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| author | Thomas Gleixner <tglx@linutronix.de> | 2022-01-05 15:35:12 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-01-07 21:33:03 +0300 |
| commit | 980fe2fddcff21937c93532b4597c8ea450346c1 (patch) | |
| tree | bc14f810c770b0229f35c02cecd9e8bd6ac7a043 /arch/x86/include/asm/fpu | |
| parent | 96c1a6285568d31a8125c36974a140fccbe548af (diff) | |
| download | linux-980fe2fddcff21937c93532b4597c8ea450346c1.tar.xz | |
x86/fpu: Extend fpu_xstate_prctl() with guest permissions
KVM requires a clear separation of host user space and guest permissions
for dynamic XSTATE components.
Add a guest permissions member to struct fpu and a separate set of prctl()
arguments: ARCH_GET_XCOMP_GUEST_PERM and ARCH_REQ_XCOMP_GUEST_PERM.
The semantics are equivalent to the host user space permission control
except for the following constraints:
1) Permissions have to be requested before the first vCPU is created
2) Permissions are frozen when the first vCPU is created to ensure
consistency. Any attempt to expand permissions via the prctl() after
that point is rejected.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jing Liu <jing2.liu@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20220105123532.12586-2-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/fpu')
| -rw-r--r-- | arch/x86/include/asm/fpu/api.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu/types.h | 9 |
2 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index c2767a6a387e..d8c222290e68 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -132,6 +132,8 @@ static inline void fpstate_free(struct fpu *fpu) { } /* fpstate-related functions which are exported to KVM */ extern void fpstate_clear_xstate_component(struct fpstate *fps, unsigned int xfeature); +extern inline u64 xstate_get_guest_group_perm(void); + /* KVM specific functions */ extern bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu); extern void fpu_free_guest_fpstate(struct fpu_guest *gfpu); diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 3c06c82ab355..6ddf80637697 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -387,6 +387,8 @@ struct fpstate { /* @regs is dynamically sized! Don't add anything after @regs! */ } __aligned(64); +#define FPU_GUEST_PERM_LOCKED BIT_ULL(63) + struct fpu_state_perm { /* * @__state_perm: @@ -477,6 +479,13 @@ struct fpu { struct fpu_state_perm perm; /* + * @guest_perm: + * + * Permission related information for guest pseudo FPUs + */ + struct fpu_state_perm guest_perm; + + /* * @__fpstate: * * Initial in-memory storage for FPU registers which are saved in |