Commit 15e9e35c authored by Huacai Chen's avatar Huacai Chen Committed by Paolo Bonzini

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: default avatarHuacai Chen <chenhc@lemote.com>
Message-Id: <1599734031-28746-1-git-send-email-chenhc@lemote.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f6f6195b
...@@ -137,6 +137,8 @@ extern void kvm_init_loongson_ipi(struct kvm *kvm); ...@@ -137,6 +137,8 @@ extern void kvm_init_loongson_ipi(struct kvm *kvm);
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{ {
switch (type) { switch (type) {
case KVM_VM_MIPS_AUTO:
break;
#ifdef CONFIG_KVM_MIPS_VZ #ifdef CONFIG_KVM_MIPS_VZ
case KVM_VM_MIPS_VZ: case KVM_VM_MIPS_VZ:
#else #else
......
...@@ -790,9 +790,10 @@ struct kvm_ppc_resize_hpt { ...@@ -790,9 +790,10 @@ struct kvm_ppc_resize_hpt {
#define KVM_VM_PPC_HV 1 #define KVM_VM_PPC_HV 1
#define KVM_VM_PPC_PR 2 #define KVM_VM_PPC_PR 2
/* on MIPS, 0 forces trap & emulate, 1 forces VZ ASE */ /* on MIPS, 0 indicates auto, 1 forces VZ ASE, 2 forces trap & emulate */
#define KVM_VM_MIPS_TE 0 #define KVM_VM_MIPS_AUTO 0
#define KVM_VM_MIPS_VZ 1 #define KVM_VM_MIPS_VZ 1
#define KVM_VM_MIPS_TE 2
#define KVM_S390_SIE_PAGE_OFFSET 1 #define KVM_S390_SIE_PAGE_OFFSET 1
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment