id = 1011
title = "hvf: RDTSCP capability not passed to guests"
state = "closed"
created_at = "2022-05-02T20:34:23.082Z"
closed_at = "2022-07-14T13:25:47.363Z"
labels = ["accel: HVF"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/1011"
host-os = "macOS Monterey 12.3.1"
host-arch = "x86_64"
qemu-version = "6.2.0, master"
guest-os = "Alpine 3.15.4"
guest-arch = "x86_64"
description = """"""
reproduce = """1. Run:
wget https://dl-cdn.alpinelinux.org/alpine/v3.15/releases/x86/alpine-standard-3.15.4-x86.iso
./qemu-system-x86_64 -cpu host,+rdtscp -machine q35,accel=hvf -m 512 -cdrom ./alpine-standard-3.15.4-x86.iso

2. login as "root"
3. type

cat /etc/cpuinfo | grep rdtscp

Expected result: cpu flag lines including rdtscp
Actual result: empty, with:

warning: host doesn't support requested feature: CPUID.80000001H:EDX.rdtscp [bit 27]"""
additional = """This patch apparently resolves the issue according to my tests:

https://lore.kernel.org/qemu-devel/20211101054836.21471-1-dirty@apple.com/"""