KVM: PPC: Book3S HV: Clear the key field of HPTE when the page is paged out
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>
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 95abca6..33a7d1f 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -575,7 +575,8 @@
*/
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 @@
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;
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 6b3d01b..e960c83 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -265,8 +265,10 @@
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 @@
/* 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,