From 4b88ec680fc3ca03a90835040af2bee0bb6cadaf Mon Sep 17 00:00:00 2001
From: Alexander Potapenko <glider@google.com>
Date: Thu, 20 Nov 2025 10:57:11 +0100
Subject: executor: sys/linux/test: basic CPUID handling in L2

Ensure L2 correctly exits to L1 on CPUID and resumes properly.
Add a test.
---
 sys/linux/test/amd64-syz_kvm_nested_vmresume-cpuid | 27 ++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 sys/linux/test/amd64-syz_kvm_nested_vmresume-cpuid

(limited to 'sys/linux')

diff --git a/sys/linux/test/amd64-syz_kvm_nested_vmresume-cpuid b/sys/linux/test/amd64-syz_kvm_nested_vmresume-cpuid
new file mode 100644
index 000000000..43abd7cc3
--- /dev/null
+++ b/sys/linux/test/amd64-syz_kvm_nested_vmresume-cpuid
@@ -0,0 +1,27 @@
+#
+# requires: arch=amd64 -threaded
+#
+r0 = openat$kvm(0, &AUTO='/dev/kvm\x00', 0x0, 0x0)
+r1 = ioctl$KVM_CREATE_VM(r0, AUTO, 0x0)
+r2 = syz_kvm_setup_syzos_vm$x86(r1, &(0x7f0000c00000/0x400000)=nil)
+
+# Create a nested VM that performs CPUID (0f a2) and HLT (f4).
+#
+r3 = syz_kvm_add_vcpu$x86(r2, &AUTO={0x0, &AUTO=[@enable_nested={AUTO, AUTO, 0x0}, @nested_create_vm={AUTO, AUTO, 0x0}, @nested_load_code={AUTO, AUTO, {0x0, "0fa2f4"}}, @nested_vmlaunch={AUTO, AUTO, 0x0}, @nested_vmresume={AUTO, AUTO, 0x0}], AUTO})
+r4 = ioctl$KVM_GET_VCPU_MMAP_SIZE(r0, AUTO)
+r5 = mmap$KVM_VCPU(&(0x7f0000009000/0x1000)=nil, r4, 0x3, 0x1, r3, 0x0)
+
+# L2 VM executes CPUID. Exit reason is mapped to 0xe2e20003.
+#
+ioctl$KVM_RUN(r3, AUTO, 0x0)
+syz_kvm_assert_syzos_uexit$x86(r5, 0xe2e20003)
+
+# L1 resumes L2, which executes HLT. Exit reason is mapped to 0xe2e20001.
+#
+ioctl$KVM_RUN(r3, AUTO, 0x0)
+syz_kvm_assert_syzos_uexit$x86(r5, 0xe2e20001)
+
+# guest_main should finish with guest_uexit(-1).
+#
+ioctl$KVM_RUN(r3, AUTO, 0x0)
+syz_kvm_assert_syzos_uexit$x86(r5, 0xffffffff)
-- 
cgit mrf-deployment