[PATCH v2] KVM: PPC: Make KVM_CAP_IRQFD_RESAMPLE support platform

Timothy Pearson tpearson at raptorengineering.com
Tue Mar 7 04:35:00 AEDT 2023


 dependent

When introduced, IRQFD resampling worked on POWER8 with XICS. However
KVM on POWER9 has never implemented it - the compatibility mode code
("XICS-on-XIVE") misses the kvm_notify_acked_irq() call and the native
XIVE mode does not handle INTx in KVM at all.

This moved the capability support advertising to platforms and stops
advertising it on XIVE, i.e. POWER9 and later.

Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
Signed-off-by: Timothy Pearson <tpearson at raptorengineering.com>
---
 arch/arm64/kvm/arm.c       | 3 +++
 arch/mips/kvm/mips.c       | 3 +++
 arch/powerpc/kvm/powerpc.c | 6 ++++++
 arch/riscv/kvm/vm.c        | 3 +++
 arch/s390/kvm/kvm-s390.c   | 3 +++
 arch/x86/kvm/x86.c         | 3 +++
 virt/kvm/kvm_main.c        | 1 -
 7 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 3bd732eaf087..0ad50969430a 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -220,6 +220,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_VCPU_ATTRIBUTES:
 	case KVM_CAP_PTP_KVM:
 	case KVM_CAP_ARM_SYSTEM_SUSPEND:
+#ifdef CONFIG_HAVE_KVM_IRQFD
+	case KVM_CAP_IRQFD_RESAMPLE:
+#endif
 		r = 1;
 		break;
 	case KVM_CAP_SET_GUEST_DEBUG2:
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 36c8991b5d39..52bdc479875d 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -1046,6 +1046,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_READONLY_MEM:
 	case KVM_CAP_SYNC_MMU:
 	case KVM_CAP_IMMEDIATE_EXIT:
+#ifdef CONFIG_HAVE_KVM_IRQFD
+	case KVM_CAP_IRQFD_RESAMPLE:
+#endif
 		r = 1;
 		break;
 	case KVM_CAP_NR_VCPUS:
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 4c5405fc5538..d23e25e8432d 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -576,6 +576,12 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		break;
 #endif
 
+#ifdef CONFIG_HAVE_KVM_IRQFD
+	case KVM_CAP_IRQFD_RESAMPLE:
+		r = !xive_enabled();
+		break;
+#endif
+
 	case KVM_CAP_PPC_ALLOC_HTAB:
 		r = hv_enabled;
 		break;
diff --git a/arch/riscv/kvm/vm.c b/arch/riscv/kvm/vm.c
index 65a964d7e70d..0ef7a6168018 100644
--- a/arch/riscv/kvm/vm.c
+++ b/arch/riscv/kvm/vm.c
@@ -65,6 +65,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_READONLY_MEM:
 	case KVM_CAP_MP_STATE:
 	case KVM_CAP_IMMEDIATE_EXIT:
+#ifdef CONFIG_HAVE_KVM_IRQFD
+	case KVM_CAP_IRQFD_RESAMPLE:
+#endif
 		r = 1;
 		break;
 	case KVM_CAP_NR_VCPUS:
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 39b36562c043..6ca84bfdd2dc 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -573,6 +573,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_S390_VCPU_RESETS:
 	case KVM_CAP_SET_GUEST_DEBUG:
 	case KVM_CAP_S390_DIAG318:
+#ifdef CONFIG_HAVE_KVM_IRQFD
+	case KVM_CAP_IRQFD_RESAMPLE:
+#endif
 		r = 1;
 		break;
 	case KVM_CAP_SET_GUEST_DEBUG2:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7713420abab0..891aeace811e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4432,6 +4432,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_VAPIC:
 	case KVM_CAP_ENABLE_CAP:
 	case KVM_CAP_VM_DISABLE_NX_HUGE_PAGES:
+#ifdef CONFIG_HAVE_KVM_IRQFD
+	case KVM_CAP_IRQFD_RESAMPLE:
+#endif
 		r = 1;
 		break;
 	case KVM_CAP_EXIT_HYPERCALL:
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d255964ec331..b1679d08a216 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4479,7 +4479,6 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
 #endif
 #ifdef CONFIG_HAVE_KVM_IRQFD
 	case KVM_CAP_IRQFD:
-	case KVM_CAP_IRQFD_RESAMPLE:
 #endif
 	case KVM_CAP_IOEVENTFD_ANY_LENGTH:
 	case KVM_CAP_CHECK_EXTENSION_VM:
-- 
2.30.2


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