2021-01-28 08:10:43

by Yu Zhang

Subject: [PATCH] KVM: Documentation: Fix documentation for nested.

Nested VMX was enabled by default in commit <1e58e5e59148> ("KVM:
VMX: enable nested virtualization by default"), which was merged
in Linux 4.20. This patch is to fix the documentation accordingly.

Signed-off-by: Yu Zhang <[email protected]>
---
Documentation/virt/kvm/nested-vmx.rst | 6 ++++--
Documentation/virt/kvm/running-nested-guests.rst | 2 +-
2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/Documentation/virt/kvm/nested-vmx.rst b/Documentation/virt/kvm/nested-vmx.rst
index 6ab4e35..ac2095d 100644
--- a/Documentation/virt/kvm/nested-vmx.rst
+++ b/Documentation/virt/kvm/nested-vmx.rst
@@ -37,8 +37,10 @@ call L2.
Running nested VMX
------------------

-The nested VMX feature is disabled by default. It can be enabled by giving
-the "nested=1" option to the kvm-intel module.
+The nested VMX feature is enabled by default since Linux kernel v4.20. For
+older Linux kernel, it can be enabled by giving the "nested=1" option to the
+kvm-intel module.
+

No modifications are required to user space (qemu). However, qemu's default
emulated CPU type (qemu64) does not list the "VMX" CPU feature, so it must be
diff --git a/Documentation/virt/kvm/running-nested-guests.rst b/Documentation/virt/kvm/running-nested-guests.rst
index d0a1fc7..bd70c69 100644
--- a/Documentation/virt/kvm/running-nested-guests.rst
+++ b/Documentation/virt/kvm/running-nested-guests.rst
@@ -74,7 +74,7 @@ few:
Enabling "nested" (x86)
-----------------------

-From Linux kernel v4.19 onwards, the ``nested`` KVM parameter is enabled
+From Linux kernel v4.20 onwards, the ``nested`` KVM parameter is enabled
by default for Intel and AMD. (Though your Linux distribution might
override this default.)

--
1.9.1

2021-01-28 08:21:47

by Paolo Bonzini

Subject: Re: [PATCH] KVM: Documentation: Fix documentation for nested.

On 28/01/21 16:47, Yu Zhang wrote:
> Nested VMX was enabled by default in commit <1e58e5e59148> ("KVM:
> VMX: enable nested virtualization by default"), which was merged
> in Linux 4.20. This patch is to fix the documentation accordingly.
>
> Signed-off-by: Yu Zhang <[email protected]>
> ---
> Documentation/virt/kvm/nested-vmx.rst | 6 ++++--
> Documentation/virt/kvm/running-nested-guests.rst | 2 +-
> 2 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/virt/kvm/nested-vmx.rst b/Documentation/virt/kvm/nested-vmx.rst
> index 6ab4e35..ac2095d 100644
> --- a/Documentation/virt/kvm/nested-vmx.rst
> +++ b/Documentation/virt/kvm/nested-vmx.rst
> @@ -37,8 +37,10 @@ call L2.
> Running nested VMX
> ------------------
>
> -The nested VMX feature is disabled by default. It can be enabled by giving
> -the "nested=1" option to the kvm-intel module.
> +The nested VMX feature is enabled by default since Linux kernel v4.20. For
> +older Linux kernel, it can be enabled by giving the "nested=1" option to the
> +kvm-intel module.
> +
>
> No modifications are required to user space (qemu). However, qemu's default
> emulated CPU type (qemu64) does not list the "VMX" CPU feature, so it must be
> diff --git a/Documentation/virt/kvm/running-nested-guests.rst b/Documentation/virt/kvm/running-nested-guests.rst
> index d0a1fc7..bd70c69 100644
> --- a/Documentation/virt/kvm/running-nested-guests.rst
> +++ b/Documentation/virt/kvm/running-nested-guests.rst
> @@ -74,7 +74,7 @@ few:
> Enabling "nested" (x86)
> -----------------------
>
> -From Linux kernel v4.19 onwards, the ``nested`` KVM parameter is enabled
> +From Linux kernel v4.20 onwards, the ``nested`` KVM parameter is enabled
> by default for Intel and AMD. (Though your Linux distribution might
> override this default.)
>
>

Queued, thanks.

Paolo