[RFC PATCH v3 06/11] KVM: arm64: Add vendor hypervisor firmware register
Raghavendra Rao Ananta
rananta at google.com
Tue Jan 4 11:49:13 PST 2022
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 | 2 ++
arch/arm64/include/uapi/asm/kvm.h | 4 ++++
arch/arm64/kvm/hypercalls.c | 23 ++++++++++++++++++++++-
include/kvm/arm_hypercalls.h | 3 +++
4 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 1daf2c0b3b85..877096737ee1 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -107,10 +107,12 @@ struct kvm_arch_memory_slot {
*
* @hvc_std_bmap: Bitmap of standard secure service calls
* @hvc_std_hyp_bmap: Bitmap of standard hypervisor service calls
+ * @hvc_vendor_hyp_bmap: Bitmap of vendor specific hypervisor service calls
*/
struct kvm_hvc_desc {
u64 hvc_std_bmap;
u64 hvc_std_hyp_bmap;
+ u64 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 af59c434ae33..7f076da55f30 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 9df0221834a3..2403ad50d759 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -79,6 +79,9 @@ 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;
@@ -87,6 +90,7 @@ bool kvm_hvc_call_supported(struct kvm_vcpu *vcpu, u32 func_id)
int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
{
+ struct kvm_hvc_desc *hvc_desc = &vcpu->kvm->arch.hvc_desc;
u32 func_id = smccc_get_function(vcpu);
u64 val[4] = {SMCCC_RET_NOT_SUPPORTED};
u32 feature;
@@ -159,7 +163,14 @@ 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 << 1;
break;
case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
kvm_ptp_get_time(vcpu, val);
@@ -188,6 +199,7 @@ static const u64 kvm_arm_fw_reg_ids[] = {
static const u64 kvm_arm_fw_reg_bmap_ids[] = {
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)
@@ -196,6 +208,7 @@ void kvm_arm_init_hypercalls(struct kvm *kvm)
hvc_desc->hvc_std_bmap = ARM_SMCCC_STD_FEATURES;
hvc_desc->hvc_std_hyp_bmap = ARM_SMCCC_STD_HYP_FEATURES;
+ hvc_desc->hvc_vendor_hyp_bmap = ARM_SMCCC_VENDOR_HYP_FEATURES;
}
int kvm_arm_num_fw_bmap_regs(void)
@@ -296,6 +309,9 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
case KVM_REG_ARM_STD_HYP_BMAP:
kvm_arm_get_fw_reg_bmap(vcpu, hvc_desc->hvc_std_hyp_bmap, &val);
break;
+ case KVM_REG_ARM_VENDOR_HYP_BMAP:
+ kvm_arm_get_fw_reg_bmap(vcpu, hvc_desc->hvc_vendor_hyp_bmap, &val);
+ break;
default:
return -ENOENT;
}
@@ -322,6 +338,10 @@ static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val)
fw_reg_bmap = &hvc_desc->hvc_std_hyp_bmap;
fw_reg_features = ARM_SMCCC_STD_HYP_FEATURES;
break;
+ case KVM_REG_ARM_VENDOR_HYP_BMAP:
+ fw_reg_bmap = &hvc_desc->hvc_vendor_hyp_bmap;
+ fw_reg_features = ARM_SMCCC_VENDOR_HYP_FEATURES;
+ break;
default:
return -ENOENT;
}
@@ -425,6 +445,7 @@ 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 1a79b5f89a24..8f54cacfbf40 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)
--
2.34.1.448.ga2b2bfdf31-goog
More information about the linux-arm-kernel
mailing list