[v2] Virtualize architectural LBRs

[RFC PATCH v2 05/10] x86: Keep a copy of XSAVE area size

Posted by Tu Dinh 10 months ago

Signed-off-by: Tu Dinh <ngoc-tu.dinh@vates.tech>
---
 xen/arch/x86/include/asm/domain.h | 1 +
 xen/arch/x86/xstate.c             | 1 +
 2 files changed, 2 insertions(+)

diff --git a/xen/arch/x86/include/asm/domain.h b/xen/arch/x86/include/asm/domain.h
index b79d6badd7..d3f2695c20 100644
--- a/xen/arch/x86/include/asm/domain.h
+++ b/xen/arch/x86/include/asm/domain.h
@@ -638,6 +638,7 @@ struct arch_vcpu
      * #NM handler, we XRSTOR the states we XSAVE-ed;
      */
     struct xsave_struct *xsave_area;
+    unsigned int xsave_area_size;
     uint64_t xcr0;
     /* Accumulated eXtended features mask for using XSAVE/XRESTORE by Xen
      * itself, as we can never know whether guest OS depends on content
diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
index af9e345a7a..baae8e1a13 100644
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -550,6 +550,7 @@ int xstate_alloc_save_area(struct vcpu *v)
     save_area->fpu_sse.mxcsr = MXCSR_DEFAULT;
 
     v->arch.xsave_area = save_area;
+    v->arch.xsave_area_size = size;
     v->arch.xcr0 = 0;
     v->arch.xcr0_accum = 0;
 
-- 
2.43.0



Ngoc Tu Dinh | Vates XCP-ng Developer

XCP-ng & Xen Orchestra - Vates solutions

web: https://vates.tech

Re: [RFC PATCH v2 05/10] x86: Keep a copy of XSAVE area size

Posted by Jan Beulich 9 months, 3 weeks ago

On 02.01.2025 09:45, Tu Dinh wrote:
> Signed-off-by: Tu Dinh <ngoc-tu.dinh@vates.tech>

This needs a non-empty description to clarify why this would be needed.

Jan

> --- a/xen/arch/x86/include/asm/domain.h
> +++ b/xen/arch/x86/include/asm/domain.h
> @@ -638,6 +638,7 @@ struct arch_vcpu
>       * #NM handler, we XRSTOR the states we XSAVE-ed;
>       */
>      struct xsave_struct *xsave_area;
> +    unsigned int xsave_area_size;
>      uint64_t xcr0;
>      /* Accumulated eXtended features mask for using XSAVE/XRESTORE by Xen
>       * itself, as we can never know whether guest OS depends on content
> diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
> index af9e345a7a..baae8e1a13 100644
> --- a/xen/arch/x86/xstate.c
> +++ b/xen/arch/x86/xstate.c
> @@ -550,6 +550,7 @@ int xstate_alloc_save_area(struct vcpu *v)
>      save_area->fpu_sse.mxcsr = MXCSR_DEFAULT;
>  
>      v->arch.xsave_area = save_area;
> +    v->arch.xsave_area_size = size;
>      v->arch.xcr0 = 0;
>      v->arch.xcr0_accum = 0;
>