All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thomas Huth <thuth@redhat.com>
To: Paul Mackerras <paulus@samba.org>, kvm-ppc@vger.kernel.org
Cc: kvm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	Michael Ellerman <mpe@ellerman.id.au>,
	Alexander Graf <agraf@suse.com>,
	stable@vger.kernel.org
Subject: [PATCH] KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register
Date: Wed, 21 Sep 2016 15:06:45 +0200	[thread overview]
Message-ID: <1474463205-5965-1-git-send-email-thuth@redhat.com> (raw)

The MMCR2 register is available twice, one time with number 785
(privileged access), and one time with number 769 (unprivileged,
but it can be disabled completely). In former times, the Linux
kernel was using the unprivileged register 769 only, but since
commit 8dd75ccb571f3c92c ("powerpc: Use privileged SPR number
for MMCR2"), it uses the privileged register 785 instead.
The KVM-PR code then of course also switched to use the SPR 785,
but this is causing older guest kernels to crash, since these
kernels still access 769 instead. So to support older kernels
with KVM-PR again, we have to support register 769 in KVM-PR, too.

Fixes: 8dd75ccb571f3c92c48014b3dabd3d51a115ab41
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 arch/powerpc/include/asm/reg.h    | 1 +
 arch/powerpc/kvm/book3s_emulate.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index f69f40f..978dada 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -737,6 +737,7 @@
 #define   MMCR0_FCHV	0x00000001UL /* freeze conditions in hypervisor mode */
 #define SPRN_MMCR1	798
 #define SPRN_MMCR2	785
+#define SPRN_UMMCR2	769
 #define SPRN_MMCRA	0x312
 #define   MMCRA_SDSYNC	0x80000000UL /* SDAR synced with SIAR */
 #define   MMCRA_SDAR_DCACHE_MISS 0x40000000UL
diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 2afdb9c..729f8fa 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -498,6 +498,7 @@ int kvmppc_core_emulate_mtspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val)
 	case SPRN_MMCR0:
 	case SPRN_MMCR1:
 	case SPRN_MMCR2:
+	case SPRN_UMMCR2:
 #endif
 		break;
 unprivileged:
@@ -640,6 +641,7 @@ int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val
 	case SPRN_MMCR0:
 	case SPRN_MMCR1:
 	case SPRN_MMCR2:
+	case SPRN_UMMCR2:
 	case SPRN_TIR:
 #endif
 		*spr_val = 0;
-- 
1.8.3.1


WARNING: multiple messages have this Message-ID (diff)
From: Thomas Huth <thuth@redhat.com>
To: Paul Mackerras <paulus@samba.org>, kvm-ppc@vger.kernel.org
Cc: kvm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	Michael Ellerman <mpe@ellerman.id.au>,
	Alexander Graf <agraf@suse.com>,
	stable@vger.kernel.org
Subject: [PATCH] KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register
Date: Wed, 21 Sep 2016 13:06:45 +0000	[thread overview]
Message-ID: <1474463205-5965-1-git-send-email-thuth@redhat.com> (raw)

The MMCR2 register is available twice, one time with number 785
(privileged access), and one time with number 769 (unprivileged,
but it can be disabled completely). In former times, the Linux
kernel was using the unprivileged register 769 only, but since
commit 8dd75ccb571f3c92c ("powerpc: Use privileged SPR number
for MMCR2"), it uses the privileged register 785 instead.
The KVM-PR code then of course also switched to use the SPR 785,
but this is causing older guest kernels to crash, since these
kernels still access 769 instead. So to support older kernels
with KVM-PR again, we have to support register 769 in KVM-PR, too.

Fixes: 8dd75ccb571f3c92c48014b3dabd3d51a115ab41
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 arch/powerpc/include/asm/reg.h    | 1 +
 arch/powerpc/kvm/book3s_emulate.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index f69f40f..978dada 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -737,6 +737,7 @@
 #define   MMCR0_FCHV	0x00000001UL /* freeze conditions in hypervisor mode */
 #define SPRN_MMCR1	798
 #define SPRN_MMCR2	785
+#define SPRN_UMMCR2	769
 #define SPRN_MMCRA	0x312
 #define   MMCRA_SDSYNC	0x80000000UL /* SDAR synced with SIAR */
 #define   MMCRA_SDAR_DCACHE_MISS 0x40000000UL
diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c
index 2afdb9c..729f8fa 100644
--- a/arch/powerpc/kvm/book3s_emulate.c
+++ b/arch/powerpc/kvm/book3s_emulate.c
@@ -498,6 +498,7 @@ int kvmppc_core_emulate_mtspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong spr_val)
 	case SPRN_MMCR0:
 	case SPRN_MMCR1:
 	case SPRN_MMCR2:
+	case SPRN_UMMCR2:
 #endif
 		break;
 unprivileged:
@@ -640,6 +641,7 @@ int kvmppc_core_emulate_mfspr_pr(struct kvm_vcpu *vcpu, int sprn, ulong *spr_val
 	case SPRN_MMCR0:
 	case SPRN_MMCR1:
 	case SPRN_MMCR2:
+	case SPRN_UMMCR2:
 	case SPRN_TIR:
 #endif
 		*spr_val = 0;
-- 
1.8.3.1


             reply	other threads:[~2016-09-21 13:06 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-21 13:06 Thomas Huth [this message]
2016-09-21 13:06 ` [PATCH] KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register Thomas Huth
2016-09-27  5:45 ` Paul Mackerras
2016-09-27  5:45   ` Paul Mackerras

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1474463205-5965-1-git-send-email-thuth@redhat.com \
    --to=thuth@redhat.com \
    --cc=agraf@suse.com \
    --cc=kvm-ppc@vger.kernel.org \
    --cc=kvm@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mpe@ellerman.id.au \
    --cc=paulus@samba.org \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.