diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c index 89aad7e897..78a13e6812 100644 --- a/xen/arch/x86/domain.c +++ b/xen/arch/x86/domain.c @@ -1186,9 +1186,10 @@ int arch_set_info_guest( is_pv_64bit_domain(d) ) v->arch.flags &= ~TF_kernel_mode; - vcpu_setup_fpu(v, v->arch.xsave_area, - flags & VGCF_I387_VALID ? &c.nat->fpu_ctxt : NULL, - FCW_DEFAULT); + if ( flags & VGCF_I387_VALID ) + vcpu_setup_fpu(v, &c.nat->fpu_ctxt); + else + vcpu_reset_fpu(v); if ( !compat ) { diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 000b40d7b1..018d44a08b 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -1163,10 +1163,10 @@ static int cf_check hvm_load_cpu_ctxt(struct domain *d, hvm_domain_context_t *h) seg.attr = ctxt.ldtr_arbytes; hvm_set_segment_register(v, x86_seg_ldtr, &seg); - /* Cover xsave-absent save file restoration on xsave-capable host. */ - vcpu_setup_fpu(v, xsave_enabled(v) ? NULL : v->arch.xsave_area, - ctxt.flags & XEN_X86_FPU_INITIALISED ? ctxt.fpu_regs : NULL, - FCW_RESET); + if ( ctxt.flags & XEN_X86_FPU_INITIALISED ) + vcpu_setup_fpu(v, &ctxt.fpu_regs); + else + vcpu_reset_fpu(v); v->arch.user_regs.rax = ctxt.rax; v->arch.user_regs.rbx = ctxt.rbx; @@ -4013,9 +4013,7 @@ void hvm_vcpu_reset_state(struct vcpu *v, uint16_t cs, uint16_t ip) v->arch.guest_table = pagetable_null(); } - if ( v->arch.xsave_area ) - v->arch.xsave_area->xsave_hdr.xstate_bv = 0; - vcpu_setup_fpu(v, v->arch.xsave_area, NULL, FCW_RESET); + vcpu_reset_fpu(v); arch_vcpu_regs_init(v); v->arch.user_regs.rip = ip; diff --git a/xen/arch/x86/i387.c b/xen/arch/x86/i387.c index b0a50f9489..83f9b2502b 100644 --- a/xen/arch/x86/i387.c +++ b/xen/arch/x86/i387.c @@ -304,41 +304,26 @@ int vcpu_init_fpu(struct vcpu *v) return xstate_alloc_save_area(v); } -void vcpu_setup_fpu(struct vcpu *v, struct xsave_struct *xsave_area, - const void *data, unsigned int fcw_default) +void vcpu_reset_fpu(struct vcpu *v) { - fpusse_t *fpu_sse = &v->arch.xsave_area->fpu_sse; + v->fpu_initialised = false; + *v->arch.xsave_area = (struct xsave_struct) { + .fpu_sse = { + .mxcsr = MXCSR_DEFAULT, + .fcw = FCW_RESET, + .ftw = FXSAVE_FTW_RESET, + }, + .xsave_hdr.xstate_bv = X86_XCR0_X87, + }; +} - ASSERT(!xsave_area || xsave_area == v->arch.xsave_area); - - v->fpu_initialised = !!data; - - if ( data ) - { - memcpy(fpu_sse, data, sizeof(*fpu_sse)); - if ( xsave_area ) - xsave_area->xsave_hdr.xstate_bv = XSTATE_FP_SSE; - } - else if ( xsave_area && fcw_default == FCW_DEFAULT ) - { - xsave_area->xsave_hdr.xstate_bv = 0; - fpu_sse->mxcsr = MXCSR_DEFAULT; - } - else - { - memset(fpu_sse, 0, sizeof(*fpu_sse)); - fpu_sse->fcw = fcw_default; - fpu_sse->mxcsr = MXCSR_DEFAULT; - if ( v->arch.xsave_area ) - { - v->arch.xsave_area->xsave_hdr.xstate_bv &= ~XSTATE_FP_SSE; - if ( fcw_default != FCW_DEFAULT ) - v->arch.xsave_area->xsave_hdr.xstate_bv |= X86_XCR0_X87; - } - } - - if ( xsave_area ) - xsave_area->xsave_hdr.xcomp_bv = 0; +void vcpu_setup_fpu(struct vcpu *v, const void *data) +{ + v->fpu_initialised = true; + *v->arch.xsave_area = (struct xsave_struct) { + .fpu_sse = *(const fpusse_t*)data, + .xsave_hdr.xstate_bv = XSTATE_FP_SSE, + }; } /* Free FPU's context save area */ diff --git a/xen/arch/x86/include/asm/i387.h b/xen/arch/x86/include/asm/i387.h index a783549db9..652d7ad2de 100644 --- a/xen/arch/x86/include/asm/i387.h +++ b/xen/arch/x86/include/asm/i387.h @@ -31,10 +31,23 @@ void vcpu_restore_fpu_nonlazy(struct vcpu *v, bool need_stts); void vcpu_restore_fpu_lazy(struct vcpu *v); void vcpu_save_fpu(struct vcpu *v); void save_fpu_enable(void); - int vcpu_init_fpu(struct vcpu *v); -struct xsave_struct; -void vcpu_setup_fpu(struct vcpu *v, struct xsave_struct *xsave_area, - const void *data, unsigned int fcw_default); void vcpu_destroy_fpu(struct vcpu *v); + +/* + * Restore v's FPU to power-on reset values + * + * @param v vCPU containing the FPU + */ +void vcpu_reset_fpu(struct vcpu *v); + +/* + * Load x87/SSE state into v's FPU + * + * Overrides the XSAVE header to set the state components to be x87 and SSE. + * + * @param v vCPU containing the FPU + * @param data 512-octet blob for x87/SSE state + */ +void vcpu_setup_fpu(struct vcpu *v, const void *data); #endif /* __ASM_I386_I387_H */ diff --git a/xen/arch/x86/include/asm/xstate.h b/xen/arch/x86/include/asm/xstate.h index b4ee555953..07017cc4ed 100644 --- a/xen/arch/x86/include/asm/xstate.h +++ b/xen/arch/x86/include/asm/xstate.h @@ -14,6 +14,7 @@ #define FCW_DEFAULT 0x037f #define FCW_RESET 0x0040 +#define FXSAVE_FTW_RESET 0xFF /* Abridged Tag Word format */ #define MXCSR_DEFAULT 0x1f80 extern uint32_t mxcsr_mask;