x86/cpu: Don't write CSTAR MSR on Intel CPUs

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Intel CPUs do not support SYSCALL in 32-bit mode, but the kernel
initializes MSR_CSTAR unconditionally. That MSR write is normally
ignored by the CPU, but in a TDX guest it raises a #VE trap.

Exclude Intel CPUs from the MSR_CSTAR initialization.

[ tglx: Fixed the subject line and removed the redundant comment. ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20211119035803.4012145-1-sathyanarayanan.kuppuswamy@linux.intel.com

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Andi Kleen 2021-11-18 19:58:03 -08:00 • committed by Thomas Gleixner

parent 1360572566

commit 9c7e2634f6

1 changed files with 13 additions and 2 deletions

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arch/x86/kernel/cpu/common.c

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