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| author | Huacai Chen <chenhc@lemote.com> | 2020-09-10 13:33:51 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-23 13:10:59 +0300 |
| commit | 6da40b74efca9aa9d709ae36a825d14439af9b40 (patch) | |
| tree | fa139f8ee794886d7280070078542a036688b7cf | |
| parent | 80c468d9abc9d4129809c1ffc90b3c835a1202c2 (diff) | |
| download | linux-6da40b74efca9aa9d709ae36a825d14439af9b40.tar.xz | |
KVM: MIPS: Change the definition of kvm type
[ Upstream commit 15e9e35cd1dec2bc138464de6bf8ef828df19235 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/mips/kvm/mips.c | 2 | ||||
| -rw-r--r-- | include/uapi/linux/kvm.h | 5 |
2 files changed, 5 insertions, 2 deletions
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index e7f5ef6bed0f..79485790f7b5 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -131,6 +131,8 @@ void kvm_arch_check_processor_compat(void *rtn) 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 66ce6659ecb6..c297abc4e669 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -746,9 +746,10 @@ 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 |