Re: [PATCH v2] x86: disable PKU when running on Apple Virtualization
From: Akihiro Suda
Date: Thu Mar 13 2025 - 20:00:08 EST
Thank you Ingo, and sorry for adding #ifdef CONFIG_ACPI
Regards,
Akihiro Suda
2025年3月14日(金) 2:02 Ingo Molnar <mingo@xxxxxxxxxx>:
>
>
> * Akihiro Suda <suda.gitsendemail@xxxxxxxxx> wrote:
>
> > OSPKE seems broken on Apple Virtualization.
> >
> > WARNING: CPU: 0 PID: 1 at arch/x86/kernel/fpu/xstate.c:1003 get_xsave_addr_user+0x28/0x40
> > (...)
> > Call Trace:
> > <TASK>
> > ? get_xsave_addr_user+0x28/0x40
> > ? __warn.cold+0x8e/0xea
> > ? get_xsave_addr_user+0x28/0x40
> > ? report_bug+0xff/0x140
> > ? handle_bug+0x3b/0x70
> > ? exc_invalid_op+0x17/0x70
> > ? asm_exc_invalid_op+0x1a/0x20
> > ? get_xsave_addr_user+0x28/0x40
> > copy_fpstate_to_sigframe+0x1be/0x380
> > ? __put_user_8+0x11/0x20
> > get_sigframe+0xf1/0x280
> > x64_setup_rt_frame+0x67/0x2c0
> > arch_do_signal_or_restart+0x1b3/0x240
> > syscall_exit_to_user_mode+0xb0/0x130
> > do_syscall_64+0xab/0x1a0
> > entry_SYSCALL_64_after_hwframe+0x77/0x7f
> >
> > Tested on macOS 13.5.1 running on MacBook Pro 2020 with
> > Intel(R) Core(TM) i7-1068NG7 CPU @ 2.30GHz.
> >
> > Fixes: 70044df250d0 ("x86/pkeys: Update PKRU to enable all pkeys before XSAVE")
> > Link: https://lore.kernel.org/regressions/CAG8fp8QvH71Wi_y7b7tgFp7knK38rfrF7rRHh-gFKqeS0gxY6Q@xxxxxxxxxxxxxx/T/#u
> > Link: https://github.com/lima-vm/lima/issues/3334
> > Signed-off-by: Akihiro Suda <akihiro.suda.cz@xxxxxxxxxxxxx>
> > ---
> > v2: check oem_table_id rather than oem_id for better robustness
>
> So this is rather weird, but I've applied the quirk as it upgrades
> broken guest side code into a boot time warning.
>
> > + /*
> > + * OSPKE seems broken on Apple Virtualization.
> > + * https://lore.kernel.org/regressions/CAG8fp8QvH71Wi_y7b7tgFp7knK38rfrF7rRHh-gFKqeS0gxY6Q@xxxxxxxxxxxxxx/T/#u
> > + *
> > + * TODO: conditionally enable pku depending on the DMI BIOS version when Apple
> > + * fixes the issue.
> > + *
> > + * However, this would be still not enough because DMI is missing when vmlinuz
> > + * is directly loaded into VM.
> > + */
> > + if (!memcmp(acpi_gbl_FADT.header.oem_table_id, "Apple Vz", 8)) {
> > + pr_info("pku: disabled on Apple Virtualization platform (Intel) due to a bug\n");
> > + pku_disabled = true;
> > + }
>
> Note that I updated the comments here (the git log gives enough
> information), plus enclosed this into #ifdef CONFIG_ACPI, as
> acpi_gbl_FADT is not available on !CONFIG_ACPI builds.
>
> Thanks,
>
> Ingo