#
# 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:
# 1. Sets R15 to a magic value.
# 2. Does UEXIT(1) to L1.
# 3. L1 clobbers R15 and resumes L2.
# 4. L2 does UEXIT(R15).
# 5. Host verifies that L2's R15 was preserved despite L1 clobber.
#
# L2 Payload:
#   49bf563412efbeadde00  movabs $0x00deadbeef123456, %r15
#   b801000000            mov $1, %rax
#   48ba0001040000000000  mov $0x40100, %rdx
#   488902                mov %rax, (%rdx)  --> UEXIT(1)
#   4c89f8                mov %r15, %rax
#   488902                mov %rax, (%rdx)  --> UEXIT(R15)
#   f4                    hlt
#
# L1 Clobber:
#   49bf0000000000000000  movabs $0, %r15
#
r3 = syz_kvm_add_vcpu$x86(r2, &AUTO={0x0, &AUTO=[@enable_nested={AUTO, AUTO, 0x0}, @nested_create_vm={AUTO, AUTO, 0x0}, @nested_load_code={AUTO, AUTO, {0x0, "49bf563412efbeadde00b80100000048ba00010400000000004889024c89f8488902f4"}}, @nested_vmlaunch={AUTO, AUTO, 0x0}, @code={AUTO, AUTO, {"49bf0000000000000000", 0xc3}}, @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)

# 1. Run until first UEXIT (L2 notifies it's ready).
# Expected L2 exit code 1 -> L1 uexit 0x0100000000000001.
#
ioctl$KVM_RUN(r3, AUTO, 0x0)
syz_kvm_assert_syzos_uexit$x86(r3, r5, 0x0100000000000001)

# 2. Run until second UEXIT (L2 returns its R15).
# L1 clobbered its own R15 in between.
# Expected L2 exit code 0x00deadbeef123456 -> L1 uexit 0x01deadbeef123456.
#
ioctl$KVM_RUN(r3, AUTO, 0x0)
syz_kvm_assert_syzos_uexit$x86(r3, r5, 0x01deadbeef123456)

# Final exit.
#
ioctl$KVM_RUN(r3, AUTO, 0x0)
syz_kvm_assert_syzos_uexit$x86(r3, r5, 0xffffffffffffffff)