On Mon, 19 Feb 2018 12:52:49 +0000
Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote:
> Some facilities should only provided to the guest, if these are
s/provided/be provided/
s/these/they/
> enabled by a CPU model. This allows to avoid capabilities and
s/allows/allows us/
> simply fallback to the cpumodel for deciding about a facility
s/simply fallback/to simply fall back/
> without enabling it for older QEMUs or QEMUs without a CPU
> model.
>
> Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> ---
> arch/s390/kvm/kvm-s390.c | 54 ++++++++++++++++++++++++++--------------
> arch/s390/kvm/kvm-s390.h | 2 --
> arch/s390/tools/gen_facilities.c | 20 +++++++++++++++
> 3 files changed, 55 insertions(+), 21 deletions(-)
>
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index ba4c7092335a..9c05767c95be 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -151,13 +151,34 @@ static int nested;
> module_param(nested, int, S_IRUGO);
> MODULE_PARM_DESC(nested, "Nested virtualization support");
>
> -/* upper facilities limit for kvm */
> -unsigned long kvm_s390_fac_list_mask[16] = { FACILITIES_KVM };
>
> -unsigned long kvm_s390_fac_list_mask_size(void)
> +/*
> + * For now we handle not more than 16 double words as this is what
"For now, we handle at most..."
> + * the s390 base kernel handles and stores in prefix page. If we
s/in prefix page/in the prefix page/
> + * ever need to go beyond this, this requires changes to code, but
> + * the external uapi can stay.
> + */
> +#define SIZE_INTERNAL 16
> +
> +/*
> + * Base feature mask that defines default mask for facilities. Consists of
> + * the defines in FACILITIES_KVM and the non-hypervisor managed bits.
> + */
> +static unsigned long kvm_s390_fac_base[SIZE_INTERNAL] = { FACILITIES_KVM };
> +/*
> + * Extended feature mask. Consists of the defines in FACILITIES_KVM_CPUMODEL
> + * and defines the facilities that can be enabled via a cpu model.
> + */
> +static unsigned long kvm_s390_fac_ext[SIZE_INTERNAL] = { FACILITIES_KVM_CPUMODEL };
> +
(...)
> diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c
> index 424a1ba4f874..37a77a3f280c 100644
> --- a/arch/s390/tools/gen_facilities.c
> +++ b/arch/s390/tools/gen_facilities.c
> @@ -62,6 +62,13 @@ static struct facility_def facility_defs[] = {
> }
> },
> {
> + /*
> + * FACILITIES_KVM contains the list of facilities that are
> + * part of the default facility mask and list passed to the
"mask and list that are passed..."
(I stumbled over this, even if the sentence is fine...)
> + * initial CPU model. If no CPU model is used this, together
s/is used this,/is used, this,/
> + * with the non-hypervisor managed bits, is the maximum list
> + * of guest facilities supported by KVM.
> + */
> .name = "FACILITIES_KVM",
> .bits = (int[]){
> 0, /* N3 instructions */
> @@ -89,6 +96,19 @@ static struct facility_def facility_defs[] = {
> -1 /* END */
> }
> },
> + {
> + /*
> + * FACILITIES_KVM_CPUMODEL contains the list of facilities
> + * that can be enabled by CPU model code if the host supports
> + * it. These facilities are not passed to the guest without
> + * CPU model support.
> + */
> +
> + .name = "FACILITIES_KVM_CPUMODEL",
> + .bits = (int[]){
> + -1 /* END */
> + }
> + },
> };
>
> static void print_facility_list(struct facility_def *def)
Only nitpickery, else
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
