diff mbox

[v2,1/2] KVM: PPC: Book3S HV: Clear the key field of HPTE when the page is paged out

Message ID 1478238912-30680-2-git-send-email-xyjxie@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Yongji Xie Nov. 4, 2016, 5:55 a.m. UTC 
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>
---
 arch/powerpc/kvm/book3s_64_mmu_hv.c |    4 +++-
 arch/powerpc/kvm/book3s_hv_rm_mmu.c |    5 ++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

Comments

Paul Mackerras Nov. 21, 2016, 5:06 a.m. UTC | #1 
On Fri, Nov 04, 2016 at 01:55:11PM +0800, Yongji Xie wrote:
> 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>

Thanks, applied to kvm-ppc-next.

Paul.
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 05f09ae..ec9e545 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -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;
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 99b4e9d..61ff8ee 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -264,8 +264,10 @@  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)) {
@@ -351,6 +353,7 @@  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,