From: Alexander Graf <agraf@suse.de> To: kvm-ppc@vger.kernel.org Cc: kvm list <kvm@vger.kernel.org>, Marcelo Tosatti <mtosatti@redhat.com>, Bharat Bhushan <r65777@freescale.com>, Bharat Bhushan <bharat.bhushan@freescale.com> Subject: [PATCH 14/14] PPC: Fix race in mtmsr paravirt implementation Date: Mon, 31 Oct 2011 08:53:16 +0100 [thread overview] Message-ID: <1320047596-20577-15-git-send-email-agraf@suse.de> (raw) In-Reply-To: <1320047596-20577-1-git-send-email-agraf@suse.de> From: Bharat Bhushan <r65777@freescale.com> The current implementation of mtmsr and mtmsrd are racy in that it does: * check (int_pending == 0) ---> host sets int_pending = 1 <--- * write shared page * done while instead we should check for int_pending after the shared page is written. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> --- arch/powerpc/kernel/kvm_emul.S | 10 ++++------ 1 files changed, 4 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/kvm_emul.S b/arch/powerpc/kernel/kvm_emul.S index f2b1b25..3d64c57 100644 --- a/arch/powerpc/kernel/kvm_emul.S +++ b/arch/powerpc/kernel/kvm_emul.S @@ -167,6 +167,9 @@ maybe_stay_in_guest: kvm_emulate_mtmsr_reg2: ori r30, r0, 0 + /* Put MSR into magic page because we don't call mtmsr */ + STL64(r30, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0) + /* Check if we have to fetch an interrupt */ lwz r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0) cmpwi r31, 0 @@ -174,15 +177,10 @@ kvm_emulate_mtmsr_reg2: /* Check if we may trigger an interrupt */ andi. r31, r30, MSR_EE - beq no_mtmsr - - b do_mtmsr + bne do_mtmsr no_mtmsr: - /* Put MSR into magic page because we don't call mtmsr */ - STL64(r30, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0) - SCRATCH_RESTORE /* Go back to caller */ -- 1.6.0.2
WARNING: multiple messages have this Message-ID (diff)
From: Alexander Graf <agraf@suse.de> To: kvm-ppc@vger.kernel.org Cc: kvm list <kvm@vger.kernel.org>, Marcelo Tosatti <mtosatti@redhat.com>, Bharat Bhushan <r65777@freescale.com>, Bharat Bhushan <bharat.bhushan@freescale.com> Subject: [PATCH 14/14] PPC: Fix race in mtmsr paravirt implementation Date: Mon, 31 Oct 2011 07:53:16 +0000 [thread overview] Message-ID: <1320047596-20577-15-git-send-email-agraf@suse.de> (raw) In-Reply-To: <1320047596-20577-1-git-send-email-agraf@suse.de> From: Bharat Bhushan <r65777@freescale.com> The current implementation of mtmsr and mtmsrd are racy in that it does: * check (int_pending = 0) ---> host sets int_pending = 1 <--- * write shared page * done while instead we should check for int_pending after the shared page is written. Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> --- arch/powerpc/kernel/kvm_emul.S | 10 ++++------ 1 files changed, 4 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/kvm_emul.S b/arch/powerpc/kernel/kvm_emul.S index f2b1b25..3d64c57 100644 --- a/arch/powerpc/kernel/kvm_emul.S +++ b/arch/powerpc/kernel/kvm_emul.S @@ -167,6 +167,9 @@ maybe_stay_in_guest: kvm_emulate_mtmsr_reg2: ori r30, r0, 0 + /* Put MSR into magic page because we don't call mtmsr */ + STL64(r30, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0) + /* Check if we have to fetch an interrupt */ lwz r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0) cmpwi r31, 0 @@ -174,15 +177,10 @@ kvm_emulate_mtmsr_reg2: /* Check if we may trigger an interrupt */ andi. r31, r30, MSR_EE - beq no_mtmsr - - b do_mtmsr + bne do_mtmsr no_mtmsr: - /* Put MSR into magic page because we don't call mtmsr */ - STL64(r30, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0) - SCRATCH_RESTORE /* Go back to caller */ -- 1.6.0.2
next prev parent reply other threads:[~2011-10-31 7:44 UTC|newest] Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-10-31 7:53 [PULL 00/14] ppc patch queue 2011-10-31 Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 7:53 ` [PATCH 01/14] KVM: PPC: e500: don't translate gfn to pfn with preemption disabled Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 12:50 ` Avi Kivity 2011-10-31 12:50 ` [PATCH 01/14] KVM: PPC: e500: don't translate gfn to pfn with Avi Kivity 2011-10-31 18:52 ` [PATCH 01/14] KVM: PPC: e500: don't translate gfn to pfn with preemption disabled Scott Wood 2011-10-31 18:52 ` [PATCH 01/14] KVM: PPC: e500: don't translate gfn to pfn with Scott Wood 2011-11-01 9:00 ` [PATCH 01/14] KVM: PPC: e500: don't translate gfn to pfn with preemption disabled Avi Kivity 2011-11-01 9:00 ` [PATCH 01/14] KVM: PPC: e500: don't translate gfn to pfn with Avi Kivity 2011-10-31 7:53 ` [PATCH 02/14] KVM: PPC: e500: Eliminate preempt_disable in local_sid_destroy_all Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 7:53 ` [PATCH 03/14] KVM: PPC: e500: clear up confusion between host and guest entries Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 7:53 ` [PATCH 04/14] KVM: PPC: e500: MMU API Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 13:24 ` Avi Kivity 2011-10-31 13:24 ` Avi Kivity 2011-10-31 20:12 ` Scott Wood 2011-10-31 20:12 ` Scott Wood 2011-11-01 8:58 ` Avi Kivity 2011-11-01 8:58 ` Avi Kivity 2011-11-01 9:55 ` Avi Kivity 2011-11-01 9:55 ` Avi Kivity 2011-11-01 16:16 ` Scott Wood 2011-11-01 16:16 ` Scott Wood 2011-11-02 10:33 ` Avi Kivity 2011-11-02 10:33 ` Avi Kivity 2011-11-10 14:20 ` Alexander Graf 2011-11-10 14:20 ` Alexander Graf 2011-11-10 14:16 ` Avi Kivity 2011-11-10 14:16 ` Avi Kivity 2011-10-31 7:53 ` [PATCH 05/14] KVM: PPC: e500: tlbsx: fix tlb0 esel Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 7:53 ` [PATCH 06/14] KVM: PPC: e500: Don't hardcode PIR=0 Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 13:27 ` Avi Kivity 2011-10-31 13:27 ` Avi Kivity 2011-10-31 7:53 ` [PATCH 07/14] KVM: PPC: Fix build failure with HV KVM and CBE Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 7:53 ` [PATCH 08/14] Revert "KVM: PPC: Add support for explicit HIOR setting" Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 13:30 ` Avi Kivity 2011-10-31 13:30 ` [PATCH 08/14] Revert "KVM: PPC: Add support for explicit HIOR Avi Kivity 2011-10-31 23:49 ` [PATCH 08/14] Revert "KVM: PPC: Add support for explicit HIOR setting" Alexander Graf 2011-10-31 23:49 ` Alexander Graf 2011-10-31 7:53 ` [PATCH 09/14] KVM: PPC: Add generic single register ioctls Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 13:36 ` Avi Kivity 2011-10-31 13:36 ` Avi Kivity 2011-10-31 17:26 ` Jan Kiszka 2011-10-31 17:26 ` Jan Kiszka 2011-11-10 14:22 ` Alexander Graf 2011-11-10 14:22 ` Alexander Graf 2011-11-10 16:05 ` Marcelo Tosatti 2011-11-10 16:05 ` Marcelo Tosatti 2011-11-10 16:49 ` Alexander Graf 2011-11-10 16:49 ` Alexander Graf 2011-11-10 17:35 ` Marcelo Tosatti 2011-11-10 17:35 ` Marcelo Tosatti 2011-11-15 23:45 ` Alexander Graf 2011-11-15 23:45 ` Alexander Graf 2011-11-23 12:47 ` Marcelo Tosatti 2011-11-23 12:47 ` Marcelo Tosatti 2011-12-19 12:58 ` Alexander Graf 2011-12-19 12:58 ` Alexander Graf 2011-12-19 17:29 ` Marcelo Tosatti 2011-12-19 17:29 ` Marcelo Tosatti 2011-10-31 7:53 ` [PATCH 10/14] KVM: PPC: Add support for explicit HIOR setting Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 7:53 ` [PATCH 11/14] KVM: PPC: Whitespace fix for kvm.h Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 7:53 ` [PATCH 12/14] KVM: Fix whitespace in kvm_para.h Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 7:53 ` [PATCH 13/14] KVM: PPC: E500: Support hugetlbfs Alexander Graf 2011-10-31 7:53 ` Alexander Graf 2011-10-31 13:38 ` Avi Kivity 2011-10-31 13:38 ` Avi Kivity 2011-11-10 14:24 ` Alexander Graf 2011-11-10 14:24 ` Alexander Graf 2011-10-31 7:53 ` Alexander Graf [this message] 2011-10-31 7:53 ` [PATCH 14/14] PPC: Fix race in mtmsr paravirt implementation Alexander Graf
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