* Akihiro Suda suda.gitsendemail@gmail.com wrote:
Even when X86_FEATURE_PKU and X86_FEATURE_OSPKE are available, XFEATURE_PKRU can be missing. In such a case, pkeys has to be disabled to avoid hanging up.
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
This fix is known to be needed on Apple Virtualization. Tested with macOS 13.5.2 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-g... Link: https://github.com/lima-vm/lima/issues/3334
Signed-off-by: Akihiro Suda akihiro.suda.cz@hco.ntt.co.jp
arch/x86/kernel/cpu/common.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index e9464fe411ac..4c2c268af214 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -517,7 +517,8 @@ static bool pku_disabled; static __always_inline void setup_pku(struct cpuinfo_x86 *c) { if (c == &boot_cpu_data) {
if (pku_disabled || !cpu_feature_enabled(X86_FEATURE_PKU))
if (pku_disabled || !cpu_feature_enabled(X86_FEATURE_PKU) ||!cpu_has_xfeatures(XFEATURE_PKRU, NULL)) return;
Note that silent quirks are counterproductive, as they don't give VM vendors any incentives to fix their VM for such bugs.
So I changed your quirk to be:
--- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -519,6 +519,17 @@ static __always_inline void setup_pku(struct cpuinfo_x86 *c) if (c == &boot_cpu_data) { if (pku_disabled || !cpu_feature_enabled(X86_FEATURE_PKU)) return; + if (!cpu_has_xfeatures(XFEATURE_PKRU, NULL)) { + /* + * Missing XFEATURE_PKRU is not really a valid CPU + * configuration at this point, but apparently + * Apple Virtualization is affected by this, + * so return with a FW warning instead of crashing + * the bootup: + */ + WARN_ONCE(1, FW_BUG "Invalid XFEATURE_PKRU configuration.\n"); + return; + } /* * Setting CR4.PKE will cause the X86_FEATURE_OSPKE cpuid * bit to be set. Enforce it.
This is noisy in the syslog, but it's a WARN_ONCE() and it doesn't crash the bootup.
Thanks,
Ingo