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From: Paul Mackerras <paulus@samba.org>
To: Alexander Graf <agraf@suse.de>, kvm-ppc@vger.kernel.org
Cc: kvm@vger.kernel.org
Subject: [PATCH 1/5] KVM: PPC: Book3S PR: Fix proto-VSID calculations
Date: Sat, 22 Jun 2013 17:13:32 +1000	[thread overview]
Message-ID: <20130622071332.GB2791@iris.ozlabs.ibm.com> (raw)
In-Reply-To: <20130622071244.GA2791@iris.ozlabs.ibm.com>

This makes sure the calculation of the proto-VSIDs used by PR KVM
is done with 64-bit arithmetic.  Since vcpu3s->context_id[] is int,
when we do vcpu3s->context_id[0] << ESID_BITS the shift will be done
with 32-bit instructions, possibly leading to significant bits
getting lost, as the context id can be up to 524283 and ESID_BITS is
18.  To fix this we cast the context id to u64 before shifting.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/kvm/book3s_64_mmu_host.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
index 3a9a1ac..2c6e7ee 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -325,9 +325,9 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 		return -1;
 	vcpu3s->context_id[0] = err;
 
-	vcpu3s->proto_vsid_max = ((vcpu3s->context_id[0] + 1)
+	vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
 				  << ESID_BITS) - 1;
-	vcpu3s->proto_vsid_first = vcpu3s->context_id[0] << ESID_BITS;
+	vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
 	vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 
 	kvmppc_mmu_hpte_init(vcpu);
-- 
1.8.3.1

WARNING: multiple messages have this Message-ID (diff)
From: Paul Mackerras <paulus@samba.org>
To: Alexander Graf <agraf@suse.de>, kvm-ppc@vger.kernel.org
Cc: kvm@vger.kernel.org
Subject: [PATCH 1/5] KVM: PPC: Book3S PR: Fix proto-VSID calculations
Date: Sat, 22 Jun 2013 07:13:32 +0000	[thread overview]
Message-ID: <20130622071332.GB2791@iris.ozlabs.ibm.com> (raw)
In-Reply-To: <20130622071244.GA2791@iris.ozlabs.ibm.com>

This makes sure the calculation of the proto-VSIDs used by PR KVM
is done with 64-bit arithmetic.  Since vcpu3s->context_id[] is int,
when we do vcpu3s->context_id[0] << ESID_BITS the shift will be done
with 32-bit instructions, possibly leading to significant bits
getting lost, as the context id can be up to 524283 and ESID_BITS is
18.  To fix this we cast the context id to u64 before shifting.

Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/kvm/book3s_64_mmu_host.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_mmu_host.c b/arch/powerpc/kvm/book3s_64_mmu_host.c
index 3a9a1ac..2c6e7ee 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_host.c
@@ -325,9 +325,9 @@ int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
 		return -1;
 	vcpu3s->context_id[0] = err;
 
-	vcpu3s->proto_vsid_max = ((vcpu3s->context_id[0] + 1)
+	vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
 				  << ESID_BITS) - 1;
-	vcpu3s->proto_vsid_first = vcpu3s->context_id[0] << ESID_BITS;
+	vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
 	vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
 
 	kvmppc_mmu_hpte_init(vcpu);
-- 
1.8.3.1


  reply	other threads:[~2013-06-22  7:13 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-22  7:12 [PATCH 0/5] Some fixes and improvements for PR KVM Paul Mackerras
2013-06-22  7:12 ` Paul Mackerras
2013-06-22  7:13 ` Paul Mackerras [this message]
2013-06-22  7:13   ` [PATCH 1/5] KVM: PPC: Book3S PR: Fix proto-VSID calculations Paul Mackerras
2013-06-22  7:14 ` [PATCH 2/5] KVM: PPC: Book3S PR: Fix invalidation of SLB entry 0 on guest entry Paul Mackerras
2013-06-22  7:14   ` Paul Mackerras
2013-06-22  7:14 ` [PATCH 3/5] KVM: PPC: Book3S PR: Don't keep scanning HPTEG after we find a match Paul Mackerras
2013-06-22  7:14   ` Paul Mackerras
2013-06-22 17:42   ` Alexander Graf
2013-06-22 17:42     ` Alexander Graf
2013-06-22  7:15 ` [PATCH 4/5] KVM: PPC: Book3S PR: Invalidate SLB entries properly Paul Mackerras
2013-06-22  7:15   ` Paul Mackerras
2013-06-22 17:48   ` Alexander Graf
2013-06-22 17:48     ` Alexander Graf
2013-06-22 23:30     ` Paul Mackerras
2013-06-22 23:30       ` Paul Mackerras
2013-06-22 23:38       ` Alexander Graf
2013-06-22 23:38         ` Alexander Graf
2013-06-22  7:16 ` [PATCH 5/5] KVM: PPC: Book3S PR: Allow guest to use 1TB segments Paul Mackerras
2013-06-22  7:16   ` Paul Mackerras
2013-06-22 17:57 ` [PATCH 0/5] Some fixes and improvements for PR KVM Alexander Graf
2013-06-22 17:57   ` Alexander Graf

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