Commit 92b591a4 authored by Alexander Graf's avatar Alexander Graf
Browse files

KVM: Allow KVM_CHECK_EXTENSION on the vm fd 



The KVM_CHECK_EXTENSION is only available on the kvm fd today. Unfortunately
on PPC some of the capabilities change depending on the way a VM was created.

So instead we need a way to expose capabilities as VM ioctl, so that we can
see which VM type we're using (HV or PR). To enable this, add the
KVM_CHECK_EXTENSION ioctl to our vm ioctl portfolio.

Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
Acked-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 784aa3d7

Documentation/virtual/kvm/api.txt

+5 −2
Original line number Original line Diff line number Diff line
@@ -148,9 +148,9 @@ of banks, as set via the KVM_X86_SETUP_MCE ioctl. 




4.4 KVM_CHECK_EXTENSION

4.4 KVM_CHECK_EXTENSION





Capability: basic

Capability: basic, KVM_CAP_CHECK_EXTENSION_VM for vm ioctl

Architectures: all

Architectures: all

Type: system ioctl

Type: system ioctl, vm ioctl

Parameters: extension identifier (KVM_CAP_*)

Parameters: extension identifier (KVM_CAP_*)

Returns: 0 if unsupported; 1 (or some other positive integer) if supported

Returns: 0 if unsupported; 1 (or some other positive integer) if supported
@@ -160,6 +160,9 @@ receives an integer that describes the extension availability. 
Generally 0 means no and 1 means yes, but some extensions may report

Generally 0 means no and 1 means yes, but some extensions may report

additional information in the integer return value.

additional information in the integer return value.





Based on their initialization different VMs may have different capabilities.

It is thus encouraged to use the vm ioctl to query for capabilities (available

with KVM_CAP_CHECK_EXTENSION_VM on the vm fd)





4.5 KVM_GET_VCPU_MMAP_SIZE

4.5 KVM_GET_VCPU_MMAP_SIZE

include/uapi/linux/kvm.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -759,6 +759,7 @@ struct kvm_ppc_smmu_info { 
#define KVM_CAP_ARM_PSCI_0_2 102

#define KVM_CAP_ARM_PSCI_0_2 102

#define KVM_CAP_PPC_FIXUP_HCALL 103

#define KVM_CAP_PPC_FIXUP_HCALL 103

#define KVM_CAP_PPC_ENABLE_HCALL 104

#define KVM_CAP_PPC_ENABLE_HCALL 104

#define KVM_CAP_CHECK_EXTENSION_VM 105





#ifdef KVM_CAP_IRQ_ROUTING

#ifdef KVM_CAP_IRQ_ROUTING

virt/kvm/kvm_main.c

+31 −27
Original line number Original line Diff line number Diff line
@@ -2324,6 +2324,34 @@ static int kvm_ioctl_create_device(struct kvm *kvm, 
	return 0;

	return 0;

}

}





static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)

{

	switch (arg) {

	case KVM_CAP_USER_MEMORY:

	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:

	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:

#ifdef CONFIG_KVM_APIC_ARCHITECTURE

	case KVM_CAP_SET_BOOT_CPU_ID:

#endif

	case KVM_CAP_INTERNAL_ERROR_DATA:

#ifdef CONFIG_HAVE_KVM_MSI

	case KVM_CAP_SIGNAL_MSI:

#endif

#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING

	case KVM_CAP_IRQFD_RESAMPLE:

#endif

	case KVM_CAP_CHECK_EXTENSION_VM:

		return 1;

#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING

	case KVM_CAP_IRQ_ROUTING:

		return KVM_MAX_IRQ_ROUTES;

#endif

	default:

		break;

	}

	return kvm_vm_ioctl_check_extension(kvm, arg);

}



static long kvm_vm_ioctl(struct file *filp,

static long kvm_vm_ioctl(struct file *filp,

			   unsigned int ioctl, unsigned long arg)

			   unsigned int ioctl, unsigned long arg)

{

{
@@ -2487,6 +2515,9 @@ static long kvm_vm_ioctl(struct file *filp, 
		r = 0;

		r = 0;

		break;

		break;

	}

	}

	case KVM_CHECK_EXTENSION:

		r = kvm_vm_ioctl_check_extension_generic(kvm, arg);

		break;

	default:

	default:

		r = kvm_arch_vm_ioctl(filp, ioctl, arg);

		r = kvm_arch_vm_ioctl(filp, ioctl, arg);

		if (r == -ENOTTY)

		if (r == -ENOTTY)
@@ -2571,33 +2602,6 @@ static int kvm_dev_ioctl_create_vm(unsigned long type) 
	return r;

	return r;

}

}





static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)

{

	switch (arg) {

	case KVM_CAP_USER_MEMORY:

	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:

	case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:

#ifdef CONFIG_KVM_APIC_ARCHITECTURE

	case KVM_CAP_SET_BOOT_CPU_ID:

#endif

	case KVM_CAP_INTERNAL_ERROR_DATA:

#ifdef CONFIG_HAVE_KVM_MSI

	case KVM_CAP_SIGNAL_MSI:

#endif

#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING

	case KVM_CAP_IRQFD_RESAMPLE:

#endif

		return 1;

#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING

	case KVM_CAP_IRQ_ROUTING:

		return KVM_MAX_IRQ_ROUTES;

#endif

	default:

		break;

	}

	return kvm_vm_ioctl_check_extension(kvm, arg);

}



static long kvm_dev_ioctl(struct file *filp,

static long kvm_dev_ioctl(struct file *filp,

			  unsigned int ioctl, unsigned long arg)

			  unsigned int ioctl, unsigned long arg)

{

{

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