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[Xen-devel] [PATCH][RFC] FPU LWP 3/5: define new FPU interface functions

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Subject: [Xen-devel] [PATCH][RFC] FPU LWP 3/5: define new FPU interface functions: fpu_save, fpu_restore, fpu_reload
From: Wei Huang <wei.huang2@xxxxxxx>
Date: Thu, 14 Apr 2011 15:38:47 -0500
Delivery-date: Thu, 14 Apr 2011 13:46:00 -0700
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Current Xen implementation only support lazy FPU reload via CR0.TS. But new FPU state isn't always tracked by CR0.TS bit. One example is AMD's lightweight profiling. With this patch, Xen calls fpu_save() on vcpu which is being scheduled out and fpu_restore() on vcpu which is being scheduled in. The nonlazy FPU state is saved and restored in these two functions.

This patch also defines fpu_reload() to handle lazy FPU state when #NM is triggered.

Signed-off-by: Wei Huang <wei.huang2@xxxxxxx>

Attachment: lwp3.txt
Description: lwp3.txt

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