[v2,3/6] KVM: arm64: Support pvlock preempted via shared structure
Commit Message
Implement the service call for configuring a shared structure between a
VCPU and the hypervisor in which the hypervisor can tell whether the
VCPU is running or not.
The preempted field is zero if the VCPU is not preempted.
Any other value means the VCPU has been preempted.
Signed-off-by: Zengruan Ye <yezengruan@huawei.com>
Signed-off-by: Usama Arif <usama.arif@bytedance.com>
---
Documentation/virt/kvm/arm/hypercalls.rst | 3 ++
arch/arm64/include/asm/kvm_host.h | 18 ++++++++++
arch/arm64/include/uapi/asm/kvm.h | 1 +
arch/arm64/kvm/Makefile | 2 +-
arch/arm64/kvm/arm.c | 8 +++++
arch/arm64/kvm/hypercalls.c | 8 +++++
arch/arm64/kvm/pvlock.c | 43 +++++++++++++++++++++++
tools/arch/arm64/include/uapi/asm/kvm.h | 1 +
8 files changed, 83 insertions(+), 1 deletion(-)
create mode 100644 arch/arm64/kvm/pvlock.c
Comments
Usama Arif <usama.arif@bytedance.com> writes:
> Implement the service call for configuring a shared structure between a
> VCPU and the hypervisor in which the hypervisor can tell whether the
> VCPU is running or not.
>
> The preempted field is zero if the VCPU is not preempted.
> Any other value means the VCPU has been preempted.
>
> Signed-off-by: Zengruan Ye <yezengruan@huawei.com>
> Signed-off-by: Usama Arif <usama.arif@bytedance.com>
> ---
> Documentation/virt/kvm/arm/hypercalls.rst | 3 ++
> arch/arm64/include/asm/kvm_host.h | 18 ++++++++++
> arch/arm64/include/uapi/asm/kvm.h | 1 +
> arch/arm64/kvm/Makefile | 2 +-
> arch/arm64/kvm/arm.c | 8 +++++
> arch/arm64/kvm/hypercalls.c | 8 +++++
> arch/arm64/kvm/pvlock.c | 43 +++++++++++++++++++++++
> tools/arch/arm64/include/uapi/asm/kvm.h | 1 +
> 8 files changed, 83 insertions(+), 1 deletion(-)
> create mode 100644 arch/arm64/kvm/pvlock.c
>
> diff --git a/Documentation/virt/kvm/arm/hypercalls.rst b/Documentation/virt/kvm/arm/hypercalls.rst
> index 3e23084644ba..872a16226ace 100644
> --- a/Documentation/virt/kvm/arm/hypercalls.rst
> +++ b/Documentation/virt/kvm/arm/hypercalls.rst
> @@ -127,6 +127,9 @@ The pseudo-firmware bitmap register are as follows:
> Bit-1: KVM_REG_ARM_VENDOR_HYP_BIT_PTP:
> The bit represents the Precision Time Protocol KVM service.
>
> + Bit-2: KVM_REG_ARM_VENDOR_HYP_BIT_PV_LOCK:
> + The bit represents the Paravirtualized lock service.
> +
> Errors:
>
> ======= =============================================================
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 45e2136322ba..18303b30b7e9 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -417,6 +417,11 @@ struct kvm_vcpu_arch {
> u64 last_steal;
> gpa_t base;
> } steal;
> +
> + /* Guest PV lock state */
> + struct {
> + gpa_t base;
> + } pv;
Using "pv" for the structure isn't quite describing the usage well. It'd
be better to call it "pv_lock" or "pvlock" at the least.
[...]
On 07/11/2022 18:02, Punit Agrawal wrote:
> Usama Arif <usama.arif@bytedance.com> writes:
>
>> Implement the service call for configuring a shared structure between a
>> VCPU and the hypervisor in which the hypervisor can tell whether the
>> VCPU is running or not.
>>
>> The preempted field is zero if the VCPU is not preempted.
>> Any other value means the VCPU has been preempted.
>>
>> Signed-off-by: Zengruan Ye <yezengruan@huawei.com>
>> Signed-off-by: Usama Arif <usama.arif@bytedance.com>
>> ---
>> Documentation/virt/kvm/arm/hypercalls.rst | 3 ++
>> arch/arm64/include/asm/kvm_host.h | 18 ++++++++++
>> arch/arm64/include/uapi/asm/kvm.h | 1 +
>> arch/arm64/kvm/Makefile | 2 +-
>> arch/arm64/kvm/arm.c | 8 +++++
>> arch/arm64/kvm/hypercalls.c | 8 +++++
>> arch/arm64/kvm/pvlock.c | 43 +++++++++++++++++++++++
>> tools/arch/arm64/include/uapi/asm/kvm.h | 1 +
>> 8 files changed, 83 insertions(+), 1 deletion(-)
>> create mode 100644 arch/arm64/kvm/pvlock.c
>>
>> diff --git a/Documentation/virt/kvm/arm/hypercalls.rst b/Documentation/virt/kvm/arm/hypercalls.rst
>> index 3e23084644ba..872a16226ace 100644
>> --- a/Documentation/virt/kvm/arm/hypercalls.rst
>> +++ b/Documentation/virt/kvm/arm/hypercalls.rst
>> @@ -127,6 +127,9 @@ The pseudo-firmware bitmap register are as follows:
>> Bit-1: KVM_REG_ARM_VENDOR_HYP_BIT_PTP:
>> The bit represents the Precision Time Protocol KVM service.
>>
>> + Bit-2: KVM_REG_ARM_VENDOR_HYP_BIT_PV_LOCK:
>> + The bit represents the Paravirtualized lock service.
>> +
>> Errors:
>>
>> ======= =============================================================
>> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
>> index 45e2136322ba..18303b30b7e9 100644
>> --- a/arch/arm64/include/asm/kvm_host.h
>> +++ b/arch/arm64/include/asm/kvm_host.h
>> @@ -417,6 +417,11 @@ struct kvm_vcpu_arch {
>> u64 last_steal;
>> gpa_t base;
>> } steal;
>> +
>> + /* Guest PV lock state */
>> + struct {
>> + gpa_t base;
>> + } pv;
>
> Using "pv" for the structure isn't quite describing the usage well. It'd
> be better to call it "pv_lock" or "pvlock" at the least.
>
Yes makes sense, will change in next patchset, Thanks.
> [...]
>
@@ -127,6 +127,9 @@ The pseudo-firmware bitmap register are as follows:
Bit-1: KVM_REG_ARM_VENDOR_HYP_BIT_PTP:
The bit represents the Precision Time Protocol KVM service.
+ Bit-2: KVM_REG_ARM_VENDOR_HYP_BIT_PV_LOCK:
+ The bit represents the Paravirtualized lock service.
+
Errors:
======= =============================================================
@@ -417,6 +417,11 @@ struct kvm_vcpu_arch {
u64 last_steal;
gpa_t base;
} steal;
+
+ /* Guest PV lock state */
+ struct {
+ gpa_t base;
+ } pv;
};
/*
@@ -840,6 +845,19 @@ static inline bool kvm_arm_is_pvtime_enabled(struct kvm_vcpu_arch *vcpu_arch)
return (vcpu_arch->steal.base != GPA_INVALID);
}
+static inline void kvm_arm_pvlock_preempted_init(struct kvm_vcpu_arch *vcpu_arch)
+{
+ vcpu_arch->pv.base = GPA_INVALID;
+}
+
+static inline bool kvm_arm_is_pvlock_preempted_ready(struct kvm_vcpu_arch *vcpu_arch)
+{
+ return (vcpu_arch->pv.base != GPA_INVALID);
+}
+
+gpa_t kvm_init_pvlock(struct kvm_vcpu *vcpu);
+void kvm_update_pvlock_preempted(struct kvm_vcpu *vcpu, u64 preempted);
+
void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 syndrome);
struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
@@ -365,6 +365,7 @@ enum {
enum {
KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT = 0,
KVM_REG_ARM_VENDOR_HYP_BIT_PTP = 1,
+ KVM_REG_ARM_VENDOR_HYP_BIT_PV_LOCK = 2,
#ifdef __KERNEL__
KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_COUNT,
#endif
@@ -10,7 +10,7 @@ include $(srctree)/virt/kvm/Makefile.kvm
obj-$(CONFIG_KVM) += kvm.o
obj-$(CONFIG_KVM) += hyp/
-kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \
+kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o pvlock.o \
inject_fault.o va_layout.o handle_exit.o \
guest.o debug.o reset.o sys_regs.o stacktrace.o \
vgic-sys-reg-v3.o fpsimd.o pkvm.o \
@@ -345,6 +345,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
kvm_arm_pvtime_vcpu_init(&vcpu->arch);
+ kvm_arm_pvlock_preempted_init(&vcpu->arch);
+
vcpu->arch.hw_mmu = &vcpu->kvm->arch.mmu;
err = kvm_vgic_vcpu_init(vcpu);
@@ -420,6 +422,10 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
if (vcpu_has_ptrauth(vcpu))
vcpu_ptrauth_disable(vcpu);
+
+ if (kvm_arm_is_pvlock_preempted_ready(&vcpu->arch))
+ kvm_update_pvlock_preempted(vcpu, 0);
+
kvm_arch_vcpu_load_debug_state_flags(vcpu);
if (!cpumask_test_cpu(smp_processor_id(), vcpu->kvm->arch.supported_cpus))
@@ -433,6 +439,8 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
if (has_vhe())
kvm_vcpu_put_sysregs_vhe(vcpu);
kvm_timer_vcpu_put(vcpu);
+ if (kvm_arm_is_pvlock_preempted_ready(&vcpu->arch))
+ kvm_update_pvlock_preempted(vcpu, 1);
kvm_vgic_put(vcpu);
kvm_vcpu_pmu_restore_host(vcpu);
kvm_arm_vmid_clear_active();
@@ -116,6 +116,9 @@ static bool kvm_hvc_call_allowed(struct kvm_vcpu *vcpu, u32 func_id)
case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
return test_bit(KVM_REG_ARM_VENDOR_HYP_BIT_PTP,
&smccc_feat->vendor_hyp_bmap);
+ case ARM_SMCCC_VENDOR_HYP_KVM_PV_LOCK_FUNC_ID:
+ return test_bit(KVM_REG_ARM_VENDOR_HYP_BIT_PV_LOCK,
+ &smccc_feat->vendor_hyp_bmap);
default:
return kvm_hvc_call_default_allowed(func_id);
}
@@ -201,6 +204,11 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
if (gpa != GPA_INVALID)
val[0] = gpa;
break;
+ case ARM_SMCCC_VENDOR_HYP_KVM_PV_LOCK_FUNC_ID:
+ gpa = kvm_init_pvlock(vcpu);
+ if (gpa != GPA_INVALID)
+ val[0] = gpa;
+ break;
case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
val[0] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0;
val[1] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1;
new file mode 100644
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright(c) 2019 Huawei Technologies Co., Ltd
+ * Author: Zengruan Ye <yezengruan@huawei.com>
+ * Usama Arif <usama.arif@bytedance.com>
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/kvm_host.h>
+
+#include <asm/pvlock-abi.h>
+
+#include <kvm/arm_hypercalls.h>
+
+gpa_t kvm_init_pvlock(struct kvm_vcpu *vcpu)
+{
+ struct pvlock_vcpu_state init_values = {};
+ struct kvm *kvm = vcpu->kvm;
+ u64 base = vcpu->arch.pv.base;
+ int idx;
+
+ if (base == GPA_INVALID)
+ return base;
+
+ idx = srcu_read_lock(&kvm->srcu);
+ kvm_write_guest(kvm, base, &init_values, sizeof(init_values));
+ srcu_read_unlock(&kvm->srcu, idx);
+
+ return base;
+}
+
+void kvm_update_pvlock_preempted(struct kvm_vcpu *vcpu, u64 preempted)
+{
+ int idx;
+ u64 offset;
+ struct kvm *kvm = vcpu->kvm;
+ u64 base = vcpu->arch.pv.base;
+
+ idx = srcu_read_lock(&kvm->srcu);
+ offset = offsetof(struct pvlock_vcpu_state, preempted);
+ kvm_put_guest(kvm, base + offset, cpu_to_le64(preempted));
+ srcu_read_unlock(&kvm->srcu, idx);
+}
@@ -365,6 +365,7 @@ enum {
enum {
KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT = 0,
KVM_REG_ARM_VENDOR_HYP_BIT_PTP = 1,
+ KVM_REG_ARM_VENDOR_HYP_BIT_PV_LOCK = 2,
#ifdef __KERNEL__
KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_COUNT,
#endif