diff options
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 94706a596aaa..e02705187bbf 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -243,19 +243,22 @@ bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) struct fpstate *fpstate; unsigned int size; - size = fpu_kernel_cfg.default_size + ALIGN(offsetof(struct fpstate, regs), 64); + size = guest_default_cfg.size + ALIGN(offsetof(struct fpstate, regs), 64); + fpstate = vzalloc(size); if (!fpstate) return false; + /* Initialize indicators to reflect properties of the fpstate */ + fpstate->is_valloc = true; + fpstate->is_guest = true; + /* Leave xfd to 0 (the reset value defined by spec) */ __fpstate_reset(fpstate, 0); fpstate_init_user(fpstate); - fpstate->is_valloc = true; - fpstate->is_guest = true; gfpu->fpstate = fpstate; - gfpu->xfeatures = fpu_kernel_cfg.default_features; + gfpu->xfeatures = guest_default_cfg.features; /* * KVM sets the FP+SSE bits in the XSAVE header when copying FPU state @@ -544,10 +547,22 @@ void fpstate_init_user(struct fpstate *fpstate) static void __fpstate_reset(struct fpstate *fpstate, u64 xfd) { - /* Initialize sizes and feature masks */ - fpstate->size = fpu_kernel_cfg.default_size; + /* + * Supervisor features (and thus sizes) may diverge between guest + * FPUs and host FPUs, as some supervisor features are supported + * for guests despite not being utilized by the host. User + * features and sizes are always identical, which allows for + * common guest and userspace ABI. + */ + if (fpstate->is_guest) { + fpstate->size = guest_default_cfg.size; + fpstate->xfeatures = guest_default_cfg.features; + } else { + fpstate->size = fpu_kernel_cfg.default_size; + fpstate->xfeatures = fpu_kernel_cfg.default_features; + } + fpstate->user_size = fpu_user_cfg.default_size; - fpstate->xfeatures = fpu_kernel_cfg.default_features; fpstate->user_xfeatures = fpu_user_cfg.default_features; fpstate->xfd = xfd; } |