{"id":2230835,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2230835/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260430054906.94431-3-amachhiw@linux.ibm.com/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/1.1/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/"},"msgid":"<20260430054906.94431-3-amachhiw@linux.ibm.com>","date":"2026-04-30T05:49:01","name":"[2/6] KVM: PPC: Introduce KVM_CAP_PPC_COMPAT_CAPS and KVM_PPC_GET_COMPAT_CAPS","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"0db89b4d98b89427d527b589799adc7d5c5ba248","submitter":{"id":87864,"url":"http://patchwork.ozlabs.org/api/1.1/people/87864/?format=json","name":"Amit Machhiwal","email":"amachhiw@linux.ibm.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260430054906.94431-3-amachhiw@linux.ibm.com/mbox/","series":[{"id":502205,"url":"http://patchwork.ozlabs.org/api/1.1/series/502205/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=502205","date":"2026-04-30T05:48:59","name":"KVM: PPC: Handle CPU compatibility mode for nested guests","version":1,"mbox":"http://patchwork.ozlabs.org/series/502205/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2230835/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2230835/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=ibm.com header.i=@ibm.com header.a=rsa-sha256\n header.s=pp1 header.b=UkvMBih0;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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This is particularly relevant for nested virtualization, where\nnested KVM guests may need to run with a specific processor compatibility\nlevel.\n\nThe new ioctl returns a bitmap describing the compatibility modes\nsupported by the host in respective bit numbers. This allows userspace\nto select an appropriate compatibility level when configuring nested KVM\nguests.\n\nSigned-off-by: Amit Machhiwal \n---\n arch/powerpc/include/uapi/asm/kvm.h | 6 ++++++\n include/uapi/linux/kvm.h | 4 ++++\n 2 files changed, 10 insertions(+)","diff":"diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h\nindex 077c5437f521..a38dff7a8aea 100644\n--- a/arch/powerpc/include/uapi/asm/kvm.h\n+++ b/arch/powerpc/include/uapi/asm/kvm.h\n@@ -437,6 +437,12 @@ struct kvm_ppc_cpu_char {\n \t__u64\tbehaviour_mask;\t\t/* valid bits in behaviour */\n };\n \n+/* For KVM_PPC_GET_COMPAT_CAPS */\n+struct kvm_ppc_compat_caps {\n+\t__u32\tflags;\n+\t__u64\tcompat_capabilities;\t/* Capabilities supported by the host */\n+};\n+\n /*\n * Values for character and character_mask.\n * These are identical to the values used by H_GET_CPU_CHARACTERISTICS.\ndiff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h\nindex 6c8afa2047bf..1788a0068662 100644\n--- a/include/uapi/linux/kvm.h\n+++ b/include/uapi/linux/kvm.h\n@@ -996,6 +996,7 @@ struct kvm_enable_cap {\n #define KVM_CAP_S390_USER_OPEREXEC 246\n #define KVM_CAP_S390_KEYOP 247\n #define KVM_CAP_S390_VSIE_ESAMODE 248\n+#define KVM_CAP_PPC_COMPAT_CAPS 249\n \n struct kvm_irq_routing_irqchip {\n \t__u32 irqchip;\n@@ -1349,6 +1350,9 @@ struct kvm_s390_keyop {\n #define KVM_GET_DEVICE_ATTR\t _IOW(KVMIO, 0xe2, struct kvm_device_attr)\n #define KVM_HAS_DEVICE_ATTR\t _IOW(KVMIO, 0xe3, struct kvm_device_attr)\n \n+/* Available with KVM_CAP_PPC_COMPAT_CAPS */\n+#define KVM_PPC_GET_COMPAT_CAPS\t_IOR(KVMIO, 0xe4, struct kvm_ppc_compat_caps)\n+\n /*\n * ioctls for vcpu fds\n */\n","prefixes":["2/6"]}