From f7a9f9c4982d10223771d3aa2287538bc08b9024 Mon Sep 17 00:00:00 2001
From: Alexander Potapenko <glider@google.com>
Date: Thu, 20 Nov 2025 12:10:41 +0100
Subject: executor: sys/linux/test: handle RDTSC in L2

Enable basic RDTSC handling. Ensure that Intel hosts exit on RDTSC
in L2, and that both Intel and AMD can handle RDTSC exits.

Add amd64-syz_kvm_nested_vmresume-rdtsc to test that.
---
 sys/linux/test/amd64-syz_kvm_nested_vmresume-rdtsc | 27 ++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 sys/linux/test/amd64-syz_kvm_nested_vmresume-rdtsc

(limited to 'sys')

diff --git a/sys/linux/test/amd64-syz_kvm_nested_vmresume-rdtsc b/sys/linux/test/amd64-syz_kvm_nested_vmresume-rdtsc
new file mode 100644
index 000000000..3c0e25635
--- /dev/null
+++ b/sys/linux/test/amd64-syz_kvm_nested_vmresume-rdtsc
@@ -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$x86(r1, &(0x7f0000c00000/0x400000)=nil)
+
+# Create a nested VM that performs RDTSC (0f 31) and HLT (f4).
+#
+r3 = syz_kvm_add_vcpu$x86(r2, &AUTO={0x0, &AUTO=[@enable_nested={AUTO, AUTO, 0x0}, @nested_create_vm={AUTO, AUTO, 0x0}, @nested_load_code={AUTO, AUTO, {0x0, "0f31f4"}}, @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 0xe2e20004.
+#
+ioctl$KVM_RUN(r3, AUTO, 0x0)
+syz_kvm_assert_syzos_uexit$x86(r5, 0xe2e20004)
+
+# 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