| Message ID | 20241028154932.6797-13-alejandro.vallejo@cloud.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | x86: Address Space Isolation FPU preparations | expand |
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
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;
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(-)