[syzbot ci] Re: KVM Planes + SEV-SNP Support

[syzbot ci <syzbot+ci5127b91b8837842d@syzkaller.appspotmail.com>]

syzbot ci has tested the following series

[v1] KVM Planes + SEV-SNP Support
https://lore.kernel.org/all/20260608144252.351443-1-joro@8bytes.org
* [PATCH 01/60] x86/sev: Define the #HV doorbell page structure
* [PATCH 02/60] KVM: SVM: Add support for the SEV-SNP #HV doorbell page NAE event
* [PATCH 03/60] KVM: SVM: Inject #HV when Restricted Injection is active
* [PATCH 04/60] KVM: SVM: Inject NMIs when Restricted Injection is active
* [PATCH 05/60] KVM: SVM: Inject MCEs when Restricted Injection is active
* [PATCH 06/60] KVM: SVM: Enable Restricted Injection for an SEV-SNP guest
* [PATCH 07/60] KVM: SVM: Add support for the SEV-SNP #HV IPI NAE event
* [PATCH 08/60] Documentation: kvm: introduce "VM plane" concept
* [PATCH 09/60] kvm: Introduce struct kvm_plane
* [PATCH 10/60] kvm: Move vcpu_array to struct kvm_plane
* [PATCH 11/60] kvm: Introduce struct kvm_vcpu_common
* [PATCH 12/60] kvm: Move vcpu accounting to struct kvm_vcpu_common
* [PATCH 13/60] kvm: Add read accessors for kvm_vcpu scheduling state
* [PATCH 14/60] kvm: Make kvm_running_vcpus point to struct kvm_vcpu_common
* [PATCH 15/60] kvm: Move VCPU scheduling state to struct kvm_vcpu_common
* [PATCH 16/60] kvm: Add accessors for kvm_vcpu->mutex
* [PATCH 17/60] kvm: Move VCPU locking to struct kvm_vcpu_common
* [PATCH 18/60] kvm: Move kvm_vcpu->rcuwait to struct kvm_vcpu_common
* [PATCH 19/60] kvm: Introduce accessors for kvm_vcpu->mode
* [PATCH 20/60] kvm: Move kvm_vcpu mode and requests field to struct kvm_vcpu_common
* [PATCH 21/60] kvm: Introduce per-plane VCPU requests
* [PATCH 22/60] kvm: Move kvm_vcpu pid members to struct kvm_vcpu_common
* [PATCH 23/60] kvm: Move kvm_vcpu sigset members to struct kvm_vcpu_common
* [PATCH 24/60] kvm: Move kvm_vcpu spinloop members to struct kvm_vcpu_common
* [PATCH 25/60] kvm: Move kvm_vcpu->dirty_ring to struct kvm_vcpu_common
* [PATCH 26/60] kvm: Introduce arch-specific plane state
* [PATCH 27/60] kvm: Introduce arch-specific part of struct kvm_vcpu_common
* [PATCH 28/60] kvm: Implement KVM_CAP_PLANES
* [PATCH 29/60] kvm: Implement KVM_CREATE_PLANE ioctl
* [PATCH 30/60] kvm: Add KVM_EXIT_PLANE_EVENT
* [PATCH 31/60] kvm: Allocate struct kvm_plane in architecture code
* [PATCH 32/60] kvm: Allocate struct kvm_run only for struct kvm_vcpu_common
* [PATCH 33/60] KVM: Implement KVM_CREATE_VCPU ioctl for planes
* [PATCH 34/60] kvm: Keep track of plane VCPUs in struct kvm_vcpu_common
* [PATCH 35/60] kvm: Add VCPU plane-scheduling state and helpers
* [PATCH 36/60] kvm: Add plane_level to kvm_kernel_irq_routing_entry
* [PATCH 37/60] kvm: Pass plane_level to kvm_set_routing_entry()
* [PATCH 38/60] kvm: Make KVM_SIGNAL_MSI per plane
* [PATCH 39/60] kvm: Make KVM_SET_GSI_ROUTING per plane
* [PATCH 40/60] kvm: x86: Handle IOAPIC EOIs per plane
* [PATCH 41/60] kvm: x86: Make apic_map per plane
* [PATCH 42/60] kvm: x86: Make local APIC code aware of planes
* [PATCH 43/60] kvm: x86: Move CPUID state to struct kvm_vcpu_arch_common
* [PATCH 44/60] kvm: x86: Move cpu_caps to struct kvm_vcpu_arch_common
* [PATCH 45/60] kvm: x86: Update state for all plane VCPUs after CPUID update
* [PATCH 46/60] kvm: x86: Share MTRR state across planes
* [PATCH 47/60] kvm: x86: Select a plane to run
* [PATCH 48/60] kvm: x86: Make event injection VCPU requests per-plane
* [PATCH 49/60] kvm: x86: Allow hardware backend to overwrite struct kvm_plane allocation
* [PATCH 50/60] kvm: x86: Make KVM_REQ_UPDATE_PROTECTED_GUEST_STATE per plane
* [PATCH 51/60] kvm: x86: Share pio_data across planes
* [PATCH 52/60] kvm: x86: Switch to plane0 if it has events
* [PATCH 53/60] kvm: x86: Introduce max_planes x86-op
* [PATCH 54/60] kvm: x86: Restrict KVM planes support to KVM_IRQCHIP_SPLIT
* [PATCH 55/60] kvm: svm: Track vmsa_features per plane
* [PATCH 56/60] kvm: svm: Implement GET_AP_APIC_IDS NAE event
* [PATCH 57/60] kvm: sev: Allow for VMPL level specification in AP create
* [PATCH 58/60] kvm: svm: Invoke a specified VMPL level VMSA for the vCPU
* [PATCH 59/60] kvm: svm: Implement max_planes x86 operation
* [PATCH 60/60] kvm: svm: Advertise full multi-VMPL support to the SNP guest

and found the following issue:
WARNING in __kvm_plane_ioctl

Full report is available here:
https://ci.syzbot.org/series/7426b4e7-e1df-4f2e-8464-acda36316e29

***

WARNING in __kvm_plane_ioctl

tree:      torvalds
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
base:      2d3090a8aeb596a26935db0955d46c9a5db5c6ce
arch:      amd64
compiler:  Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
config:    https://ci.syzbot.org/builds/f9f7af87-a544-413f-b7e0-662f92794f11/config
syz repro: https://ci.syzbot.org/findings/751865bf-494c-4000-9b11-d8aa15f03893/syz_repro

------------[ cut here ]------------
r == -EBUSY
WARNING: arch/x86/kvm/../../../virt/kvm/kvm_main.c:4412 at kvm_plane_ioctl_create_vcpu virt/kvm/kvm_main.c:4412 [inline], CPU#1: syz.2.19/5809
WARNING: arch/x86/kvm/../../../virt/kvm/kvm_main.c:4412 at __kvm_plane_ioctl+0x8bd/0xa70 virt/kvm/kvm_main.c:4908, CPU#1: syz.2.19/5809
Modules linked in:
CPU: 1 UID: 0 PID: 5809 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:kvm_plane_ioctl_create_vcpu virt/kvm/kvm_main.c:4412 [inline]
RIP: 0010:__kvm_plane_ioctl+0x8bd/0xa70 virt/kvm/kvm_main.c:4908
Code: e8 c8 0a 09 00 4c 89 f7 e8 80 a3 ff ff 48 8b 3d a9 a8 fd 11 4c 89 f6 e8 c1 35 e7 00 49 63 c7 e9 8c fc ff ff e8 94 2f 87 00 90 <0f> 0b 90 41 bf f0 ff ff ff eb bc e8 e3 eb 68 0a 89 f9 80 e1 07 80
RSP: 0018:ffffc9000318f940 EFLAGS: 00010293
RAX: ffffffff813f480c RBX: ffff8881ba113410 RCX: ffff88810d4f4a80
RDX: 0000000000000000 RSI: ffffffff8e6fa0b0 RDI: 00000000fffffff0
RBP: ffffc9000318fa70 R08: ffff88810d4f4a80 R09: 0000000000000002
R10: 00000000fffffff0 R11: 0000000000000000 R12: 1ffff92000631f34
R13: dffffc0000000000 R14: ffff8881b446cb18 R15: 00000000fffffff0
FS:  00007f13e64ad6c0(0000) GS:ffff8882a929c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f13e64acff8 CR3: 00000001a6053000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 kvm_vm_ioctl+0x88e/0xbf0 virt/kvm/kvm_main.c:5546
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f13e559ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f13e64ad028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f13e5816090 RCX: 00007f13e559ce59
RDX: 0000000000000000 RSI: 000000000000ae41 RDI: 0000000000000004
RBP: 00007f13e5632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f13e5816128 R14: 00007f13e5816090 R15: 00007fff90c39748
 </TASK>


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
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