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authorHuacai Chen <chenhc@lemote.com>2020-09-10 18:33:51 +0800
committerPaolo Bonzini <pbonzini@redhat.com>2020-09-11 13:22:52 -0400
commit15e9e35cd1dec2bc138464de6bf8ef828df19235 (patch)
treef3111c1722ecea4875fdd8030a551aeae814c321
parentf6f6195b888c28a0b59ceb0562daff92a2be86c3 (diff)
downloadlinux-sh-15e9e35cd1dec2bc138464de6bf8ef828df19235.tar.gz
KVM: MIPS: Change the definition of kvm type
MIPS defines two kvm types: #define KVM_VM_MIPS_TE 0 #define KVM_VM_MIPS_VZ 1 In Documentation/virt/kvm/api.rst it is said that "You probably want to use 0 as machine type", which implies that type 0 be the "automatic" or "default" type. And, in user-space libvirt use the null-machine (with type 0) to detect the kvm capability, which returns "KVM not supported" on a VZ platform. I try to fix it in QEMU but it is ugly: https://lists.nongnu.org/archive/html/qemu-devel/2020-08/msg05629.html And Thomas Huth suggests me to change the definition of kvm type: https://lists.nongnu.org/archive/html/qemu-devel/2020-09/msg03281.html So I define like this: #define KVM_VM_MIPS_AUTO 0 #define KVM_VM_MIPS_VZ 1 #define KVM_VM_MIPS_TE 2 Since VZ and TE cannot co-exists, using type 0 on a TE platform will still return success (so old user-space tools have no problems on new kernels); the advantage is that using type 0 on a VZ platform will not return failure. So, the only problem is "new user-space tools use type 2 on old kernels", but if we treat this as a kernel bug, we can backport this patch to old stable kernels. Signed-off-by: Huacai Chen <chenhc@lemote.com> Message-Id: <1599734031-28746-1-git-send-email-chenhc@lemote.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/mips/kvm/mips.c2
-rw-r--r--include/uapi/linux/kvm.h5
2 files changed, 5 insertions, 2 deletions
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 7de85d2253ff..0c50ac444222 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -137,6 +137,8 @@ extern void kvm_init_loongson_ipi(struct kvm *kvm);
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
switch (type) {
+ case KVM_VM_MIPS_AUTO:
+ break;
#ifdef CONFIG_KVM_MIPS_VZ
case KVM_VM_MIPS_VZ:
#else
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 3d8023474f2a..7d8eced6f459 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -790,9 +790,10 @@ struct kvm_ppc_resize_hpt {
#define KVM_VM_PPC_HV 1
#define KVM_VM_PPC_PR 2
-/* on MIPS, 0 forces trap & emulate, 1 forces VZ ASE */
-#define KVM_VM_MIPS_TE 0
+/* on MIPS, 0 indicates auto, 1 forces VZ ASE, 2 forces trap & emulate */
+#define KVM_VM_MIPS_AUTO 0
#define KVM_VM_MIPS_VZ 1
+#define KVM_VM_MIPS_TE 2
#define KVM_S390_SIE_PAGE_OFFSET 1