lkml.org 
[lkml]   [2020]   [Sep]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC PATCH 20/35] KVM: SVM: Add SEV/SEV-ES support for intercepting INVD
From
Date
On 9/14/20 5:00 PM, Sean Christopherson wrote:
> On Mon, Sep 14, 2020 at 03:15:34PM -0500, Tom Lendacky wrote:
>> From: Tom Lendacky <thomas.lendacky@amd.com>
>>
>> The INVD instruction intercept performs emulation. Emulation can't be done
>> on an SEV or SEV-ES guest because the guest memory is encrypted.
>>
>> Provide a specific intercept routine for the INVD intercept. Within this
>> intercept routine, skip the instruction for an SEV or SEV-ES guest since
>> it is emulated as a NOP anyway.
>>
>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>> ---
>> arch/x86/kvm/svm/svm.c | 13 ++++++++++++-
>> 1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
>> index 37c98e85aa62..ac64a5b128b2 100644
>> --- a/arch/x86/kvm/svm/svm.c
>> +++ b/arch/x86/kvm/svm/svm.c
>> @@ -2275,6 +2275,17 @@ static int iret_interception(struct vcpu_svm *svm)
>> return 1;
>> }
>>
>> +static int invd_interception(struct vcpu_svm *svm)
>> +{
>> + /*
>> + * Can't do emulation on any type of SEV guest and INVD is emulated
>> + * as a NOP, so just skip it.
>> + */
>> + return (sev_guest(svm->vcpu.kvm))
>
> Should this be a standalone/backported fix for SEV?

Yes. Let me split it out and send it separately.

Thanks,
Tom

>
>> + ? kvm_skip_emulated_instruction(&svm->vcpu)
>> + : kvm_emulate_instruction(&svm->vcpu, 0);
>> +}
>> +
>> static int invlpg_interception(struct vcpu_svm *svm)
>> {
>> if (!static_cpu_has(X86_FEATURE_DECODEASSISTS))
>> @@ -2912,7 +2923,7 @@ static int (*const svm_exit_handlers[])(struct vcpu_svm *svm) = {
>> [SVM_EXIT_RDPMC] = rdpmc_interception,
>> [SVM_EXIT_CPUID] = cpuid_interception,
>> [SVM_EXIT_IRET] = iret_interception,
>> - [SVM_EXIT_INVD] = emulate_on_interception,
>> + [SVM_EXIT_INVD] = invd_interception,
>> [SVM_EXIT_PAUSE] = pause_interception,
>> [SVM_EXIT_HLT] = halt_interception,
>> [SVM_EXIT_INVLPG] = invlpg_interception,
>> --
>> 2.28.0
>>

\
 
 \ /
  Last update: 2020-09-15 17:49    [W:0.073 / U:4.188 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site