[RFC PATCH v2 06/11] KVM: arm64: Add vendor hypervisor firmware register
Raghavendra Rao Ananta
rananta at google.com
Fri Nov 12 17:22:29 PST 2021
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 at google.com>
---
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/include/uapi/asm/kvm.h | 4 ++++
arch/arm64/kvm/hypercalls.c | 30 +++++++++++++++++++++++++++++-
include/kvm/arm_hypercalls.h | 3 +++
4 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index e8e540bd1fe5..ef1d10bdf562 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -114,6 +114,7 @@ struct hvc_reg_desc {
struct hvc_fw_reg_bmap hvc_std_bmap;
struct hvc_fw_reg_bmap hvc_std_hyp_bmap;
+ struct hvc_fw_reg_bmap hvc_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 5890cbcd6385..8468e5d265df 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -289,6 +289,10 @@ struct kvm_arm_copy_mte_tags {
#define KVM_REG_ARM_STD_HYP_BIT_PV_TIME BIT(0)
#define KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX 0 /* Last valid bit */
+#define KVM_REG_ARM_VENDOR_HYP_BMAP KVM_REG_ARM_FW_REG(5)
+#define KVM_REG_ARM_VENDOR_HYP_BIT_PTP BIT(0)
+#define KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX 0 /* Last valid bit */
+
/* SVE registers */
#define KVM_REG_ARM64_SVE (0x15 << KVM_REG_ARM_COPROC_SHIFT)
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
index b3320adc068c..e1361029101e 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -88,6 +88,9 @@ bool kvm_hvc_call_supported(struct kvm_vcpu *vcpu, u32 func_id)
case ARM_SMCCC_HV_PV_TIME_ST:
return kvm_arm_fw_reg_feat_enabled(&hvc_desc->hvc_std_hyp_bmap,
KVM_REG_ARM_STD_HYP_BIT_PV_TIME);
+ case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
+ return kvm_arm_fw_reg_feat_enabled(&hvc_desc->hvc_vendor_hyp_bmap,
+ KVM_REG_ARM_VENDOR_HYP_BIT_PTP);
default:
/* By default, allow the services that aren't listed here */
return true;
@@ -99,6 +102,7 @@ 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;
@@ -173,7 +177,14 @@ 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->hvc_vendor_hyp_bmap.bmap << 1;
break;
case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
kvm_ptp_get_time(vcpu, val);
@@ -202,6 +213,7 @@ static const u64 fw_reg_ids[] = {
static const u64 fw_reg_bmap_ids[] = {
KVM_REG_ARM_STD_BMAP,
KVM_REG_ARM_STD_HYP_BMAP,
+ KVM_REG_ARM_VENDOR_HYP_BMAP,
};
static void kvm_arm_fw_reg_init_hvc(struct hvc_reg_desc *hvc_desc,
@@ -222,6 +234,8 @@ void kvm_arm_init_hypercalls(struct kvm *kvm)
KVM_REG_ARM_STD_BMAP, ARM_SMCCC_STD_FEATURES);
kvm_arm_fw_reg_init_hvc(hvc_desc, &hvc_desc->hvc_std_hyp_bmap,
KVM_REG_ARM_STD_HYP_BMAP, ARM_SMCCC_STD_HYP_FEATURES);
+ kvm_arm_fw_reg_init_hvc(hvc_desc, &hvc_desc->hvc_vendor_hyp_bmap,
+ KVM_REG_ARM_VENDOR_HYP_BMAP, ARM_SMCCC_VENDOR_HYP_FEATURES);
}
static void kvm_arm_fw_reg_sanitize(struct hvc_fw_reg_bmap *fw_reg_bmap)
@@ -270,6 +284,7 @@ void kvm_arm_sanitize_fw_regs(struct kvm *kvm)
kvm_arm_fw_reg_sanitize(&hvc_desc->hvc_std_bmap);
kvm_arm_fw_reg_sanitize(&hvc_desc->hvc_std_hyp_bmap);
+ kvm_arm_fw_reg_sanitize(&hvc_desc->hvc_vendor_hyp_bmap);
out:
spin_unlock(&hvc_desc->lock);
@@ -324,6 +339,9 @@ static int kvm_arm_fw_reg_set_bmap(struct kvm *kvm,
case KVM_REG_ARM_STD_HYP_BMAP:
fw_reg_features = ARM_SMCCC_STD_HYP_FEATURES;
break;
+ case KVM_REG_ARM_VENDOR_HYP_BMAP:
+ fw_reg_features = ARM_SMCCC_VENDOR_HYP_FEATURES;
+ break;
default:
ret = -EINVAL;
goto out;
@@ -453,6 +471,13 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
if (ret)
return ret;
+ break;
+ case KVM_REG_ARM_VENDOR_HYP_BMAP:
+ ret = kvm_arm_fw_reg_get_bmap(kvm,
+ &hvc_desc->hvc_vendor_hyp_bmap, &val);
+ if (ret)
+ return ret;
+
break;
default:
return -ENOENT;
@@ -547,6 +572,9 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
case KVM_REG_ARM_STD_HYP_BMAP:
return kvm_arm_fw_reg_set_bmap(kvm,
&hvc_desc->hvc_std_hyp_bmap, val);
+ case KVM_REG_ARM_VENDOR_HYP_BMAP:
+ return kvm_arm_fw_reg_set_bmap(kvm,
+ &hvc_desc->hvc_vendor_hyp_bmap, val);
default:
return -ENOENT;
}
diff --git a/include/kvm/arm_hypercalls.h b/include/kvm/arm_hypercalls.h
index 77c30e335f44..94f56562fea8 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_BIT_MAX, 0)
+#define ARM_SMCCC_VENDOR_HYP_FEATURES \
+ GENMASK_ULL(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_MAX, 0)
+
int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
static inline u32 smccc_get_function(struct kvm_vcpu *vcpu)
--
2.34.0.rc1.387.gb447b232ab-goog
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