On 9/5/2019 1:41 AM, Sean Christopherson wrote:
On Wed, Sep 04, 2019 at 02:01:18PM +0800, Xiaoyao Li wrote:
Userspace can use ioctl KVM_SET_MSRS to update a set of MSRs of guest.
This ioctl sets specified MSRs one by one. Once it fails to set an MSR
due to setting reserved bits, the MSR is not supported/emulated by kvm,
or violating other restrictions, it stops further processing and returns
the number of MSRs have been set successfully.
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
v2:
elaborate the changelog and description of ioctl KVM_SET_MSRS based on
Sean's comments.
---
Documentation/virt/kvm/api.txt | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt
index 2d067767b617..4638e893dec0 100644
--- a/Documentation/virt/kvm/api.txt
+++ b/Documentation/virt/kvm/api.txt
@@ -586,7 +586,7 @@ Capability: basic
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_msrs (in)
-Returns: 0 on success, -1 on error
+Returns: number of msrs successfully set (see below), -1 on error
Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the
data structures.
@@ -595,6 +595,11 @@ Application code should set the 'nmsrs' member (which indicates the
size of the entries array), and the 'index' and 'data' members of each
array entry.
+It tries to set the MSRs in array entries[] one by one. Once failing to
Probably better to say 'If' as opposed to 'Once', don't want to imply that
userspace is incompetent :)
+set an MSR (due to setting reserved bits, the MSR is not supported/emulated
+by kvm, or violating other restrctions),
Make it clear the list is not exhaustive, e.g.:
It tries to set the MSRs in array entries[] one by one. If setting an MSR
fails, e.g. due to setting reserved bits, the MSR isn't supported/emulated by
KVM, etc..., it stops processing the MSR list and returns the number of MSRs
that have been set successfully.
Refine it as you commented and send out v3, thanks.
it stops setting following MSRs
+and returns the number of MSRs have been set successfully.
+
4.20 KVM_SET_CPUID
--
2.19.1
