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-rw-r--r--arch/x86/kernel/fpu/core.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index e02705187bbf..aefd412a23dc 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -218,7 +218,7 @@ void fpu_reset_from_exception_fixup(void)
}
#if IS_ENABLED(CONFIG_KVM)
-static void __fpstate_reset(struct fpstate *fpstate, u64 xfd);
+static void __fpstate_reset(struct fpstate *fpstate);
static void fpu_lock_guest_permissions(void)
{
@@ -253,8 +253,7 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu)
fpstate->is_valloc = true;
fpstate->is_guest = true;
- /* Leave xfd to 0 (the reset value defined by spec) */
- __fpstate_reset(fpstate, 0);
+ __fpstate_reset(fpstate);
fpstate_init_user(fpstate);
gfpu->fpstate = fpstate;
@@ -545,7 +544,7 @@ void fpstate_init_user(struct fpstate *fpstate)
fpstate_init_fstate(fpstate);
}
-static void __fpstate_reset(struct fpstate *fpstate, u64 xfd)
+static void __fpstate_reset(struct fpstate *fpstate)
{
/*
* Supervisor features (and thus sizes) may diverge between guest
@@ -553,25 +552,29 @@ static void __fpstate_reset(struct fpstate *fpstate, u64 xfd)
* for guests despite not being utilized by the host. User
* features and sizes are always identical, which allows for
* common guest and userspace ABI.
+ *
+ * For the host, set XFD to the kernel's desired initialization
+ * value. For guests, set XFD to its architectural RESET value.
*/
if (fpstate->is_guest) {
fpstate->size = guest_default_cfg.size;
fpstate->xfeatures = guest_default_cfg.features;
+ fpstate->xfd = 0;
} else {
fpstate->size = fpu_kernel_cfg.default_size;
fpstate->xfeatures = fpu_kernel_cfg.default_features;
+ fpstate->xfd = init_fpstate.xfd;
}
fpstate->user_size = fpu_user_cfg.default_size;
fpstate->user_xfeatures = fpu_user_cfg.default_features;
- fpstate->xfd = xfd;
}
void fpstate_reset(struct fpu *fpu)
{
/* Set the fpstate pointer to the default fpstate */
fpu->fpstate = &fpu->__fpstate;
- __fpstate_reset(fpu->fpstate, init_fpstate.xfd);
+ __fpstate_reset(fpu->fpstate);
/* Initialize the permission related info in fpu */
fpu->perm.__state_perm = fpu_kernel_cfg.default_features;