Re: [Xen-devel] [Patch 2/4] Refining Xsave/Xrestore support

[Haitao Shan <maillists.shan@xxxxxxxxx>]

Then I would prefer to write XCR0 unconditionally. Otherwise, I can
only refer to the approach for handling CR4 switches: reading CR4
first and checking whether there is a need to write actually.
But I don't think <a read to XCR0 plus a data comparison> can save any
compared with one unconditional write to XCR0.
Are you OK with this?

Thanks for pointing out the memory leak when hvm_vcpu_initialize
fails. I will update accordingly.

Shan Haitao

2010/10/28 Jan Beulich <JBeulich@xxxxxxxxxx>:
>>>> On 28.10.10 at 06:58, Haitao Shan <maillists.shan@xxxxxxxxx> wrote:
>> This is the updated patch#2. Thanks.
>
> Sorry, but this is worse than not checking at all: You didn't consider
> the idle vCPU case here, and hence you may end up having more
> features enabled in xcr0 for a guest than it should have.
>
> Also I only now noticed that you're leaking the xsave_area allocation
> in vcpu_initialize() if hvm_vcpu_initialise() fails.
>
> Jan
>
>

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