On Tue, Jan 05, 2016 at 11:28:18AM -0800, Mario Smarduch wrote:
>
>
> On 1/5/2016 7:00 AM, Christoffer Dall wrote:
> > On Sat, Dec 26, 2015 at 01:54:55PM -0800, Mario Smarduch wrote:
> >> Add helper functions to enable access to fp/smid on guest entry and save host
> >> fpexc on vcpu put, check if fp/simd registers are dirty and add new vcpu
> >> fields.
> >>
> >> Signed-off-by: Mario Smarduch <m.smarduch@xxxxxxxxxxx>
> >> ---
> >> arch/arm/include/asm/kvm_emulate.h | 42 ++++++++++++++++++++++++++++++++++++
> >> arch/arm/include/asm/kvm_host.h | 6 ++++++
> >> arch/arm64/include/asm/kvm_emulate.h | 8 +++++++
> >> 3 files changed, 56 insertions(+)
> >>
> >> diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
> >> index 3095df0..d4d9da1 100644
> >> --- a/arch/arm/include/asm/kvm_emulate.h
> >> +++ b/arch/arm/include/asm/kvm_emulate.h
> >> @@ -24,6 +24,8 @@
> >> #include <asm/kvm_mmio.h>
> >> #include <asm/kvm_arm.h>
> >> #include <asm/cputype.h>
> >> +#include <asm/vfp.h>
> >> +#include "../vfp/vfpinstr.h"
> >
> > this looks dodgy...
> >
> > can you move vfpinstr.h instead?
> Sure I'll fix it up, it's in couple other places in kernel and kvm
> - copied it.
> >
> >>
> >> unsigned long *vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num);
> >> unsigned long *vcpu_spsr(struct kvm_vcpu *vcpu);
> >> @@ -255,4 +257,44 @@ static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
> >> }
> >> }
> >>
> >> +#ifdef CONFIG_VFPv3
> >> +/* Called from vcpu_load - save fpexc and enable guest access to fp/simd unit */
> >
> > the comment is misleading, you're not enabling guest access to the
> > fp/simd unit, you're just setting the enabled bit to ensure guest
> > accesses trap.
>
> That's more accurate.
> >
> >> +static inline void vcpu_trap_vfp_enable(struct kvm_vcpu *vcpu)
> >> +{
> >> + u32 fpexc;
> >> +
> >> + /* Save host fpexc, and enable guest access to fp unit */
> >> + fpexc = fmrx(FPEXC);
> >> + vcpu->arch.host_fpexc = fpexc;
> >> + fpexc |= FPEXC_EN;
> >> + fmxr(FPEXC, fpexc);
> >> +
> >> + /* Configure HCPTR to trap on tracing and fp/simd access */
> >> + vcpu->arch.hcptr = HCPTR_TTA | HCPTR_TCP(10) | HCPTR_TCP(11);
> >> +}
> >> +
> >> +/* Called from vcpu_put - restore host fpexc */
> >
> > I would probably get rid of the "Called from" stuff and just describe
> > what these functions do locally. Comments like this are likely to be
> > out of date soon'ish.
>
> Yeah true, will do.
> >
> >> +static inline void vcpu_restore_host_fpexc(struct kvm_vcpu *vcpu)
> >> +{
> >> + fmxr(FPEXC, vcpu->arch.host_fpexc);
> >> +}
> >> +
> >> +/* If trap bits are reset then fp/simd registers are dirty */
> >> +static inline bool vcpu_vfp_isdirty(struct kvm_vcpu *vcpu)
> >> +{
> >> + return !(vcpu->arch.hcptr & (HCPTR_TCP(10) | HCPTR_TCP(11)));
> >> +}
> >> +#else
> >> +static inline void vcpu_trap_vfp_enable(struct kvm_vcpu *vcpu)
> >> +{
> >> + vcpu->arch.hcptr = HCPTR_TTA;
> >> +}
> >> +
> >> +static inline void vcpu_restore_host_fpexc(struct kvm_vcpu *vcpu) {}
> >> +static inline bool vcpu_vfp_isdirty(struct kvm_vcpu *vcpu)
> >> +{
> >> + return false;
> >> +}
> >> +#endif
> >
> > this kind of feels like it belongs in its own C-file instead of a header
> > file, perhaps arch/arm/kvm/vfp.C.
> >
> > Marc, what do you think?
> >
>
> That would be starting from vcpu_trap_vfp_enable()? The file is getting
> little overloaded.
yes, starting from vcpu_trap_vfp_enable.
Which file is getting overloaded?
I'm thinking the assembly file you add in the next patch could be
inline assembly in a C-file combined with this code, perhaps.
>
> I'm also thinking that 3rd patch should have one function call for vcpu_put
> like vcpu_load does instead of exposing arm32/arm64, arm32 only relevant logic.
> When you have a chance to review that patch please keep that in mind.
>
ok, will try ;)
-Christoffer
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
