From: Alexander Graf <agraf@suse.de>
To: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	KVM list <kvm@vger.kernel.org>
Subject: [PATCH 08/27] KVM: PPC: Add PV guest critical sections
Date: Thu,  1 Jul 2010 12:42:43 +0200	[thread overview]
Message-ID: <1277980982-12433-9-git-send-email-agraf@suse.de> (raw)
In-Reply-To: <1277980982-12433-1-git-send-email-agraf@suse.de>
When running in hooked code we need a way to disable interrupts without
clobbering any interrupts or exiting out to the hypervisor.
To achieve this, we have an additional critical field in the shared page. If
that field is equal to the r1 register of the guest, it tells the hypervisor
that we're in such a critical section and thus may not receive any interrupts.
Signed-off-by: Alexander Graf <agraf@suse.de>
---
v1 -> v2:
  - make crit detection only trigger in supervisor mode
---
 arch/powerpc/include/asm/kvm_para.h |    1 +
 arch/powerpc/kvm/book3s.c           |   18 ++++++++++++++++--
 arch/powerpc/kvm/booke.c            |   15 +++++++++++++++
 3 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_para.h b/arch/powerpc/include/asm/kvm_para.h
index 89c2760..d9c06ab 100644
--- a/arch/powerpc/include/asm/kvm_para.h
+++ b/arch/powerpc/include/asm/kvm_para.h
@@ -23,6 +23,7 @@
 #include <linux/types.h>
 
 struct kvm_vcpu_arch_shared {
+	__u64 critical;		/* Guest may not get interrupts if == r1 */
 	__u64 sprg0;
 	__u64 sprg1;
 	__u64 sprg2;
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 10afa48..ab43744 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -251,14 +251,28 @@ int kvmppc_book3s_irqprio_deliver(struct kvm_vcpu *vcpu, unsigned int priority)
 	int deliver = 1;
 	int vec = 0;
 	ulong flags = 0ULL;
+	ulong crit_raw = vcpu->arch.shared->critical;
+	ulong crit_r1 = kvmppc_get_gpr(vcpu, 1);
+	bool crit;
+
+	/* Truncate crit indicators in 32 bit mode */
+	if (!(vcpu->arch.shared->msr & MSR_SF)) {
+		crit_raw &= 0xffffffff;
+		crit_r1 &= 0xffffffff;
+	}
+
+	/* Critical section when crit == r1 */
+	crit = (crit_raw == crit_r1);
+	/* ... and we're in supervisor mode */
+	crit = crit && !(vcpu->arch.shared->msr & MSR_PR);
 
 	switch (priority) {
 	case BOOK3S_IRQPRIO_DECREMENTER:
-		deliver = vcpu->arch.shared->msr & MSR_EE;
+		deliver = (vcpu->arch.shared->msr & MSR_EE) && !crit;
 		vec = BOOK3S_INTERRUPT_DECREMENTER;
 		break;
 	case BOOK3S_IRQPRIO_EXTERNAL:
-		deliver = vcpu->arch.shared->msr & MSR_EE;
+		deliver = (vcpu->arch.shared->msr & MSR_EE) && !crit;
 		vec = BOOK3S_INTERRUPT_EXTERNAL;
 		break;
 	case BOOK3S_IRQPRIO_SYSTEM_RESET:
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index bd812f4..b9f8ecf 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -147,6 +147,20 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
 	int allowed = 0;
 	ulong uninitialized_var(msr_mask);
 	bool update_esr = false, update_dear = false;
+	ulong crit_raw = vcpu->arch.shared->critical;
+	ulong crit_r1 = kvmppc_get_gpr(vcpu, 1);
+	bool crit;
+
+	/* Truncate crit indicators in 32 bit mode */
+	if (!(vcpu->arch.shared->msr & MSR_SF)) {
+		crit_raw &= 0xffffffff;
+		crit_r1 &= 0xffffffff;
+	}
+
+	/* Critical section when crit == r1 */
+	crit = (crit_raw == crit_r1);
+	/* ... and we're in supervisor mode */
+	crit = crit && !(vcpu->arch.shared->msr & MSR_PR);
 
 	switch (priority) {
 	case BOOKE_IRQPRIO_DTLB_MISS:
@@ -181,6 +195,7 @@ static int kvmppc_booke_irqprio_deliver(struct kvm_vcpu *vcpu,
 	case BOOKE_IRQPRIO_DECREMENTER:
 	case BOOKE_IRQPRIO_FIT:
 		allowed = vcpu->arch.shared->msr & MSR_EE;
+		allowed = allowed && !crit;
 		msr_mask = MSR_CE|MSR_ME|MSR_DE;
 		break;
 	case BOOKE_IRQPRIO_DEBUG:
-- 
1.6.0.2
next prev parent reply	other threads:[~2010-07-01 10:43 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-07-01 10:42 [PATCH 00/27] KVM PPC PV framework Alexander Graf
2010-07-01 10:42 ` [PATCH 01/27] KVM: PPC: Introduce shared page Alexander Graf
2010-07-01 10:42 ` [PATCH 02/27] KVM: PPC: Convert MSR to " Alexander Graf
2010-07-01 10:42 ` [PATCH 03/27] KVM: PPC: Convert DSISR " Alexander Graf
2010-07-01 10:42 ` [PATCH 04/27] KVM: PPC: Convert DAR " Alexander Graf
2010-07-01 10:42 ` [PATCH 05/27] KVM: PPC: Convert SRR0 and SRR1 " Alexander Graf
2010-07-01 10:42 ` [PATCH 06/27] KVM: PPC: Convert SPRG[0-4] " Alexander Graf
2010-07-01 10:42 ` [PATCH 07/27] KVM: PPC: Implement hypervisor interface Alexander Graf
2010-07-01 10:42 ` Alexander Graf [this message]
2010-07-01 10:42 ` [PATCH 09/27] KVM: PPC: Add PV guest scratch registers Alexander Graf
2010-07-01 10:42 ` [PATCH 10/27] KVM: PPC: Tell guest about pending interrupts Alexander Graf
2010-07-01 10:42 ` [PATCH 11/27] KVM: PPC: Make RMO a define Alexander Graf
2010-07-02 16:23   ` Segher Boessenkool
2010-07-01 10:42 ` [PATCH 12/27] KVM: PPC: First magic page steps Alexander Graf
2010-07-01 10:42 ` [PATCH 13/27] KVM: PPC: Magic Page Book3s support Alexander Graf
2010-07-02 15:37   ` Alexander Graf
2010-07-04  9:42     ` Avi Kivity
2010-07-01 10:42 ` [PATCH 14/27] KVM: PPC: Magic Page BookE support Alexander Graf
2010-07-01 11:18   ` Josh Boyer
2010-07-01 12:25     ` Alexander Graf
2010-07-12 11:24   ` Liu Yu-B13201
2010-07-01 10:42 ` [PATCH 15/27] KVM: PPC: Expose magic page support to guest Alexander Graf
2010-07-01 10:42 ` [PATCH 16/27] KVM: Move kvm_guest_init out of generic code Alexander Graf
2010-07-02  7:41   ` Geert Uytterhoeven
2010-07-02  7:44     ` Alexander Graf
2010-07-01 10:42 ` [PATCH 17/27] KVM: PPC: Generic KVM PV guest support Alexander Graf
2010-07-01 10:42 ` [PATCH 18/27] KVM: PPC: KVM PV guest stubs Alexander Graf
2010-07-01 10:42 ` [PATCH 19/27] KVM: PPC: PV instructions to loads and stores Alexander Graf
2010-07-01 10:42 ` [PATCH 20/27] KVM: PPC: PV tlbsync to nop Alexander Graf
2010-07-01 10:42 ` [PATCH 21/27] KVM: PPC: Introduce kvm_tmp framework Alexander Graf
2010-07-01 10:42 ` [PATCH 22/27] KVM: PPC: Introduce branch patching helper Alexander Graf
2010-07-01 10:42 ` [PATCH 23/27] KVM: PPC: PV assembler helpers Alexander Graf
2010-07-01 10:42 ` [PATCH 24/27] KVM: PPC: PV mtmsrd L=1 Alexander Graf
2010-07-01 10:43 ` [PATCH 25/27] KVM: PPC: PV mtmsrd L=0 and mtmsr Alexander Graf
2010-07-01 10:43 ` [PATCH 26/27] KVM: PPC: PV wrteei Alexander Graf
2010-07-01 10:43 ` [PATCH 27/27] KVM: PPC: Add Documentation about PV interface Alexander Graf
2010-07-02 16:27   ` Segher Boessenkool
2010-07-02 18:41     ` Alexander Graf
2010-07-03 22:42       ` Benjamin Herrenschmidt
2010-07-04  9:04         ` Alexander Graf
2010-07-03 22:41     ` Benjamin Herrenschmidt
2010-07-04  9:04       ` Alexander Graf
2010-07-04  9:10         ` Avi Kivity
2010-07-04  9:17           ` Alexander Graf
2010-07-04  9:30             ` Alexander Graf
2010-07-04  9:41               ` Avi Kivity
2010-07-04  9:37             ` Avi Kivity
2010-07-02 17:59   ` Hollis Blanchard
2010-07-02 18:47     ` Alexander Graf
2010-07-02 19:10       ` Scott Wood
2010-07-04  9:02         ` Alexander Graf
2010-07-09  9:11   ` MJ embd
2010-07-09  9:15     ` Alexander Graf
2010-07-02 16:22 ` [PATCH 00/27] KVM PPC PV framework Segher Boessenkool
2010-07-02 16:59   ` Alexander Graf
2010-07-09  4:57 ` MJ embd
2010-07-09  6:33   ` Alexander Graf
  -- strict thread matches above, loose matches on Subject: below --
2010-07-29 12:47 [PATCH 00/27] KVM PPC PV framework v3 Alexander Graf
2010-07-29 12:47 ` [PATCH 08/27] KVM: PPC: Add PV guest critical sections Alexander Graf
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