[PULL 1/8] KVM: arm/arm64: Fix bug in advertising KVM_CAP_MSI_DEVID capability

[PULL 1/8] KVM: arm/arm64: Fix bug in advertising KVM_CAP_MSI_DEVID capability

[Christoffer Dall]

From: Shanker Donthineni <shankerd@codeaurora.org>

Commit 0e4e82f154e3 ("KVM: arm64: vgic-its: Enable ITS emulation as
a virtual MSI controller") tried to advertise KVM_CAP_MSI_DEVID, but
the code logic was not updating the dist->msis_require_devid field
correctly. If hypervisor tool creates the ITS device after VGIC
initialization then we don't advertise KVM_CAP_MSI_DEVID capability.

Update the field msis_require_devid to true inside vgic_its_create()
to fix the issue.

Cc: stable@vger.kernel.org
Fixes: 0e4e82f154e3 ("vgic-its: Enable ITS emulation as a virtual MSI controller")
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/vgic/vgic-init.c | 3 ---
 virt/kvm/arm/vgic/vgic-its.c  | 1 +
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 3a0b899..5801261 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -285,9 +285,6 @@ int vgic_init(struct kvm *kvm)
 	if (ret)
 		goto out;
 
-	if (vgic_has_its(kvm))
-		dist->msis_require_devid = true;
-
 	kvm_for_each_vcpu(i, vcpu, kvm)
 		kvm_vgic_vcpu_enable(vcpu);
 
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 2dff288..aa6b68d 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1598,6 +1598,7 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
 	INIT_LIST_HEAD(&its->device_list);
 	INIT_LIST_HEAD(&its->collection_list);
 
+	dev->kvm->arch.vgic.msis_require_devid = true;
 	dev->kvm->arch.vgic.has_its = true;
 	its->enabled = false;
 	its->dev = dev;
-- 
2.9.0

[PULL 2/8] KVM: arm/arm64: PMU: Fix overflow interrupt injection

[Christoffer Dall]

From: Andrew Jones <drjones@redhat.com>

kvm_pmu_overflow_set() is called from perf's interrupt handler,
making the call of kvm_vgic_inject_irq() from it introduced with
"KVM: arm/arm64: PMU: remove request-less vcpu kick" a really bad
idea, as it's quite easy to try and retake a lock that the
interrupted context is already holding. The fix is to use a vcpu
kick, leaving the interrupt injection to kvm_pmu_sync_hwstate(),
like it was doing before the refactoring. We don't just revert,
though, because before the kick was request-less, leaving the vcpu
exposed to the request-less vcpu kick race, and also because the
kick was used unnecessarily from register access handlers.

Cc: stable@vger.kernel.org
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm64/kvm/sys_regs.c |  2 +-
 include/kvm/arm_pmu.h     |  2 --
 virt/kvm/arm/pmu.c        | 43 +++++++++++++++----------------------------
 3 files changed, 16 insertions(+), 31 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 7786288..2e070d3 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -764,7 +764,7 @@ static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 	if (p->is_write) {
 		if (r->CRm & 0x2)
 			/* accessing PMOVSSET_EL0 */
-			kvm_pmu_overflow_set(vcpu, p->regval & mask);
+			vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= (p->regval & mask);
 		else
 			/* accessing PMOVSCLR_EL0 */
 			vcpu_sys_reg(vcpu, PMOVSSET_EL0) &= ~(p->regval & mask);
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index f6e0306..f87fe20 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -48,7 +48,6 @@ void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu);
 void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu);
 void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val);
-void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu);
 void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu);
 bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu);
@@ -86,7 +85,6 @@ static inline void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu) {}
 static inline void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu) {}
 static inline void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val) {}
-static inline void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu) {}
 static inline void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu) {}
 static inline bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu)
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index fc8a723..8a9c423 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -203,11 +203,15 @@ static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu)
 	return reg;
 }
 
-static void kvm_pmu_check_overflow(struct kvm_vcpu *vcpu)
+static void kvm_pmu_update_state(struct kvm_vcpu *vcpu)
 {
 	struct kvm_pmu *pmu = &vcpu->arch.pmu;
-	bool overflow = !!kvm_pmu_overflow_status(vcpu);
+	bool overflow;
+
+	if (!kvm_arm_pmu_v3_ready(vcpu))
+		return;
 
+	overflow = !!kvm_pmu_overflow_status(vcpu);
 	if (pmu->irq_level == overflow)
 		return;
 
@@ -215,33 +219,11 @@ static void kvm_pmu_check_overflow(struct kvm_vcpu *vcpu)
 
 	if (likely(irqchip_in_kernel(vcpu->kvm))) {
 		int ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
-					      pmu->irq_num, overflow,
-					      &vcpu->arch.pmu);
+					      pmu->irq_num, overflow, pmu);
 		WARN_ON(ret);
 	}
 }
 
-/**
- * kvm_pmu_overflow_set - set PMU overflow interrupt
- * @vcpu: The vcpu pointer
- * @val: the value guest writes to PMOVSSET register
- */
-void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val)
-{
-	if (val == 0)
-		return;
-
-	vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= val;
-	kvm_pmu_check_overflow(vcpu);
-}
-
-static void kvm_pmu_update_state(struct kvm_vcpu *vcpu)
-{
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return;
-	kvm_pmu_check_overflow(vcpu);
-}
-
 bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu)
 {
 	struct kvm_pmu *pmu = &vcpu->arch.pmu;
@@ -303,7 +285,7 @@ static inline struct kvm_vcpu *kvm_pmc_to_vcpu(struct kvm_pmc *pmc)
 }
 
 /**
- * When perf event overflows, call kvm_pmu_overflow_set to set overflow status.
+ * When the perf event overflows, set the overflow status and inform the vcpu.
  */
 static void kvm_pmu_perf_overflow(struct perf_event *perf_event,
 				  struct perf_sample_data *data,
@@ -313,7 +295,12 @@ static void kvm_pmu_perf_overflow(struct perf_event *perf_event,
 	struct kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc);
 	int idx = pmc->idx;
 
-	kvm_pmu_overflow_set(vcpu, BIT(idx));
+	vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(idx);
+
+	if (kvm_pmu_overflow_status(vcpu)) {
+		kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
+		kvm_vcpu_kick(vcpu);
+	}
 }
 
 /**
@@ -341,7 +328,7 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val)
 			reg = lower_32_bits(reg);
 			vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg;
 			if (!reg)
-				kvm_pmu_overflow_set(vcpu, BIT(i));
+				vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(i);
 		}
 	}
 }
-- 
2.9.0

[PULL 3/8] KVM: arm/arm64: Handle hva aging while destroying the vm

[Christoffer Dall]

From: Suzuki K Poulose <Suzuki.Poulose@arm.com>

The mmu_notifier_release() callback of KVM triggers cleaning up
the stage2 page table on kvm-arm. However there could be other
notifier callbacks in parallel with the mmu_notifier_release(),
which could cause the call backs ending up in an empty stage2
page table. Make sure we check it for all the notifier callbacks.

Cc: stable@vger.kernel.org
Fixes: commit 293f29363 ("kvm-arm: Unmap shadow pagetables properly")
Reported-by: Alex Graf <agraf@suse.de>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 virt/kvm/arm/mmu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 0e1fc75..2ea21da 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1718,12 +1718,16 @@ static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *
 
 int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
 {
+	if (!kvm->arch.pgd)
+		return 0;
 	trace_kvm_age_hva(start, end);
 	return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
 }
 
 int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
 {
+	if (!kvm->arch.pgd)
+		return 0;
 	trace_kvm_test_age_hva(hva);
 	return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
 }
-- 
2.9.0