kvm: move advertising of KVM_CAP_IRQFD to common code

[ Upstream commit dc9be0fac70a2ad86e31a81372bb0bdfb6945353 ]

POWER supports irqfds but forgot to advertise them.  Some userspace does
not check for the capability, but others check it---thus they work on
x86 and s390 but not POWER.

To avoid that other architectures in the future make the same mistake, let
common code handle KVM_CAP_IRQFD the same way as KVM_CAP_IRQFD_RESAMPLE.

Reported-and-tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 297e21053a52f060944e9f0de4c64fad9bcd72fc
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ced09d8..49e4d64 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -152,7 +152,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
        case KVM_CAP_ONE_REG:
        case KVM_CAP_ENABLE_CAP:
        case KVM_CAP_S390_CSS_SUPPORT:
-       case KVM_CAP_IRQFD:
        case KVM_CAP_IOEVENTFD:
        case KVM_CAP_DEVICE_CTRL:
        case KVM_CAP_ENABLE_CAP_VM:

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8b92cf4..a38dd81 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2713,7 +2713,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
        case KVM_CAP_USER_NMI:
        case KVM_CAP_REINJECT_CONTROL:
        case KVM_CAP_IRQ_INJECT_STATUS:
-       case KVM_CAP_IRQFD:
        case KVM_CAP_IOEVENTFD:
        case KVM_CAP_IOEVENTFD_NO_LENGTH:
        case KVM_CAP_PIT2:

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3cee7b1..cfbe0e7 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2417,6 +2417,7 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
        case KVM_CAP_SIGNAL_MSI:
 #endif
 #ifdef CONFIG_HAVE_KVM_IRQFD
+       case KVM_CAP_IRQFD:
        case KVM_CAP_IRQFD_RESAMPLE:
 #endif
        case KVM_CAP_CHECK_EXTENSION_VM: