[PATCH v4 06/13] KVM: arm64: Add standard hypervisor firmware register
Raghavendra Rao Ananta
rananta at google.com
Thu Feb 24 09:25:52 PST 2022
Introduce the firmware register to hold the standard hypervisor
service calls (owner value 5) 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
Paravirtualized time, represented by bit-0.
The register is also added to the kvm_arm_vm_scope_fw_regs[] list
as it maintains its state per-VM.
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/guest.c | 1 +
arch/arm64/kvm/hypercalls.c | 20 +++++++++++++++++++-
include/kvm/arm_hypercalls.h | 3 +++
5 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 1909ced3208f..318148b69279 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -105,9 +105,11 @@ struct kvm_arch_memory_slot {
* struct kvm_hvc_desc: KVM ARM64 hypercall descriptor
*
* @hvc_std_bmap: Bitmap of standard secure service calls
+ * @hvc_std_hyp_bmap: Bitmap of standard hypervisor service calls
*/
struct kvm_hvc_desc {
u64 hvc_std_bmap;
+ u64 hvc_std_hyp_bmap;
};
struct kvm_arch {
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 2decc30d6b84..9a2caead7359 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -295,6 +295,10 @@ struct kvm_arm_copy_mte_tags {
#define KVM_REG_ARM_STD_BIT_TRNG_V1_0 BIT(0)
#define KVM_REG_ARM_STD_BMAP_BIT_MAX 0 /* Last valid bit */
+#define KVM_REG_ARM_STD_HYP_BMAP KVM_REG_ARM_FW_BMAP_REG(1)
+#define KVM_REG_ARM_STD_HYP_BIT_PV_TIME BIT(0)
+#define KVM_REG_ARM_STD_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/guest.c b/arch/arm64/kvm/guest.c
index d66e6c742bbe..c42426d6137e 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -66,6 +66,7 @@ static const u64 kvm_arm_vm_scope_fw_regs[] = {
KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1,
KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2,
KVM_REG_ARM_STD_BMAP,
+ KVM_REG_ARM_STD_HYP_BMAP,
};
/**
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
index 48c126c3da72..ebc0cc26cf2e 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -75,6 +75,10 @@ static bool kvm_hvc_call_supported(struct kvm_vcpu *vcpu, u32 func_id)
case ARM_SMCCC_TRNG_RND64:
return kvm_arm_fw_reg_feat_enabled(hvc_desc->hvc_std_bmap,
KVM_REG_ARM_STD_BIT_TRNG_V1_0);
+ case ARM_SMCCC_HV_PV_TIME_FEATURES:
+ 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);
default:
/* By default, allow the services that aren't listed here */
return true;
@@ -83,6 +87,7 @@ static 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;
@@ -134,7 +139,10 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
}
break;
case ARM_SMCCC_HV_PV_TIME_FEATURES:
- val[0] = SMCCC_RET_SUCCESS;
+ if (kvm_arm_fw_reg_feat_enabled(
+ hvc_desc->hvc_std_hyp_bmap,
+ KVM_REG_ARM_STD_HYP_BIT_PV_TIME))
+ val[0] = SMCCC_RET_SUCCESS;
break;
}
break;
@@ -179,6 +187,7 @@ static const u64 kvm_arm_fw_reg_ids[] = {
KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1,
KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2,
KVM_REG_ARM_STD_BMAP,
+ KVM_REG_ARM_STD_HYP_BMAP,
};
void kvm_arm_init_hypercalls(struct kvm *kvm)
@@ -186,6 +195,7 @@ void kvm_arm_init_hypercalls(struct kvm *kvm)
struct kvm_hvc_desc *hvc_desc = &kvm->arch.hvc_desc;
hvc_desc->hvc_std_bmap = ARM_SMCCC_STD_FEATURES;
+ hvc_desc->hvc_std_hyp_bmap = ARM_SMCCC_STD_HYP_FEATURES;
}
int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
@@ -272,6 +282,9 @@ int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
case KVM_REG_ARM_STD_BMAP:
val = READ_ONCE(hvc_desc->hvc_std_bmap);
break;
+ case KVM_REG_ARM_STD_HYP_BMAP:
+ val = READ_ONCE(hvc_desc->hvc_std_hyp_bmap);
+ break;
default:
return -ENOENT;
}
@@ -294,6 +307,10 @@ static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val)
fw_reg_bmap = &hvc_desc->hvc_std_bmap;
fw_reg_features = ARM_SMCCC_STD_FEATURES;
break;
+ case KVM_REG_ARM_STD_HYP_BMAP:
+ fw_reg_bmap = &hvc_desc->hvc_std_hyp_bmap;
+ fw_reg_features = ARM_SMCCC_STD_HYP_FEATURES;
+ break;
default:
return -ENOENT;
}
@@ -398,6 +415,7 @@ 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:
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 64d30b452809..a1cb6e839c74 100644
--- a/include/kvm/arm_hypercalls.h
+++ b/include/kvm/arm_hypercalls.h
@@ -9,6 +9,9 @@
#define ARM_SMCCC_STD_FEATURES \
GENMASK_ULL(KVM_REG_ARM_STD_BMAP_BIT_MAX, 0)
+#define ARM_SMCCC_STD_HYP_FEATURES \
+ GENMASK_ULL(KVM_REG_ARM_STD_HYP_BMAP_BIT_MAX, 0)
+
int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
static inline u32 smccc_get_function(struct kvm_vcpu *vcpu)
--
2.35.1.473.g83b2b277ed-goog
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