From c60427dd50ba9b20063ccaed0e98d62e886d7a3b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 5 Jan 2022 04:35:28 -0800 Subject: [PATCH] x86/fpu: Add uabi_size to guest_fpu Userspace needs to inquire KVM about the buffer size to work with the new KVM_SET_XSAVE and KVM_GET_XSAVE2. Add the size info to guest_fpu for KVM to access. Signed-off-by: Thomas Gleixner Signed-off-by: Wei Wang Signed-off-by: Jing Liu Signed-off-by: Yang Zhong Message-Id: <20220105123532.12586-18-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/fpu/types.h | 5 +++++ arch/x86/kernel/fpu/core.c | 1 + arch/x86/kernel/fpu/xstate.c | 1 + 3 files changed, 7 insertions(+) diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 3795d05..eb7cd11 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -523,6 +523,11 @@ struct fpu_guest { u64 xfd_err; /* + * @uabi_size: Size required for save/restore + */ + unsigned int uabi_size; + + /* * @fpstate: Pointer to the allocated guest fpstate */ struct fpstate *fpstate; diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 271fd5b..de8e8c2 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -240,6 +240,7 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) gfpu->fpstate = fpstate; gfpu->xfeatures = fpu_user_cfg.default_features; gfpu->perm = fpu_user_cfg.default_features; + gfpu->uabi_size = fpu_user_cfg.default_size; fpu_init_guest_permissions(gfpu); return true; diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 0c0b232..10fe072 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1545,6 +1545,7 @@ static int fpstate_realloc(u64 xfeatures, unsigned int ksize, newfps->is_confidential = curfps->is_confidential; newfps->in_use = curfps->in_use; guest_fpu->xfeatures |= xfeatures; + guest_fpu->uabi_size = usize; } fpregs_lock(); -- 2.7.4