From: Paolo Bonzini <pbonzini@redhat.com>
To: Xiao Guangrong <guangrong.xiao@linux.intel.com>,
Huaitong Han <huaitong.han@intel.com>,
gleb@kernel.org
Cc: kvm@vger.kernel.org
Subject: Re: [PATCH V4 7/7] KVM, pkeys: disable PKU feature without ept
Date: Tue, 8 Mar 2016 11:02:35 +0100 [thread overview]
Message-ID: <56DEA33B.1010005@redhat.com> (raw)
In-Reply-To: <56DE9C45.4090504@linux.intel.com>
On 08/03/2016 10:32, Xiao Guangrong wrote:
> On 03/08/2016 04:47 PM, Paolo Bonzini wrote:
>> Some XSAVE features (currently only MPX, but in the future PKRU too)
>> will force eagerfpu on, see fpu__init_system_ctx_switch:
>>
>> if (xfeatures_mask & XFEATURE_MASK_EAGER) {
>> if (eagerfpu == DISABLE) {
>> xfeatures_mask &= ~XFEATURE_MASK_EAGER;
>
> So if the kernel parameter, eagerfpu is set to "off", then eager is not
> enabled, so PKRU can not work in KVM?
Yes. Neither PKRU nor MPX.
>> KVM will use eager FPU if the host uses it. See arch/x86/kvm/cpuid.c:
>>
>> vcpu->arch.eager_fpu =
>> use_eager_fpu() || guest_cpuid_has_mpx(vcpu);
>>
>
> Sorry, i missread the code, yes, if vcpu->arch.eager_fpu is true, it is
> always save/load fpu for every vm-exit/vm-enter.
No problem, it's impossible to know all the code. :)
Paolo
next prev parent reply other threads:[~2016-03-08 10:02 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-05 11:27 [PATCH V4 0/7] KVM, pkeys: add memory protection-key support Huaitong Han
2016-03-05 11:27 ` [PATCH V4 1/7] KVM, pkeys: expose CPUID/CR4 to guest Huaitong Han
2016-03-06 7:15 ` Xiao Guangrong
2016-03-06 23:20 ` Paolo Bonzini
2016-03-08 7:39 ` Xiao Guangrong
2016-03-08 7:58 ` Paolo Bonzini
2016-03-05 11:27 ` [PATCH V4 2/7] KVM, pkeys: disable pkeys for guests in non-paging mode Huaitong Han
2016-03-06 7:19 ` Xiao Guangrong
2016-03-08 12:09 ` Yang Zhang
2016-03-08 12:11 ` Paolo Bonzini
2016-03-08 13:02 ` Yang Zhang
2016-03-05 11:27 ` [PATCH V4 3/7] KVM, pkeys: update memeory permission bitmask for pkeys Huaitong Han
2016-03-06 7:42 ` Xiao Guangrong
2016-03-06 23:14 ` Paolo Bonzini
2016-03-08 7:35 ` Xiao Guangrong
2016-03-08 8:29 ` Paolo Bonzini
2016-03-08 9:19 ` Xiao Guangrong
2016-03-08 10:01 ` Paolo Bonzini
2016-03-09 5:03 ` Xiao Guangrong
2016-03-09 8:10 ` Paolo Bonzini
2016-03-05 11:27 ` [PATCH V4 4/7] KVM, pkeys: add pkeys support for permission_fault logic Huaitong Han
2016-03-06 8:00 ` Xiao Guangrong
2016-03-06 20:36 ` Paolo Bonzini
2016-03-06 23:29 ` Paolo Bonzini
2016-03-08 5:57 ` Xiao Guangrong
2016-03-05 11:27 ` [PATCH V4 5/7] KVM, pkeys: Add pkeys support for gva_to_gpa funcions Huaitong Han
2016-03-06 8:01 ` Xiao Guangrong
2016-03-06 21:33 ` Paolo Bonzini
2016-03-05 11:27 ` [PATCH V4 6/7] KVM, pkeys: add pkeys support for xsave state Huaitong Han
2016-03-06 8:27 ` Xiao Guangrong
2016-03-05 11:27 ` [PATCH V4 7/7] KVM, pkeys: disable PKU feature without ept Huaitong Han
2016-03-06 9:28 ` Xiao Guangrong
2016-03-06 20:32 ` Paolo Bonzini
2016-03-08 5:54 ` Xiao Guangrong
2016-03-08 8:47 ` Paolo Bonzini
2016-03-08 9:32 ` Xiao Guangrong
2016-03-08 10:02 ` Paolo Bonzini [this message]
2016-03-09 5:51 ` Xiao Guangrong
2016-03-09 6:37 ` Yang Zhang
2016-03-09 7:21 ` Xiao Guangrong
2016-03-09 7:41 ` Yang Zhang
2016-03-09 7:50 ` Xiao Guangrong
2016-03-09 8:00 ` Yang Zhang
2016-03-09 8:05 ` Xiao Guangrong
2016-03-09 8:18 ` Paolo Bonzini
2016-03-09 8:13 ` Paolo Bonzini
2016-03-09 6:24 ` Yang Zhang
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