[PATCH 28/60] kvm: Implement KVM_CAP_PLANES

["Jörg Rödel" <joro@8bytes.org>]

From: Paolo Bonzini <pbonzini@redhat.com>

Introduce an architecture call-back to request the VM-specific maximum
number of supported planes. Use that to implement the KVM_CAP_PLANES
capability check.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Co-developed-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
 arch/arm64/kvm/arm.c       | 5 +++++
 arch/loongarch/kvm/vm.c    | 5 +++++
 arch/mips/kvm/mips.c       | 5 +++++
 arch/powerpc/kvm/powerpc.c | 5 +++++
 arch/riscv/kvm/main.c      | 5 +++++
 arch/s390/kvm/kvm-s390.c   | 5 +++++
 arch/x86/kvm/x86.c         | 5 +++++
 include/linux/kvm_host.h   | 2 ++
 virt/kvm/kvm_main.c        | 4 ++++
 9 files changed, 41 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 1e2f42134b74..7e6d2773fd39 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -200,6 +200,11 @@ static int kvm_arm_default_max_vcpus(void)
 	return vgic_present ? kvm_vgic_get_max_vcpus() : KVM_MAX_VCPUS;
 }
 
+unsigned kvm_arch_max_planes(struct kvm *kvm)
+{
+	return 1;
+}
+
 /**
  * kvm_arch_init_vm - initializes a VM data structure
  * @kvm:	pointer to the KVM struct
diff --git a/arch/loongarch/kvm/vm.c b/arch/loongarch/kvm/vm.c
index 1317c718f896..14f1232c6e0c 100644
--- a/arch/loongarch/kvm/vm.c
+++ b/arch/loongarch/kvm/vm.c
@@ -109,6 +109,11 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	kvm->arch.phyid_map = NULL;
 }
 
+unsigned kvm_arch_max_planes(struct kvm *kvm)
+{
+	return 1;
+}
+
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 {
 	int r;
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 776aba0af096..60870452119d 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -115,6 +115,11 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
 	return !!(vcpu->arch.pending_exceptions);
 }
 
+unsigned kvm_arch_max_planes(struct kvm *kvm)
+{
+	return 1;
+}
+
 bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
 {
 	return false;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 5d94e0f676ec..cfa40be20e00 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -499,6 +499,11 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	module_put(kvm->arch.kvm_ops->owner);
 }
 
+unsigned kvm_arch_max_planes(struct kvm *kvm)
+{
+	return 1;
+}
+
 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 {
 	int r;
diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
index cb8a65273c1f..5adba3a455a3 100644
--- a/arch/riscv/kvm/main.c
+++ b/arch/riscv/kvm/main.c
@@ -17,6 +17,11 @@
 
 DEFINE_STATIC_KEY_FALSE(kvm_riscv_vsstage_tlb_no_gpa);
 
+unsigned kvm_arch_max_planes(struct kvm *kvm)
+{
+	return 1;
+}
+
 static void kvm_riscv_setup_vendor_features(void)
 {
 	/* Andes AX66: split two-stage TLBs */
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index e6fe83da172f..24f24ea95f86 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -3186,6 +3186,11 @@ static void sca_dispose(struct kvm *kvm)
 	kvm->arch.sca = NULL;
 }
 
+unsigned kvm_arch_max_planes(struct kvm *kvm)
+{
+	return 1;
+}
+
 void kvm_arch_free_vm(struct kvm *kvm)
 {
 	if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM))
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 50601ac2828f..25299c8c28e3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -482,6 +482,11 @@ static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all_except_vmx) +
 			      (KVM_LAST_EMULATED_VMX_MSR - KVM_FIRST_EMULATED_VMX_MSR + 1)];
 static unsigned int num_msr_based_features;
 
+unsigned kvm_arch_max_planes(struct kvm *kvm)
+{
+	return 1;
+}
+
 /*
  * All feature MSRs except uCode revID, which tracks the currently loaded uCode
  * patch, are immutable once the vCPU model is defined.
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 291bccce9b74..3ecd472c7cfa 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1156,6 +1156,8 @@ void kvm_unlock_all_vcpus(struct kvm *kvm);
 void vcpu_load(struct kvm_vcpu *vcpu);
 void vcpu_put(struct kvm_vcpu *vcpu);
 
+unsigned kvm_arch_max_planes(struct kvm *kvm);
+
 #ifdef CONFIG_KVM_IOAPIC
 void kvm_arch_post_irq_ack_notifier_list_update(struct kvm *kvm);
 #else
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 7a0b632e3ac0..5a0277e2ac7c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -5079,6 +5079,10 @@ static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
 	case KVM_CAP_GUEST_MEMFD_FLAGS:
 		return kvm_gmem_get_supported_flags(kvm);
 #endif
+	case KVM_CAP_PLANES:
+		if (kvm)
+			return kvm_arch_max_planes(kvm);
+		return 1;
 	default:
 		break;
 	}
-- 
2.53.0