On Tue, Apr 16, 2019 at 04:52:28PM +0100, Dave Martin wrote:
> On Tue, Apr 16, 2019 at 04:28:31PM +0200, Andrew Jones wrote:
> > On Tue, Apr 16, 2019 at 03:10:55PM +0100, Dave Martin wrote:
>
> [...]
>
> > > arch/arm64/include/uapi/asm/kvm.h:
> > >
> > > #include <asm/sve_context.h> /* which we already have anyway */
> > >
> > > #define KVM_ARM64_SVE_VQ_MAX __SVE_VQ_MAX
> > > #define KVM_ARM64_SVE_VQ_MIN __SVE_VQ_MIN
> > >
> > > /* Vector lengths pseudo-register: */
> > > #define KVM_REG_ARM64_SVE_VLS (KVM_REG_ARM64 | KVM_REG_ARM64_SVE | \
> > > KVM_REG_SIZE_U512 | 0xffff)
> > > #define KVM_ARM64_SVE_VLS_WORDS \
> > > ((KVM_ARM64_SVE_VQ_MAX - KVM_ARM64_SVE_VQ_MIN) / 64 + 1)
> > >
> > >
> > > Then document as follows:
> > > Documentation/virtual/kvm/api.txt:
> > >
> > > __u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS];
> > >
> > > if (vq >= KVM_ARM64_SVE_VQ_MIN && vq <= KVM_ARM64_SVE_VQ_MAX)
> > > (vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >>
> > > ((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1)
> > > /* Vector length vq * 16 bytes supported */
> > > else
> > > /* Vector length vq * 16 bytes not supported */
> > >
> > >
> > > Does that work for you?
> > >
> > > Doing things this way avoids people having to include <asm/sigcontext.h>
> > > (and the consequent clashes with glibc headers).
> > >
> >
> > I like that.
>
> OK, are you happy with the following on top of this patch?
>
> Cheers
> ---Dave
>
> --8<--
>
> diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
> index 68509de..03df379 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -2171,13 +2171,15 @@ and KVM_ARM_VCPU_FINALIZE for more information about this procedure.
> KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector
> lengths supported by the vcpu to be discovered and configured by
> userspace. When transferred to or from user memory via KVM_GET_ONE_REG
> -or KVM_SET_ONE_REG, the value of this register is of type __u64[8], and
> -encodes the set of vector lengths as follows:
> +or KVM_SET_ONE_REG, the value of this register is of type
> +__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as
> +follows:
>
> -__u64 vector_lengths[8];
> +__u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS];
>
> if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX &&
> - ((vector_lengths[(vq - 1) / 64] >> ((vq - 1) % 64)) & 1))
> + ((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >>
> + ((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1))
> /* Vector length vq * 16 bytes supported */
> else
> /* Vector length vq * 16 bytes not supported */
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index 2a04ef0..edd2db8 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -258,9 +258,14 @@ struct kvm_vcpu_events {
> KVM_REG_SIZE_U256 | \
> ((i) & (KVM_ARM64_SVE_MAX_SLICES - 1)))
>
> +#define KVM_ARM64_SVE_VQ_MIN __SVE_VQ_MIN
> +#define KVM_ARM64_SVE_VQ_MAX __SVE_VQ_MAX
> +
> /* Vector lengths pseudo-register: */
> #define KVM_REG_ARM64_SVE_VLS (KVM_REG_ARM64 | KVM_REG_ARM64_SVE | \
> KVM_REG_SIZE_U512 | 0xffff)
> +#define KVM_ARM64_SVE_VLS_WORDS \
> + ((KVM_ARM64_SVE_VQ_MAX - KVM_ARM64_SVE_VQ_MIN) / 64 + 1)
>
> /* Device Control API: ARM VGIC */
> #define KVM_DEV_ARM_VGIC_GRP_ADDR 0
> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
> index f025a2f..5bb909c 100644
> --- a/arch/arm64/kvm/guest.c
> +++ b/arch/arm64/kvm/guest.c
> @@ -208,10 +208,8 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> #define vq_word(vq) (((vq) - SVE_VQ_MIN) / 64)
> #define vq_mask(vq) ((u64)1 << ((vq) - SVE_VQ_MIN) % 64)
>
> -#define SVE_VLS_WORDS (vq_word(SVE_VQ_MAX) + 1)
> -
> static bool vq_present(
> - const u64 (*const vqs)[SVE_VLS_WORDS],
> + const u64 (*const vqs)[KVM_ARM64_SVE_VLS_WORDS],
> unsigned int vq)
> {
> return (*vqs)[vq_word(vq)] & vq_mask(vq);
> @@ -220,7 +218,7 @@ static bool vq_present(
> static int get_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> {
> unsigned int max_vq, vq;
> - u64 vqs[SVE_VLS_WORDS];
> + u64 vqs[KVM_ARM64_SVE_VLS_WORDS];
>
> if (!vcpu_has_sve(vcpu))
> return -ENOENT;
> @@ -244,7 +242,7 @@ static int get_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> static int set_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> {
> unsigned int max_vq, vq;
> - u64 vqs[SVE_VLS_WORDS];
> + u64 vqs[KVM_ARM64_SVE_VLS_WORDS];
>
> if (!vcpu_has_sve(vcpu))
> return -ENOENT;
>
Yup
Reviewed-by: Andrew Jones <drjones@xxxxxxxxxx>
Thanks,
drew
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