Hi Haibu,
Thanks for having a look at the patches!
On 11/5/20 9:58 AM, Haibo Xu wrote:
> On Wed, 28 Oct 2020 at 01:26, Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote:
>> From: Sudeep Holla <sudeep.holla@xxxxxxx>
>>
>> To configure the virtual SPE buffer management interrupt number, we use a
>> VCPU kvm_device ioctl, encapsulating the KVM_ARM_VCPU_SPE_IRQ attribute
>> within the KVM_ARM_VCPU_SPE_CTRL group.
>>
>> After configuring the SPE, userspace is required to call the VCPU ioctl
>> with the attribute KVM_ARM_VCPU_SPE_INIT to initialize SPE on the VCPU.
>>
>> [Alexandru E: Fixed compilation errors, don't allow userspace to set the
>> VCPU feature, removed unused functions, fixed mismatched
>> descriptions, comments and error codes, reworked logic, rebased on
>> top of v5.10-rc1]
>>
>> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
>> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
>> ---
>> Documentation/virt/kvm/devices/vcpu.rst | 40 ++++++++
>> arch/arm64/include/uapi/asm/kvm.h | 3 +
>> arch/arm64/kvm/Makefile | 1 +
>> arch/arm64/kvm/guest.c | 9 ++
>> arch/arm64/kvm/reset.c | 23 +++++
>> arch/arm64/kvm/spe.c | 129 ++++++++++++++++++++++++
>> include/kvm/arm_spe.h | 27 +++++
>> include/uapi/linux/kvm.h | 1 +
>> 8 files changed, 233 insertions(+)
>> create mode 100644 arch/arm64/kvm/spe.c
>>
>> diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst
>> index 2acec3b9ef65..6135b9827fbe 100644
>> --- a/Documentation/virt/kvm/devices/vcpu.rst
>> +++ b/Documentation/virt/kvm/devices/vcpu.rst
>> @@ -161,3 +161,43 @@ Specifies the base address of the stolen time structure for this VCPU. The
>> base address must be 64 byte aligned and exist within a valid guest memory
>> region. See Documentation/virt/kvm/arm/pvtime.rst for more information
>> including the layout of the stolen time structure.
>> +
>> +4. GROUP: KVM_ARM_VCPU_SPE_CTRL
>> +===============================
>> +
>> +:Architectures: ARM64
>> +
>> +4.1 ATTRIBUTE: KVM_ARM_VCPU_SPE_IRQ
>> +-----------------------------------
>> +
>> +:Parameters: in kvm_device_attr.addr the address for the SPE buffer management
>> + interrupt is a pointer to an int
>> +
>> +Returns:
>> +
>> + ======= ========================================================
>> + -EBUSY The SPE buffer management interrupt is already set
>> + -EINVAL Invalid SPE overflow interrupt number
>> + -EFAULT Could not read the buffer management interrupt number
>> + -ENXIO SPE not supported or not properly configured
>> + ======= ========================================================
>> +
>> +A value describing the SPE (Statistical Profiling Extension) overflow interrupt
>> +number for this vcpu. This interrupt should be a PPI and the interrupt type and
>> +number must be same for each vcpu.
>> +
>> +4.2 ATTRIBUTE: KVM_ARM_VCPU_SPE_INIT
>> +------------------------------------
>> +
>> +:Parameters: no additional parameter in kvm_device_attr.addr
>> +
>> +Returns:
>> +
>> + ======= ======================================================
>> + -EBUSY SPE already initialized
>> + -ENODEV GIC not initialized
>> + -ENXIO SPE not supported or not properly configured
>> + ======= ======================================================
>> +
>> +Request the initialization of the SPE. Must be done after initializing the
>> +in-kernel irqchip and after setting the interrupt number for the VCPU.
>> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
>> index 489e12304dbb..ca57dfb7abf0 100644
>> --- a/arch/arm64/include/uapi/asm/kvm.h
>> +++ b/arch/arm64/include/uapi/asm/kvm.h
>> @@ -360,6 +360,9 @@ struct kvm_vcpu_events {
>> #define KVM_ARM_VCPU_TIMER_IRQ_PTIMER 1
>> #define KVM_ARM_VCPU_PVTIME_CTRL 2
>> #define KVM_ARM_VCPU_PVTIME_IPA 0
>> +#define KVM_ARM_VCPU_SPE_CTRL 3
>> +#define KVM_ARM_VCPU_SPE_IRQ 0
>> +#define KVM_ARM_VCPU_SPE_INIT 1
>>
>> /* KVM_IRQ_LINE irq field index values */
>> #define KVM_ARM_IRQ_VCPU2_SHIFT 28
>> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
>> index 1504c81fbf5d..f6e76f64ffbe 100644
>> --- a/arch/arm64/kvm/Makefile
>> +++ b/arch/arm64/kvm/Makefile
>> @@ -25,3 +25,4 @@ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \
>> vgic/vgic-its.o vgic/vgic-debug.o
>>
>> kvm-$(CONFIG_KVM_ARM_PMU) += pmu-emul.o
>> +kvm-$(CONFIG_KVM_ARM_SPE) += spe.o
>> diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
>> index dfb5218137ca..2ba790eeb782 100644
>> --- a/arch/arm64/kvm/guest.c
>> +++ b/arch/arm64/kvm/guest.c
>> @@ -926,6 +926,9 @@ int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
>> case KVM_ARM_VCPU_PVTIME_CTRL:
>> ret = kvm_arm_pvtime_set_attr(vcpu, attr);
>> break;
>> + case KVM_ARM_VCPU_SPE_CTRL:
>> + ret = kvm_arm_spe_set_attr(vcpu, attr);
>> + break;
>> default:
>> ret = -ENXIO;
>> break;
>> @@ -949,6 +952,9 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
>> case KVM_ARM_VCPU_PVTIME_CTRL:
>> ret = kvm_arm_pvtime_get_attr(vcpu, attr);
>> break;
>> + case KVM_ARM_VCPU_SPE_CTRL:
>> + ret = kvm_arm_spe_get_attr(vcpu, attr);
>> + break;
>> default:
>> ret = -ENXIO;
>> break;
>> @@ -972,6 +978,9 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
>> case KVM_ARM_VCPU_PVTIME_CTRL:
>> ret = kvm_arm_pvtime_has_attr(vcpu, attr);
>> break;
>> + case KVM_ARM_VCPU_SPE_CTRL:
>> + ret = kvm_arm_spe_has_attr(vcpu, attr);
>> + break;
>> default:
>> ret = -ENXIO;
>> break;
>> diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
>> index f32490229a4c..4dc205fa4be1 100644
>> --- a/arch/arm64/kvm/reset.c
>> +++ b/arch/arm64/kvm/reset.c
>> @@ -87,6 +87,9 @@ int kvm_arch_vm_ioctl_check_extension(struct kvm *kvm, long ext)
>> case KVM_CAP_ARM_PTRAUTH_GENERIC:
>> r = system_has_full_ptr_auth();
>> break;
>> + case KVM_CAP_ARM_SPE:
>> + r = kvm_arm_supports_spe();
>> + break;
>> default:
>> r = 0;
>> }
>> @@ -223,6 +226,19 @@ static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
>> return 0;
>> }
>>
>> +static int kvm_vcpu_enable_spe(struct kvm_vcpu *vcpu)
>> +{
>> + if (!kvm_arm_supports_spe())
>> + return -EINVAL;
>> +
>> + /* SPE is disabled if the PE is in AArch32 state */
>> + if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features))
>> + return -EINVAL;
>> +
>> + vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_SPE;
>> + return 0;
>> +}
>> +
>> /**
>> * kvm_reset_vcpu - sets core registers and sys_regs to reset value
>> * @vcpu: The VCPU pointer
>> @@ -274,6 +290,13 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
>> }
>> }
>>
>> + if (test_bit(KVM_ARM_VCPU_SPE, vcpu->arch.features)) {
>> + if (kvm_vcpu_enable_spe(vcpu)) {
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> + }
>> +
>> switch (vcpu->arch.target) {
>> default:
>> if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
>> diff --git a/arch/arm64/kvm/spe.c b/arch/arm64/kvm/spe.c
>> new file mode 100644
>> index 000000000000..f91a52cd7cd3
>> --- /dev/null
>> +++ b/arch/arm64/kvm/spe.c
>> @@ -0,0 +1,129 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) 2019 ARM Ltd.
>> + */
>> +
>> +#include <linux/kvm.h>
>> +#include <linux/kvm_host.h>
>> +#include <linux/uaccess.h>
>> +
>> +#include <kvm/arm_spe.h>
>> +#include <kvm/arm_vgic.h>
>> +
>> +static bool kvm_arm_vcpu_supports_spe(struct kvm_vcpu *vcpu)
>> +{
>> + if (!vcpu_has_spe(vcpu))
>> + return false;
>> +
>> + if (!irqchip_in_kernel(vcpu->kvm))
>> + return false;
>> +
> nit: should we move the irqchip_in_kernel() check to the caller?
Yes, definitely, I can move the irqchip_in_kernel() check to the callers because
it's a VM, not VCPU property, and use vcpu_has_spe() directly.
Thanks,
Alex
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