FAILED: patch "[PATCH] KVM: arm64: Eagerly init vgic dist/redist on vgic creation" failed to apply to 6.19-stable tree

FAILED: patch "[PATCH] KVM: arm64: Eagerly init vgic dist/redist on vgic creation" failed to apply to 6.19-stable tree

[gregkh]

The patch below does not apply to the 6.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.19.y
git checkout FETCH_HEAD
git cherry-pick -x ac6769c8f948dff33265c50e524aebf9aa6f1be0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026031607-maimed-erasable-eac8@gregkh' --subject-prefix 'PATCH 6.19.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ac6769c8f948dff33265c50e524aebf9aa6f1be0 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz@kernel.org>
Date: Sat, 28 Feb 2026 16:45:59 +0000
Subject: [PATCH] KVM: arm64: Eagerly init vgic dist/redist on vgic creation

If vgic_allocate_private_irqs_locked() fails for any odd reason,
we exit kvm_vgic_create() early, leaving dist->rd_regions uninitialised.

kvm_vgic_dist_destroy() then comes along and walks into the weeds
trying to free the RDs. Got to love this stuff.

Solve it by moving all the static initialisation early, and make
sure that if we fail halfway, we're in a reasonable shape to
perform the rest of the teardown. While at it, reset the vgic model
on failure, just in case...

Reported-by: syzbot+f6a46b038fc243ac0175@syzkaller.appspotmail.com
Tested-by: syzbot+f6a46b038fc243ac0175@syzkaller.appspotmail.com
Fixes: b3aa9283c0c50 ("KVM: arm64: vgic: Hoist SGI/PPI alloc from vgic_init() to kvm_create_vgic()")
Link: https://lore.kernel.org/r/69a2d58c.050a0220.3a55be.003b.GAE@google.com
Link: https://patch.msgid.link/20260228164559.936268-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 9b3091ad868c..e9b8b5fc480c 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -143,23 +143,6 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	kvm->arch.vgic.in_kernel = true;
 	kvm->arch.vgic.vgic_model = type;
 	kvm->arch.vgic.implementation_rev = KVM_VGIC_IMP_REV_LATEST;
-
-	kvm_for_each_vcpu(i, vcpu, kvm) {
-		ret = vgic_allocate_private_irqs_locked(vcpu, type);
-		if (ret)
-			break;
-	}
-
-	if (ret) {
-		kvm_for_each_vcpu(i, vcpu, kvm) {
-			struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
-			kfree(vgic_cpu->private_irqs);
-			vgic_cpu->private_irqs = NULL;
-		}
-
-		goto out_unlock;
-	}
-
 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
 
 	aa64pfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;
@@ -176,6 +159,23 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, aa64pfr0);
 	kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, pfr1);
 
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		ret = vgic_allocate_private_irqs_locked(vcpu, type);
+		if (ret)
+			break;
+	}
+
+	if (ret) {
+		kvm_for_each_vcpu(i, vcpu, kvm) {
+			struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+			kfree(vgic_cpu->private_irqs);
+			vgic_cpu->private_irqs = NULL;
+		}
+
+		kvm->arch.vgic.vgic_model = 0;
+		goto out_unlock;
+	}
+
 	if (type == KVM_DEV_TYPE_ARM_VGIC_V3)
 		kvm->arch.vgic.nassgicap = system_supports_direct_sgis();
 

[PATCH 6.19.y 1/2] KVM: arm64: gic: Set vgic_model before initing private IRQs

[Sasha Levin]

From: Sascha Bischoff <Sascha.Bischoff@arm.com>

[ Upstream commit 9435c1e1431003e23aa34ef8e46c30d09c3dbcb5 ]

Different GIC types require the private IRQs to be initialised
differently. GICv5 is the culprit as it supports both a different
number of private IRQs, and all of these are PPIs (there are no
SGIs). Moreover, as GICv5 uses the top bits of the interrupt ID to
encode the type, the intid also needs to computed differently.

Up until now, the GIC model has been set after initialising the
private IRQs for a VCPU. Move this earlier to ensure that the GIC
model is available when configuring the private IRQs. While we're at
it, also move the setting of the in_kernel flag and implementation
revision to keep them grouped together as before.

Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260128175919.3828384-7-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Stable-dep-of: ac6769c8f948 ("KVM: arm64: Eagerly init vgic dist/redist on vgic creation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-init.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index dc9f9db310264..86c149537493f 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -140,6 +140,10 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 		goto out_unlock;
 	}
 
+	kvm->arch.vgic.in_kernel = true;
+	kvm->arch.vgic.vgic_model = type;
+	kvm->arch.vgic.implementation_rev = KVM_VGIC_IMP_REV_LATEST;
+
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		ret = vgic_allocate_private_irqs_locked(vcpu, type);
 		if (ret)
@@ -156,10 +160,6 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 		goto out_unlock;
 	}
 
-	kvm->arch.vgic.in_kernel = true;
-	kvm->arch.vgic.vgic_model = type;
-	kvm->arch.vgic.implementation_rev = KVM_VGIC_IMP_REV_LATEST;
-
 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
 
 	aa64pfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;
-- 
2.51.0

[PATCH 6.19.y 2/2] KVM: arm64: Eagerly init vgic dist/redist on vgic creation

[Sasha Levin]

From: Marc Zyngier <maz@kernel.org>

[ Upstream commit ac6769c8f948dff33265c50e524aebf9aa6f1be0 ]

If vgic_allocate_private_irqs_locked() fails for any odd reason,
we exit kvm_vgic_create() early, leaving dist->rd_regions uninitialised.

kvm_vgic_dist_destroy() then comes along and walks into the weeds
trying to free the RDs. Got to love this stuff.

Solve it by moving all the static initialisation early, and make
sure that if we fail halfway, we're in a reasonable shape to
perform the rest of the teardown. While at it, reset the vgic model
on failure, just in case...

Reported-by: syzbot+f6a46b038fc243ac0175@syzkaller.appspotmail.com
Tested-by: syzbot+f6a46b038fc243ac0175@syzkaller.appspotmail.com
Fixes: b3aa9283c0c50 ("KVM: arm64: vgic: Hoist SGI/PPI alloc from vgic_init() to kvm_create_vgic()")
Link: https://lore.kernel.org/r/69a2d58c.050a0220.3a55be.003b.GAE@google.com
Link: https://patch.msgid.link/20260228164559.936268-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm64/kvm/vgic/vgic-init.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 86c149537493f..6ed01c7faa91d 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -143,6 +143,21 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	kvm->arch.vgic.in_kernel = true;
 	kvm->arch.vgic.vgic_model = type;
 	kvm->arch.vgic.implementation_rev = KVM_VGIC_IMP_REV_LATEST;
+	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
+
+	aa64pfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;
+	pfr1 = kvm_read_vm_id_reg(kvm, SYS_ID_PFR1_EL1) & ~ID_PFR1_EL1_GIC;
+
+	if (type == KVM_DEV_TYPE_ARM_VGIC_V2) {
+		kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+	} else {
+		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
+		aa64pfr0 |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, GIC, IMP);
+		pfr1 |= SYS_FIELD_PREP_ENUM(ID_PFR1_EL1, GIC, GICv3);
+	}
+
+	kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, aa64pfr0);
+	kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, pfr1);
 
 	kvm_for_each_vcpu(i, vcpu, kvm) {
 		ret = vgic_allocate_private_irqs_locked(vcpu, type);
@@ -157,25 +172,10 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 			vgic_cpu->private_irqs = NULL;
 		}
 
+		kvm->arch.vgic.vgic_model = 0;
 		goto out_unlock;
 	}
 
-	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
-
-	aa64pfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1) & ~ID_AA64PFR0_EL1_GIC;
-	pfr1 = kvm_read_vm_id_reg(kvm, SYS_ID_PFR1_EL1) & ~ID_PFR1_EL1_GIC;
-
-	if (type == KVM_DEV_TYPE_ARM_VGIC_V2) {
-		kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
-	} else {
-		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
-		aa64pfr0 |= SYS_FIELD_PREP_ENUM(ID_AA64PFR0_EL1, GIC, IMP);
-		pfr1 |= SYS_FIELD_PREP_ENUM(ID_PFR1_EL1, GIC, GICv3);
-	}
-
-	kvm_set_vm_id_reg(kvm, SYS_ID_AA64PFR0_EL1, aa64pfr0);
-	kvm_set_vm_id_reg(kvm, SYS_ID_PFR1_EL1, pfr1);
-
 	if (type == KVM_DEV_TYPE_ARM_VGIC_V3)
 		kvm->arch.vgic.nassgicap = system_supports_direct_sgis();
 
-- 
2.51.0