No functional change.

Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
---
 xen/arch/x86/i387.c               | 16 ++++++++++------
 xen/arch/x86/include/asm/xstate.h |  2 +-
 xen/arch/x86/xstate.c             |  3 +--
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/xen/arch/x86/i387.c b/xen/arch/x86/i387.c
index a571bcb23c91..5950fbcf272e 100644
--- a/xen/arch/x86/i387.c
+++ b/xen/arch/x86/i387.c
@@ -130,7 +130,7 @@ static inline uint64_t vcpu_xsave_mask(const struct vcpu *v)
 }
 
 /* Save x87 extended state */
-static inline void fpu_xsave(struct vcpu *v)
+static inline void fpu_xsave(struct vcpu *v, struct xsave_struct *xsave_area)
 {
     bool ok;
     uint64_t mask = vcpu_xsave_mask(v);
@@ -143,15 +143,14 @@ static inline void fpu_xsave(struct vcpu *v)
      */
     ok = set_xcr0(v->arch.xcr0_accum | XSTATE_FP_SSE);
     ASSERT(ok);
-    xsave(v, mask);
+    xsave(v, xsave_area, mask);
     ok = set_xcr0(v->arch.xcr0 ?: XSTATE_FP_SSE);
     ASSERT(ok);
 }
 
 /* Save x87 FPU, MMX, SSE and SSE2 state */
-static inline void fpu_fxsave(struct vcpu *v)
+static inline void fpu_fxsave(struct vcpu *v, fpusse_t *fpu_ctxt)
 {
-    fpusse_t *fpu_ctxt = &v->arch.xsave_area->fpu_sse;
     unsigned int fip_width = v->domain->arch.x87_fip_width;
 
     if ( fip_width != 4 )
@@ -266,6 +265,8 @@ void vcpu_restore_fpu_lazy(struct vcpu *v)
  */
 static bool _vcpu_save_fpu(struct vcpu *v)
 {
+    struct xsave_struct *xsave_area;
+
     if ( !v->fpu_dirtied && !v->arch.nonlazy_xstate_used )
         return false;
 
@@ -274,11 +275,14 @@ static bool _vcpu_save_fpu(struct vcpu *v)
     /* This can happen, if a paravirtualised guest OS has set its CR0.TS. */
     clts();
 
+    xsave_area = vcpu_map_xsave_area(v);
+
     if ( cpu_has_xsave )
-        fpu_xsave(v);
+        fpu_xsave(v, xsave_area);
     else
-        fpu_fxsave(v);
+        fpu_fxsave(v, &xsave_area->fpu_sse);
 
+    vcpu_unmap_xsave_area(v, xsave_area);
     v->fpu_dirtied = 0;
 
     return true;
diff --git a/xen/arch/x86/include/asm/xstate.h b/xen/arch/x86/include/asm/xstate.h
index 36260459667c..104fe0d44173 100644
--- a/xen/arch/x86/include/asm/xstate.h
+++ b/xen/arch/x86/include/asm/xstate.h
@@ -97,7 +97,7 @@ uint64_t get_xcr0(void);
 void set_msr_xss(u64 xss);
 uint64_t get_msr_xss(void);
 uint64_t read_bndcfgu(void);
-void xsave(struct vcpu *v, uint64_t mask);
+void xsave(struct vcpu *v, struct xsave_struct *ptr, uint64_t mask);
 void xrstor(struct vcpu *v, uint64_t mask);
 void xstate_set_init(uint64_t mask);
 bool xsave_enabled(const struct vcpu *v);
diff --git a/xen/arch/x86/xstate.c b/xen/arch/x86/xstate.c
index a9a7ee2cd1e6..518388e6e272 100644
--- a/xen/arch/x86/xstate.c
+++ b/xen/arch/x86/xstate.c
@@ -300,9 +300,8 @@ void compress_xsave_states(struct vcpu *v, const void *src, unsigned int size)
     vcpu_unmap_xsave_area(v, xstate);
 }
 
-void xsave(struct vcpu *v, uint64_t mask)
+void xsave(struct vcpu *v, struct xsave_struct *ptr, uint64_t mask)
 {
-    struct xsave_struct *ptr = v->arch.xsave_area;
     uint32_t hmask = mask >> 32;
     uint32_t lmask = mask;
     unsigned int fip_width = v->domain->arch.x87_fip_width;
-- 
2.47.0

On 28.10.2024 16:49, Alejandro Vallejo wrote:
> --- a/xen/arch/x86/xstate.c
> +++ b/xen/arch/x86/xstate.c
> @@ -300,9 +300,8 @@ void compress_xsave_states(struct vcpu *v, const void *src, unsigned int size)
>      vcpu_unmap_xsave_area(v, xstate);
>  }
>  
> -void xsave(struct vcpu *v, uint64_t mask)
> +void xsave(struct vcpu *v, struct xsave_struct *ptr, uint64_t mask)
>  {
> -    struct xsave_struct *ptr = v->arch.xsave_area;
>      uint32_t hmask = mask >> 32;
>      uint32_t lmask = mask;
>      unsigned int fip_width = v->domain->arch.x87_fip_width;

Imo this change wants to constify v at the same time, to demonstrate that
nothing is changed through v anymore. The comment may extend to other functions
as well that are being altered here; I only closely looks at this one.

Jan

On Tue Oct 29, 2024 at 8:37 AM GMT, Jan Beulich wrote:
> On 28.10.2024 16:49, Alejandro Vallejo wrote:
> > --- a/xen/arch/x86/xstate.c
> > +++ b/xen/arch/x86/xstate.c
> > @@ -300,9 +300,8 @@ void compress_xsave_states(struct vcpu *v, const void *src, unsigned int size)
> >      vcpu_unmap_xsave_area(v, xstate);
> >  }
> >  
> > -void xsave(struct vcpu *v, uint64_t mask)
> > +void xsave(struct vcpu *v, struct xsave_struct *ptr, uint64_t mask)
> >  {
> > -    struct xsave_struct *ptr = v->arch.xsave_area;
> >      uint32_t hmask = mask >> 32;
> >      uint32_t lmask = mask;
> >      unsigned int fip_width = v->domain->arch.x87_fip_width;
>
> Imo this change wants to constify v at the same time, to demonstrate that
> nothing is changed through v anymore. The comment may extend to other functions
> as well that are being altered here; I only closely looks at this one.
>
> Jan

I didn't think of that angle... I'll have a look and take it into account for
v2.

Cheers,
Alejandro