[PATCH v4 09/21] x86/fpu: Provide fpu_update_guest_xfd() for IA32_XFD emulation
From: Yang Zhong <hidden>
Date: 2021-12-29 13:14:03
Also in:
kvm, linux-kselftest, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Kevin Tian <kevin.tian@intel.com> Guest XFD can be updated either in the emulation path or in the restore path. Provide a wrapper to update guest_fpu::fpstate::xfd. If the guest fpstate is currently in-use, also update the per-cpu xfd cache and the actual MSR. Signed-off-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jing Liu <redacted> Signed-off-by: Yang Zhong <redacted> --- arch/x86/include/asm/fpu/api.h | 6 ++++++ arch/x86/kernel/fpu/core.c | 12 ++++++++++++ 2 files changed, 18 insertions(+)
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h
index 8e934e571273..100b535cd3de 100644
--- a/arch/x86/include/asm/fpu/api.h
+++ b/arch/x86/include/asm/fpu/api.h@@ -140,6 +140,12 @@ extern void fpu_free_guest_fpstate(struct fpu_guest *gfpu); extern int fpu_swap_kvm_fpstate(struct fpu_guest *gfpu, bool enter_guest); extern int fpu_update_guest_perm_features(struct fpu_guest *guest_fpu); +#ifdef CONFIG_X86_64 +extern void fpu_update_guest_xfd(struct fpu_guest *guest_fpu, u64 xfd); +#else +static inline void fpu_update_guest_xfd(struct fpu_guest *guest_fpu, u64 xfd) { } +#endif + extern void fpu_copy_guest_fpstate_to_uabi(struct fpu_guest *gfpu, void *buf, unsigned int size, u32 pkru); extern int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf, u64 xcr0, u32 *vpkru);
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 2560a95980aa..3daea097c618 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c@@ -288,6 +288,18 @@ int fpu_update_guest_perm_features(struct fpu_guest *guest_fpu) } EXPORT_SYMBOL_GPL(fpu_update_guest_perm_features); +#ifdef CONFIG_X86_64 +void fpu_update_guest_xfd(struct fpu_guest *guest_fpu, u64 xfd) +{ + fpregs_lock(); + guest_fpu->fpstate->xfd = xfd; + if (guest_fpu->fpstate->in_use) + xfd_update_state(guest_fpu->fpstate); + fpregs_unlock(); +} +EXPORT_SYMBOL_GPL(fpu_update_guest_xfd); +#endif /* CONFIG_X86_64 */ + int fpu_swap_kvm_fpstate(struct fpu_guest *guest_fpu, bool enter_guest) { struct fpstate *guest_fps = guest_fpu->fpstate;