write_ok)
r = hpte_make_readonly(r);
ret = RESUME_GUEST;
@ -758,6 +759,7 @@ static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
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;

5
arch/powerpc/kvm/book3s_hv_rm_mmu.c
View File

@ -265,8 +265,10 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
if (pa)
pteh |= HPTE_V_VALID;
else
else {
pteh |= HPTE_V_ABSENT;
ptel &= ~(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
}
/*If we had host pte mapping then Check WIMG */
if (ptep && !hpte_cache_flags_ok(ptel, is_ci)) {
@ -352,6 +354,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
/* inval in progress, write a non-present HPTE */
pteh |= HPTE_V_ABSENT;
pteh &= ~HPTE_V_VALID;
ptel &= ~(HPTE_R_KEY_HI | HPTE_R_KEY_LO);
unlock_rmap(rmap);
} else {
kvmppc_add_revmap_chain(kvm, rev, rmap, pte_index,