diff options
author | Sean Christopherson <seanjc@google.com> | 2022-01-05 04:35:18 -0800 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-01-14 13:43:21 -0500 |
commit | 0781d60f658e25fbad3b6e4261f54eb1cd3dc302 (patch) | |
tree | e30eee0777466ca2a4bcc24f466cc806b35e0540 /arch/x86/kernel/fpu | |
parent | c270ce393dfd700e7510a4579568deeefba954fd (diff) | |
download | linux-stable-0781d60f658e25fbad3b6e4261f54eb1cd3dc302.tar.gz linux-stable-0781d60f658e25fbad3b6e4261f54eb1cd3dc302.tar.bz2 linux-stable-0781d60f658e25fbad3b6e4261f54eb1cd3dc302.zip |
x86/fpu: Provide fpu_enable_guest_xfd_features() for KVM
Provide a wrapper for expanding the guest fpstate buffer according
to requested xfeatures. KVM wants to call this wrapper to manage
any dynamic xstate used by the guest.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20220105123532.12586-8-yang.zhong@intel.com>
[Remove unnecessary 32-bit check. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kernel/fpu')
-rw-r--r-- | arch/x86/kernel/fpu/core.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index a78bc547fc03..64b2ee39bece 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -261,6 +261,28 @@ void fpu_free_guest_fpstate(struct fpu_guest *gfpu) } EXPORT_SYMBOL_GPL(fpu_free_guest_fpstate); +/* + * fpu_enable_guest_xfd_features - Check xfeatures against guest perm and enable + * @guest_fpu: Pointer to the guest FPU container + * @xfeatures: Features requested by guest CPUID + * + * Enable all dynamic xfeatures according to guest perm and requested CPUID. + * + * Return: 0 on success, error code otherwise + */ +int fpu_enable_guest_xfd_features(struct fpu_guest *guest_fpu, u64 xfeatures) +{ + lockdep_assert_preemption_enabled(); + + /* Nothing to do if all requested features are already enabled. */ + xfeatures &= ~guest_fpu->xfeatures; + if (!xfeatures) + return 0; + + return __xfd_enable_feature(xfeatures, guest_fpu); +} +EXPORT_SYMBOL_GPL(fpu_enable_guest_xfd_features); + int fpu_swap_kvm_fpstate(struct fpu_guest *guest_fpu, bool enter_guest) { struct fpstate *guest_fps = guest_fpu->fpstate; |