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 only for Precision Time Protocol (PTP), represented by bit-0. Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx> --- Documentation/virt/kvm/arm/hypercalls.rst | 23 +++++++++++----- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/include/uapi/asm/kvm.h | 6 +++++ arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/hypercalls.c | 33 ++++++++++++++++++++++- include/kvm/arm_hypercalls.h | 3 +++ 6 files changed, 59 insertions(+), 8 deletions(-) diff --git a/Documentation/virt/kvm/arm/hypercalls.rst b/Documentation/virt/kvm/arm/hypercalls.rst index 2cb82c694868..61d95f4f1ddf 100644 --- a/Documentation/virt/kvm/arm/hypercalls.rst +++ b/Documentation/virt/kvm/arm/hypercalls.rst @@ -20,13 +20,14 @@ pseudo-registers" that can be manipulated using the GET/SET_ONE_REG interface. These registers can be saved/restored by userspace, and set to a convenient value if required. -The firmware registers, KVM_REG_ARM_STD and KVM_REG_ARM_STD_HYP exposes -the hypercall services in the form of a feature bitmap. Upon VM creation, -by default, KVM exposes all the features to the guest, which can be learnt -using GET_ONE_REG interface. Conversely, the features can be enabled or -disabled via the SET_ONE_REG interface. These registers allow the user-space -modification only until the VM has started running, after which they turn to -read-only registers. SET_ONE_REG in this scenario will return -EBUSY. +The firmware registers, KVM_REG_ARM_STD, KVM_REG_ARM_STD_HYP and +KVM_REG_ARM_VENDOR_HYP exposes the hypercall services in the form of a +feature bitmap. Upon VM creation, by default, KVM exposes all the features +to the guest, which can be learnt using GET_ONE_REG interface. Conversely, +the features can be enabled or disabled via the SET_ONE_REG interface. +These registers allow the user-space modification only until the VM has +started running, after which they turn to read-only registers. +SET_ONE_REG in this scenario will return -EBUSY. The following register is defined: @@ -100,4 +101,12 @@ The following register is defined: The bit represents the Paravirtualized Time service (also known as stolen time) as represented by ARM DEN0057A. +* KVM_REG_ARM_VENDOR_HYP + Controls the bitmap of the Vendor specific Hypervisor Service Calls. + + The following bits are accepted: + + KVM_REG_ARM_STD_HYP_PTP: + The bit represents the Precision Time Protocol KVM service. + .. [1] https://developer.arm.com/-/media/developer/pdf/ARM_DEN_0070A_Firmware_interfaces_for_mitigating_CVE-2017-5715.pdf diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index cee4f4b8a756..27861b3bd25f 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -108,6 +108,7 @@ struct hvc_reg_desc { u64 kvm_std_bmap; u64 kvm_std_hyp_bmap; + u64 kvm_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 46701da1a27d..a1d0e8e69eed 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -293,6 +293,12 @@ enum kvm_reg_arm_std_hyp_bmap { KVM_REG_ARM_STD_HYP_BMAP_MAX, }; +#define KVM_REG_ARM_VENDOR_HYP KVM_REG_ARM_FW_REG(5) +enum kvm_reg_arm_vendor_hyp_bmap { + KVM_REG_ARM_VENDOR_HYP_PTP, + KVM_REG_ARM_VENDOR_HYP_BMAP_MAX, +}; + /* SVE registers */ #define KVM_REG_ARM64_SVE (0x15 << KVM_REG_ARM_COPROC_SHIFT) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 1c69d2a71b86..5c89db8336eb 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -136,6 +136,7 @@ static void set_default_hypercalls(struct kvm *kvm) hvc_desc->kvm_std_bmap = ARM_SMCCC_STD_FEATURES; hvc_desc->kvm_std_hyp_bmap = ARM_SMCCC_STD_HYP_FEATURES; + hvc_desc->kvm_vendor_hyp_bmap = ARM_SMCCC_VENDOR_HYP_FEATURES; } /** diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c index 46064c515058..74ebe5355dc0 100644 --- a/arch/arm64/kvm/hypercalls.c +++ b/arch/arm64/kvm/hypercalls.c @@ -67,6 +67,8 @@ static u64 *kvm_fw_reg_to_bmap(struct kvm *kvm, u64 fw_reg) return &hvc_desc->kvm_std_bmap; case KVM_REG_ARM_STD_HYP: return &hvc_desc->kvm_std_hyp_bmap; + case KVM_REG_ARM_VENDOR_HYP: + return &hvc_desc->kvm_vendor_hyp_bmap; default: return NULL; } @@ -93,6 +95,10 @@ static const struct kvm_hvc_func_map hvc_std_hyp_map[] = { HVC_FUNC_MAP_DESC(ARM_SMCCC_HV_PV_TIME_ST, KVM_REG_ARM_STD_HYP_PV_TIME_ST), }; +static const struct kvm_hvc_func_map hvc_vendor_hyp_map[] = { + HVC_FUNC_MAP_DESC(ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID, KVM_REG_ARM_VENDOR_HYP_PTP), +}; + bool kvm_hvc_call_supported(struct kvm_vcpu *vcpu, u32 func_id) { struct kvm *kvm = vcpu->kvm; @@ -113,6 +119,11 @@ bool kvm_hvc_call_supported(struct kvm_vcpu *vcpu, u32 func_id) hvc_func_map = hvc_std_hyp_map; map_sz = ARRAY_SIZE(hvc_std_hyp_map); break; + case ARM_SMCCC_OWNER_VENDOR_HYP: + fw_reg = KVM_REG_ARM_VENDOR_HYP; + hvc_func_map = hvc_vendor_hyp_map; + map_sz = ARRAY_SIZE(hvc_vendor_hyp_map); + break; default: /* Allow all the owners that aren't mapped */ return true; @@ -133,6 +144,7 @@ bool kvm_hvc_call_supported(struct kvm_vcpu *vcpu, u32 func_id) int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) { + struct hvc_reg_desc *hvc_desc = &vcpu->kvm->arch.hvc_desc; u32 func_id = smccc_get_function(vcpu); u64 val[4] = {SMCCC_RET_NOT_SUPPORTED}; u32 feature; @@ -204,7 +216,14 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) 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); + + /* + * The feature bits exposed to user-space doesn't include + * ARM_SMCCC_KVM_FUNC_FEATURES. However, we expose this to + * the guest as bit-0. Hence, left-shift the user-space + * exposed bitmap by 1 to accommodate this. + */ + val[0] |= (hvc_desc->kvm_vendor_hyp_bmap << 1); break; case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID: kvm_ptp_get_time(vcpu, val); @@ -230,6 +249,7 @@ static const u64 fw_reg_ids[] = { KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2, KVM_REG_ARM_STD, KVM_REG_ARM_STD_HYP, + KVM_REG_ARM_VENDOR_HYP, }; int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu) @@ -310,6 +330,9 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) case KVM_REG_ARM_STD_HYP: val = hvc_desc->kvm_std_hyp_bmap; break; + case KVM_REG_ARM_VENDOR_HYP: + val = hvc_desc->kvm_vendor_hyp_bmap; + break; default: return -ENOENT; } @@ -446,6 +469,14 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) hvc_desc->kvm_std_hyp_bmap = val; return 0; + + case KVM_REG_ARM_VENDOR_HYP: + if (val & ~ARM_SMCCC_VENDOR_HYP_FEATURES) + return -EINVAL; + + hvc_desc->kvm_vendor_hyp_bmap = val; + return 0; + default: return -ENOENT; } diff --git a/include/kvm/arm_hypercalls.h b/include/kvm/arm_hypercalls.h index bbb3b12b10e3..d8c17d161ee5 100644 --- a/include/kvm/arm_hypercalls.h +++ b/include/kvm/arm_hypercalls.h @@ -12,6 +12,9 @@ #define ARM_SMCCC_STD_HYP_FEATURES \ GENMASK_ULL(KVM_REG_ARM_STD_HYP_BMAP_MAX - 1, 0) +#define ARM_SMCCC_VENDOR_HYP_FEATURES \ + GENMASK_ULL(KVM_REG_ARM_VENDOR_HYP_BMAP_MAX - 1, 0) + int kvm_hvc_call_handler(struct kvm_vcpu *vcpu); static inline u32 smccc_get_function(struct kvm_vcpu *vcpu) -- 2.33.1.1089.g2158813163f-goog _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm