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.smard...@samsung.com>
> ---
> 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?
>
> 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.
> +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out of date soon'ish.
> +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?
> +
> #endif /* __ARM_KVM_EMULATE_H__ */
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index f9f2779..d3ef58a 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -105,6 +105,12 @@ struct kvm_vcpu_arch {
> /* HYP trapping configuration */
> u32 hcr;
>
> + /* HYP Co-processor fp/simd and trace trapping configuration */
> + u32 hcptr;
> +
> + /* Save host FPEXC register to later restore on vcpu put */
> + u32 host_fpexc;
> +
> /* Interrupt related fields */
> u32 irq_lines; /* IRQ and FIQ levels */
>
> diff --git a/arch/arm64/include/asm/kvm_emulate.h
> b/arch/arm64/include/asm/kvm_emulate.h
> index 3066328..ffe8ccf 100644
> --- a/arch/arm64/include/asm/kvm_emulate.h
> +++ b/arch/arm64/include/asm/kvm_emulate.h
> @@ -299,4 +299,12 @@ static inline unsigned long
> vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
> return data; /* Leave LE untouched */
> }
>
> +static inline void vcpu_trap_vfp_enable(struct kvm_vcpu *vcpu) {}
> +static inline void vcpu_restore_host_fpexc(struct kvm_vcpu *vcpu) {}
> +
> +static inline bool vcpu_vfp_isdirty(struct kvm_vcpu *vcpu)
> +{
> + return false;
> +}
> +
> #endif /* __ARM64_KVM_EMULATE_H__ */
> --
> 1.9.1
>
Thanks,
-Christoffer
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