Commit 99a1db7a authored by Christoffer Dall's avatar Christoffer Dall
Browse files

KVM: arm/arm64: Allow setting the timer IRQ numbers from userspace 



First we define an ABI using the vcpu devices that lets userspace set
the interrupt numbers for the various timers on both the 32-bit and
64-bit KVM/ARM implementations.

Second, we add the definitions for the groups and attributes introduced
by the above ABI.  (We add the PMU define on the 32-bit side as well for
symmetry and it may get used some day.)

Third, we set up the arch-specific vcpu device operation handlers to
call into the timer code for anything related to the
KVM_ARM_VCPU_TIMER_CTRL group.

Fourth, we implement support for getting and setting the timer interrupt
numbers using the above defined ABI in the arch timer code.

Fifth, we introduce error checking upon enabling the arch timer (which
is called when first running a VCPU) to check that all VCPUs are
configured to use the same PPI for the timer (as mandated by the
architecture) and that the virtual and physical timers are not
configured to use the same IRQ number.

Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 85e69ad7

Documentation/virtual/kvm/devices/vcpu.txt

+25 −0
Original line number Diff line number Diff line
@@ -35,3 +35,28 @@ Returns: -ENODEV: PMUv3 not supported or GIC not initialized 
Request the initialization of the PMUv3.  If using the PMUv3 with an in-kernel

virtual GIC implementation, this must be done after initializing the in-kernel

irqchip.





2. GROUP: KVM_ARM_VCPU_TIMER_CTRL

Architectures: ARM,ARM64



2.1. ATTRIBUTE: KVM_ARM_VCPU_TIMER_IRQ_VTIMER

2.2. ATTRIBUTE: KVM_ARM_VCPU_TIMER_IRQ_PTIMER

Parameters: in kvm_device_attr.addr the address for the timer interrupt is a

            pointer to an int

Returns: -EINVAL: Invalid timer interrupt number

         -EBUSY:  One or more VCPUs has already run



A value describing the architected timer interrupt number when connected to an

in-kernel virtual GIC.  These must be a PPI (16 <= intid < 32).  Setting the

attribute overrides the default values (see below).



KVM_ARM_VCPU_TIMER_IRQ_VTIMER: The EL1 virtual timer intid (default: 27)

KVM_ARM_VCPU_TIMER_IRQ_PTIMER: The EL1 physical timer intid (default: 30)



Setting the same PPI for different timers will prevent the VCPUs from running.

Setting the interrupt number on a VCPU configures all VCPUs created at that

time to use the number provided for a given timer, overwriting any previously

configured values on other VCPUs.  Userspace should configure the interrupt

numbers on at least one VCPU after creating all VCPUs and before running any

VCPUs.

arch/arm/include/uapi/asm/kvm.h

+8 −0
Original line number Diff line number Diff line
@@ -203,6 +203,14 @@ struct kvm_arch_memory_slot { 
#define KVM_DEV_ARM_VGIC_LINE_LEVEL_INTID_MASK 0x3ff

#define VGIC_LEVEL_INFO_LINE_LEVEL	0



/* Device Control API on vcpu fd */

#define KVM_ARM_VCPU_PMU_V3_CTRL	0

#define   KVM_ARM_VCPU_PMU_V3_IRQ	0

#define   KVM_ARM_VCPU_PMU_V3_INIT	1

#define KVM_ARM_VCPU_TIMER_CTRL		1

#define   KVM_ARM_VCPU_TIMER_IRQ_VTIMER		0

#define   KVM_ARM_VCPU_TIMER_IRQ_PTIMER		1



#define   KVM_DEV_ARM_VGIC_CTRL_INIT		0

#define   KVM_DEV_ARM_ITS_SAVE_TABLES		1

#define   KVM_DEV_ARM_ITS_RESTORE_TABLES	2

arch/arm/kvm/guest.c

+9 −0
Original line number Diff line number Diff line
@@ -308,6 +308,9 @@ int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, 
	int ret;



	switch (attr->group) {

	case KVM_ARM_VCPU_TIMER_CTRL:

		ret = kvm_arm_timer_set_attr(vcpu, attr);

		break;

	default:

		ret = -ENXIO;

		break;
@@ -322,6 +325,9 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, 
	int ret;



	switch (attr->group) {

	case KVM_ARM_VCPU_TIMER_CTRL:

		ret = kvm_arm_timer_get_attr(vcpu, attr);

		break;

	default:

		ret = -ENXIO;

		break;
@@ -336,6 +342,9 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, 
	int ret;



	switch (attr->group) {

	case KVM_ARM_VCPU_TIMER_CTRL:

		ret = kvm_arm_timer_has_attr(vcpu, attr);

		break;

	default:

		ret = -ENXIO;

		break;

arch/arm64/include/uapi/asm/kvm.h

+3 −0
Original line number Diff line number Diff line
@@ -232,6 +232,9 @@ struct kvm_arch_memory_slot { 
#define KVM_ARM_VCPU_PMU_V3_CTRL	0

#define   KVM_ARM_VCPU_PMU_V3_IRQ	0

#define   KVM_ARM_VCPU_PMU_V3_INIT	1

#define KVM_ARM_VCPU_TIMER_CTRL		1

#define   KVM_ARM_VCPU_TIMER_IRQ_VTIMER		0

#define   KVM_ARM_VCPU_TIMER_IRQ_PTIMER		1



/* KVM_IRQ_LINE irq field index values */

#define KVM_ARM_IRQ_TYPE_SHIFT		24

arch/arm64/kvm/guest.c

+9 −0
Original line number Diff line number Diff line
@@ -390,6 +390,9 @@ int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu, 
	case KVM_ARM_VCPU_PMU_V3_CTRL:

		ret = kvm_arm_pmu_v3_set_attr(vcpu, attr);

		break;

	case KVM_ARM_VCPU_TIMER_CTRL:

		ret = kvm_arm_timer_set_attr(vcpu, attr);

		break;

	default:

		ret = -ENXIO;

		break;
@@ -407,6 +410,9 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu, 
	case KVM_ARM_VCPU_PMU_V3_CTRL:

		ret = kvm_arm_pmu_v3_get_attr(vcpu, attr);

		break;

	case KVM_ARM_VCPU_TIMER_CTRL:

		ret = kvm_arm_timer_get_attr(vcpu, attr);

		break;

	default:

		ret = -ENXIO;

		break;
@@ -424,6 +430,9 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, 
	case KVM_ARM_VCPU_PMU_V3_CTRL:

		ret = kvm_arm_pmu_v3_has_attr(vcpu, attr);

		break;

	case KVM_ARM_VCPU_TIMER_CTRL:

		ret = kvm_arm_timer_has_attr(vcpu, attr);

		break;

	default:

		ret = -ENXIO;

		break;

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