Re: [PATCH v6 4/9] KVM: arm64: Add vendor hypervisor firmware register

From: Gavin Shan
Date: Tue Apr 26 2022 - 02:42:39 EST

On 4/23/22 8:03 AM, Raghavendra Rao Ananta 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@xxxxxxxxxx>
---
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(-)


Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>

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
#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);