[PATCH v6 4/9] KVM: arm64: Add vendor hypervisor firmware register
Raghavendra Rao Ananta
rananta at google.com
Mon Apr 25 09:51:56 PDT 2022
Hi Reiji,
On Sun, Apr 24, 2022 at 11:22 PM Reiji Watanabe <reijiw at google.com> wrote:
>
> Hi Raghu,
>
> On Fri, Apr 22, 2022 at 5:03 PM Raghavendra Rao Ananta
> <rananta at google.com> wrote:
> >
> > Introduce the firmware register to hold the vendor specific
> > hypervisor service calls (owner value 6) as a bitmap. The
> > bitmap represents the features that'll be enabled for the
> > guest, as configured by the user-space. Currently, this
> > includes support for KVM-vendor features along with
> > reading the UID, represented by bit-0, and Precision Time
> > Protocol (PTP), represented by bit-1.
> >
> > Signed-off-by: Raghavendra Rao Ananta <rananta at google.com>
> > ---
> > arch/arm64/include/asm/kvm_host.h | 2 ++
> > arch/arm64/include/uapi/asm/kvm.h | 4 ++++
> > arch/arm64/kvm/hypercalls.c | 23 ++++++++++++++++++-----
> > include/kvm/arm_hypercalls.h | 2 ++
> > 4 files changed, 26 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> > index 27d4b2a7970e..a025c2ba012a 100644
> > --- a/arch/arm64/include/asm/kvm_host.h
> > +++ b/arch/arm64/include/asm/kvm_host.h
> > @@ -106,10 +106,12 @@ struct kvm_arch_memory_slot {
> > *
> > * @std_bmap: Bitmap of standard secure service calls
> > * @std_hyp_bmap: Bitmap of standard hypervisor service calls
> > + * @vendor_hyp_bmap: Bitmap of vendor specific hypervisor service calls
> > */
> > struct kvm_smccc_features {
> > unsigned long std_bmap;
> > unsigned long std_hyp_bmap;
> > + unsigned long vendor_hyp_bmap;
> > };
> >
> > struct kvm_arch {
> > diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> > index 9eecc7ee8c14..e7d5ae222684 100644
> > --- a/arch/arm64/include/uapi/asm/kvm.h
> > +++ b/arch/arm64/include/uapi/asm/kvm.h
> > @@ -344,6 +344,10 @@ struct kvm_arm_copy_mte_tags {
> > #define KVM_REG_ARM_STD_HYP_BMAP KVM_REG_ARM_FW_FEAT_BMAP_REG(1)
> > #define KVM_REG_ARM_STD_HYP_BIT_PV_TIME 0
> >
> > +#define KVM_REG_ARM_VENDOR_HYP_BMAP KVM_REG_ARM_FW_FEAT_BMAP_REG(2)
> > +#define KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT 0
> > +#define KVM_REG_ARM_VENDOR_HYP_BIT_PTP 1
> > +
> > /* Device Control API: ARM VGIC */
> > #define KVM_DEV_ARM_VGIC_GRP_ADDR 0
> > #define KVM_DEV_ARM_VGIC_GRP_DIST_REGS 1
> > diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
> > index f097bebdad39..76e626d0e699 100644
> > --- a/arch/arm64/kvm/hypercalls.c
> > +++ b/arch/arm64/kvm/hypercalls.c
> > @@ -72,9 +72,6 @@ static bool kvm_hvc_call_default_allowed(struct kvm_vcpu *vcpu, u32 func_id)
> > */
> > case ARM_SMCCC_VERSION_FUNC_ID:
> > case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
> > - case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
> > - case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
> > - case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
> > return true;
> > default:
> > return kvm_psci_func_id_is_valid(vcpu, func_id);
> > @@ -97,6 +94,13 @@ static bool kvm_hvc_call_allowed(struct kvm_vcpu *vcpu, u32 func_id)
> > case ARM_SMCCC_HV_PV_TIME_ST:
> > return kvm_arm_fw_reg_feat_enabled(&smccc_feat->std_hyp_bmap,
> > KVM_REG_ARM_STD_HYP_BIT_PV_TIME);
> > + case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
> > + case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
> > + return kvm_arm_fw_reg_feat_enabled(&smccc_feat->vendor_hyp_bmap,
> > + KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT);
> > + case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
> > + return kvm_arm_fw_reg_feat_enabled(&smccc_feat->vendor_hyp_bmap,
> > + KVM_REG_ARM_VENDOR_HYP_BIT_PTP);
> > default:
> > return kvm_hvc_call_default_allowed(vcpu, func_id);
> > }
> > @@ -189,8 +193,7 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
> > val[3] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3;
> > break;
> > case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
> > - val[0] = BIT(ARM_SMCCC_KVM_FUNC_FEATURES);
> > - val[0] |= BIT(ARM_SMCCC_KVM_FUNC_PTP);
> > + val[0] = smccc_feat->vendor_hyp_bmap;
> > break;
> > case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
> > kvm_ptp_get_time(vcpu, val);
> > @@ -217,6 +220,7 @@ static const u64 kvm_arm_fw_reg_ids[] = {
> > KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3,
> > KVM_REG_ARM_STD_BMAP,
> > KVM_REG_ARM_STD_HYP_BMAP,
> > + KVM_REG_ARM_VENDOR_HYP_BMAP,
> > };
> >
> > void kvm_arm_init_hypercalls(struct kvm *kvm)
> > @@ -225,6 +229,7 @@ void kvm_arm_init_hypercalls(struct kvm *kvm)
> >
> > smccc_feat->std_bmap = KVM_ARM_SMCCC_STD_FEATURES;
> > smccc_feat->std_hyp_bmap = KVM_ARM_SMCCC_STD_HYP_FEATURES;
> > + smccc_feat->vendor_hyp_bmap = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
> > }
> >
> > int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
> > @@ -317,6 +322,9 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> > case KVM_REG_ARM_STD_HYP_BMAP:
> > val = READ_ONCE(smccc_feat->std_hyp_bmap);
> > break;
> > + case KVM_REG_ARM_VENDOR_HYP_BMAP:
> > + val = READ_ONCE(smccc_feat->vendor_hyp_bmap);
> > + break;
> > default:
> > return -ENOENT;
> > }
> > @@ -343,6 +351,10 @@ static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val)
> > fw_reg_bmap = &smccc_feat->std_hyp_bmap;
> > fw_reg_features = KVM_ARM_SMCCC_STD_HYP_FEATURES;
> > break;
> > + case KVM_REG_ARM_VENDOR_HYP_BMAP:
> > + fw_reg_bmap = &smccc_feat->vendor_hyp_bmap;
> > + fw_reg_features = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
> > + break;
> > default:
> > return -ENOENT;
> > }
> > @@ -445,6 +457,7 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
> > return 0;
> > case KVM_REG_ARM_STD_BMAP:
> > case KVM_REG_ARM_STD_HYP_BMAP:
> > + case KVM_REG_ARM_VENDOR_HYP_BMAP:
> > return kvm_arm_set_fw_reg_bmap(vcpu, reg->id, val);
> > default:
> > return -ENOENT;
> > diff --git a/include/kvm/arm_hypercalls.h b/include/kvm/arm_hypercalls.h
> > index aadd6ae3ab72..4ebfdd26e486 100644
> > --- a/include/kvm/arm_hypercalls.h
> > +++ b/include/kvm/arm_hypercalls.h
> > @@ -9,9 +9,11 @@
> > /* Last valid bits of the bitmapped firmware registers */
> > #define KVM_REG_ARM_STD_BMAP_BIT_MAX 0
> > #define KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX 0
> > +#define KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX 1
>
> Nit: IMHO perhaps it might be more convenient to define the MAX macro
> in arch/arm64/include/uapi/asm/kvm.h like below for maintenance ?
> (The same comments are applied to other KVM_REG_ARM_*_BMAP_BIT_MAX)
>
> #define KVM_REG_ARM_VENDOR_HYP_BIT_MAX KVM_REG_ARM_VENDOR_HYP_BIT_PTP
>
We have been going back and forth on this :)
It made sense for me to keep it in uapi as well, but I took Oliver's
suggestion of keeping it outside of uapi since this is something that
could be constantly changing [1].
Thank you.
Raghavendra
[1]: https://lore.kernel.org/lkml/CAJHc60wz5WsZWTn66i41+G4-dsjCFuFkthXU_Vf6QeXHkgzrZg@mail.gmail.com/
> Thanks,
> Reiji
>
>
> >
> > #define KVM_ARM_SMCCC_STD_FEATURES GENMASK(KVM_REG_ARM_STD_BMAP_BIT_MAX, 0)
> > #define KVM_ARM_SMCCC_STD_HYP_FEATURES GENMASK(KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX, 0)
> > +#define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES GENMASK(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX, 0)
> >
> > int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
> >
> > --
> > 2.36.0.rc2.479.g8af0fa9b8e-goog
> >
More information about the linux-arm-kernel
mailing list