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authorChang S. Bae <chang.seok.bae@intel.com>2021-10-21 15:55:18 -0700
committerBorislav Petkov <bp@suse.de>2021-10-26 10:18:09 +0200
commit8bf26758ca9659866b844dd51037314b4c0fa6bd (patch)
tree4c702e253c9112ab848855451484aef3a9148ad0 /arch/x86/kernel/fpu
parentx86/msr-index: Add MSRs for XFD (diff)
downloadlinux-dev-8bf26758ca9659866b844dd51037314b4c0fa6bd.tar.xz
linux-dev-8bf26758ca9659866b844dd51037314b4c0fa6bd.zip
x86/fpu: Add XFD state to fpstate
Add storage for XFD register state to struct fpstate. This will be used to store the XFD MSR state. This will be used for switching the XFD MSR when FPU content is restored. Add a per-CPU variable to cache the current MSR value so the MSR has only to be written when the values are different. Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211021225527.10184-15-chang.seok.bae@intel.com
Diffstat (limited to 'arch/x86/kernel/fpu')
-rw-r--r--arch/x86/kernel/fpu/core.c2
-rw-r--r--arch/x86/kernel/fpu/xstate.h4
2 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 3349068cef7d..3b72cddf990d 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -27,6 +27,7 @@
#ifdef CONFIG_X86_64
DEFINE_STATIC_KEY_FALSE(__fpu_state_size_dynamic);
+DEFINE_PER_CPU(u64, xfd_state);
#endif
/* The FPU state configuration data for kernel and user space */
@@ -409,6 +410,7 @@ static void __fpstate_reset(struct fpstate *fpstate)
fpstate->user_size = fpu_user_cfg.default_size;
fpstate->xfeatures = fpu_kernel_cfg.default_features;
fpstate->user_xfeatures = fpu_user_cfg.default_features;
+ fpstate->xfd = init_fpstate.xfd;
}
void fpstate_reset(struct fpu *fpu)
diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h
index 4ce1dc030f38..32a4dee4de3b 100644
--- a/arch/x86/kernel/fpu/xstate.h
+++ b/arch/x86/kernel/fpu/xstate.h
@@ -5,6 +5,10 @@
#include <asm/cpufeature.h>
#include <asm/fpu/xstate.h>
+#ifdef CONFIG_X86_64
+DECLARE_PER_CPU(u64, xfd_state);
+#endif
+
static inline void xstate_init_xcomp_bv(struct xregs_state *xsave, u64 mask)
{
/*